CVS – Anatomy

CVS

CVS-Anatomy

Compiled Topical Questions of CVS-Anatomy

“Please enter your name and email so that we maybe able to send you statistics, but more importantly, a nice certificate upon completion. Thank you for using MedifyHelp!”

The heart must build enough pressure in the ventricles before it can push blood into the arteries. What happens to the blood inside the ventricles during this period? and well after you answer that, consider what happens to the ventricles themselves.

1 / 95

Tags: 2020

What occurs in isovolumetric contraction?

Atrial muscles contract

Ventricles are filling

Ventricles contract but no emptying occurs

AV valves are open

Mitral valves open

Isovolumetric contraction is the early phase of systole, during which the ventricles contract but no blood is ejected because both the atrioventricular (AV) valves and semilunar valves remain closed.

Key Events During Isovolumetric Contraction:

1️⃣ Ventricular Contraction Begins:

The ventricles depolarize (QRS complex on ECG) and start contracting.
Pressure inside the ventricles rises rapidly.

2️⃣ AV Valves Close:

As ventricular pressure exceeds atrial pressure, the mitral and tricuspid valves (AV valves) close, preventing backflow into the atria.
This produces the first heart sound (S1, “lub”).

3️⃣ Semilunar Valves Remain Closed:

Aortic and pulmonary valves (semilunar valves) remain closed because the pressure in the aorta and pulmonary artery is still higher than in the ventricles.

4️⃣ No Blood Ejection Occurs:

Since both AV and semilunar valves are closed, blood volume in the ventricles remains constant.
This phase is called “isovolumetric” because the volume of blood does not change, even though the ventricles are contracting.

5️⃣ End of Isovolumetric Contraction:

When ventricular pressure exceeds aortic and pulmonary artery pressure, the semilunar valves open, and blood is ejected into the arteries.
This marks the beginning of the ejection phase.

Thus, the correct statement is “Ventricles contract but no emptying occurs.”

Analysis of Each Option:

✅ Correct Option:
🔹 “Ventricles contract but no emptying occurs.”
✔️ True – The ventricles contract but do not eject blood yet, since both AV and semilunar valves are closed.

🚫 Incorrect Options:

🔹 “Mitral valve opens.”
❌ Incorrect – The mitral valve closes at the beginning of isovolumetric contraction to prevent backflow into the left atrium.
❌ If the mitral valve were open, ventricular contraction would push blood back into the atrium.

🔹 “Atrial muscles contract.”
❌ Incorrect – Atrial contraction occurs before isovolumetric contraction, during late diastole (atrial systole).
❌ Isovolumetric contraction is part of ventricular systole, not atrial systole.

🔹 “AV valves are open.”
❌ Incorrect – AV valves (mitral and tricuspid) are closed to prevent blood from flowing back into the atria.
❌ Closure of the AV valves produces the first heart sound (S1, “lub”).

🔹 “Ventricles are filling.”
❌ Incorrect – Ventricular filling occurs during diastole, not during isovolumetric contraction.
❌ In isovolumetric contraction, the ventricles contain the end-diastolic volume (EDV) but are not filling further.

Think about how blood returns to the heart. The SVC carries blood from the upper body and needs to connect efficiently to the right atrium. Where would it logically open?

2 / 95

Tags: 2020

Which of the following is correct regarding the heart?

Superior vena cava opens on the posterior side of right atrium.

Opening of superior vena cava is larger than inferior vena cava

The right ventricle forms the apex

Opening of inferior vena cava is smaller than superior vena cava

The left ventricle forms the base

Before birth, the foramen ovale is an essential shunt that bypasses the lungs. After birth, it normally closes. If it remains open, where do you think this defect would be located?

3 / 95

Tags: 2020

A patient presented to the clinic with cardiovascular symptoms. Examination revealed a patent foramen ovale which is caused by the failure of a valve. Where is this valve located?

Inter atrial wall

Left ventricle

Right atrium

Interventricular wall

Left atrium

A patent foramen ovale (PFO) occurs when the foramen ovale fails to close properly after birth. The foramen ovale is an embryological structure in the interatrial wall (septum) that allows oxygenated blood from the placenta to bypass the lungs in fetal circulation.

Embryological Development of the Interatrial Septum:

Septum Primum Forms:
- A thin flap called the septum primum grows downward to separate the atria.
- Before it fully closes, a temporary opening called the foramen primum allows blood to shunt right-to-left.
Foramen Secundum Forms:
- Before the foramen primum closes, small perforations appear in the upper part of the septum primum, forming the foramen secundum, which maintains blood flow between atria.
Septum Secundum Forms:
- A second, thicker membrane called the septum secundum develops to the right of the septum primum, leaving a small opening called the foramen ovale.
- This allows right-to-left shunting of blood in fetal life.
Closure of the Foramen Ovale at Birth:
- After birth, increased left atrial pressure pushes the septum primum against the septum secundum, functionally closing the foramen ovale.
- In some individuals (25-30% of people), the foramen ovale remains patent (open), leading to a patent foramen ovale (PFO).

Thus, the valve that fails to close is located in the interatrial wall.

Analysis of Each Option:

✅ Correct Option:
🔹 “Interatrial wall”
✔️ True – The foramen ovale is an embryological opening in the interatrial septum, and failure of its closure leads to a patent foramen ovale (PFO).

🚫 Incorrect Options:

🔹 “Left ventricle”
❌ The foramen ovale is not related to the left ventricle.
❌ The left ventricle is involved in systemic circulation, but PFO is an interatrial defect.

🔹 “Interventricular wall”
❌ The interventricular septum separates the right and left ventricles.
❌ Ventricular septal defects (VSDs) occur here, but PFO is an atrial septal defect (ASD), not a ventricular defect.

🔹 “Right atrium”
❌ The foramen ovale connects the right and left atria, but it is a defect in the interatrial septum, not just the right atrium.

🔹 “Left atrium”
❌ The left atrium receives oxygenated blood, but the PFO is a defect in the interatrial wall, not a structure of the left atrium alone.

Consider how the pulmonary trunk needs to efficiently carry deoxygenated blood from the right ventricle to the lungs while maintaining a strategic anatomical position relative to the aorta.

4 / 95

Tags: 2020

Which of the following is true regarding the pulmonary trunk?

Carries oxygenated blood

Arise anterior to root of aorta

Bifurcates posterior to the arch of aorta

Lies posterior to the arch of aorta

Pumps blood to lungs

The first arteries to receive blood from the heart itself must be positioned strategically to supply the myocardium. Where do you think they would be located relative to the heart’s major outflow tract?

5 / 95

Tags: 2020

What is true about the coronary arteries?

Each give interventricular artery

Forms anastomoses only at the apex

Arise from the ascending aorta

Arise in the posterior part of aorta

Nodal branch in most of the people is from left coronary artery

The coronary arteries are the first branches of the ascending aorta and are responsible for supplying oxygenated blood to the myocardium. They arise from the left and right coronary sinuses located in the ascending aorta, just above the aortic valve.

Key Features of Coronary Arteries:

✔️ Right Coronary Artery (RCA)

Arises from the right aortic sinus.
Supplies the right atrium, right ventricle, SA node (in most people), AV node (in right-dominant circulation), and posterior part of the interventricular septum.

✔️ Left Coronary Artery (LCA)

Arises from the left aortic sinus.
Immediately divides into the left anterior descending (LAD) artery and the left circumflex (LCX) artery.
Supplies the left atrium, left ventricle, anterior 2/3 of the interventricular septum, and part of the right ventricle.

Thus, the correct answer is that the coronary arteries arise from the ascending aorta.

Analysis of Each Option:

✅ Correct Option:
🔹 “Arise from the ascending aorta”
✔️ True – The right and left coronary arteries arise from the ascending aorta, just above the aortic valve.

🚫 Incorrect Options:

🔹 “Forms anastomoses only at the apex”
❌ While coronary arteries do form anastomoses at the apex, they also have collateral anastomoses in other regions, such as the posterior interventricular groove and around the SA node.

🔹 “Nodal branch in most of the people is from left coronary artery”
❌ In ~60-70% of people, the SA nodal branch comes from the right coronary artery (RCA).
❌ In ~30-40% of people, it arises from the left circumflex artery (LCX), which is a branch of the left coronary artery (LCA).

🔹 “Each give interventricular artery”
❌ Only the left coronary artery (LAD branch) and the right coronary artery (PDA branch) contribute to interventricular arteries.
❌ The RCA and LCA themselves do not both directly give interventricular arteries.

🔹 “Arise in the posterior part of aorta”
❌ The coronary arteries arise from the anterior part of the ascending aorta, not the posterior part.

The left coronary artery is the primary supplier of the left side of the heart. Which major parts of the heart are responsible for pumping oxygenated blood to the entire body?

6 / 95

Tags: 2020

What does the left coronary artery supply?

Diaphragmatic part of left ventricle

Posteroinferior third of the interventricular septum

Small part of right side of anterior interventricular groove

Most of left atrium, left ventricle, and interventricular septum

Complete right artrium and some part of left ventricle

What is the heart’s most critical pumping chamber ? Which artery supplies most of one of it’s walls

7 / 95

Tags: 2020

Occlusion in coronary artery disease occurs most commonly in which artery?

Left circumflex branch of left coronary artery

Left main coronary artery

Middle coronary artery

Right coronary artery

Left anterior descending artery

Coronary artery disease (CAD) is the leading cause of myocardial infarction (heart attack) due to the occlusion of coronary arteries by atherosclerotic plaque. The most commonly affected artery in CAD is the Left Anterior Descending (LAD) artery, which is sometimes called the “widow-maker” because of its critical role in supplying blood to the heart.

Why is the LAD Most Commonly Affected?

1️⃣ Largest Supply Area:

The LAD supplies blood to:
- Anterior wall of the left ventricle
- Anterior two-thirds of the interventricular septum
- Apex of the heart
Since the left ventricle is the main pumping chamber, an occlusion in the LAD is often fatal.

2️⃣ Higher Susceptibility to Atherosclerosis:

The LAD is a high-flow artery with turbulent blood flow, which makes it more prone to plaque deposition and occlusion.

3️⃣ Most Common Site for Myocardial Infarction:

Occlusion of the LAD accounts for nearly 40-50% of all myocardial infarctions.
A blockage in the proximal LAD is especially dangerous, as it affects a large portion of the myocardium.

Analysis of Each Option:

✅ Correct Answer:
🔹 “Left anterior descending artery (LAD)”
✔️ Most common site of occlusion in CAD.
✔️ Affects the anterior left ventricle and interventricular septum, leading to severe myocardial infarction if blocked.

🚫 Incorrect Options:

🔹 “Middle coronary artery”
❌ No such anatomical term – the coronary arteries are divided into right, left, and their branches.

🔹 “Left main coronary artery (LMCA)”
❌ The left main coronary artery (LMCA) is important because it branches into the LAD and the left circumflex artery, but occlusions most commonly occur in its branches (like the LAD) rather than in the LMCA itself.
❌ LMCA occlusion is rare but highly fatal because it supplies a large part of the heart.

🔹 “Left circumflex branch of the left coronary artery”
❌ The left circumflex artery (LCX) supplies the lateral and posterior parts of the left ventricle, but it is less frequently occluded than the LAD.
❌ LCX occlusion accounts for about 15-20% of myocardial infarctions, compared to 40-50% for LAD.

🔹 “Right coronary artery (RCA)”
❌ The RCA supplies the right ventricle, right atrium, SA node, AV node, and part of the posterior left ventricle.
❌ RCA occlusion can cause infarction (especially inferior MI), but it is not as common as LAD occlusion.

Some organs have backup routes for blood supply, while others do not. Think about which organs are highly dependent on a single artery and which ones have multiple routes for blood to reach them in case of an emergency.

8 / 95

Tags: 2020

The detour for blood flow through potential numerous branches that comes into play in case of an obstruction in a vessel is called:

Venules

Anastomosis

End arterioles

Terminal arteries

Functional terminal arteries

An anastomosis is a connection between two or more blood vessels, allowing blood to detour around a blockage or obstruction in a primary vessel. This network of alternative pathways is critical for maintaining blood supply to tissues when a vessel is occluded or damaged.

Anastomoses can be classified into different types based on their location and function:

Arterial anastomosis – Connection between two arteries, allowing collateral circulation (e.g., circle of Willis in the brain, coronary artery branches).
Venous anastomosis – Connection between veins, which are more common and help in venous drainage.
Arteriovenous anastomosis – Direct connection between an artery and a vein, bypassing capillary beds (e.g., in thermoregulation of skin).

These vascular detours ensure that tissues continue to receive oxygen and nutrients even when the primary blood supply is compromised.

Analysis of Each Option:

✅ Correct Option:
🔹 “Anastomosis”
✔️ Anastomoses provide an alternate route for blood flow in case of blockage or injury to a primary artery. This is seen in coronary circulation, cerebral circulation, and limb arteries, where collateral circulation plays a life-saving role.

🚫 Incorrect Options:

🔹 “Functional terminal arteries”
❌ These arteries have limited anastomosis but still provide some degree of collateral circulation. Examples include coronary arteries and cerebral arteries. However, if they are occluded, the alternative blood supply is often insufficient, leading to ischemia.

🔹 “Venules”
❌ Venules are small veins that drain blood from capillary beds into larger veins. They do not serve as a bypass mechanism for arterial obstructions.

🔹 “Terminal arteries”
❌ Terminal arteries (end arteries) do not form anastomoses. They supply blood exclusively to a specific area, meaning if they are blocked, ischemia and necrosis occur. Examples include the central artery of the retina and some coronary arteries.

🔹 “End arterioles”
❌ End arterioles are similar to terminal arteries in that they lack significant collateral circulation. Blockage leads to tissue infarction (e.g., in the retina or heart).

Each heart valve has an anatomical position, but the best place to listen to it is not necessarily where it is located. Consider why auscultation sites are strategically placed and how the direction of blood flow influences where we hear murmurs most clearly.

9 / 95

Tags: 2020

A 50-year-old female arrives in the emergency department with complaints of shortness of breath, chest pain, and sweating. The doctor is going to examine her cardiovascular system in detail. On examination, the left parasternal line in the fourth intercostal space on the precordium corresponds to which area?

Tricuspid area

Aortic area

Epigastrium

Pulmonary area

Mitral area

Think about which artery typically supplies the posterior descending artery (PDA) — in most people, it’s the right coronary artery.

10 / 95

Tags: 2017

The angiography report of a patient reveals an infarction of cardiac muscle located near the posterior interventricular sulcus of the heart. The infarction indicates blockage of which of the following blood vessels?

Left coronary artery

Right coronary artery

Left anterior descending artery

Circumflex artery

Left marginal artery

The mitral valve’s sound transmission aligns with the heart’s apex, so you’ll always hear it best where the left ventricle’s contraction is most palpable — in the left fifth intercostal space, midclavicular line.

11 / 95

Tags: 2017

A 45-year-old patient has been diagnosed with a case of mitral insufficiency that results in the regurgitation of blood in the left atrium. Where should the physician place the stethoscope to hear the murmur?

Lower end of sternum

At manubrium sterni

Right second intercostal space

Right fifth intercostal space

Left fifth intercostal space

Think about the surface landmark where the aortic valve’s blood flow is best transmitted to the chest wall, rather than where the valve itself is anatomically located. Consider the usual auscultation points used in cardiac examination.

12 / 95

Tags: 2017

If a newborn baby is diagnosed with congenital aortic stenosis, where should a physician place the stethoscope to listen to the sound of aortic valves?

Right third intercostal space

Left second intercostal space

Right second intercostal space

Lower end of sternum

Upper end of sternum

Think of the nerves controlling the diaphragm and glottis — the two essential players in the hiccup reflex arc.

13 / 95

Tags: 2017

Persistent hiccups can be caused by the irritation of which of the following nerves?

Vagus nerve

Phrenic nerve

Recurrent laryngeal nerve

Both vagus and phrenic nerves

Glossopharyngeal nerve

Persistent hiccups (singultus) are caused by involuntary, repetitive contractions of the diaphragm, followed by a sudden closure of the glottis, which produces the characteristic “hic” sound. This reflex involves both the vagus and phrenic nerves, as well as the medullary centers controlling respiration. Let’s break this down:

Phrenic Nerve (C3, C4, C5):
- Provides motor supply to the diaphragm — the primary muscle of respiration.
- Irritation of the phrenic nerve causes abnormal diaphragmatic contractions, leading to hiccups.
Vagus Nerve (Cranial Nerve X):
- Carries sensory information from the thoracic and abdominal organs.
- Vagal irritation can trigger the hiccup reflex arc due to its connections with the respiratory centers.
- Conditions like gastroesophageal reflux (GERD), pharyngeal irritation, or thoracic tumors can stimulate the vagus nerve, resulting in hiccups.
Reflex Arc of Hiccups:
1. Afferent limb: Vagus and phrenic nerves, and sympathetic fibers.
2. Central processing: Respiratory centers in the medulla oblongata.
3. Efferent limb: Phrenic nerve → diaphragmatic contraction; vagus nerve → glottic closure.

Why the Other Options Are Incorrect:

Vagus Nerve Alone:
- While the vagus nerve contributes to the hiccup reflex, it works together with the phrenic nerve.
- Hiccups involve diaphragmatic spasms, which require phrenic nerve involvement.
Glossopharyngeal Nerve (Cranial Nerve IX):
- Primarily involved in sensory innervation of the pharynx and taste from the posterior third of the tongue.
- Plays no direct role in the hiccup reflex arc.
Phrenic Nerve Alone:
- The phrenic nerve controls the diaphragm, but it does not initiate the glottic closure necessary for the “hic” sound — that’s the role of the vagus nerve.
Recurrent Laryngeal Nerve:
- A branch of the vagus nerve, it controls the intrinsic muscles of the larynx.
- While laryngeal closure contributes to the sound of hiccups, the recurrent laryngeal nerve alone does not cause persistent hiccups.

The parietal pericardium shares its nerve supply with the diaphragm — think of the nerve that keeps the diaphragm alive!

14 / 95

Tags: 2017

The parietal layer of the serous pericardium is supplied by which of the following nerves?

Phrenic nerve

Cardiac plexus

Sympathetic nerve fibers

Parasympathetic nerve fibers

Vagus nerve

The crista terminalis is a ridge inside the right atrium that separates the smooth sinus venarum from the rough pectinate muscles. Now think about what external structure marks this same division on the outside of the right atrium.

15 / 95

Tags: 2017

Which of the following structures is present on the external surface of the right atrium and corresponds to the crista terminalis on the internal surface of the heart?

Trabeculae carneae

Fossa ovalis

Pectinate muscles

Sulcus terminalis

Sinus venarum

Imagine the mid-clavicular line at the left fifth intercostal space — right around where you’d place a stethoscope to listen to the mitral valve. What part of the heart lies closest to the chest wall here, forming the inferior tip of the heart?

16 / 95

Tags: 2017

A patient is brought to the emergency room with a stab wound to the left side of his chest. The physician identifies that the injury is located at the left fifth intercostal space in the mid-clavicular line. Which of the following structures would most likely be injured?

Right ventricle

Left atrium

Apex of the heart

Sinus of venae cavae

Ascending aorta

“Think about the major vein that carries deoxygenated blood from the upper body to the right atrium. Which embryonic veins would combine to form this crucial structure?”

17 / 95

Tags: 2019

Right anterior and right common cardinal veins combine to form which of the following?

Right brachiocephalic vein

Sinus venosus

Ductus venosus

Superior vena cava

Left brachiocephalic vein

“The layer responsible for the heartbeat must contain both contractile and conductive elements. Which layer of the heart is responsible for pumping and also houses the pacemaker cells?”

18 / 95

Tags: 2019

The heart is able to generate and conduct its own impulses. The impulse generating and conducting system of heart is present in which of the following layers?

Epicardium

Pericardium

Myocardium

None of these

Endocardium

The arch of the aorta gives off three major branches in a very specific order. Think about the arteries that supply the head, neck, and upper limbs — but only one side of the body gets two direct branches!

19 / 95

Tags: 2017

Which of the following is a direct branch of the arch of the aorta?

Left pulmonary artery

Right common carotid artery

Right subclavian artery

Right external carotid artery

Left subclavian artery

The arch of the aorta has three direct branches (from right to left):

Brachiocephalic trunk (also called the innominate artery):
- This is the first and largest branch.
- It bifurcates into:
  - Right subclavian artery (supplying the right upper limb)
  - Right common carotid artery (supplying the right side of the head and neck)
Left common carotid artery:
- The second branch of the arch.
- It directly supplies the left side of the head and neck.
Left subclavian artery:
- The third and final branch.
- It supplies the left upper limb.

So, the left subclavian artery is indeed a direct branch of the aortic arch.

Why the other options are incorrect:

Right external carotid artery:
- Why it’s wrong: The right external carotid artery is a branch of the right common carotid artery, not a direct branch of the aorta.
- When it branches: The right common carotid artery splits into:
  - Right internal carotid artery (supplying the brain)
  - Right external carotid artery (supplying the face and scalp)
Right common carotid artery:
- Why it’s wrong: This artery comes from the brachiocephalic trunk, not directly from the aortic arch.
- How it branches: The brachiocephalic trunk gives rise to the right common carotid artery and right subclavian artery.
Left pulmonary artery:
- Why it’s wrong: The left pulmonary artery arises from the pulmonary trunk, not from the aortic arch.
- Function: It carries deoxygenated blood from the right ventricle to the left lung.
Right subclavian artery:
- Why it’s wrong: The right subclavian artery arises from the brachiocephalic trunk, not directly from the aortic arch.
- What it supplies: It provides blood to the right upper limb.

Conclusion:
The left subclavian artery is a direct branch of the arch of the aorta, along with the brachiocephalic trunk and left common carotid artery. Understanding this anatomy is crucial for identifying major vascular supply routes to the head, neck, and upper limbs.

“The right coronary artery follows a specific path as it emerges from the aorta. Think about which structures it passes between at the heart’s surface.”

20 / 95

Tags: 2019

What is correct about the right coronary artery?

It gives nodal artery in 40% of the cases

It emerges at the surface of the heart between the root of the pulmonary trunk and the right auricle

It ends by anastomosing with the right marginal artery

It is larger than the left coronary artery

It arises from the lateral aortic sinus

“Consider the number of leaflets these valves have in common.”

21 / 95

Tags: 2019

Which of the following is true regarding both the tricuspid and semilunar valves?

Have two cusps

Have three cusps

Produce the second heart sound

Have tendinous filaments attached

Produce the first heart sound

Consider the arteries that supply blood directly to the brain. Which artery, when blocked, would most disrupt blood flow to brain tissues?

22 / 95

Tags: 2018

Occlusion of which of the following arteries is most likely to cause cerebral ischemia?

Internal carotid artery

Left coronary artery

External carotid artery

Facial artery

None of these

“Consider the basic physiological characteristics that enable both muscle types to function.”

23 / 95

Tags: 2019

What is the similarity between cardiac and skeletal muscle?

Plateau

Rhythmicity

Resting membrane potential

Length of muscle fibers

Refractory period

“This fetal structure helps direct oxygenated blood toward the left atrium before the lungs are functional.”

24 / 95

Tags: 2019

Which valve guides the blood in the right-to-left shunt through the foramen ovale?

Thebesian valve

Cephalic valve

Inferior vena cava valve

Tricuspid valve

None of these

“Consider how lymph from different parts of the body is drained and the major pathways involved.”

25 / 95

Tags: 2019

What is incorrect regarding lymphatic ducts?

Same as veins except that veins have more muscle in the media

Converge into two large trunks: thoracic duct and the left lymphatic duct

Contain horizontally and longitudinally running muscle fibers

The adventitia is poorly defined

Blind tubes

“This vein forms from an embryonic connection between two major veins that drain the head and upper limb, ultimately contributing to the superior vena cava.”

26 / 95

Tags: 2019

The anastomosis between the right anterior and left anterior cardinal vein forms which vein?

External iliac vein

Digital palmar veins

Popliteal vein

All of these

Brachiocephalic vein

“This large vein begins where the two brachiocephalic veins unite, but its exact location might be slightly higher than you think.”

27 / 95

Tags: 2019

What is not true about the superior vena cava?

Receives azygous vein

Begins at the first costal cartilage

Is not separated from right atrium via any valves

Formed by right and left brachiocephalic veins

Has 10 cm length

“This structure provides support and protection, keeping the heart in place while allowing it to function properly.”

28 / 95

Tags: 2019

To what structure is fibrous pericardium attached?

Is not attached to any part of the heart

Left ventricle

Right atrium

Left atrium

Right ventricle

“This structure is a remnant of a fetal heart opening. Its upper border forms a distinct ridge that once played a role in directing blood flow before birth.”

29 / 95

Tags: 2019

What is true regarding fossa ovalis?

Thebesian valves are present

Upper border of the fossa is called limbus of fossa ovalis

None of these

Lies anterior to atrium proper

Euschtasian valve is present

“This chamber of the heart has thick, muscular walls and is responsible for pumping oxygenated blood into the systemic circulation.”

30 / 95

Tags: 2019

The left border of the heart is mainly formed by which of the following?

Right ventricle

Left atrium

Left ventricle

None of these

Right atrium

“This large vein delivers deoxygenated blood from the upper body directly into the right atrium without any valve.”

31 / 95

Tags: 2019

Which of the following is not guarded by a valve in right atrium?

Inferior vena cava

Superior vena cava

Atrioventricular orifice

None of these

Coronary sinus

Think about the direction of blood flow in the heart. Oxygenated blood is pumped from the left ventricle into the largest artery in the body. Which valve ensures this blood flows forward and does not return to the ventricle?

32 / 95

Tags: 2018

The blood moves out of left ventricle by passing through which of the following?

Pulmonary valve

Mitral valve

None of these

Tricuspid valve

Aortic valve

Cardiac cells must rapidly and efficiently conduct electrical impulses to maintain synchronized contraction. Which type of cell-cell connection allows direct ion flow between cardiac cells, enabling low-resistance electrical transmission?

33 / 95

Tags: 2019

Which of the following is the area of least resistance between cardiac cells?

Desmosomes

Gap junctions

Fascia adherens

Tight junctions

None of these

“This large vein carries blood from the upper body back to the heart. It drains into the chamber that acts as the entry point for deoxygenated blood.”

34 / 95

Tags: 2022

Which of the following provides an afferent blood supply to the right atrium?

Pulmonary veins

Aorta

Superior vena cava

Coronary arteries

Pulmonary arteries

“This chamber is a gateway for oxygenated blood before it gets pumped into the body. It must pass through a one-way valve before entering the heart’s most powerful pumping chamber.”

35 / 95

Tags: 2022

Which of the following structures does the left atrium open into?

Left ventricle

Right ventricle

Pulmonary veins

Right atrium

Pulmonary arteries

The ascending aorta is the first segment of the aorta, emerging from the left ventricle. It primarily supplies blood to the heart itself. Which arteries branch directly from the ascending aorta before it continues as the aortic arch?

36 / 95

Tags: 2022

Which of the following is a branch of the ascending aorta?

Coronary arteries

Posterior intercostal arteries

Esophageal arteries

Mediastinal arteries

Pericardial arteries

The coronary sinus is the largest cardiac vein and is responsible for draining most of the venous blood from the heart into the right atrium. Consider where it lies.. serving as a pathway to both coronary arteries and veins

37 / 95

Tags: 2022

In which of the following locations is the coronary sinus located?

Posterior interventricular sulcus

Posterior atrioventricular sulcus

Coronary sulcus

Anterior atrioventricular sulcus

Anterior interventricular sulcus

The location of the stab wound is crucial in determining which structure is most likely to be injured. The right intercostal space suggests what?

38 / 95

Tags: 2022

A stab wound in the right intercostal space is most likely to injure which one of the following structures?

Liver

Apex of heart

Right atrium

Right ventricle

Pulmonary artery

“Consider the pathway of the heart’s electrical conduction system. Which structure directly delivers the electrical impulse to the left ventricular myocardium after the Bundle of His divides?”

39 / 95

Tags: 2022

Which of the following provides the nerve supply to the left ventricle?

Bundle of His

Right bundle branch

Posterior nodal fibers

Left bundle branch

Anterior nodal fibers

“Think about the pathway of blood flow through the heart. Which vessels carry oxygenated blood from the lungs to the heart, and which chamber receives this oxygen-rich blood?”

40 / 95

Tags: 2022

Which of the following structures opens into the left atrium?

Coronary sinus

Inferior vena cava

Pulmonary veins

Aorta

Superior vena cava

“Think about the pathway of blood flow through the heart. Which vessels carry oxygenated blood from the lungs to the heart, and which chamber receives this oxygen-rich blood?”

41 / 95

Tags: 2022

Which of the following structures opens into the left atrium?

Aorta

Coronary sinus

Pulmonary veins

Inferior vena cava

Superior vena cava

“Both structures share a structural similarity, except for one notable exception in the heart.”

42 / 95

Tags: 2020

Which of the following is the correct comparison between the tricuspid and semilunar valves?

Mitral valve closure cause second heart sound

Both are tricuspid

Chordae tendinae attach to semilunar valves

Chordae tendineae of both are attached to papillary muscles

Aortic valve closure cause first heart sound

Consider how the body might adapt to compensate for reduced blood flow in coronary artery disease. What is the role of the bodys natural compensatory mechanisms in maintaining blood supply to the heart?

43 / 95

Tags: 2018

Which of the following is correct about collateral circulation in the case of ischemic heart diseases?

None of these

Alternate pathway of blood flow from other arteries that may protect against myocardial infarction

Is actively involved in the development of ischemic heart disease

Causes reperfusion injury in tissues receiving continuous blood flow

Alternate pathway of blood flow from other arteries but provides no protection against myocardial infarction

Think about the anatomy of coronary dominance and the typical areas supplied by the left and right coronary arteries. Consider how dominance affects the supply of the interventricular septum.

44 / 95

Tags: 2018

Regarding the coronary arteries, which of the following statements is correct?

The left coronary artery arises from the left posterior aortic sinus

The left coronary artery arises from the right posterior aortic sinus

The left coronary artery supplies the posterior part of interventricular septum

The right coronary artery supplies the anterior part of interventricular septum

The left coronary artery does not supply the interventricular septum

Think about which artery supplies the AV node under normal circumstances. Consider also the dominance pattern and how that affects blood flow to the hearts conduction system.

45 / 95

Tags: 2018

Regarding the left coronary artery, which of the following is incorrect?

Supplies the atrioventricular node in some exceptional cases

Has anastomosis with the right coronary artery

Arises from the anterior aortic sinus

None of these

Runs between the pulmonary trunk and left auricle

Consider which artery is primarily responsible for supplying the front versus the back parts of the interventricular septum. The artery supplying the posterior region plays a crucial role in the inferior part of the heart.

46 / 95

Tags: 2018

Regarding the right coronary artery, which of the following is incorrect?

Supplies the atrioventricular node

Mostly the right coronary artery is dominant

Arises from the right aortic sinus

Supplies the posteroinferior two-thirds of interventricular septum

None of these

These capillaries are part of a system responsible for transporting fluid and immune cells, not oxygenated blood. Look closely at the fluid type they carry and their structural features.

47 / 95

Tags: 2018

Which of the following is incorrect about Iympathic capillaries?

None of these

They carry oxygenated blood

They are close ended vessels

They have single endothelium

They have incomplete basal lamina

These muscular ridges are located on the inner surface of the ventricles and play a role in maintaining the structure of the heart wall during contraction. They are distinct from the structures associated with valve support.

48 / 95

Tags: 2018

A first year resident recalling terminology for the ridges found in ventricles of the heart calls them which of the following?

PapiIIary muscle

Chordae tendinae

Musculi pectinati

Omentum

Trabeculae carnae

“This valve regulates blood flow between the left atrium and left ventricle — so it wouldn’t be part of the right-sided heart structures.”

49 / 95

Tags: 2019

Which of the following is not found in the right ventricle?

Chordae tendineae

Supraventricular crest

Conus arteriosus

Trabeculae carneae

Mitral valve

“These capillaries have the largest gaps between their endothelial cells, allowing free exchange of large molecules and cells — essential for organs involved in filtration and blood cell turnover.”

50 / 95

Tags: 2019

Bone marrow, spleen, and liver contain which of the following types of vessels?

None of these

Continuous capillaries

Sinusoidal capillaries

Fenestrated capillaries

Elastic arteries

Think about the large veins that return blood to the heart. Which one relies on gravity and pressure gradients rather than valves to ensure blood flow?

51 / 95

Tags: 2020

Which of the following veins does not have valves?

Superior vena cava

Atrioventricular orifice

Thebesian veins

Inferior vena cava

Coronary sinus

“Think about the largest artery in the body that originates directly from the heart and branches out to supply oxygenated blood to nearly every organ and tissue.”

52 / 95

Tags: 2018

Which of the following is a major vessel emerging from an adult human heart that is responsible for supplying blood to almost all parts of the body?

Truncus arteriosus

Subclavian artery

Carotid artery

Aorta

Dorsal aorta

“Imagine you have to pump water through a garden hose versus a fire hose. Which pump would need to be stronger? Now, think about which heart chamber has to push blood the farthest and against the highest resistance!”

53 / 95

Tags: 2018

Which of the following chambers of heart has the thickest layer of myocardium?

None of these

Right atrium

Left atrium

Right ventricle

Left ventricle

Think about the difference between arteries with no collateral circulation and those with insufficient collateral circulation.

54 / 95

Tags: 2018

What is incorrect regarding anatomical end arteries?

They are the same as functional end arteries

Their damage leads to necrosis of supplied tissue

They supply specific tissue of an organ

They occur where no anastamosis exists

They supply the kidneys, brain, and retina

“Which major veins in the upper body merge at a certain point and are essential for venous return to the heart?”

55 / 95

Tags: 2020

Regarding the brachiocephalic veins, which of the following is correct?

All of these

Both are large trunks

Present on either side at the root of the neck

Formed by the union of internal jugular vein and subclavian vein

Devoid of valves

“Which fetal shunt must close almost immediately after birth to ensure that oxygenated and deoxygenated blood no longer mix in the atria?”

56 / 95

Tags: 2022

The fetal cardiovascular system is designed to serve prenatal needs and permit modifications at birth that establish the neonatal circulatory pattern. Which of the following events is included in the transition from fetal to neonatal circulation?

Closure of foramen ovale

Dilation of the ductus venous sphincter

Vasodilation of umbilical arteries

Patent Ductus arteriosus

Thicker walls of the ventricles

Understanding the Transition from Fetal to Neonatal Circulation

At birth, the newborn undergoes major cardiovascular changes to transition from fetal circulation (placenta-dependent) to neonatal circulation (lung-dependent). One of the key changes is the closure of the foramen ovale, which occurs due to changes in atrial pressures.

Closure of the Foramen Ovale – A Key Event in Neonatal Circulation:

In fetal life, the foramen ovale allows oxygenated blood from the placenta to bypass the non-functional fetal lungs by shunting blood from the right atrium to the left atrium.
At birth:
1. The first breath expands the lungs, lowering pulmonary vascular resistance and increasing pulmonary blood flow.
2. This increases left atrial pressure while right atrial pressure drops due to the loss of placental circulation.
3. The pressure shift forces the septum primum against the septum secundum, functionally closing the foramen ovale within minutes to hours after birth.
4. Anatomical closure (forming the fossa ovalis) occurs over weeks to months.

Breakdown of Incorrect Options:

Vasodilation of Umbilical Arteries → Incorrect
- Umbilical arteries constrict, not dilate, after birth due to increased oxygen levels and loss of placental blood flow.
- They eventually become the medial umbilical ligaments.
Patent Ductus Arteriosus → Incorrect
- The ductus arteriosus closes, not remains patent, as part of the neonatal transition.
- Functional closure begins within 12–24 hours, with complete anatomical closure by 1–3 weeks.
Thicker Walls of the Ventricles → Incorrect
- Ventricular walls do not immediately thicken at birth; instead, the left ventricle gradually hypertrophies in response to the increased workload in systemic circulation.
- This is a long-term adaptation, not an immediate event in neonatal transition.
Dilatation of the Ductus Venosus Sphincter → Incorrect
- The ductus venosus (which shunted oxygenated blood from the placenta to the IVC) closes rather than dilates after birth.
- It becomes the ligamentum venosum over the next few weeks.

“Inferior wall infarctions are seen on ECG leads.. Which artery is primarily responsible for supplying this region in the majority of people?”

57 / 95

Tags: 2022

Which of the following arteries is responsible for the myocardial infarction of the inferior wall of the myocardium?

Right marginal artery

Posterior interventricular artery

Left coronary artery

Right coronary artery

Anterior interventricular artery

Understanding Inferior Myocardial Infarction and Coronary Supply

An inferior wall myocardial infarction (MI) occurs due to ischemia affecting the inferior (diaphragmatic) surface of the heart, which is primarily supplied by the right coronary artery (RCA) in most individuals.

Coronary Supply to the Inferior Wall of the Heart:

The inferior wall of the myocardium corresponds mainly to the inferior portion of the left ventricle and part of the right ventricle.
The right coronary artery (RCA) supplies the inferior wall via its terminal branches, particularly the posterior interventricular artery (posterior descending artery, PDA) in right-dominant circulation (which is present in ~85% of people).
Occlusion of the RCA leads to inferior wall infarction, often seen with ST-segment elevation in leads II, III, and aVF on ECG.

Breakdown of Incorrect Options:

Anterior Interventricular Artery (Left Anterior Descending, LAD) → Incorrect
- The LAD supplies the anterior wall, the anterior interventricular septum, and the apex of the heart.
- Occlusion of the LAD leads to an anterior wall MI, not an inferior wall MI.
- ECG changes would be seen in V1–V4, not in the inferior leads.
Left Coronary Artery (LCA) → Incorrect
- The LCA branches into the LAD and circumflex arteries, but it does not directly supply the inferior wall in most people.
- While the circumflex artery may supply the inferior wall in left-dominant circulation (~15% of cases), the RCA is the more common culprit.
Posterior Interventricular Artery (PDA) → Incorrect
- The PDA supplies the posterior interventricular septum and part of the inferior wall, but it usually branches from the RCA in right-dominant circulation.
- Since the RCA is the parent artery, the correct answer remains the right coronary artery.
Right Marginal Artery → Incorrect
- The right marginal artery is a branch of the RCA and mainly supplies the right ventricular free wall, not the inferior wall of the left ventricle.
- It is not the main artery responsible for inferior wall MI.

“During cardiac surgery, a surgeon may need to isolate the major arteries before connecting a heart-lung machine. Which pericardial sinus allows this maneuver?”

58 / 95

Tags: 2022

During cardiac surgery, the surgeon passes his finger through a potential space, that separates the great arteries from the atria and the veins. Which of the following potential spaces is it?

Transverse pericardial sinus

Oblique pericardial sinus

Anterior costomediastinal recess

Costodiaphragmatic recess

Superior aortic recess

“The bundle branches run within the interventricular septum. Which artery is responsible for supplying the majority of this structure?”

59 / 95

Tags: 2022

A 50-year-old man presents to the emergency department with a complaint of chest pain for the past hour. An electrocardiogram (ECG) of the patient suggests a complete block of the right and left bundle of His. Which one of the following arteries is occluded in the patient?

Right marginal artery]

Main diagonal branch

Anterior interventricular artery

Left marginal artery

Circumflex artery

“Which nerve/s work together in controlling both the diaphragm’s movement and the sensory reflex arc that triggers hiccups?”

60 / 95

Tags: 2022

Persistent hiccups can be caused by the irritation of which of the following nerves?

Both vagus and phrenic nerves

Vagus nerve

Phrenic nerve

Glossopharyngeal nerve

Recurrent laryngeal nerve

Think about the structure that surrounds the heart and provides a rigid, protective layer to limit its expansion.

61 / 95

Tags: 2018

During normal diastole, which of the following is most important in preventing overdistension of the ventricles?

Adjacent lungs

Aortic valves

Diaphragm

Fibrous pericardium

MitraI valve

Consider which artery runs along the anterior interventricular groove and supplies the largest portion of the left ventricular myocardium.

62 / 95

Tags: 2019

Damage to which of the following arteries can lead to anterior wall infarction?

Posterior interventricular artery

Left anterior descending artery

Right marginal artery

None of these

Marginal branch of circumflex artery

“These muscular ridges in the ventricles prevent suction and aid in contraction—unlike the ones found in the atria.”

63 / 95

Tags: 2019

What is the name of anastomosing ridges found in ventricles?

Oblique sinus

Papillary muscles

Pectinate muscles

Trabeculae carneae

Chordae tendineae

“Think about the outflow tract of the right ventricle. Which valve is located at the end of this funnel-shaped region?”

64 / 95

Tags: 2019

A first-year resident is studying the valvular outlet of the ventricle and is positioned at the infundibulum. This is present at which valve?

Pulmonary

Right atrioventricular

None of these

Aortic

Left atrioventricular

“Which vessel is unique in that it carries oxygen-poor blood away from the heart, unlike most arteries that carry oxygen-rich blood?”

65 / 95

Tags: 2022

Lungs are supplied by pulmonary and bronchial vessels. Which of the following blood vessels carries poorly oxygenated blood from the heart to the lungs?

Pulmonary veins

Pulmonary capillaries

Bronchial arteries

Pulmonary arteries

Bronchial veins

“The heart must pause momentarily to allow the atria to complete their job before the ventricles take over. Where in the conduction system does this deliberate delay occur?”

66 / 95

Tags: 2022

Which part of the conduction pathway has the slowest conduction rate?

AV Node

Internodal Pathway

RIght Bundle Branch

SA Node

Purkinje Fibers

Understanding the Cardiac Conduction System and Conduction Velocity

The cardiac conduction system consists of specialized pathways that ensure the sequential contraction of the atria and ventricles. Each part of this system has a different conduction velocity, which is crucial for the timing and coordination of heartbeats.

Relative Conduction Speeds (Fastest to Slowest)

Conduction Pathway	Approximate Conduction Velocity
Purkinje fibers	2–4 m/s (fastest)
Bundle branches (RBB, LBB)	1.5–3 m/s
Atrial muscle & internodal pathways	1–1.2 m/s
Ventricular muscle	0.3–1 m/s
SA node	0.05 m/s
AV node	0.02–0.05 m/s (slowest)

Why is the AV Node the Slowest?

Physiological Purpose:
- The delay at the AV node allows time for the atria to contract completely before ventricular contraction begins.
- This ensures optimal ventricular filling before ejection occurs.
Cellular Structure:
- The AV node has fewer gap junctions compared to other conduction tissues, reducing electrical coupling and slowing conduction.
Autonomic Regulation:
- The AV node is heavily influenced by the autonomic nervous system:
  - Parasympathetic (vagal) stimulation → further slows conduction (negative dromotropic effect).
  - Sympathetic stimulation → increases conduction velocity (positive dromotropic effect).

Breakdown of Incorrect Options:

Purkinje Fibers → Incorrect
- Purkinje fibers have the fastest conduction velocity (2–4 m/s) to ensure rapid and synchronized ventricular contraction.
Right Bundle Branch (RBB) → Incorrect
- The bundle branches conduct impulses rapidly (1.5–3 m/s), allowing coordinated activation of both ventricles.
SA Node → Incorrect
- The SA node has a slow conduction velocity (0.05 m/s) but is still faster than the AV node.
- It serves as the pacemaker but does not significantly delay conduction.
Internodal Pathway → Incorrect
- The internodal pathways transmit impulses from the SA node to the AV node at a moderate speed (1–1.2 m/s), which is faster than the AV node.

“Which ventricular outflow tract is smooth and ensures proper direction of blood toward the lungs?

67 / 95

Tags: 2022

A first-year resident is studying the valvular outlet of the ventricle and is positioned at the infundibulum. This is present at which valve?

Left atrioventricular

Aortic

Right atrioventricular

None of these

Pulmonary

Remember the vertebral levels of the major diaphragm openings: “I 8 10 Eggs At 12” (IVC – T8, Esophagus – T10, Aorta – T12). The structure accompanying the aorta is part of the venous drainage system of the thorax.

68 / 95

Tags: 2020

Which of these is the structure that accompanies the aorta through the aortic hiatus?

Vagus nerve

Vena cava

Azygous vein

Phrenic nerve

Esophagus

“This structure serves as a bridge that connects veins from one side of the body to the other in the upper thorax.”

69 / 95

Tags: 2016

Shunt between the right and left anterior cardinal vein forms which of the following?

Inferior vena cava

Left brachiocephalic vein

Renal vein

Gonadal vein

Superior vena cava

“This vessel does contribute to venous return, but it does not empty directly into the right atrium—instead, it first forms a larger vein that does.”

70 / 95

Tags: 2016

Which of the following is not a tributary of the right atrium?

Superior vena cava

Brachiocephalic vein

Anterior cardinal vein

Coronary sinus

Inferior vena cava

it is located at the bottom and left side of the heart and has the strongest wall

71 / 95

Tags: 2021

Which of the following forms the apex of the heart?

Left ventricle

Right and left atrium

Right atrium

Right and left ventricle

Left atrium

Consider the general layout of the thoracic cavity. Where is the heart situated relative to the lungs and the other structures within the chest? Which subdivision of the mediastinum houses the heart and its surrounding pericardium?

72 / 95

Tags: 2021

Heart belongs to which of the following mediastinum divisions?

Inferior

Superior

Middle

This is the layer responsible for the contractile function of the heart. It’s the part of the heart that thickens in response to increased workload, especially in conditions that affect the right side of the heart.

73 / 95

Tags: 2021

Which cardiac layer is involved in right ventricular hypertrophy?

Parietal layer of pericardium

Epicardium

Endocardium

Visceral layer of pericardium

Myocardium

“The heart is surrounded by multiple protective layers. Before reaching the muscle, a penetrating object must first pass through the outermost one. Which layer provides the most external structural protection?”

74 / 95

Tags: 2016

Tom was stabbed with a sword. The sword pierced the right side of his chest and went straight through his heart. Which of the following was the first structure pierced by the sword?

Fibrous pericardium

Visceral serous pericardium

Myocardium

Parietal serous pericardium

Epicardium

“The blood supply to the AV node is linked to the dominance of coronary circulation. Since one pattern is more common in the general population, consider which artery is most frequently responsible.”

75 / 95

Tags: 2016

Which of the following is true regarding the blood supply of the atrioventricular node?

From right coronary artery in 80% of the population

From left coronary artery in 80% of the population

From left coronary artery in 60% of the population

From right coronary artery in 20% of the population

From right coronary artery in 50% of the population

“Consider the major blood vessel that curves in the superior mediastinum and gives rise to three major branches supplying the head, neck, and upper limbs. Unlike its ascending counterpart, this portion is not enclosed within the pericardium.”

76 / 95

Tags: 2016

Which of the following structures present in the superior mediastinum is not enclosed by the pericardium?

Arch of aorta

Upper half of superior vena cava

Descending aorta

Initial part of inferior vena cava

Ascending aorta

“Think of a groove that runs like a ‘crown’ around the heart, dividing the upper chambers (atria) from the lower chambers (ventricles). This groove also houses major coronary arteries and veins.”

77 / 95

Tags: 2016

Which one of the following separates the atria from the ventricles?

Interventricular sulcus

Interatrial groove

Anterior interventricular groove

Posterior interventricular groove

Coronary sulcus

“Imagine standing at the base of the aorta, looking up at the three sinuses behind the aortic valve cusps. One of these sinuses is specifically named after the artery it gives rise to—think about which artery runs along the right side of the heart.”

78 / 95

Tags: 2016

The right coronary artery arises from which of the following sinuses?

Left posterior aortic sinus

From anterior and posterior aortic sinuses

Anterior aortic sinus

Right posterior aortic sinus

From left pulmonary vein

The right coronary artery (RCA) arises from the anterior aortic sinus of the ascending aorta, also known as the right coronary sinus. This artery supplies blood to the right atrium, right ventricle, part of the left ventricle, the sinoatrial (SA) node (in about 60% of individuals), and the atrioventricular (AV) node (in about 80% of individuals).

Now, let’s analyze each option carefully:

Correct Answer:

✅ Anterior aortic sinus

The right coronary artery originates from the anterior aortic sinus of the aorta, which is also called the right coronary sinus. This is one of the three aortic sinuses, located behind the right cusp of the aortic valve.
After arising from this sinus, the RCA courses through the right atrioventricular groove (coronary sulcus), supplying various structures of the heart.

Incorrect Options:

❌ From anterior and posterior aortic sinuses

The right coronary artery does not arise from both the anterior and posterior aortic sinuses. It arises only from the anterior aortic sinus.
The left coronary artery (LCA) arises from the left posterior aortic sinus (left coronary sinus).

❌ Right posterior aortic sinus

There is no anatomical structure referred to as the right posterior aortic sinus.
The three aortic sinuses are:
- Anterior aortic sinus (right coronary sinus) → Gives rise to RCA
- Left posterior aortic sinus (left coronary sinus) → Gives rise to LCA
- Right posterior aortic sinus (non-coronary sinus) → No artery arises from here

❌ Left posterior aortic sinus

This sinus is also known as the left coronary sinus and gives rise to the left coronary artery (LCA), not the RCA.
The left coronary artery further divides into the left anterior descending (LAD) artery and the circumflex artery, which primarily supply the left side of the heart.

❌ From left pulmonary vein

The left pulmonary vein is not a site of coronary artery origin.
The pulmonary veins are responsible for carrying oxygenated blood from the lungs to the left atrium, and they have no direct connection with the coronary arteries.

Think about the blood supply to the heart itself. Where do the arteries that nourish the heart muscle originate? Which portion of the aorta is closest to the heart, and contains the openings to these crucial arteries?

79 / 95

Tags: 2021

Which of the following gives rise to the right and left coronary arteries?

Coronary sinus

Arch of aorta

Abdominal aorta

Thoracic aorta

Aortic sinus of ascending aorta

Think about the pathway of oxygenated blood from the lungs to the heart. Which vessels carry oxygenated blood to the left atrium, not the right atrium?”

80 / 95

Tags: 2021

Which of the following does not open in the right atrium?

Pulmonary veins

Superior vena cava

Coronary sinus

None of these

Inferior vena cava

Think about the valve that separates the left ventricle from the largest artery in the body. Which valve allows oxygenated blood to be pumped into the systemic circulation?”

81 / 95

Tags: 2021

Blood leaves the left ventricle through which of the following valves?

None of these

Pulmonary valve

Aortic valve

Mitral valve

Tricuspid valve

This valve is located between the left atrium and left ventricle and lies slightly left of the sternum at the level of a lower costal cartilage in the thorax.

82 / 95

Tags: 2021

What is the correct anatomical position of the mitral valves?

Third costal cartilage

Fourth intercostal space

Fourth costal cartilage

Second intercostal space

Second costal cartilage

“Think about the type of cells that line the internal surfaces of vessels in the body. Which cells create a smooth surface for fluid flow and are found in both blood and lymphatic vessels?”

83 / 95

Tags: 2021

Lymphatic vessels are internally lined with which of the following?

Myocytes

Collagen fibres

Elastic fibres

Fibroblasts

Endothelial cells

“Think about the largest artery in the body and its role in handling the high-pressure blood flow from the heart. Which type of artery has walls rich in elastic fibers to accommodate this function?”

84 / 95

Tags: 2021

Coarctation of the aorta is common in children. The aorta is classified as which type of artery?

Medium muscular artery

Large elastic artery

Large muscular artery

Small muscular artery

Medium elastic artery

Think about a condition where not just the heart, but all major internal organs are reversed in position, forming a mirror image of normal anatomy.

85 / 95

Tags: 2018

Dextrocardia is commonly associated with which of the following conditions?

Tetralogy of Fallot

Aortic stenosis

Patent ductus arteriosus

Situs inversus

Coarctation of aorta

Think about the cranial nerve responsible for parasympathetic regulation of heart rate. It slows down the pacemaker activity of the SA node.

86 / 95

Tags: 2018

Which of the following is true regarding sinoatrial (SA) nodal cells?

Supplied by left coronary artery

Supplied by vagus nerve

Connected to AV node via fine Purkinje fibres

Present in both atria

Can not generate impulse at all once denervated

Think about the structure that directs blood from the right ventricle into the lungs. This outflow tract is smooth-walled and prevents turbulent blood flow before reaching the semilunar valve.

87 / 95

Tags: 2018

A first-year resident is studying the valvular outlet of the ventricle and is positioned at the infundibulum. This is present at which valve?

Aortic

None of these

Right atrioventricular

Pulmonary

Left atrioventricular

“Think about the posterior structures of the heart and their relationship to the esophagus. Which chamber is most likely to compress the esophagus when enlarged?”

88 / 95

Tags: 2023

When performing a clinical examination, if the middle part of the esophagus is compressed, which part of the heart is most likely causing this compression?

Left atrium

Right atrium

Left ventricle

Right ventricle

Aorta

“Think about the muscular ridges that give the inner walls of the ventricles a rough, sponge-like appearance. Which structure helps to strengthen the ventricular walls and prevent suction during contraction?”

89 / 95

Tags: 2023

What is the sponge-like structure found in the ventricle of the heart?

Trabeculae carneae

Fossa ovalis

Sulcus terminalis

Sulcus chrysalis

Musculi pectinati

Consider the heart’s electrical pathway: there is only one “gateway” that ensures a brief pause—allowing the upper chambers to complete their work—before passing the signal to the lower chambers. Which structure plays that crucial timing role?

90 / 95

Tags: 2023

What is the name of the structure that connects the atria to the ventricles in the conducting system?

Sinoatrial node

Interventricular septum

Purkinje fiber

Atrioventricular node

Bundle of His

“This natural pacemaker is found in the right atrium, close to where a major vein enters the heart, at the superior end of a distinct groove.”

91 / 95

Tags: 2016

Which of the following is true regarding the location of a sinoatrial node?

Superficial to the epicardium at the junction of superior and inferior vena cava

Near the coronary sinus

Posterolaterally at the junction of inferior vena cava and right atrium

Superior end of the sulcus terminalis

Postero-inferior region of the inter atrial septum

“Consider where blood flows before reaching the lungs and where it goes after leaving them. The right atrium collects blood returning from certain areas, but not all vessels follow this path.”

92 / 95

Tags: 2016

During a class discussion, the teacher asked about the tributaries opening in the right atrium. Which of the following does not open in the right atrium?

Inferior vena cava

None of these

Pulmonary vein

Inferior vena cava

Coronary sinus

The right atrium is the chamber of the heart that receives deoxygenated blood from various veins and then sends it to the right ventricle. Several major veins drain into the right atrium, but the pulmonary veins do not.

Tributaries That Open into the Right Atrium:

Superior vena cava (SVC):
- Drains deoxygenated blood from the upper body (head, neck, upper limbs, and thorax).
- Opens into the upper part of the right atrium.
Inferior vena cava (IVC):
- Drains deoxygenated blood from the lower body (abdomen, pelvis, and lower limbs).
- Opens into the lower part of the right atrium.
Coronary sinus:
- Collects venous blood from the heart’s myocardium (cardiac veins).
- Opens into the posterior part of the right atrium near the tricuspid valve.
Anterior cardiac veins:
- Small veins that directly drain the anterior surface of the right ventricle into the right atrium.
Smallest cardiac veins (Thebesian veins):
- Tiny veins draining directly into all four heart chambers, including the right atrium.

Why Pulmonary Veins Do Not Open into the Right Atrium:

Pulmonary veins carry oxygenated blood from the lungs to the left atrium, not the right atrium.
There are typically four pulmonary veins (two from each lung), and they directly open into the left atrium to supply the oxygenated blood needed for systemic circulation.

Thus, the correct answer is pulmonary vein, as it does not drain into the right atrium.

Why the Other Options Are Incorrect:

Coronary sinus (Incorrect)
- It is the main venous drainage of the heart muscle and empties into the right atrium.
Inferior vena cava (Incorrect)
- It returns deoxygenated blood from the lower body and opens into the right atrium.
Superior vena cava (Incorrect)
- It returns deoxygenated blood from the upper body and opens into the right atrium.
None of these (Incorrect)
- This would mean that all the given options drain into the right atrium, which is incorrect since the pulmonary veins drain into the left atrium.

“Think about the anatomical location of the coronary arteries and their relationship to the aortic valve. Which structure directly connects the aorta to the coronary arteries?”

93 / 95

Tags: 2023

From which structure does the right coronary artery originate?

Left ventricles

Pulmonary trunk

Right posterior aortic sinus

Left posterior aortic sinus

Anterior aortic sinus

“Think about the artery in the body and its role in handling the high-pressure blood flow from the heart. Which blood vessel needs the most elasticity to perform this function?”

94 / 95

Tags: 2023

Which of the following blood vessels has the highest amount of elastic tissue?

Pulmonary artery

Medium size arteries

Muscular artery

Aorta

Arterioles

Think about the chamber that receives oxygenated blood from the lungs.

95 / 95

Tags: 2018

Which of the following does not open into the right atrium?

Pulmonary veins

Sinus venosum

Inferior vena Cava

Coronary sinus

Superior vena cava

Your score is

The average score is 0%

0%

Thank you for your feedback.

CVS – Anatomy

Report a question

Key Events During Isovolumetric Contraction:

Analysis of Each Option:

Anatomy of the Right Atrium & SVC:

Analysis of Each Option:

Embryological Development of the Interatrial Septum:

Analysis of Each Option:

Anatomical Position of the Pulmonary Trunk:

Analysis of Each Option:

Key Features of Coronary Arteries:

Analysis of Each Option:

Regions Supplied by the Left Coronary Artery (LCA):

Analysis of Each Option:

Why is the LAD Most Commonly Affected?

Analysis of Each Option:

Analysis of Each Option:

Why the Other Options Are Incorrect:

Why the Other Options Are Incorrect:

Breakdown of Answer Choices:

Breakdown of Valve Structures:

Why the Other Options Are Incorrect:

❌ Why the other options are incorrect

External carotid artery

Left coronary artery

Facial artery

None of these

Resting Membrane Potential in Cardiac and Skeletal Muscle:

Why the Other Options Are Incorrect:

Role of the IVC Valve in Fetal Circulation:

Why the Other Options Are Incorrect:

Why the Other Options Are Correct:

Development of the Venous System:

Formation of Major Veins:

Why the Other Options Are Incorrect:

Correct Anatomical Features of the SVC:

Why the Other Options Are Correct:

Why the Other Options Are Incorrect:

Why the Other Options Are Incorrect:

Why the other options are incorrect:

❌ Mitral valve

❌ Pulmonary valve

❌ Tricuspid valve

❌ None of these

Why the Other Options Are Incorrect?

Sources of Afferent Blood Supply to the Right Atrium:

Why the Other Options Are Incorrect:

Step-by-Step Breakdown of Blood Flow:

Why the Other Options Are Incorrect:

Why “Coronary Arteries” is the Correct Answer?

Why the Other Options Are Incorrect?

Why “Coronary Sulcus (Posterior Atrioventricular Sulcus)” is the Correct Answer?

Why the Other Options Are Incorrect?

Why “Right Atrium” is the Correct Answer?

Why the Other Options Are Incorrect?

Why the Other Options Are Incorrect:

Why the Other Options Are Incorrect:

Why the Other Options Are Incorrect:

✅ Correct Answer: “Both are tricuspid”

Why the Other Options are Incorrect:

❌ Why the Other Options Are Incorrect

❌ The right coronary artery supplies the anterior part of interventricular septum

❌ The left coronary artery does not supply the interventricular septum

❌ The left coronary artery arises from the right posterior aortic sinus

✅ The left coronary artery supplies the posterior part of the interventricular septum

❌ The left coronary artery arises from the left posterior aortic sinus

✔️ Arises from the right aortic sinus

✔️ Mostly the right coronary artery is dominant

✔️ Supplies the atrioventricular (AV) node

Why “None of these” is Incorrect

Why Trabeculae Carneae is Correct

Why the Other Options Are Incorrect

❌ Omentum

❌ Chordae Tendineae

❌ Musculi Pectinati

❌ Papillary Muscles

Analysis of the Incorrect Options

Role of the Aorta:

Why the Other Options Are Incorrect:

Why the Other Options Are Incorrect: