BMS1058 - The Cardiovascular system

Question 1

What are the 4 layers of the heart?

Answer 1

Pericardium (outer) - membrane protecting heart

Epicardium - firboelastic tissue, blood vessels, lymphatics and nerves

Myocardium- striated cardiac muscle tissue, discs that allow electrical impulses

Endocardium (inner)

Question 2

The myocardium has ts own network of blood vessels called the _______ circulation. These arteries branch from the ______ and circle the heart.

Answer 2

coronary

aorta

Question 3

Tissue damage caused by an
interruption in blood flow is known as ________ .

Answer 3

infarction

(Myocardial infarction = heart attack)

Question 4

What is the inner, middle and outer layer of blood vessels?

Answer 4

(Inner) Tunica intima - endothelial cells and connective tissue

(middle) Tunica media - smooth muscle and elastic connective tissue

(outer) Tunica adventitia - connective tissue (collagen), nerves, small blood vessels

(Detecting atheroslerosis -> A-M thickness)

Question 5

What is the precapillary sphincter?

Answer 5

A band of smooth muscle that adjusts blood flow into capillaries

Question 6

Describe the transmission of the cardiac impulse.

Answer 6

Question 7

___________ causes coontraction and ______________ causes relaxation of cardiac muscle fibres.

Answer 7

Depolarization
Repolarization

Question 8

Describe Diastole and Systole

Answer 8

Question 9

What happens to pressure across the cardiac cycle?

Answer 9

Question 10

What causes the ‘lubb dubb’ heart sounds?

Answer 10

mitral valve = bicupsid valve

lubb = bicupsid valve closing
dubb = aortic valve closing

Question 11

What is Venour Return?

Answer 11

The total blood volume returning to the heart by vena cava into the atria

Question 12

What is Ventricular end diastolic volume? (EDV)

Answer 12

Total blood volume in each ventricle at the end of diastole

Question 13

What is Ventricular end systolic volume (ESV)?

Answer 13

Total blood volume in each ventricle at the end of systole (ejection)

Question 14

What is Stroke Volume (SV)?

Answer 14

The blood volume ejected per beat from each ventricle

Question 15

What is the equation for ejection fraction?

Answer 15

Question 16

What is the equation for cardiac output?

Answer 16

Question 17

What is the equation for blood flow?

Answer 17

Change in pressure / resistance

Question 18

What is normal blood pressure?

Answer 18

Question 19

What is the equation for Mean arterial blood pressure?

Answer 19

Blood flow x resistance

Question 20

The rate and strength of heart contraction can be altered by ______ innervation and ________ secretion stimulated through the activation of the ____________ Nervous System.

Answer 20

neural
hormone
Autonomic

Question 21

What are Epinephrine and Norepinephrine called in England? What are they collectively known as?

Answer 21

Adrenaline and Noradrenaline

Known as catecholamines

Question 22

How does adrenaline increase heart rate?

Answer 22

Adrenaline released from adrenal medulla.
Binds to receptors in the heart called beta-1 receptors.

Increasing activity of sympathetics nerves to the heart - neurotrasmitter = noradrenaline

Decreases activity of parasympathetic nerves - neurotransmitter = acetylcholine

Increasing heart rate.

Question 23

How is resistance in blood vessels controlled?

Answer 23

Locally - dilation/constriction
Systemically - changes in blood vol and pressure controlled by neural and hormonal mechanisms

Question 24

THE ACTION OF VASOMOTOR NERVES:

Noradrenalin and circulating adrenaline act on _____ adrenergic receptors in the arterioles of ________ muscle causing vasodilation -> increasing the blood flow to the active muscle.
They also act on _____-________ receptors in the arterials of less active tissue causing ________________ -> blood diverted to more active tissue.

Answer 24

beta-2
skeletal

alpha-adrenergic
vasocontriction

Question 25

How does the activation of the parasympathetic NS affect heart rate? - release of ___________ from the ______ nerve. - binds to muscarinic ________ on cardiac cells - causes ___________________ of cells in SA and AV node, ______ HR.

Answer 25

acetylcholine Vagus receptors hyperpolarization decreasing

Question 26

How does the activation of the sympathetic NS affect heart rate etc? - Stimulates release of _________. ______ is released from sympathetic fibres. __________ is released form the ________ gland. - These act on _____ adrenergic receptors on the cardiac cells, ________ HR and contractility, therefore increasing cardiac _______. - Also act on ______ adrenergic receptors in the ___________ of skeletal muscle, causing ____________. - Also act on _______-adrenergic receptors in the arterioles of less active tissue, causing _____________.

Answer 26

Catecholamines Noradrenaline Adrenaline Adrenal

Question 27

Blood flow is distriuted to were it is needed via local vasodilation. What causes this?

Answer 27

Metabolic regulation: build up of metabolic by-products Endothelium-mediated: vasodilators (e.g. prostaglandins, Nitric Oxide) produced by endothelium

Question 28

How does peripheral resistance change during exercise?

Answer 28

Resistance decreases as vasodilation occurs

Question 29

How does the CV system change as we age?

Answer 29

Decreased compliance of blood vessels / increased stiffness Reduced endothelial function Reduction in cardiac muscle fiber size Progressive loss of cardiac muscular strength Reduced cardiac output A decline in maximum heart rate (around 1beat per year) Increase in systolic blood pressure

Question 30

The flow of blood from the left ventricles to the right atrium is called what?

Answer 30

Systemic circulation

Question 31

Which of the following are also referred to as 'capacitance vessels' because at rest they hold ~ 65% of total blood volume? a. Aortas b. Arterioles c. Capillaries d. Arteries e. Veins

Answer 31

Veins

Question 32

Rank the blood vessels in order of their average pressures in order from highest to lowest. vein, aorta, artery, capillary, ateriole

Answer 32

Artery, vein, arteriole, venule, aorta, capillary

Question 33

Which of the following regulates blood flow at the entrance to each true capillary? a. Tunica intima b. Precapillary sphincter c. Lymph nodes d. Tunica adventitia e. Valves

Answer 33

Precapillary sphincter

Question 34

Describe the intrinsic rhythmicity and conduction system of the heart.

Answer 34

SA node is pacemaker as has the highest intrinsic rhythm. SA node--> atrial muscle --> AV node (delay) --> Perkinje fibres ---> ventricular muscle

Question 35

Where is the SA node located?

Answer 35

The upper wall of the right atrium

Question 36

What is Bradycardia?

Answer 36

Slow heart rate (fewer than 60 beats per min at rest)

Question 37

What is Tachycardia?

Answer 37

A fast heart rate (over 100 beats per min)

Question 38

What is vagal tone?

Answer 38

The balance of activity between the parasympathetic and sympathetic nervous systems through the vagus nerve. High vagal tone -> relaxes faster after stress

Question 39

In an ECG, what does the P wave, QRS complex, ST segment and T-wave represent?

Answer 39

Depolarization causes contraction Repolarization causes relaxation of cardiac muscle fibers.

Question 40

What is Myocardoa ischemia?

Answer 40

Reduced blood flow to the heart muscle