Brainscape's Knowledge GenomeTM

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


See full index

Physiology and Pharmacology > The Circulatory System > Flashcards

The Circulatory System Flashcards

1
Q

why do we have a circulatory system?

A

an evolutionary consequence of increased size and complexity

to create a steep conc gradients to deliver nutrients/remove waste from centrally located cells

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

primary function of circulatory system

A

deliver gases and other molecules for nutrition, growth and repair

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

secondary function of circulatory system

A

fast chemical signalling (hormones), dissapation of heat, mediates inflammatory and host defense responses to invading microbes

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

organisation of circulatory system - human

A

3 parts:
heart = pump (dual)
blood = fluid
blood vessels = containers

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

left side of circulatory system

A

systemic circualtion
parallel pathways left to right
usually lows through single extensive capillary bed
can have capillary beds in series e.g. kidney
or in parallel and series e.g. spell, intestines, liver

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

right side of circulatory system

A

pulmonary circulation

single pathways from right to left side of heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

vasculature

A

arteries - away from heart - distribution system
veins - into heart - collection system (reservoir)
microcirculation - diffusion and filtration system
arterioles —– capillaries —– venules

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

variations of branching in vasculature

A

vessel radius dec with branching
combined cross sectional area of daughter vessels is greater than parent vessels
sharpest increase occurs in microcirculation, but total volume of flow = same so velocity = low

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

structure of vascular walls

A

endothelial cells
elastic fibres
collagen fibres
smooth muscle cells

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

endthelial cells

A

line blood vessels, single continuous layer lining all vasculature, junctionla complexes keeping cells together in arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

elastic fibres

A

privides stretch for vessels due to weave and loose attachment to other elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

collagen fibres

A

less extensible, maintain integrity, prevent bursting

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

smooth muscle cells

A

different arrangements in vascular arteries or muscular arteries etc - determines diameter of vessels

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

3 layers of blood vessel walls

A

intima - tunica interna
media - tunica media
adventitia - tunica externa
capillaries - only intimal layer resting on basement membrane

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

tunica interna

A

endothelial cells rest on basement mem, seen in all types if vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

tunica media

A

smooth muscle and elastic fibres, have elastin core surrounded by microfibrils

17
Q

tunica externa

A

collagen fibres, elastic fibres and blood supply to vessel itself, supplied by vaser vasorum, also nerves to regulate and control

18
Q

variation in structure of vessels

A

aorta = highest pressure so most elastic fibres
smooth muscle - higher in capillary sphincter to close off capillary
increase in smooth muscle - smaller vessel is
decrease in elastic fibres - smaller vessel is

19
Q

elastic arteries

A

largest artery
hgihly compliant, stretch easy without tearing in response to pressure increase
enables vessels to cope with peak ejection pressure
recoil of elsatic fibres forces blood to move even when ventricles are relaxed

20
Q

muscular arteries

A

smooth muscle cells arranged circumferentially
capable of greater vasoconstriction and vasodilation to adjust rate of blood flow
vascular tone = state if partial contraction, maintains vessel pressure and efficient flow

21
Q

arterioles

A

smooth muscle enabling regulation of blood flow into capillary networks
terminal regions of arterioles = metarterioles, pre capillary sphincters monitor blood flow into capillary (mesenteric / cerebral circulation)

22
Q

venules

A

post capillary venules are porous - act as exchange sites for nutrients and waste, muscualr venules have thin smooth muscle cell layer (less muscular than arterioles)
(arterioles more spherical than venues)
thin walls allow expansion = excellent reservoirs for blood, allow expansion without sacrificing integrity

23
Q

veins

A

less musclular and elastic but distensible enough to adapt to variations in volume and pressure
can ‘store’ blood

24
Q

large veins

A

mroe muscular than other veins, have valves to prevent back flow, defective, leaky valves can lead to varicose veins

25
Q

capillary exchange

A 
function of CVS to maintain suitable environment for tissues
principle of exchange sites: gases, water, nutrients, waste
most tissue capillaries serve nutritional needs, in addition: glomerular filtrate, skin temperature regulation, hormone and platelet delivery
26
Q

capillaries

A

only endothelial cells on basement membrane

exchange of substances between blood and intersitial fluid, 3 groups based on degree of leakiness

27
Q

types of capillaries

A

continuous
fenestrated
sinusoidal

28
Q

continuous capillaries

A

intercellular junctions, apart from blood brain barrier where they have tight junctions

29
Q

fenestrated capillaries

A

found where extensive molecular exchange occurs e.g. small intestines
fenestrae allow much larger molecules to pass through = ‘leakier’

30
Q

sinusoidal capillaries

A

discontinuous
found in liver and bone marrow
gaps allows some blood cells through = ‘leakiest’

31
Q

fluid transfer in capillaries

A

starlings forces
driven by sum of hydrostatic and osmotic pressures
oncotic pressure due to serum proteins
Kf haydraulic conductance - water permeability of capillary wall - variety with tissue

32
Q

starlings forces equation

A

remove +/- signs from values when calculating
Jv = fluid movement
Kf = hydraulic conductance
Pc/Pi = hydrostatic pressure of capillary / interstitial
pi = oncotic pressure

33
Q

Pc changes across capillary wall …

A

Pc declines along length of capillary through fluid filtration
net filtration becomes net absorption
arteriole filtration exceeds venular absorption
2-4L fluid/day in interstitium

34
Q

lymphatic system

A

drains excess interstitial fluid
formed in lymph capillary
have 1 way valves
blockage leads to oedema

35
Q

maintenance of blood volume

A

lympathic system returns lymphatic fluid to CVS via subclavian veins

Physiology and Pharmacology (17 decks)

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