Cardiovascular system and diseases I

Question 1

what is the purpose of the valves in the heart

Answer 1

maintain uniddirectional blood flow through the heart

Question 2

what is the cardiac muscle mainly composed of

Answer 2

cardiac myocytes

Question 3

ventricular myocytes are arranged how

this is to enable what

Answer 3

CIRCUMFERENTIALLY in a SPIRAL ORIENTATION

enables contraction and relaxation

Question 4

what are the 3 major epicardial coronary arteries

Answer 4

1) left anterior descending (LAD) artery
2) left circumflex (LCX) artey
3) right coronary artery

Question 5

when does most coronary arterial blood flow occur

Answer 5

during VENTRICULAR DIASTOLE when the microcirculation is not COMPRESSED by cardiac contraction

Question 6

the SA node does what

Answer 6

pacemaker of the heart

Question 7

where is the SA node located

Answer 7

near the junction of the right atrial appendage and the superior vena cava

Question 8

the AV node location

Answer 8

right atrium along atrial septum

Question 9

bundle of His location

Answer 9

from right atrium to summit of ventricular septum

Question 10

in the PQRST wave what does each wave/segment mean

inc PR segment

Answer 10

P: atrial depolarisation
PR segment: time taken from atria to ventricle
QRS: ventricular depolarisation
ST segment: period between ventricular depolarisation to myocardial contraction
T wave: ventricular repolarisation

Question 11

conduction defects (eg arrhythmias) are caused by what

Answer 11

uncoordinated impulse generation

Question 12

what is the Frank-Starling mechanism

Answer 12

a compensatory mechanism: inc FILLING VOLS DILATE the heart and O INC FUNCTIONAL CROSS-BRIDGE formation within sarcomeres O INC CONTRACTILITY

Question 13

give 3 compensatory mechanisms for the heart

Answer 13

1) Frank-Starling mechanism
2) Activation of neurohormonal systems
3) myocardial mechanisms

Question 14

give examples of ways NEUROHORMONAL SYSTEMS can act as compensatory mechanisms

Answer 14

1) release NORADRENALINE by adrenergic cardiac nerves of the autonomic NS (inc HR, myocardial contractility, vascular resistance)
2) renin-angiotensisn-aldosterone system ACTIVATION
3) release of atrial natriuretic peptide

Question 15

common cardiovascular diseases

Answer 15

• atherosclerosis
• hypertension
• stroke
• heart failure
• arrhythmia
• heart valve problems

Question 16

hypotension results in what

Answer 16

inadequate organ perfusion and can lead to dysfunction or tissue death

Question 17

hypertension results in what

Answer 17

vessel and end-organ damage

Question 18

hypertension is responsible for what % of deaths due to heart disease

Answer 18

45%

Question 19

hypertension is responsible for what % of deaths due to stroke

Answer 19

51%

Question 20

what is classed as clinically significant hypertension

Answer 20

sustained systolic >139 mm Hg

sustained diastolic > 89mm Hg

Question 21

what are the risk factors for hypertension

Answer 21

• age
• genetics: African and Caribbean origin
• BMI
• diet (Na+ intake)
• stress

Question 22

what are the 2 types of hypertension

Answer 22

1) ESSENTIAL (idiopathic)
- 90-95% of cases
- complex, multifactorial (inc genetics)

2) SECONDARY

Question 23

how is blood pressue calculated

Answer 23

cardiac output x peripheral resistance

Question 24

what can affect cardiac output

Answer 24

1) BLOOD VOLUME
(Na, mineralocorticoids, atriopeptin)
2) CARDIAC FACTORS
(heart rate, contractility)

Question 25

what can affect peripheral resistance

Answer 25

1) HUMORAL FACTORS - constrictors: Angiotensin II, Catecholamines, Endothelin - dilators: Prostaglandins, Kinins, NO 2) LOCAL FACTORS: pH, hypoxia 3) NEURAL FACTORS: - constrictors: α-adrenergic - dilators: β-adrenergic

Question 26

what are the symptoms of hypertension

Answer 26

- persistent headache - blurred/double vision - nosebleeds - shortness of breath

Question 27

what is a possible effect of hypertension on the brain

Answer 27

- TIA (transient ischaemic attack) | - stroke

Question 28

what is a possible effect of hypertension on the EYE

Answer 28

retinopathy

Question 29

what is a possible effect of hypertension on the legs

Answer 29

peripheral vascular disease

Question 30

what is a possible effect of hypertension on the kidneys

Answer 30

renal failure

Question 31

what is a possible effect of hypertension on the heart

Answer 31

LVH- left ventricular hypertrophy CHD- coronary heart disease HF- heart failure

Question 32

what are the 4 types of antihypertensive drugs

Answer 32

1) ACE inhibitors/ angiotensin receptor antagonists 2) Beta-blockers 3) Ca channel blockers 4) Diuretics

Question 33

what heart diseases can hypertension cause

Answer 33

- systemic hypertension causes LEFT HEART HYPERTROPHY | - pulmonary hypertension causes RIGHT HEART HYPERTROPHY

Question 34

what is the morphology of hypertensive left ventricular hypertrophy

Answer 34

- left ventricle wall thickens - inc HEART WEIGHT - ventricular wall STIFFENS which impairs DIASTOLIC filling causing LEFT ATRIAL enlargement

Question 35

if hypertensive heart disease is in the early stages, what is experienced by patient how is it diagnosed if it progresses what can it cause

Answer 35

usually ASYMPTOMATIC - diagnosed using ELECTROCARDIOGRAM or ECHOCARDIOGRAPHY - if progression: can cuase HF or ISCHAEMIC HEART DISEASE