Brainscape's Knowledge GenomeTM

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


See full index

BIOL 112 > Lecture 4: Blood Vessels & Hemodynamics > Flashcards

Lecture 4: Blood Vessels & Hemodynamics Flashcards

1
Q

what is hemodynamics

A

study of flow together with the differnet forces that regulate blood flow int he body

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

what is the capillary blood flow in healthy conditions

A

-equals cardiac output
-determined by pressure (P) and resistance (R)

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

what is pressure (P)

A

the force generated by the heart to overcome resistance

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

pressure gradient (^P)

A

difference in pressure from one end of a vessel to the other

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

what is vascular resistance (R)

A

opposition to blood flow due to friction between blood and the walls of blood vessels

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

what does higher resistance (R) mean

A

it shows smaller blood flow

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

what does resistance (R) depend on

A

-Lumen size (vessels diameter): inverse relationship; has the greatest influence
-Blood Viscosity: direct proportional relationship
-Total blood vessels length: direct proportional relationship

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

what is velocity

A

the rate of change of the object’s position with respect to a frame of reference and time

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

describe the velocity of blood flow

A

-blood flow is the volume of blood that moves througha tissue in a given period

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

velocity of blood flow between aorta and capillaries

A

fastest aorta, slowest in capillaries, then increases again in veins

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

what is speed in velocity of blood flow related to

A

speed is inversely related to total cross-sectional area

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

why is blood flow the slowest in the capillaries

A

-capillaries have the largest area so the slowest flow
-slow capillary flow allows aadewuate time for exchange between blood and tissues

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

what is tissue perfusion

A

the flow of blood through body tissues

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

what is tissue perfusion involved in

A
  1. delivery of O2 and nutrients to, and removal of wastes from tissue cells
  2. gas exchange (lungs)
  3. absorption of nutrients (digestive tract)
  4. urine formation (kidneys)
    -rate of flow is right amount to provide proper function to that tissue of organ
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how is blood flow controlled

A

rate of flow is controlled by intrinsic and extrinsic factors

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

what are intrinsic controls of blood flow

A

-control is entirely from within the tissue or organ
-uses paracrines or or properties of muscle tissue
-also known as autoregulation or local control

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

what are extrinsic controls on blood flow

A

-control is from outside of the tissue or organ
-uses nerves or hormones

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

what are examples of when both intrinsic and extrinsic control mechanisms occur

A

-stroke volume in the heart
-arteriolar diameter
-glomerular filtration in kidneys

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

blood flow to the skeletal muscles at rest vs. during exercise

A

-at rest: they receive ~20% of total body
-during exercise: >70% of blood

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

what are some intrsinsic controls for blood flow to skeletal muscles during exercise

A

skeletal muscle arterioles dilate, increasing blood flow to muscle

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

what are some extrinsic controls for blood flow to skeletal muscles during exercise

A

decrease blood flow to organs such as kidneys and digestive organs

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

what is autoregulation

A

local (intrinsic) conditions that regulate blood flow to that area

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

what two types of intrinsic machanisms determine final autoregulatory response

A

-metabolic controls
-myogenic controls

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

what is active hyperemia

A
  1. intial stimulus: exercising skeletal muscle
  2. physiological response: lower O2, higher CO2 and H+ and other metabolic factors in extracellular fluid -> vasodilation of arterioles (overrides extrinsic sympathetic input)
  3. result: higher muscle blood flow (active hyperemia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is taken during vital signs (V/S)

A

pluse (HR), BP, respiratory (breathing) rate, and body temp

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

what is a pulse

A

-pressure wave due to alternating expansion and recoil of elastic arteries
-after systole of left ventricle
-strongest in aorta; weaker in arterioles and disappears in capillaries
-pulse rate is same as normal heart rate

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

taking a pulse

A

-radial pulse (taken at wrist): most routinely used, but there are other clinically important pulse points
-pressure points: areas where arteries are close to body surface, can be compressed to stop blood flow in event of hemorrhaging

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

what are some common pulse points and where to find them

A

-superficial temporal artery: found medial to ear
-facial artery: found on mandible (lower jawbone) on line with corners of mouth
-common carotid artery: lateral to larynx (voice box)
-brachial artery: found medial side of biceps brachii muscle

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

what is the relationship between blood flow and pressure

A

blood flow (F) is directly proportional to blood pressure gradient (^P)
-if ^P increases, blood flow speeds up

30
Q

what is the relationship between blood flow and resistance

A

blood flow (F) is inversely proportional to peripheral resistance (R)
-if R increases, blood flow decreases, so F= ^P/R

31
Q

where is systemic BP highest

A

it’s highest in aorta and declines throughout pathway
-ssteepest drop occurs in arterioles

32
Q

what are the two factors that determine to arterial BP

A
  1. Elasticity (compliance or distensibility) of arteries close to heart
  2. volume of blood: forced into them at any time
33
Q

BP near heart is what?

A

it is pulsatile: rises and falls with each heartbeat

34
Q

what is systolic pressure

A

-pressure exerted in aorta during ventricular contraction
-left ventricle pumps blood into aorta-> stretches aorta
-averages ~120 mm Hg in normal adult

35
Q

what is diastolic pressure

A

lowest level of aortic pressure when heart is at rest; ~80 mm Hg

36
Q

what is pulse pressure

A

difference between systolic and diastolic pressure

37
Q

what is mean arterial pressure (MAP)

A

-average pressure during one cardiac cycle
-pressure that propels blood tiissues
-pulse pressure phases out near end of arterial tree
-both pulse pressure nad MAP decline with increasing distance from heart

38
Q

how do you calculate MAP

A

diastolic pressure + 1/3 pulse pressure

39
Q

how do you measure blood pressure

A

systemic arterial BP is measured indirectly bu ausculatory methods usinf a sphygmomanometer

40
Q

steps in taking BP

A
  1. wrap cuff around arm superior to elbow
  2. increase pressure in cuff until it exceeds systolic pressure in brachial artery
  3. pressure is released slowly, and examiner listens for sounds of Korotkoff with a stethescope
41
Q

SBP and DBP when taking BP

A

systolic pressure: pressure when sounds first occur as blood starts to spurt through artery
diastolic pressure: pressure when sounds disappear because artery is no longer constricted; blood is flowing freely

42
Q

what is venous BP

A

-changes little during cardiac cycle
-small pressure gradient, only ~15 mmHg
-if vein is cut, low pressure of venous system causes blood to flow out smoothly
-if artery cut, blood spurts out because pressure is higher
-low pressure is due to cumulative effects of peripheral resistance
-low pressure of venous side requies adaptations to helo with venous return

43
Q

what is venous return

A

volume of blood flowing back to the heart through the systemic veins, occurs due to the pressure generated by contractions of the left ventricle

44
Q

what are the three factors aiding venous return and explain them

A
  1. muscular pump: contraction of skeletal muscles “milks” blood back toward heart; valves prevent backflow
  2. respiratory pump: pressure changes during breathing move blood toward heart by squeezing abdonimal veins as thoracic veins expand
  3. sympathetic venoconstriction: under sympathetic control, smooth muscles constrict, pushing blood back toward hearrt
45
Q

whaat different body systems maintain BP

A

it requires cooperation of heart, blood vessels, and kidneys which are all supervised by the brain

46
Q

what three main factors regulate blood pressure

A
  1. cardiac output (CO)
  2. peripheral resistance (PR)
  3. blood volume
47
Q

recall slide 19

A
48
Q

recall slide 19

A
49
Q

recall slide 19

A
50
Q

recall slide 19

A
51
Q

factors that increase MAP (review slide 20)

A

^ SV & ^ HR = ^ CO= ^MAP
lower diameter of blood vessels, ^blood viscosity, ^blood vessel length=^ total peripheral resistance= ^MAP

52
Q

direct renal mechanism for control of BP

A
53
Q

indirect renal machanism (renin-angiotensin-aldosterone) for control of BP

A
54
Q

effects of some selected hormones on BP

A
55
Q

effects of some selected hormones on BP

A
56
Q

what are homeostatic imbalances in BP

A

-transient elevations in BP occur during changes in poster, physical exertion, emotional upset, fever
-age, sex, weight, mood, and posture may also cause BP to vary

57
Q

what is hypertension

A

-sustained elevated arterial pressure of 140/90 mmHg or higher
-prolonged hypertension is major cause of heart failure, vascular disease, renal failure, and stroke

58
Q

what is prehypertension

A

-values elevated but not yet in hypertension range
-may be trnasient adaptations during fever, physical exertion, and emotional uspset
-often persistent in obese people

59
Q

what is primary hypertension

A

-90% of hypertensive conditions
-no underlying cause identified
-risk factos: heredity, diet, obesity, age, diabetes mellitus, stress, and smoking
-no cure but can be controlled by: restrict salt/ fat/ cholesterol intake, increase exercise, lose weight, stop smoking, antihypertensive drugs

60
Q

what is secondary hypertension

A

-less common
-due to identifiable disorders: obstructed renal arteries, kidney diease, and endocrine disorders such a hyperthyroidism and Cushing’s syndrome
-treatment: focuses on correcting underlying cause

61
Q

what is hypotension

A

-low BP <90/60
-usually not a concern unless it causes inadequate blood flow to tissues
-often asssociated with long life; and lack of cardiovascular illness

62
Q

what is orthostatic hypotension

A

temporarylow BP and dizziness when suddenly rising from sitting or reclining position

63
Q

what is chronic hypotension

A

suggests poor nutrition and warning signs for Addison’s disease or hypothyroidism

64
Q

what is acute hypotension

A

important sign of circulatory shock

65
Q

what is circulatory shock

A

condition where blood vessels inadequately fill and cannot circulate blood normally-> inadequate CO: inadequate blood flow cannot meet tissue needs (lack of O2 delivery)

66
Q

what is hypovolemic shock

A

large-scale blood loss due to trauma, vessel rupture

67
Q

what is vascular shock

A

extreme vasodilation and decreased PR: anaphylactic shock, neurogenic shock, spetic shock

68
Q

what is cardiogenic shock

A

an inefficient heart cannot sustain adequate circulation: ischemia, valve defects, impaired CCS

69
Q

what is obstructive shock

A

blockade of blood circulation: pulmonary embolism

70
Q

what are homeostatic responses to shock

A

-negative feedback mechanisms work to return CO to normal
-activation of renin-angiotensin-aldosterine system
-secretion of antidiuretic hormone
-activation of the sympathetic division of the ANS
-release of local vasodilators

BIOL 112 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions