CBM self tests

Question 1

Four of the following statements accurately describe the position of the heart in the chest. Which statement does NOT?

Answer 1

Middle of superior mediastinum

The heart is located in the middle of the INFERIOR mediastinum, mainly left of midline.

Question 2

What lines the inner pericardium?

Answer 2

Mesothelial cells
Pericardium is lined by a single layer of cells called mesothelial cells with surrounding fibroconnective tissue rich in blood vessels and nerves.

Question 3

In the normal adult what is the name of the oval depression in the right atrium where the septum is thin?

Answer 3

Oval fossa

Question 4

Which is the most posterior of the cardiac chambers?

Answer 4

Left atrium

Question 5

The supraventricular crest is an expanse of muscle which separates two valves from each other. Which two valves does it separate?

Answer 5

Tricuspid and pulmonary

Question 6

Which of the following is NOT a major coronary artery?

Answer 6

Left carotid artery

Question 7

Which of the following components of a blood vessel contains a small network of blood vessels called the vasa vasorum?

Answer 7

Adventitia
The adventitia is the outer layer of connective tissue and nerve fibres that contains a small network of vessels called ‘vasa vasorum’.
Elastic lamina= layers of elastic fibres in vessel walls - internal layer below intima, external layer between adventitia and media.
Media= smooth muscle (strength) and muscle fibres (elasticity).
Intima= endothelial cells and connective tissue.

Question 8

What is meant by the term ‘right coronary dominance’?

Answer 8

Right coronary artery supplies posterior descending coronary artery.
In 85% of cases, the right coronary artery (RCA) is a dominant vessel and supplies the posterior descending branch that travels in the posterior interventricular groove.

Question 9

Which heart valve contains leaflets that are attached to the septal papillary muscle via chordae tendineae?

Answer 9

Tricuspid valve

• Only the tricuspid and mitral valves have chordae tendineae attached to their leaflets.
• The mitral valve is bicuspid, and the leaflets are supported by anteromedial and posterolateral papillary muscles of the left ventricle.
• The tricuspid valve leaflets are supported by anterior, posterior and septal papillary muscles of the right ventricle.

Question 10

k) Under physiological conditions at rest, hemoglobin in this vessel is approx. 75% saturated with oxygen. The blood pressure is at 15 mmHg. Which vessel is it?

Answer 10

N |AND| (Left) Pulmonary artery
When blood leaves the tissues the partial pressure of oxygen is such that the hemoglobin is still 75% saturated. Therefore, the blood must either be in either of the vena cava or the pulmonary artery. In the vena cava, the pressure approaches 3-5 mm Hg before it enters the heart and if ejected out of the right ventricle at a pressure of 10-20 mmHg in the pulmonary artery.

Question 11

Which vessel supplies the left arm?

Answer 11

C |AND| Left subclavian artery
The arms are supplied by subclavian arteries. The right arm is supplied by the right subclavian and the left by the left subclavian. Unlike the right subclavian artery, the left subclavian arises directly from the arch of the aorta.

Question 12

Consultant Smith attempts to palpate an arterial pulse with his fingers between the anterior border of the left sternocleidomastoid muscle and the lateral border of the thyroid cartilage. Which artery is responsible for this pulse at this location? (

Answer 12

B |AND| Left (common) carotid artery
This pulse is felt by placing your index and middle fingers at the side of the neck between the sternocleidomastoid muscle and the thyroid cartilage. The sternocleidomastoid muscle connects the clavicle and the first ribs to the mastoid process of the skull. Normally the pulsation of an artery is palpable whilst that of a vein is not palpable. The main artery that runs up the neck at this location is called common carotid artery. The pulse is called the carotid pulse.

Question 13

what type of calcium channels do SA node use?

Answer 13

T-type Ca2+ channels are important in Ca2+ entry in the SA node (pacemaker) cells, but not ventricular cells.

Question 14

which limb of the cardia is important for normal cardiac muscle?

Answer 14

Only the ascending limb is important for normal cardiac muscle

Question 15

preload can be though as?

after load can be thought as?

Answer 15

preload as the End-diastolic volume (i.e. the volume of blood that fills and stretches the ventricle), and afterload as Total peripheral resistance (the force the ventricle is pushing against once it begins contraction, i.e. how difficult it is for the ventricles to pump the blood out to the body).

Question 16

Which of these is NEITHER a measure of preload nor afterload? Please note that the other four options are either a measure of preload or a measure of afterload.

Answer 16

Measures of preload: end diastolic volume, end diastolic pressure, right atrial pressure.
Measures of afterload: diastolic arterial blood pressure.

Question 17

what is stroke volume and pressure influenced by?

Answer 17

Stroke volume is influenced by afterload. Pressure influenced by structure.

Question 18

Which of the following features of a cardiac myocyte facilitates an electrical connection due to its low electrical resistance?

Answer 18

Gap junctions.
Cardiac myocytes are attached to neighbouring cells via intercalated disks. These cell junctions consist of desmosomes (which hold the cells together via proteoglycan bridges) and gap junctions which allow electrical conductivity.

Question 19

is B12 deficiency a primary or secondary disorder?

Answer 19

Primary

Question 20

Patient J has had a myocardial infarction due to a clot in the left anterior descending coronary artery. There are two options of therapeutic thrombolysis that can be used to break the clot up. Which of these is a therapeutic agent whose design is based on a natural fibrinolytic protein?

Answer 20

NOT streptokinase as question asks to mimic the natural process.

Question 21

Which of the following can be classified as a protective function of macrophages in an atherosclerotic plaque?

Answer 21

Stimulation of a wound healing response involving vascular smooth muscle cells

Question 22

Which of the following statements about pulmonary embolism is incorrect?

Answer 22

It is particularly associated with thrombi formed in the superficial veins of the leg.
The thrombi are more common in the deep veins of the thigh (hence DVT).
Pulmonary air spaces filled with the remnants of red blood cells would be observed in a pulmonary infarct following occlusion of a vessel by a pulmonary embolus.

Question 23

What proportion of patients with heart failure die within 5 years?

Answer 23

50%

Question 24

here would the change be seen for turbulent flo in narrowed valve

Answer 24

Turbulent flow through the narrowed valve results in a systolic murmur.