Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bio 245 > 2B > Flashcards

2B Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Describe veins

A
  • take blood towards the heart
  • drains blood from capillaries
  • has a larger lumen than arteries
  • has valves
    -collapses when not filled
    -has largest amount of blood in the systemic veins
    -defined by size (small, medium, large, small arteries and arterioles)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe arteries

A
  • moves blood away from heart
  • smaller lumen than veins
  • retains shape/ stays open when empty
  • vessels with highest bp
  • thickest vessels with large amounts of elastic fiber and smooth muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why are arteries made of large amounts of elastic fibers and smooth muscle

A

allows for vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is vasoconstriction

A
  • shrinking of the lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is vasodilation

A

-growing of the lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three types of arteries?

A
  • elastic (aorta)
  • muscular (coronary)
  • arterioles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the tunica intima do?

A

has protrusions that form valves and prevent backflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are capillaries?

A

smallest blood vessels with a thin narrow wall (endothelium) that supports the exchange of materials between the body and blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where do CO2 and O2 go

A

they diffuse through the capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe continuous capillaries

A
  • lining of the endothelial cell is complete around the lumen (no openings)
  • basement membrane is complete
  • intercellular clefts between endothelial cells
  • least leaky
  • most common type
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe fenestrated Capillaries

A
  • same as continuous capillary but contains fenestrations
  • somewhat leaky
  • acts as a filter
  • found in most endocrine organs, kidneys, small intestines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe Sinusoid capillaries

A

-the lining of the endothelial cell is incomplete around the lumen
- basement membrane is incomplete or absent
- most leaky
- found in red bone marrow, liver, spleen, some endocrine organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do capillary beds work?

A

-most follow a simple pathway where blood enters the capillary bed from an arteriole and is drained by a venule
-blood enters the capillary bed from an arteriole
through metarteriole, the proximal part is encircled by the scattered smooth muscle cells and the distal part forms the thoroughfare channel which has no smooth muscle cells and leads to venules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a true capillaries?

A

capillaries that branch from the metarteriole and thoroughfare channel and makeup most of the capillary bed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do precapillary sphincters do?

A
  • control blood flow through the capillaries perfusing the tissues when open
  • cycle through contraction and relaxation phases called vasomotion with approx. 25%of capillary beds open at any given time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is vasomotion?

A

alternating between contraction and relaxation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When does blood go to the true capillaries?

A

when the precapillary sphincter is relaxed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do alternative pathways of circulation differ from simple pathways?

A

-differ in the number of arteries, capillaries, or venules that serve organ/region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the types of anastomosis?

A

-venule
-arteriole
-arteriovenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is venule anastamoses?

A

-multiple veins collectively drain into a single body region
- most common type
- basilic, brachial, cephalic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is arteriole anastomosis?

A

multiple arteries converge into a single body region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is arteriovenous anastomosis?

A
  • shunt
  • moves blood directly from an artery to a vein bypassing the capillary bed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a portal system?

A

when blood flows through two capillary beds connected by a portal vein
- ex hypothalamic-hypophyseal portal system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What determine venous return of blood to the heart?

A

-pressure gradients
- assisted by two pumps (skeletal muscle pump and respiratory pump)
- low with a small gradient (20 mm HG)
-non-pulsatile ( remains constant)

25
Q

How does the skeletal muscle pump work?

A
  • as muscles contract veins are squeezed
  • blood is pushed and valves prevent backflow (muscle sends blood both ways but valves make it only go to the heart)
  • blood is moved quickly during excercise
  • blood pools in leg veins with prolonged inactivity
26
Q

How does the respiratory pump work?

A
  • assists venous return in thorax
  • in inspiration: diaphragm contracts so abdominal pressure increases and thoracic pressure decreases
  • blood in abdominal veins is driven toward the thoracic cavity
  • in expiration diaphragm releases so that thoracic pressure increases while abdominal pressure decreases
  • blood in thoracic veins is driven towards the heart
  • blood in lower limbs allowed into abdominal veins
  • gives larger volume in thoracic cavity during inspiration
27
Q

What is the relationship between volume and pressure?

A

increased volume= increased pressure

28
Q

What is total cross-sectional area?

A
  • the sum of diameters of all vessels of a certain type (artery, capillary, vein)
  • collectively cross-sectional area of capillaries is largest because there are so many capillaries
29
Q

How is blood flow velocity related to cross-sectional area?

A

-inversely related, blood flow is slow in capillaries allowing for exchange between blood and fluid tissue

30
Q

What is bulk flow?

A

the movement of large amounts of fluids and dissolved substances along a gradient
- 15% of remaining materials remain in tissues and are picked up by the lymphatic system
- 55% of materials are reabsorbed

31
Q

What do negative arrows on the picture represent?

A

more going out than going in

32
Q

What is net hydrostatic pressure?

A

pushes blood out

33
Q

What is net colloid osmotic pressure

A
  • pushes blood in
34
Q

What is net filtration?

A
  • net hydrostatic- net coloid
35
Q

What does negative net filtration mean?

A

reabsorbtion

36
Q

What does positive net filtration mean?

A

filtration

37
Q

What is myogenic response

A
  • smooth muscle in artery/ arteriole wall responds to changes in bp to keep local flow relatively constant
  • we want amount of blood going into the tissues to be constant regardless of bp
38
Q

What is the relation chip between bp, circumference and bloodflow

A
  • all are positively correlated
39
Q

What happens if systemic bp rises?

A

there is an increase in blood flow
- as more blood moves into the arteriole its wall will stretch and smooth muscle in the arteriole wall will respond by constricting
- increased pb = vasoconstriction, decreasing blood flow and returning it to normal levels

40
Q

What happens if bp lowers?

A
  • there is a decrease in blood flow
  • as less blood moves into arterioles there is a decreased stretch and smooth muscle relaxes (vasodilation)
    -vasodilation increases blood flow returning flow to normal levels
41
Q

What do vasodilators do?

A

– dilate arterioles and relaz precapillary sphincters
-increase blood flow through arterioles and into capillary beds

42
Q

What are examples of vasodilators?

A
  • increased body temp, co2 levels, H+, K+, lactate ANP
  • decreased O2 and nutrient levels
43
Q

What do vasoconstrictors do?

A
  • constrict arterioles and cause contraction of precapillary sphincters
  • decrease blood flow through arterioles into capillary beds
44
Q

What are examples of vasoconstrictors?q

A
  • increased o2, nutrient levels, aldosterone, adh
  • decreased body temp, CO2, lactate, H+ K levels
45
Q

What is blood pressure?

A

force of blood pushing against vessel wall

46
Q

What is blood pressure gradient?

A

change in pressure from 2 end of the vessel to the other

47
Q

What does a blood pressure gradient do?

A
  • propels blood through vessels
  • the pressure is highest in arteries and lowest in veins
  • arterial bp varies in between systole and diastole
  • at capillaries, there is no difference between systolic and diastolic but there is a gradient between atrial (higher) and venule (lower)
48
Q

Describe atrial bp

A
  • pulsatile bc of alternating stretching and recoiling of vessel walls
  • varying
49
Q

What is systolic pressure?

A

when ventricles contract

50
Q

What is diastolic pressure?

A
  • when ventricles relax
51
Q

What is pulse pressure?

A

difference between systolic and diastolic pressure

52
Q

What is mean arterial pressure?

A

average arterial bp across the entire cardiac cycle in which diastole lasts longer
1/3 pulse pressure + diastolic pressure

53
Q

What is total blood flow?

A

amount of blood moving through system per one unit time

54
Q

How is total blood flow calculated?

A

pressure gradient established by heart/ resistance experienced by blood as it moves through the heart

55
Q

What is systemic blood pressure gradient

A

delta p
as the gradient increases blood flow increases
the gradient is increased by increasing cardiac output

56
Q

What is resistance?

A

r
as resistance increases total blood flow decreases
resistance is friction blood encounters due to contact between blood and vessel, opposing blood flow

57
Q

What does a steeper blood pressure gradient mean?

A

bigger push and blood flow

58
Q

What does a smaller blood pressure gradient mean?

A

less blood flow, potential problem

Bio 245 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions