Lecture 1 - Introduction to and Histology of the CVS

Question 1

what affects diffusion?

Answer 1

area - determined by capillary density
diffusion resistance - determined by nature of the barrier and molecules diffusing
concentration gradient - depends a lot on blood flow through capillary

Question 2

what is the blood flow to the brain?

Answer 2

min - 0.75 l/minmax - 0.75 l/min

Question 3

what is the blood flow to the heart?

Answer 3

min - 0.3 l/minmax - 1.2 l/min

Question 4

what is the blood flow to the kidneys?

Answer 4

min - 1.2 l/minmax - 1.2 l/min

Question 5

what is the blood flow to the gut?

Answer 5

min - 1.4 l/minmax - 2.4 l/min

Question 6

what is the blood flow to muscle?

Answer 6

min - 1 l/minmax - 16 l/min

Question 7

what is the blood flow to the skin?

Answer 7

min - 0.2 l/minmax - 2.5 l/min

Question 8

what is the total blood flow in the body?

Answer 8

min - 5 l/minmax - 24.5 l/min

Question 9

how is blood flow controlled?

Answer 9

resistance vessels - arterioles and pre capillary sphincters

Question 10

what is capacitance?

Answer 10

ability to cope with changes in cardiac output - store of blood in veins

Question 11

what are the two typed of artery?

Answer 11

elastic

muscular

Question 12

what is the role of elastic arteries?

Answer 12

expand slightly with each heartbeat

Question 13

what is the role of muscular arteries?

Answer 13

branch into arterioles to regulate amount of blood reaching an area
diameter controlled by ans

Question 14

what are the two types of capillary wall?

Answer 14

continuous

fenestrated

Question 15

what is a sinusoid?

Answer 15

type of capillary with a wider diameter
special lining cells
incomplete basal lamina

Question 16

how does the structure of a vein differ to an artery?

Answer 16

wall is thinner
lumen is wider and irregular
valves in large veins

Question 17

what are the three layers of vein and artery walls?

Answer 17

in to out
tunica intima
tunica media
tunica adventitia

Question 18

describe the intima layer of elastic arteries

Answer 18

endothelial cells with long axis parallel to long axis of artery; narrow subendothelium of connective tissue

Question 19

describe the media layer of elastic arteries

Answer 19

40-70 fenestrated elastic membranes with smooth muscle cells and collagen between the lamellae

Question 20

describe the adventitia layer of elastic arteries

Answer 20

layer of fibroelastic connective tissue containing vasa vasorum, lymphatic vessels and nerve fibres

Question 21

describe the intima layer of muscular arteries

Answer 21

endothelium, sunendothelial layer, thick internal elastic lamina

Question 22

describe the media layer of muscular arteries

Answer 22

40 layers of smooth muscle cells, prominent external elastic lamina

Question 23

describe the adventitia layer of muscular arteries

Answer 23

thin layer of fibroelastic connective tissue containing some vasa vasorum, lymphatic vessels and nerve fibres

Question 24

what is the role of sympathetic nerve endings in the tunica adventitia?

Answer 24

vasoconstriction

Question 25

where is the thin internal elastic lamina present?

Answer 25

larger arterioles

Question 26

what is the difference between metarterioles and arterioles?

Answer 26

smooth muscle layer is not continuous

Question 27

what is the role of a precapillary sphincter?

Answer 27

allows arterioles and metarterioles to serve as flow regulators

Question 28

what is the difference between continuous and fenestrated capillaries?

Answer 28

continuous - pericytes form a branching network on the outer surface of the endothelium fenestrated - pericytes are present but there are pores in the endothelium

Question 29

What is the role of the cardiovascular system?

Answer 29

To supply cells of the body with their metabolic needs

Question 30

Where does exchange with tissues occur?

Answer 30

Capillaries

Question 31

How is the area available for exchange determined?

Answer 31

Capillary density

Question 32

How is diffusion resistance determined?

Answer 32

The nature of the barrier | The molecules that are diffusing

Question 33

What is the most important variable in concentration gradient?

Answer 33

Flow of blood through the capillary

Question 34

What is the distribution of blood volume (5l)?

Answer 34

11% in arteries and arterioles 5% in capillaries 17% in heart and lungs 67% in veins

Question 35

What happens if blood pressure is not maintained?

Answer 35

Veins collapse

Question 36

Which 3 places do blood vessels not reach?

Answer 36

Cartilage Epithelia Cornea