Lecture 7 - Cardio microanatomy

Question 1

what are the 4 structures of the cardiovascular system?

Answer 1

1. arteries
2. capillaries
3. veins
4. heart

Question 2

as the distance from the heart increases, what happens to the diameter of the arteries

Answer 2

decreases

Question 3

what property allows arteries to accommodate large pressures

Answer 3

elasticity

Question 4

smaller arteries can restrict and limit blood flow based on what property

Answer 4

contractility

Question 5

what are the 3 categories of arteries

Answer 5

1. conducting
2. muscular
3. arterioles

Question 6

what is an example of a conducting artery

Answer 6

aorta

Question 7

what is the primary job of conducting arteries

Answer 7

maintain even flow and constant blood pressure

Question 8

summarize the properties of conducting arteries

Answer 8

• large volume
• tunica media contains elastic fibers
• tunica externa contains vessel supply

Question 9

what are the 3 layers of blood vessels innermost to outermost

Answer 9

1. tunica intima
2. tunica media
3. tunica externa

Question 10

tunica intima

Answer 10

endothelium and basement membrane; internal elastic membrane

Question 11

tunica media

Answer 11

smooth muscle; collagen and elastic fibers

Question 12

tunica externa

Answer 12

external elastic membrane; loose irregular CT; nerves and small arteries present

Question 13

summarize the properties of muscular arteries

Answer 13

• distributing (to limbs)
• tunica media contain >5 layers of smooth muscle
• regulates volume

Question 14

summarize the properties of arterioles

Answer 14

• <5 layers of smooth muscle
• last branches before capillaries
• regulate blood volume

Question 15

what two things can influence vasodilation or constriction

Answer 15

neurotransmitters and hormones

Question 16

arterioles are described as ____ without ____

Answer 16

contractility; elasticity

Question 17

capillaries consist of

Answer 17

basement membrane and endothelium

Question 18

what are the three types of capillaries

Answer 18

1. continuous
2. fenestrated
3. sinusoidal

Question 19

what is an example of continuous capillaries

Answer 19

blood-brain barrier
gap junctions

Question 20

what is an example of fenestrated capillaries

Answer 20

kidneys

Question 21

what is an example of sinusoidal capillaries

Answer 21

liver
large holes

Question 22

why are veins considered poorly developed relatives of arteries

Answer 22

same layers but more flimsy

Question 23

T/F: veins contain valves to prevent retrograde flow

Answer 23

TRUE

Question 24

venules have~____ times the diameter of capillaries

Answer 24

20

Question 25

summarize the properties of medium veins

Answer 25

- valves - increased collagen and elastic fibers - more smooth muscle - thin internal tunic, thick external

Question 26

valves are extensions of

Answer 26

the tunica intima

Question 27

summarize the properties of large veins

Answer 27

- thick subendothelium in the tunica intima - poorly developed tunica media - increased contractility

Question 28

what are the four layers of the heart outermost to innermost

Answer 28

1. pericardium 2. epicardium 3. myocardium 4. endocardium

Question 29

pericardium

Answer 29

- forms a sac around the heart with the epicardium - fibrous pericardium and parietal pericardium

Question 30

epicardium

Answer 30

- serosal surface (visceral pericardium) - nerves, vessels, fat

Question 31

myocardium

Answer 31

- same as tunica media - cardiac muscle fibers

Question 32

endocardium

Answer 32

- endothelial lining - subendothelial region contains impulse-conducting fibers

Question 33

what are the impulse-conducting fibers

Answer 33

Purkinje fibers

Question 34

T/F: the heart is a voluntary muscle

Answer 34

FALSE

Question 35

what allows for the quick transmittance of electrical impulses between muscle fibers

Answer 35

intercalated discs

Question 36

what is considered the pacemaker cells

Answer 36

sinoatrial (SA) node

Question 37

describe the SA node

Answer 37

- the medial wall of the right atrium - spontaneously depolarizes

Question 38

what transmits electrical signals to the atrioventricular bundle

Answer 38

atrioventricular (AV) node

Question 39

where is the AV node

Answer 39

between atria, cranial edge of the interventricular septum