Formative Flashcards
The chambers of the heart possess unique, distinguishing features enabling them to function effectively and efficiently. The right atrium possesses:
A. A bicuspid valve leading to the right ventricle
B. An opening for the azygos vein
C. An opening for the coronary sinus
D. An opening for the right brachiocephalic vein
E. An oval fossa in its anterior wall
C. An opening for the coronary sinus
Which of these is NOT a shared feature of skeletal and cardiac muscle:
A. Myocytes in both are electrically connected via gap junctions
B. The duration of the depolarising phase of the action potential in both is less than 5 msec
C. They both exhibit sustained contraction (tetanus) in response to high frequency simulation
D. They both have an unstable resting membrane potential
E. None of the above features are shared in common
E. None of the above features are shared in common
During embryological development, which of the following gives rise to the common carotid arteries? A. 2nd pair of aortic arches B. 3rd pair of aortic arches C. 4th pair of aortic arches D. 5th pair of aortic arches E. 6th pair of aortic arches
B. 3rd pair of aortic arches
The arterioles function as resistance vessels because:
A. They only allow blood flow in one direction
B. They have a relatively narrow lumen and a thin elastic wall
C. They have a relatively narrow lumen and strong muscular wall
D. They have a relatively wide lumen and strong muscular wall
E. The statement is wrong - arterioles are not resistance vessels
C. They have a relatively narrow lumen and strong muscular wall
In the heart, the fast depolarising phase of the cardiac action potential is caused by: A. Influx of Ca2+ B. Influx of Cl- C. Influx of K+ D. Influx of Mg2+ E. Influx of Na+
E. Influx of Na+
In the electrocardiogram, depolarisation of the atria corresponds to the: A. P-wave B. QRS complex C. T-wave D. U-wave E. None of these
A. P-wave
The second heart sound is heard when: A. Blood enters the aorta B. The atria contract C. The atrioventricular valves close D. The atrioventricular valves open E. The semilunar valves close
E. The semilunar valves close
A heart rate in excess of 150 beats per minute is likely to:
A. Decrease afterload and therefore decrease stroke volume
B. Decrease contractility and therefore decrease stroke volume
C. Decrease preload and therefore decrease stroke volume
D. Increase afterload and therefore decrease stroke volume
E. Increase preload and therefore decrease stroke volume
C. Decrease preload and therefore decrease stroke volume
Activation of beta-1 adrenoceptors on cardiac myocytes will:
A. Increase afterload and therefore decrease stroke volume
B. Increase afterload and therefore increase stroke volume
C. Increase contractility and therefore increase stroke volume
D. Increase preload and therefore decrease stroke volume
E. Increase preload and therefore increase stroke volume
C. Increase contractility and therefore increase stroke volume
Which of the following is the most significant feature of the pulmonary circulation?
A. Most pulmonary blood flow occurs during diastole
B. Pulmonary arterioles constrict in response to local hypoxia
C. Pulmonary arterioles express beta-1 adrenoceptors
D. The pulmonary circulation shows excellent pressure autoregulation
E. The pulmonary circulation shows good active (metabolic) hyperaemia
B. Pulmonary arterioles constrict in response to local hypoxia
During exercise, venous pressure (and hence venous return to the heart) may be increased by:
A. An increase in systemic filling pressure
B. Contraction of smooth muscle surrounding the veins
C. Increased rate and depth of respiration
D. Rhythmic contraction of skeletal muscle
E. All of the above
E. All of the above
A 46 year old woman is usually well but complains of inermittent rapid regular palpitations that are terminated by the valsalva manoeuvre. The most likely diagnosis is: A. Atrial fibrillation B. Supraventricular tachycardia C. Ventricular ectopics D. Ventricular fibrillation E. Ventricular tachycardia
B. Supraventricular tachycardia
A 65 year old woman with a history of hypertension presents to the acute medical admissions unit with sudden onset of severe breathlessness and paroxysmal nocturnal dyspnoea (PND). She is tachycardic with an elevated jugular venous pressure (JVP), crackles in both lung fields to the midzones and significant peripheral oedema.
Select the most appropriate drug treatment:
A. Angiotensin converting enzyme inhibitor
B. Angiotensin II blocker
C. Beta blocker
D. Intravenous diuretic
E. Oral diuretic
D. Intravenous diuretic
A 68 year old man presents with exertional angina. What is the most appropriate treatment to improve symptoms?
A. Introduce angiotensin-converting-enzyme (ACE) inhibitor
B. Start aspirin 75mg/day
C. Start beta blocker
D. Start low dose warfarin
E. Start simvastatin
C. Start beta blocker
A 40 year old man presents with severe hypertension. You believe he may suffer from ‘white coat hypertension’.
Select the single most informative investigation that could be used to confirm this:
A. 24 hour ambulatory blood pressure recording
B. 24 hour urinary catecholamines
C. Echocardiography
D. Renal arteriography
E. Renal ultrasound
A. 24 hour ambulatory blood pressure recording