Structure and function of blood vessels

Question 1

what do you call the delivery of blood to all tissues?

Answer 1

arterial supply

Question 2

what do you call taking blood away from all tissues?

Answer 2

venous drainage

Question 3

draw a flow diagram showing the vessels from heart and back to it

Answer 3

Aorta (artery)–> arteries –> arterioles –> capillaries –> venules –> vein –> inferior/superior vena cava (vein)

Question 4

what 3 features are important for blood vessels?

Answer 4

• resilience
• flexible
• always open

Question 5

what 4 parts are blood vessels made up of (structure)

Answer 5

• lumen
• tunica intima
• tunica media
• tunica adventia/ externa

Question 6

what’s the lumen?

Answer 6

the space blood flows through

Question 7

what’s the tunica intima made up of? (3)

Answer 7

endothelium (epithelium)
basal lamina
sub endothelial connective tissue

Question 8

what’s the tunica media made up of? (2)

Answer 8

smooth muscle fibres in loose connective tissue

may contain elastic fibres

Question 9

what’s the tunica adventia/externa made up of? (2)

Answer 9

connective tissue merged to surrounding connective tissue

in large BV there can be vasa vasorum (small bv to supply the BV with blood)

Question 10

Is blood in arteries under high or low pressure?

Answer 10

high

Question 11

is blood in veins under high or low pressure?

Answer 11

low

Question 12

do arteries have thick or thin walls?

Answer 12

thick

Question 13

do veins have thick or thin walls?

Answer 13

thin

Question 14

why do arteries have thick walls?

Answer 14

to maintain high BP

Question 15

why do veins have thin walls?

Answer 15

to maintain low BP

Question 16

do artery lumens stay open all the time?

Answer 16

yes (like a garden hose)

Question 17

do vein lumens stay open all the time?

Answer 17

no (like a fire hose)

Question 18

do arteries have larger or smaller lumens?

Answer 18

smaller

Question 19

do veins have larger or smaller lumens?

Answer 19

larger

Question 20

what’s more resilient- arteries or veins?

Answer 20

arteries

Question 21

do arteries have valves?

Answer 21

no

Question 22

do veins have valves?

Answer 22

some do- yes

Question 23

what are the 3 types of arteries?

Answer 23

elastic
muscular
arterioles

Question 24

what sort of arteries are elastic ones?

Answer 24

conducting- they come from heart

Question 25

what sort of arteries are muscular ones?

Answer 25

distributing- they take blood around the body

Question 26

what sort of arteries are arterioles?

Answer 26

resistance vessels- maintain blood pressure

Question 27

Which of the 3 types of arteries is the largest?

Answer 27

elastic e.g. Aorta

Question 28

What's the diameter of elastic arteries?

Answer 28

up to 2.5cm

Question 29

what are the functions of elastic arteries?

Answer 29

- can withstand changes in pressure during the cardiac cycle - ensures continuous blood flow

Question 30

what are the structural adaptations of elastic arteries? (2)

Answer 30

- tunica media with many elastic fibres (allows continuous blood by stretch and recoil) - few smooth muscle cells

Question 31

What's the diameter of muscular arteries?

Answer 31

up to 0.4cm (smaller than elastic arteries)

Question 32

What 's the function of muscular arteries?

Answer 32

distributes blood to muscles and organs

Question 33

are muscular arteries capable of vasoconstriction/dilation?

Answer 33

yes

Question 34

What are the structural adaptations of muscular arteries?

Answer 34

- lots of smooth muscle cells in tunica media - lots of distinct internal and external elastic laminae - thick tunica externa

Question 35

are arterioles capable of vasoconstriction/dilation?

Answer 35

yes

Question 36

What's the 2 main functions of arterioles?

Answer 36

- controls blood flow to organs | - involved in blood pressure control

Question 37

what's the diameter of arterioles?

Answer 37

less than 30 micrometres

Question 38

what are the structural adaptations of arterioles?

Answer 38

- 1-2 layers of smooth muscle cells in tunica media | - poorly defined tunica externa

Question 39

What's the function of capillaries?

Answer 39

- site of gaseous exchange (oxygen and carbon dioxide)

Question 40

what are the 3 types of capillaries?

Answer 40

- continued - fenestrated - sinusoidal

Question 41

where are continuous capillaries found? (3)

Answer 41

- skeletal muscle - smooth muscle - lungs

Question 42

What type of capillaries are most common in the human body?

Answer 42

continuous

Question 43

What's different about fenestrated capillaries?

Answer 43

pores penetrate the endothelial lining allowing a rapid exchange of water and large solutes (faster than diffusing through)

Question 44

where are fenestrated capillaries found? (3)

Answer 44

``` kidney choroid plexus (in brain) endocrine gland ```

Question 45

What's different about sinusoidal capillaries? (4)

Answer 45

they have spaces between endothelial cells incomplete of absent basal membrane phagocytic cells can get through blood moves slowly through

Question 46

What do sinusoidal capillaries do?

Answer 46

allow exchanges of large solutes

Question 47

What do arterioles lead to?

Answer 47

capillary beds

Question 48

what are metaartioles?

Answer 48

arterioles that supply a single capillary bed

Question 49

what can metaarterioles do?

Answer 49

can open or close to channel blood either to the capillary bed or to cut it off/bypass it and go straight to the veins

Question 50

what do venules do?

Answer 50

collect blood from the capillary bed to deliver to small veins

Question 51

what's the diameter of venules like?

Answer 51

varies, gets bigger closer to the heart

Question 52

how are veins classfied?

Answer 52

according to size (they get larger closer to the heart)

Question 53

what is meant by veins being easily distensible?

Answer 53

they can hold lots of blood

Question 54

what are the structural adaptations of veins?

Answer 54

- thin walls - tunica externa is predominant - valves

Question 55

what's the purpose of valves in veins?

Answer 55

prevent backflow

Question 56

What proportion of blood is in the venous system?

Answer 56

65-70%

Question 57

what proportion of blood is in the other vessels/heart?

Answer 57

the remaining 30-35%

Question 58

when describing things in anatomy, is the patient's or onlookers POV used?

Answer 58

patient's

Question 59

what does superior mean?

Answer 59

above something e.g. the head

Question 60

what does medial mean?

Answer 60

towards the middle e.g. the spine

Question 61

what does lateral mean?

Answer 61

towards the side of the body (opposite to medial) e.g. thumbs

Question 62

what does proximal mean?

Answer 62

closer to the midline e.g. the groin

Question 63

what does distal mean?

Answer 63

further from the midline e.g. feet or head

Question 64

what does inferior mean?

Answer 64

towards the feet e.g. feet

Question 65

What's anterior/ventral?

Answer 65

the front of the human body e.g. the chest

Question 66

What's posterior/dorsal?

Answer 66

the back of the human body e.g. the shoulder blades

Question 67

what's the coronal plane?

Answer 67

vertical plane dividing the anterior and posterior

Question 68

what's the midsagittal plane?

Answer 68

vertical plane dividing body into left and right

Question 69

what's the transverse plane?

Answer 69

Horizontal plane dividing superior and inferior body