-
Question 1
Incorrect
-
Regarding the surface anatomy of the orifices of the heart, where is the aortic valve located?
Your Answer: Opposite the left upper sternal border in the 2nd intercostal space
Correct Answer: Opposite the left 3rd intercostal space to the left of the sternum
Explanation:The aortic valve is situated in the left 3rd intercostal space just beneath the sternum.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 2
Correct
-
The coronary arteries supply which part of the heart’s subendocardial region exclusively in diastole?
Your Answer: Left ventricle
Explanation:It is only during diastole that the blood flows to the subendocardial portion of the left ventricle, as the heart muscle relaxes and the coronary arteries regain their patency.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 3
Correct
-
The initial rapid depolarization in the action potential of cardiac muscle cells is due to:
Your Answer: Opening of voltage-gated Na+ channels
Explanation:The initial depolarization of the action potential in a cardiac muscle cell is due to the sodium current generated by opening of the voltage gated sodium channels leading to an influx of sodium ions into the cell and raising the membrane potential towards threshold.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 4
Incorrect
-
When is the blood pressure at its lowest during pregnancy?
Your Answer: Third trimester
Correct Answer: Second trimester
Explanation:It is lowest during the second trimester.
Previous studies have reported changes in blood pressure (BP) throughout pregnancy, and it was generally accepted that in clinically healthy pregnant women, BP falls gradually at first trimester, reaching the lowest around 22–24 weeks, rising again from 28 weeks, and reaching preconception levels by 36 weeks of gestation
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 5
Incorrect
-
According to Poiseuille’s formula, which 1 of the following will lead to increased flow?
Your Answer: Smaller radius
Correct Answer: Shorter tube
Explanation:V = π p r4 / 8 η lwhere V = discharge volume flow (m3/s)p = pressure difference between the ends of the pipe (N/m2, Pa)r = internal radius of pipe (m)l = length of pipe (m)η = viscosity of fluid
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 6
Incorrect
-
Which of the following phases in depolarization and repolarization of cardiac muscle cells are caused by the inactivation of Na+ channels?
Your Answer: Phase 0 : rapid depolarization
Correct Answer: Phase 1 : rapid repolarization
Explanation:Phase 0 is caused by the sodium current. Voltage gated sodium channels open leading to the influx of sodium into the cardiac muscle cell. Phase 1 is the rapid transient repolarization phase which is caused by the inactivation of the voltage gated sodium channels and opening of the voltage gated potassium channels along with opening of the slow calcium channels. Phase 2 which is the plateau is caused by opening of the slow calcium channels. Phase 4 is caused by closing of the slow calcium channels and opening of the potassium channels leading to efflux of potassium leading to the establishment of the resting membrane potential.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 7
Correct
-
The function of Troponin T in cardiac muscle is?
Your Answer: Allows attachment of troponin components to tropomyosin
Explanation:Troponin T binds the troponin components to tropomyosin. Troponin I inhibits the interaction of myosin with actin, and troponin C contains the binding sites for the Ca2+ that helps initiate contraction.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 8
Incorrect
-
Direct conduction from the atrium to the ventricles is prevented by:
Your Answer: Intermodal pathways
Correct Answer: Annulus fibrosus
Explanation:The annulus fibrosus disconnects the syncytium complex. The atria are rapidly activated however the activation peters out when the insulating layer-the annulus fibrosus-is reached.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 9
Incorrect
-
Select the correct statement regarding the 4th heart sound, it?
Your Answer: Coincides with rapid ventricular filling.
Correct Answer: Can be heard in atrial systole.
Explanation:The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle by atrial systole.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 10
Incorrect
-
Question 11
Correct
-
When looking at the JVP what does the c wave signify:
Your Answer: Isovolumetric ventricular contraction
Explanation:The C wave signifies a rise in the atrial pressure during isovolumetric contraction due to the tricuspid valve bulging into the atria.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 12
Incorrect
-
A 55 year old cardiac patient is comfortable at rest but heavy housework results in fatigue, palpitations or dyspnoea. What New York Heart Association class best describes the severity of their disease?
Your Answer: NYHA Class III
Correct Answer: NYHA Class II
Explanation:New York Heart Association functional classification:
Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.
Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.
Class III: marked limitation of any activity; the patient is comfortable only at rest.
Class IV: any physical activity brings on discomfort and symptoms occur at rest.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 13
Incorrect
-
What is pulse pressure?
Your Answer: 2/3 systolic plus 1/3 diastolic
Correct Answer: Difference between systolic and diastolic pressure
Explanation:The pulse pressure is the difference between the measured systolic and diastolic pressures.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 14
Correct
-
Question 15
Incorrect
-
Where on the surface of the chest is the normal site of auscultation for the mitral area?
Your Answer: 5th left intercostal space mid-axillary line
Correct Answer: 4th left intercostal space in the mid-clavicular line
Explanation:The mitral valve is situated in the left 4th intercostal space just beneath the sternum, in the mid clavicular line.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 16
Incorrect
-
Which of the following is the most common causative organism in infective endocarditis?
Your Answer: Staphylococcus aureus
Correct Answer: Streptococcus viridans
Explanation:Viridans Alpha-haemolytic streptococci, that are present in the mouth are the most frequently isolated microorganisms when the infection is acquired in a community setting. In contrast, Staphylococcus blood stream infections are frequently acquired in a health care setting where they can enter the blood stream through procedures that cause break in the integrity of skin like surgery, catheterisation or during access of long term indwelling catheters or secondary to intravenous injection of recreational drugs.Prosthetic valve endocarditis is commonly caused by Staphylococcus epidermidis as it is capable of growing as a biofilm on plastic surfaces
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 17
Correct
-
Which of the following conditions has no effect on cardiac output?
Your Answer: Sleep
Explanation:Sleep has no effect on the cardiac output. Anxiety, excitement and pregnancy will increase the cardiac output. Standing from a lying position will decrease the cardiac output transiently.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 18
Incorrect
-
The hyperpolarization phase of pacemaker cells is dominated by ____ current.
Your Answer: Ca++
Correct Answer: K+
Explanation:The hyperpolarization phase is a continuation of the repolarization phase but the membrane potential dips below the resting membrane potential. This results due to the fact that the K+ channels take a longer time to close than the Na+ channels. Hence efflux of the K+ will result in hyperpolarization.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 19
Incorrect
-
Regarding the cardiac muscle striations as viewed under the microscope, which areas are dark?
Your Answer: I band and z line
Correct Answer: A band and z line
Explanation:Dark bands: a, h. Dark line: z. Clear band: i, m
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 20
Incorrect
-
The rate of depolarization of the SA node membrane potential is modulated by the following:
Your Answer: Autonomic tone
Correct Answer: All of the above
Explanation:Rate of depolarization of the SA node is modulated by all of these.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 21
Correct
-
Activation of nitric oxide synthesis by endothelial cells is triggered by:
Your Answer: All of the above
Explanation:Acetylcholine, histamine, bradykinin, vasoactive intestinal peptide (VIP) and shear stress on the endothelial cells causing the release of NO. NO is formed from arginine and causes vasodilatation of the blood vessels.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 22
Incorrect
-
Regarding cardiac contractility, catecholamines exert their inotropic effect via:
Your Answer: Î’2-adrenergic receptors and gs
Correct Answer: Î’1-adrenergic receptors and gs
Explanation:Catecholamines exert their inotropic effect on the heart via the B1 adrenergic receptors and Gs, stimulating adenyl cyclase and increasing the production of cAMP.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 23
Incorrect
-
Ventricular depolarization plus ventricular repolarization is shown by the _____ interval
Your Answer: ST
Correct Answer: QT
Explanation:The QT interval represents ventricular depolarization as well as ventricular repolarization.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 24
Incorrect
-
B1 adrenergic stimulation produces:
Your Answer: Decrease adenylate cyclase
Correct Answer: Increase in calcium cytosolic concentration
Explanation:Norepinephrine secreted by the sympathetic endings binds to B1 receptors, and the resulting increase in intracellular cAMP facilitates the opening of L channels, increasing Ica and the rapidity of the depolarization phase of the impulse and activates PKA which leads to phosphorylation of the voltage-gated Ca2+ channels, causing them to spend more time in the open state.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 25
Incorrect
-
The interventricular septum is supplied anteriorly by the?
Your Answer: Posterior descending artery
Correct Answer: Left anterior descending artery
Explanation:The anterior interventricular artery or left anterior descending artery supplies the anterior 2/3rds of the interventricular septum.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 26
Incorrect
-
What type of intercellular connection found between cardiac muscle fibers allow for the spread of excitation from one cell to another?
Your Answer: Tight junctions
Correct Answer: Gap junctions
Explanation:The cardiac muscles have gap junctions in-between the cells. They form low resistance passages, which allow ions to diffuse through every muscle fiber rapidly and result in the cardiac muscles functioning as a syncytium, without any protoplasmic bridges involved.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 27
Incorrect
-
The major factor in controlling coronary artery blood flow is considered to be?
Your Answer: Parasympathetic input
Correct Answer: Metabolites of oxygen consumption
Explanation:There is a strong relationship between myocardial blood flow and oxygen consumption. This indicates that products of metabolism may cause vasodilation of the coronary artery.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 28
Incorrect
-
Regarding cardiac output, an increased ejection fraction results from increases in which of the following?
Your Answer: Parasympathetic stimulation
Correct Answer: Strength of contraction without increase in muscle fiber length
Explanation:When the strength of contraction increases without an increase in fiber length, the EF increases.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 29
Correct
-
Endothelial cells are attached to adjacent cells by adherent junctions via:
Your Answer: Cadherins
Explanation:Cadherins are calcium dependant molecules that mediate cell to cell adhesions in epithelial and endothelial cells among others.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 30
Correct
-
Which of the following isoforms of Nitric oxide synthase (NOS) is found in endothelial cells?
Your Answer: Nos 3
Explanation:There are only 3 isoforms:NOS 1: found in nervous systemNOS 2: in macrophages and other immune cellsNOS 3: In endothelial cells
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Secs)