Brainscape's Knowledge GenomeTM

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


See full index

Body Systems > Blood Pressure regulation > Flashcards

Blood Pressure regulation Flashcards

1
Q

what is BP

A

the force exterted on the vessel walls as blood flows through

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

why do we need to maintain pressure

A

a minimum pressure (capillary hydrostatic pressure) is required to exhange substances across capillary networks

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

what are the 2 key determinants of BP?

A

BP = Caridac output x Total peripheral Resistance

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

what is the total peripheral resistance dependent on

A

arteriolar radius
cuz flow proportinal to r^4

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

what is autoregulation

A

regulating blood flow on a local level
for low levels of activity

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

what mechanisms need to be activated when doing vigorous exercise

A

central mechanisms that are under neural and endocrine control

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

when BP becomes low, what might be some chemical changes that take place?

A

decreased O2 (any availble o2 is used up)
increased metabolites
increased CO2
increased lactate

signals that there’s not enough local BF or BP and demands arent being met

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

Autoregulation of Blood flow: how is the disturbance in homeostasis counteracted

A

autoregulation
causes a local decrease in resistance
by relaxing precapillary sphincters (which is signalled by the inc in metabolites)
thus inc in BF

returns to homeostasis

see onenote

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

how does the sympathetic nervous system allow blood pressure to be increased (? in terms of cardiac output and total periph resis)

A

increases heart rate and strok volume
= increases cardiac output

increases vasoconstriction
= increases total periph resis

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

what occurs if autoregulation is insuffiecient and cant restore homeostasis

A

detected by baroreceptors and chemoreceptors

cardiovascular centres in the CNS (ie the medulla oblangata) are activated

short term and immediate increase in BP via activation of SNS
which increases CO and vasocontriction

see onenote for more detailed diagram

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

where are the baroreceptors located

A

aortic sinus (primarily detects changes in systemic circulation)
and
carotid sinus (primarliy detects changes in cerebral circulation)

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

what happens to baroreceptors when BP falls?

A

they’re inhibited

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

what are the 3 things that happens when baroreceptors are inhibited

A

-cardioaccelertory centre is activated
-cardioinhibitory centre is inhibited
= these lead to inc in HR and CO, by increasing the contractility
(so sympathetic is activated and parasymp is inhibited)

vasomotor centre is activated
= inc in vasoconstriction

all of this happens vice versa when BP rises

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

what hormone enhances the baroreceptor response

A

adrenaline and noradrenaline being released from the adrenal glands

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

where are the chemoreceptors located

A

in carotid bodies (detect changes in the blood)

in medulla oblangata (detects changes in the CSF)

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

what changes does the chemoreceptors in the carotid bodies detect when BP is low?

A

fall in pH
fall in O2
rise in CO2

17
Q

what are the effects when carotid chemoreceptors detect these changes

A

the same effects caused whne barorecpetors are inhibted

18
Q

what changes does the chemoreceptors in the medulla detects when BP is low?

A

rise in CO2 only (cuz O2 can’t acc cross the blood-brain barrier)

19
Q

what are the effects when medulla chemoreceptors detect these changes

A

primary job is to activate the respiratory centre
to inc respiratory rate

also
vasodilation of cerebral vessels
inc blood flow to brain

basically makes sure the cardiovascular and respiratory resposnes are coordinated

20
Q

when homeostasis still can’t be restored after this, then what happens

A

endocrine resposnse is stimulated
leading to long term events
via increasing blood volume and vasoconstriction

21
Q

What is the RAAS

A

Renin Angiotensin Aldosterone System

22
Q

what type of cells in the kidney detect a change in the BP

A

juxtaglomerular cells

23
Q

what enzyme does the kindey secrete when it detects fall in BP?

A

Renin

24
Q

what does renin do

A

converts angiotensinogen (a plasma protein produced by liver) into angiotensin 1 (which is actually inactive)

25
Q

what enzyme is needed to activate angiotensin 1 and where is it produced

A

angiotensin converting enzyme
produced by cells in the lungs
converts angiotensin 1 to angiotensin 2

26
Q

what does angiotensis 2 do

A

causes vasoconstriction - inc peripheral resistance

also stimulates the adrenal cells
to inc the steroid hormone aldosterone

27
Q

what is aldosterone and what does it do

A

steroid hormone
acts on kidneys to inc amount of Na+ reabsorption
via activating Na K channels

when more Na reabsorbed, water is also reabsorbed

increases the blood volume

28
Q

how is ADH involved in long term regulation of blood flow

A

anti-diuretic hormone (aka vasopressin)

released from pituitary

detects when blood vol low=

involved in vasoconstriction

also increases fluid retention
and inc the amount of water in the blood
stimulates thirst to increase blood volume further

29
Q

how is erythropoeitin (Epo) involved in long term regulation of blood flow

A

detects fall in BP or O2

also is a vasoconstrictor

mainly stimulates production of RBC
thus increases blood vol

30
Q

what in the heart can detect rise in BP

A

cardiac muscle cells in right atrium and ventricl

31
Q

what is released when high BP is detected by the heart

A

natriuretic peptides
ANP - atrial natriuretic peptides (secreted by atria)
BMP - brain natriuretic peptide (secreted by ventricles jus has a stupid name)

but ANP is the main one

32
Q

how does ANP affect the kidney

A

causes an increased Na+ loss
so increased water loss in urine - pee more
reduced thirst

decreased blood vol
(basically opposite to aldosterone)

33
Q

how else does ANP lead to decrease in BP?

A

inhibts all those vasocondtricting hormones
e.g. ADH, aldosterone, NA and adrenaline

leading to peripheral vasodilation
and drop in BP

34
Q

which 3 circulations need special consideration for local flow?

A

pulmonary
coronary
cerebral

35
Q

how does the pulmonary circ differ in its blood flow regulation?

A

when O2 drops
instead of vasodilation to inc blood flow
arterioles will constrict in regions of low O2 to ‘shunt’ blood flow to the O2 rich areas

36
Q

how does the cerebral circ differ in its blood flow regulation?

A

blood flow to brain must always be maintained (neurons are stupid and die vry quick if theres no blood supply)

so when there’s peripheral vasoconstriction, there will be vasodialtion of cerebral vessels to maintain its blood flow

37
Q

how does the coronary circ differ in its blood flow regulation?

A

sympathetic activity doesnt lead to vasoconstriction like usual

there are special beta receptors which mean sympathetic stimulation causes vasodilation

so coronary blood flow is maintained

Body Systems (21 decks)

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