HES 111 midterm I Flashcards

1
Q

What is the endocrine system?

A

A series of organs throughout the body that secrete horomones in response to stimulus

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

Name some bodily functions the endocrine sytsem is involved in?

A

metabolism, reg of gene expression, growth, reproduction

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

What are the two categories of endocrine organs and what are some examples in each

A

Endocrine: ant pit, thyroid, parathyroid, thymus, adrenal corte, pancreas, ovaries/testes

Neuroendocrine: hypothalamus, pineal gland, post pit, adrenal medulla

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

What are the 4 neuroendocrine organs?

A

Hypothalamus, adrenal medulla, post pit and pineal gland

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

what must a horomone bind to to exert action?

A

Its receptor

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

What is the difference between a hormone and neurotransmitter?

A

Hormone travel in bloodstream and secreted by endocrine gland. - long distance

Neurotransmitter - travel across synaptic cleft, secreted by neuron - short

BOTH: bind to a rececptor on a cell

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

What is a neurohormone?

A

a hormone secreted into blood by neuroendocrine cells (neurons)

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

What are the 2 main classes of hormones? Examples?

A
  1. amino acid based
    - amines: epinephrine, norep (deriv of tyrosine), depamine, thyroid
    - Peptide: insulin, GH
  2. Lipid based
    - Steroids: etrogen, testosterone, cortisol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do the 2 classes of hormones behave differently

A

how they travel in blood, how target. cells recognize/receive, half life

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

Are amino acid based hyrdophobic or phyllic and where does it bind?

A

Hydrophyllic, binds on plasma membrane of target cell

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

Are steroid hormones hydrophobic or phyllic, where do they bind?

A

Hydrophobic — pass thru plasma membrane and bind in the cytosol in the nucleus of target cells

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

Both steroid and peptide horomones trigger a ________ response. Steroid horomone usually involve modification of…

A

INTRAcellular response, gene expression

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

How are hormones eliminated?

A
  1. Taken up by target cell
  2. Broken down (metabolized by liver) —- eliminated via kidneys
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does rate of hormone elimination depend on?

A

structure, and wether its bound to a carrier protein

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

what is hormone half life?

A

time taken for hormone concentration to reduce by half in the blood

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

Are hydrophobic/phyllic horomones bound to carrier proteins? How does this effect half life?

A

Hydrophobic (steroids) are bound to carrier proteins (albumin) so they have longer half lives (min–hrs)

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

What are 3 ways that hormone secretion is regualted

A

Other horomones, other molecules (eg ca), glucose (glucose uptake by pancreatic cell triggers insulin secretion, neurotransmitters (symp neurons trigger epinephrine, norepinephrin)

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

Where do the horomones produced in the hypothalamus go? What is directed in the hypothalamus?

A

to the post. pit, directs horomones from ant pit

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

What 2 horomones does hypothal produce for secretion by___

A

post pit: anti-diuretic horomone (ADH) – to kidneys – water reabsorption back into blood

Oxytocin – uterus and mammary gland: uterine contraction and milk release

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

What type of horomones (made by hypothalamus) trigger release from the ant pit?

A

TROPIC - a hormone that triggers release of another horomone

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

What are 5 tropic horomones released by hypothalamus?

A

thyroid releasing hormone, corticotropin releasing hormone, prolactin releasing hormone, gonado-tropin releasing horomone, GH releasing hormone

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

what does prolactin releasing horomone lead to?

A

prolactin releasing hormone — prolactin — mammary gland –milk production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the path of thyroid releasing hormone?

A

thyroid releasing hormone — thyroid stim hormone – thyroid gland ( thyroid stim and secretion)

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

Path of corticotropin releasing hormone?

A

triggers adrenocorticotropic horomone then to adrenal cortext which secretes cortisol and aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Path of gonadotropin releasing horomone

A

lutenizing horomone and follicle stim horomone — to the female and male gonads —

IN FEMALE: Synth and secretion of estrogen, progesteron, follicle maturation, ovulation

IN MALE: synth, prep and seretion of testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Path of growth horomone releasing hormone

A

Growth hormone secretion — liver, adipose tissue, muscle tissue, boen and cartillage, — involved in metabolic processes that release energy for fuel rpod incr blood glucose and promote growth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the main function of the growth hormone?

A

Regulate growth of target tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

short term effects are… What is the goal of short term effects?

A

Metabolic – fat breakdown, new glucose in liver, inhibit gluc uptake in skel muscle

GOAL: Make glucose + fatty acids available for use for fuel and growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the long term effect of GH?

A

Tropic effect - Trigger release of Insulin-like growth factor (IGF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Where are thyroid and parathyroid glands located

A

Thyroid - ant neck, superficial to trachea
Parathyroid - post surface of thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what are the 3 tiers of horomone control form the hypothalamus?

A

1: hyporthal releases hormones
2: ant pit releases hormones
3: target organs release hormones
4: effects: hormone levels increase - effects on other cells(return to normal range)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the the 3 hormones secreted by thyroid: 2 main functions

A

T3(triiodothyronine) + T4 (thyroxine) + calcitonin
- Reg metabolism - set basal metabolic rate
- Reg body temp - thru metablism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does the parathyroid gland secrete? It is secreted in response to_____ so it therefore _____

A

Parathyroid horomone - secreted in reponse to LOW BLOOD CA so therefore INCREASES blood calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

3 ways PTH increases blood ca

A

1) Stimulates osteoclasts – incr ca release
2) increase absorbtion of ca by small intestinee
3) increase reabsorption in kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does IGF do? Where does it come from? Goal?

A

(insulin like growth factor)
- affecrs cells: protein synth, division, incr glucose uptake in cells

Long term effect of GH

Goal: growth: during developmental years (GH continues to reg blood glucose and muscl growth thru adulthood)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Calcitonin is secreted by ____ and responds to ____ blood ca therefore the effect ____

A

Secreted by thyroid hormone, responds to high blood ca by lowering blood ca:

1) inhibits osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What neurohormones are secreted by adrenal medulla?

A

epinephrine and norepinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What type of horomones does the adrenal medulla secrete? what types does the adrenal cortex secrete?

A

adrenal medulla: neurohormones: epinephrine and norepinephrine
Adrenal Cortex: steroid hormones: aldosterone and cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does aldosterone do? Secreted by?

A

Regulation of fluid, elctrolyte and pH balance in blood
secrete by the adrenal cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what does cortisol do? secreted bY?

A

promote catabolic rxns in order to provide fuel for stress response
for ex: gluconeogenesis (gluc production in liver)
protein breakdown
fat breakdown
ALSO Inhibit inflammatory responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Pancreatic islets consist of what type of cells?

A

alpha, beta, delta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

which cell is insulin produced and secreted from? Secrete in respont to..

A

B (beta) cells. high blood glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what cell is glucagon produced and secreted from

A

a cells - secreted in response to low blood sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are the two types of membranes surrounding the heart?

A

fibrous pericardium - outer conn tissue
serous pericardium - inner forms 2 layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what are the two layers if the serous pericardium

A

parietal layer: fused to inner surface of fibrous pericardium
visceral layer: inner layer closest to heart wall

pericardial cavity: between 2 layers - filled w serous fluid (pericardial fluid) - lubricant decreases friction as heart beats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Which membrane is a part of the heart wall

A

visceral pericardium (epicardium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the 3 layers of the heart wall?

A

epicardium - myocardium - endocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what layer of heart wall contains fat deposits

A

epicardium (visceral pericardium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what is the main component of wall of the heart? what does it contain

A

myocardium - contains myocytes (cardiac muscle cells). Also specialized pacemaker cells and conn tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what is the innermost layer of the heart?

A

endocardium - faces lumen of heart chambres: simple squamous epithelium + layers of conn tissue w collagen and elastic fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what compartments recieve blood from veins

A

atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what part of heart ejects blood into arteries

A

ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the major systemic veins?

A

sup and inf vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

why are ventricles larger w thicker walls

A

because they are stronger pumps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

wharts the major systemic artery

A

aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

major vessels of pulm circuit?

A

r and L pulm arteries and veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

which atria is larger

A

the right is larger, thinner, more anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are right and left ventricles seperated by?

A

interventricular septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

what are the valves between the atria and ventricles

A

Atrioventicular valves (AV valves)
Tricuspid - on right side
Bicuspid/mitral - on left side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the valves between ventricles and pulmonary arteries

A

Semilunar valves (Also tricuspid)
- Pulmonary valves - between r ventricle and pulm trunk
- aortic valve: between left ventricle and aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what is the purpose of valves

A

keep blood flowing in one direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Blood flows in response to - —- gradients

A

pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

what happens when pressure in ventricle is high (greater than aorta or atrium)

A

Pushes aortic valve open, if greater than atrium closes atrioventricular valves (tricuspid or biscupid(mitral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

what happens when pressure in aorta is greater than ventricle

A

closes aortic semilunar valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

what happens if pressure in the atrium is greater than ventricle

A

Opens AV valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Describe the steps of blood flow thru the heart

A

1) blood in systemic capillaries delivers oxygen to body
2) systemic veins bring deoexygentaed blood back to right atrium
3) Blood passes to right ventricle thru tricuspid valve
4) then thru pulmonary valve to pulmonary veins (pulmonary trunk)
5) to pulmonary capillaries in lungs where blood becomes oxygenated
6) pulm veins returns oxygenated blood to left atrium
7) blood goes from left atrium thru bicuspid (mitral valve) to left ventricle
8) left ventricle pumps thru aortic valve to aorta
9 ) aorta delivers blood to systemic capillaries and body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

what are the two types of cells in the myocardium

A

myocytes - majority (99%)
pacemaker cells - 1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

what is the source of force production of the heart muscle?

A

myocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

what generates spontaneous, rythmic action potentials

A

pacemaker cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

do pacemaker cells contribute to the contractile force of the heart

A

no - just a signal for myocyte contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

what joins myocytes together?

A

intercalated discs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

what connects pacemaker cells to contractile cells?

A

Intercalated discs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

what are intercalated discs made of?

A

Desmosomes: hold the cells together
Gap junctions; allow ions to pass rapidly form one call to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What are the steps of the cardiac conduction system?

A

1) SA node generates AP potentaial which spreads to atrial cells and AV node
2) after AV node delay, AP goes to AV bundle and then to right and left bundle branches
3) ap spreads from bundle branches along purkinje fibers to contractile cells of ventricles

71
Q

What is the purpose of the delayed conduction thru the AV node?

A

Allows atria to fully depolarize (and contract) before the ventricles, giving ventricles time to fill up w blood.

72
Q

steps of pacemaker action potentails

A

1) Slow initial depol phase: HCN channels open in response to membrane hyperpolarization –> this leads to more Na+ in then K+ out leads to depolarization to threshold

2) Full depol Phase: Ca2+ via ca channels leads to depol phase

3) Repol phase: K+ out via K+ channels, repolarization

4) Min potential phase: HCN open again in resp to hyperpol from K+ flowing out and cycle repeats

73
Q

What inititiates the HCN channels to open in pacemaker action potentials

A

during the final phase K+ flow out and hyperpolarize opening HCN channels

74
Q

Action potentials are transmitted from ___ to ___ through _____

A

from pacemaker cells to myocytes thru gap junctions

75
Q

what are the steps of myocyte action potentials

A

1) rapid depolarization phase: Na+ rushes into cell via Na+ channels

2) initial repolarization phase: Na+ channels close, K+ open, K+ leaves causing some repolarization
3) plateau phase: Ca2+ comes, via opening og ca channels, in while K+ is going out, causing balance:
- Lengthens AP to 200-300: Keeps HR slow enough to allow time for heart to fill w blood before next contraction
4) Repolarization phase: Na+ and Ca2+ channels closee as K+ continue to exit = repol

76
Q

What does the plateau phase allow for in myocyte action potentials?

A

allows enough time for the heart to fill w blood before the next contraction and prevents tetanus (another AP)

77
Q

what does chronotropic mean?

A

Heart rate

78
Q

Does the parasmpathetic ns have a positive or negative chronotopic effect?

A

negative

79
Q

Does sympathetic nervous system have a positive or negative chronotropic effect

A

positive

80
Q

does contraction and relaxation of the myocytes need to be in perfect synchrony?

A

Yes. and facilitate filling and blood flow from atria ventricles, and then out via the aorta or
pulmonary arteries

81
Q

what is preload?

A

The amount of stretch of the sarcomeres in the ventricular muscle cells (myocytes). Before contraction

82
Q

What is the perfect sequency an synchrony a result of? (3 reasons)

A

1) delay at av node
2) gap unction allow eletrical signal to spread quick thru myocytes
3) orientation of myocytes

83
Q

How does increased preload affect blood pressure?

A

Increase in preload increases edv –>incr SV, Incr CO, Incr blood pressure

84
Q

where are the electodes on a 3 lead ecg

A

RIght arm (-, -) , left arm( +, -), left leg (+, +)

85
Q

What are the 3 diffferent waves of the ECG and what does each represent

A

P wave - atrial depolarization
QRS complex - Ventricular depolarization (masking atrial repol)
T wave - Ventricular repolarization

86
Q

What does the R-R interval represent on an ECG

A

duration of cardiac cycle

87
Q

what does P-Q represent

A

duration of atrial repol and AV node delay

88
Q

What does Q-T interval represent?

A

entire duration of ventricular action potential

89
Q

what does the s-t segment represent

A

ventricular plateau phase

90
Q

The cardiac cycle describes not electrical events but ____ events of the heart

A

mechanical

91
Q

what rep contraction what rep relaxation of heart

A

contraction - systole
relaxation- diastole

92
Q

Do atrial and ventricular systoles and diastoles occur at same or different times why?

A

The occur at different times due to the AV node delay.

93
Q

Do both sides of the heart work at different times or simulataneosly

A

simulataneosly

94
Q

what are the 4 main phases of the cardiac cycle

A

filling, contraction, ejection, relaxation

95
Q

What horomone binds inside a cell and why?

A

Lipid based/steroid molecules because they are hydrophobic therefore can pass thru membrane

96
Q

if BP drops below normal range waht happens in terms of symp ns

A

Increased activity of sup ns

97
Q

What happens during the ventricular filling phase?

A

Blood flows down the pressure gradient from atria to ventricles.
Atria in systole
Ventricles in diastole
AV valves open
semilunar valves are closed

98
Q

Isovolumetric contraction Phase

A

ventricular systole
atrial diastole
all valves closed

99
Q

what the state of the atria and ventricles during ventricular ejection. Which valves open and closed. FLow of blood?

A

ventricles in systole
atria in diastole
AV valves closed
SL valves open
Blood is ejected into pulm artery and aorta

100
Q

What is end diastolic volume?

A

total amount of blood in ventricles at the end of ventricular diastole

101
Q

At rest how much blood is pumped into each ventricle

A

70ml

102
Q

what is end systolic volume? How much is it at rest

A

the amount of blood remaining in ventricle at the end of ventricular ejection
at rest about 50ml

103
Q

what the state of the atria and ventricles during isovolumetric Relaxation:. Which valves open and closed. FLow of blood?

A

ventricles in diastole
atria in diastole
all valves closes
blood is not being ejected or enter - remains constant

104
Q

what is stroke volume?

A

Volume of blood ejected out of left ventricle in one heart beat

105
Q

what is cardiac output

A

volume of blood pumped out of left ventricle in one minute (L/min)

106
Q

What is venous return>

A

volume of blood returning to heart in one min

107
Q

whats the formula for SV? Resting is?

A

EDV-ESV. 70mL

108
Q

What is formula for CO? whats resting?

A

SV x HR - 70x70 = 4900ml (around 5 L)

109
Q

What are the 3 main factors that affect stroke volume?

A

Preload, contractility, afterload

110
Q

What is preload?

A

amount of stretch of sarcomeres in ventricular myocytes before contraction - det by EDV

111
Q

How does preload affect SV? 2 factors that influence edv?

A

Higher preload = Higher volume of blood in ventricle (EDV) = more stetch on ventricle myocytes and more potential for actin-myosin overlap e
1) length of time ventricle spends in diastole
2) amount of bood returning to heart from systemic circuit (venous return)

112
Q

How does contractility increase SV?

A
  • Greater force of contraction = more blood ejected = lower ESV = greater SV
113
Q

what are inotropic agents?

A

agents that affect contractility

114
Q

What is afterload?

A

the force ventricle must overcome in order to eject blood into arteries

115
Q

How does afterload increase SV?

A

Lower afterload = ventricle pumping against lower resisistane = lower ESV

116
Q

What happens to the three factors that affect stroke volume when stroke volume decrease?

A

low preload (muscle cells less stretched) , low contractility (heart contracts more weakly), high afterload (ventricle pumping against a higher resistance)

117
Q

What are chronotropic agents?

A

Factors that influence HR

118
Q

Under normal conditions what determines HR?

A

The rate at which SA node generates AP

119
Q

What is a positive chronotropic agent? what does it include?

A

ANything that increases rate at which SA node fires (incr HR)
includes sympathetic nervous system, horomones, elevated body temp

120
Q

What is a negative chronotropic agent? and examples

A

Anything that decrease the rate of SA nod firing
included parasympathetic nervous system and decreased body temp

121
Q

How does sympathetic NS reg Cardiac output

A

Epinephrine and norepinephrin incr HR and contractility of myocytes which increases SV and HR. positive chronotropic and Inotropic effect.

122
Q

How does parasympathetic NS regulate CO?

A

Acetylcholine targets SA node and decreases HR
- Negative chronotropic effectf

123
Q

what are presuure resevoirs

A

arteries

124
Q

what are volume resevoirs

A

veins

125
Q

What is the site of variable resistance

A

the arterioles

126
Q

are there more arteries or veins

A

veins

127
Q

what holds more blood, arteries or veins?

A

veins hold much more blood than arteries (70%)

128
Q

what are the wall layers of arteries and veins from innermost to outermost

A

innermost - tunica intima
middle - tunica media
outer - tunica externa

129
Q

what layer of the arteries and veins contains smooth muscle?

A

tunica media

130
Q

what does contraction of the arteries or veins lead to vs relaxation?

A

contraction –> vasoconstiction –> decreased diametre

Relaxation –> vasodilation —> increases diameter

131
Q

veins have ____ wals, ____ elastic fibres, ____ smooth muslcle and ____ lumen

Most arteries have much thicker _______ (wall) and more ___ laminae (due tonhigher bp the ssee)

A

VEINS = thinner walls, less elastic fibres, less smooth muscle, larger lumen

Most arteries have much thocker tunica media more internal and external elastic laminae.

132
Q

Whats a main role of tunica media

A

controlling blood flow and blood pressure

133
Q

what is the fucntion of elastic arteries? primarily made up of?

A

Condict blood under high pressure to organs. Elastic laminae.

134
Q

what type of arteries are pulmonary arteries

A

elastic

135
Q

what arteries reg bP and control blood flow to organs?

A

muscular arteries

136
Q

wha tunics are arterioles made of?

A

all 3

137
Q

what is the main function of arterioles?

A

control blood to tissues, feed capillaries

138
Q

Main fucntion of venules?

A

drain capillary beds

139
Q

main function of veins

A

return blood to heart

140
Q

what are the three types of capillaries?

A

continuous, fenestrated, sinusoidal

141
Q

what is the least leaky capillary type? Joined by tight junctions

A

continuous - msucle tissue

142
Q

which type of capillary is moderately leaky?

A

fenestrated

143
Q

which type of capillary is the leakiest?

A

Sinusoidal - cellls can pass thru

144
Q

what is blood flow thru capillary bed based on?

A

tissue needs - skel msucles need more o2 more capillary beds

145
Q

what is blood flow thru tissues regulate dby?

A

1) opening/closing of precapillary sphincters
2) vasoconstriciton/dilation of arterioles

146
Q

What is the equation for blood flow?

A

Blod pressure gradient (deltap)/resistance

  • bp gradient creates the blood flow
  • the total resistance is the impedence to blood flow
147
Q

what is the current (I) equation

A

= voltage gradient (delta v) (delta v)/ Resistance

148
Q

What is the main determinant of flow rate of blood?

A

pressure gradient

149
Q

What is blood pressure?

A

outward force that the blood exerts on the walls of blood vessels (mmHg)

150
Q

What are the three things resistance is determined by?

A

Vessel radius, length, viscocity

151
Q

What is the velocity of blood flow equation?

A

1 / cross sectional area

152
Q

Total cross sectional area increase as artries bracnh into…

A

smaller vessels

153
Q

As total cross sectional area increase what happens to velcocity

A

velocity slows down

154
Q

where is blood velcocity slowest? why?

A

in capillaries, to allow more time for effective gas and nutrient exchange

155
Q

What is systolic pressure - at rest?

A

pressure of blood against artery wall during systole (120mmHg)

156
Q

what is Diastolic pressure - at rest?

A

the pressure of blood against the artery walls during diastole - 80mmHg

157
Q

what is the pulse pressure?

A

difference betwee systolic and diastolic BP - Sp-Dp - 120-80 = 40

158
Q

What dos systemic arterial bp represent?

A

the driving pressure of blood thru arteries -MAP

159
Q

what is the MAP equation

A

MAP = diastolic pressure + 1/3 (systolic pressure – diastolic pressure)

160
Q

when is pulse pressure gone on the graph? what does the black line mean?

A

when it reaches the arterioles – cap – venules – to veins– venacavae

black line is MAP

161
Q

What are the three factors that determine BP?

A

Peripheral resistance, CO, blood volume

162
Q

as peripheral resistance increase what happens to BP?

A

also increases

163
Q

what are the three things that impact peripheral resistance?

A

Blood viscocity - more viscous more molecule resistance to motion - blood has high viscocity bc of protein and cells

Blood vessel length - longer blood vessel = gerater Resistance = more pressure to propela long long vessel

Blood vessel radius - as radius increases resitance decreases, so inverse

164
Q

How does hight blood viscocity impact BP?

A

more viscous= more resistance to motion = more peripheral resistance = higher BP

165
Q

what is a reason that resistance in pulm circuit is less than systemic

A

Blood vessels are longer in systemic so reseitance is grater

166
Q

How does cardiac output impact BP

A

Increase in cardiac output leads to increase in BP

167
Q

How does blood volume imapct BP?

A

when blood contains more water, volume invrease, increase in blood volume means increase in pressure therfore increase in BP

168
Q

which circiuit does pressure remain relatively low and stable?

A

pulmonary

169
Q

in systemic circuit whre is the highest pressure? where is the lowest

A

highest is arteries than arterioles, lowest is venules and veins

170
Q

where does MAP decrease rapidly

A

arterioles

171
Q

2 mechanisms of venous return

A

valves - ensure one way flow
Skeletal muscle pump - skel muscle squeeze deeper veins to propel to heart (vasoconstirciton)

172
Q

What three systems is BP under regualtion by?

A

nervous, endocrine and urinary

173
Q

where is short term maintenance of BP? where is long term maintenance? what sytems?

A

Short term - nervous ssystem - ANS. - periph resistance and CO ( think HR and SV) - Norepinephrine and epinephrin

Long term - kdineys and endocrine sytem
- increases the water lost as urine changinging blood volume
horomones act on kdiney to manage fluid retention eg ADH

174
Q

give an example of how the endocrine system plays a role in the cardiovascular.

A

Endocrine releases ADH (anti-diuretic horomone) which alter fluid retention in the kidney therfore changinf blood volume and impacting blood pressure.

175
Q

How does Nervous system impact HR?

A

symp neurons release epinephrine and norepinephrine which increase HR and contractility and therfore cardiac output -

also cause vasocontriviton of arteriooles which increases perip resistance

176
Q

Which ssytem in the ANS decreases bp and why?

A

Parasympthetic decrease heart rate decreaseing CO and therefore blood pressure

177
Q

what are baroreceptors?

A

specialized mechanoreceptors found in walls of aortic arch and common carotid artery which respond to stretch in the artery wall

178
Q

where are baroreceptors found?

A

aortic arch and common carotid artery

179
Q

what is the baroreceptor reflex (in terms of increase in Bp)

A

Increased BP –> increased wall stretch –> increaseed firing of AP via cranial nerves of sns –> to medulla for integration –> output to lower bp

180
Q

where

A