Cardiovascular System

Question 1

Describe tunica externa

Answer 1

loose fibrous connective tissue, outer layer of vessel

Question 2

describe the tunica media

Answer 2

layer of smooth muscle, 2 outmost layer

Question 3

tunica intima

Answer 3

endothelial cells, innermost layer

Question 4

Which type of artery delivers to specific organs

Answer 4

Muscular arteries

Question 5

which type of artery is found nearest the heart?

Answer 5

elastic arteries

Question 6

which type of artery is more active in vasoconstriction

Answer 6

muscular arteries

Question 7

Describe the structure of arterioles

Answer 7

Single layer of spiralling smooth muscle

Question 8

How to arterioles react in response to e.g. cold or shock

Answer 8

Can constrict so blood flow bypasses tissues

Question 9

What are the two types of capillaries?

Answer 9

Fenestrated and continuous

Question 10

Why type of capillary is least permeable?

Answer 10

Continuous

Question 11

Where are continuous capillaries found?

Answer 11

Brain, lungs and muscles

Question 12

What is the difference between fenestrated and continuous capillaries?

Answer 12

Fenestrated are ‘leakier’ - small pores and small gaps between cells - allow for exchange of larger molecules

Question 13

What are the 3 layers of blood vessels?

Answer 13

• tunica externa/adventitia
• tunica media
  -tunica intima

Question 13

How many layers are veins made of?

Answer 13

three

Question 13

Do arteries of veins have more smooth muscle/elastin?

Answer 13

Arteries have more

Question 13

What are venules?

Answer 13

The smallest, post-capillary blood vessels

Question 14

What percentage of blood is kept as reserve in veins?

Answer 14

65%

Question 14

Why are there more venous valves in the lower limbs?

Answer 14

to stop blood flowing backwards

Question 14

Are venules porous?

Answer 14

Yes, very

Question 15

What are venous sinuses

Answer 15

Group of sinuses that drains venous blood circulating from cranial cavity

Question 16

What is the venous return

Answer 16

the volume of blood flowing back to heart through veins

Question 17

3 things that venous return is affected by?

Answer 17

1. pumping of the heart
2. skeletal muscle pump
3. respiratory pump

Question 18

What is the pericardium?

Answer 18

the fibrous sack surrounding heart

Question 19

Describe 4 functions of the pericardium

Answer 19

1. lubricated moving surfaces
2. prevents ventricles over-expanding
3. holds heart in position
4. forms a barrier to prevent the spread of infections/cancer cells

Question 20

What is pericarditis

Answer 20

Inflammation of pericardial sac

Question 21

What is pericardial effusion

Answer 21

Build up of fluid in the sack

Question 22

What is pericardial tamponade

Answer 22

Fluid build up in the sac causing problems with heart function

Question 23

What is myocardium? What is it made of?

Answer 23

The muscle of the heart, made up of myocytes

Question 24

Describe the 4 properties of the myocardium

Answer 24

1. automaticity 2. excitability 3. conductivity 4. contractability

Question 25

What is automaticity?

Answer 25

The ability to initiate a response spontaneously

Question 26

What is excitability?

Answer 26

The ability to respond to a stimulus

Question 27

What is conductivity?

Answer 27

The ability to transmit an impulse from one cell to another

Question 28

What is contractibility?

Answer 28

The ability to contract after an electrical stimulus

Question 29

At what rate does the SA node conduct?

Answer 29

60-100BPM

Question 30

At what does the AV junction conduct? Why would it do this?

Answer 30

40-60BPM. If the SA node stopped working

Question 31

At what rate do the ventricular pacemaker cells conduct? Why would they do this?

Answer 31

<30-40 BPM. If SA node and AV junc. stop working

Question 32

Describe the endocardium

Answer 32

lining of heart and valves. smooth membrane made up of flattened epithelial cells continuous with that of blood vessels

Question 33

Why is the left ventricle thicker?

Answer 33

Forces oxygenated blood into aorta and through arterial system

Question 34

Where is the pulmonary valve?

Answer 34

Between right ventricle and pulmonary artery

Question 35

Where is the tricuspid valve?

Answer 35

Between right atrium and ventricle

Question 36

Where is mitral valve?

Answer 36

Between left atrium and ventricle

Question 37

Where is aortic valve?

Answer 37

Between left ventricle and aorta

Question 38

Where does myocardium get it's blood supply?

Answer 38

From coronary arteries

Question 39

What is the function of coronary veins?

Answer 39

Return de-oxygenated blood from myocardium back into right atrium

Question 40

What are the 3 stages of the cardiac cycle?

Answer 40

- Atrial and ventricular diastole - Atrial systole - Ventricular systole

Question 41

What is the cardiac output?

Answer 41

amount of blood pumped by heart in 1 minute

Question 42

How do you calculate cardiac output?

Answer 42

Heart rate x stoke volume

Question 43

Define stroke volume

Answer 43

volume of blood pumped out of left ventricle during each systolic cardiac contraction

Question 44

Approximate adult male and female cardiac outputs:

Answer 44

male at rest: 5.5L/min female: 5L/min

Question 45

Define preload

Answer 45

stretch of myocardium of ventricles at the end of diastole

Question 46

Define afterload

Answer 46

the amount of resistance that the left ventricle must overcome to circulate blood

Question 47

What may afterload be affected by?

Answer 47

cold, stress, hyperventilation

Question 48

Define contractility

Answer 48

the strength of the contraction of the myocardium

Question 49

Identify two things that may affect contractility

Answer 49

Heart failure, ischaemia