Physiology of Vessels

Question 1

The regulation of blood pressure must change in response to ______.

Answer 1

cellular activity

Question 2

a collection of mechanisms that influence the active and changing circulation of blood

Answer 2

hemodynamics

Question 3

Circulation control mechanisms must accomplish two functions:

Answer 3

• maintain circulation

- vary the volume and distribution of the blood circulated

Question 4

_____ is the only means by which cells can receive materials necessary for survival and have wastes removed.

Answer 4

circulation

Question 5

Primary Principle of Circulation: Blood flows because a ________ exists between different parts of its volume; this is based on Newton’s first and second laws of motion.

Answer 5

pressure gradient

Question 6

the symbol used to represent a pressure gradient. ___ represents the higher pressure and ___ represents the lower pressure.

Answer 6

P1-P2

• P1
• P2

Question 7

A _____ gradient is needed to maintain blood flow through a local tissue

Answer 7

perfusion pressure (PP) gradient

Question 8

A blood pressure gradient drives blood flow from the ______ to the _____.

Answer 8

right ventricle to the left atrium

Question 9

fluid always travels from high pressure to low pressure. This is called

Answer 9

pressure gradient

Question 10

The primary determinant of arterial blood pressure is the ____ of blood in the arteries

Answer 10

volume

Question 11

A ____ relationship exists between arterial blood pressure and arterial blood volume

Answer 11

direct

Question 12

volume of blood pumped out of the heart per unit of time.

Answer 12

cardiac output (CO)

Question 13

the amount the cardiac output can increase above the resting cardiac output

Answer 13

cardiac reserve

Question 14

Within limits, the longer or more stretched the heart fibers are at the beginning of contraction, the stronger the contraction.

The amount of blood in the heart at the end of diastole determines the amount of stretch or preload placed on the heart fibers

Answer 14

Starling’s Law of the heart

Frank-Starling mechanism

Question 15

factors that affect strength of myocardial contraction and therefore stroke volume

Answer 15

inotropic factors

Question 16

one mechanical factor that helps determine stroke volume:

Answer 16

myocardial fibers at the beginning of ventricular contraction.

Question 17

Contractility can also be influenced by chemical factors:

Answer 17

• neural: norepinephrine
• endocrine: epinephrine
• triggered by stress, exercise

Question 18

ratio of stroke volume to end-diastolic volume

Answer 18

ejection fraction

usually expressed as a percentage

Question 19

In a healthy adult, the ejection fraction is at least __%

Answer 19

55%

Question 20

the pumping work the heart must do to push blood into the arteries

Answer 20

afterload

Question 21

the harder it is to push blood out of the ventricles, the lower the _____.

Answer 21

stroke volume.

Question 22

Abnormally high afterload from flow resistance in the arteries can cause _____.

Answer 22

heart failure

Question 23

_______ and _______ are located in the aorta and carotid sinus.

They affect the autonomic cardiac control center in the Medulla, and therefore parasympathetic and sympathetic outflow, to aid in control of blood pressure.

Answer 23

Cardiac pressoreflexes:

aortic baroreceptors and carotid baroreceptors

Question 24

factors that change the rate of the heartbeat

Answer 24

chronotropic factors

Question 25

_________ reflex: - located at the beginning of the internal carotid artery - sensory fibers from carotid sinus baroreceptors run through the carotid sinus nerve and the glossopharyngeal nerve to the cardiac control center - parasympathetic impulses leave the cardiac control center and travel through the vagus nerve to reach the SA node

Answer 25

carotid sinus reflex

Question 26

_____ reflex: - sensory fibers extend from baroreceptors in the wall of the aortic arch through the aortic nerve and through the vagus nerve to terminate in the cardiac control center - stimulation causes the cardiac control center to increase vagal inhibition, thus slowing the heart

Answer 26

aortic reflex

Question 27

______ produce changes in the heart rate through the influence of impulses from the cerebrum by way of the hypothalamus

Answer 27

emotions

Question 28

other reflexes that influence heart rate (4):

Answer 28

- emotions - exercise - increased blood temperature or stimulation of skin heat receptors - decreased blood temperature or stimulation of skin cold receptors

Question 29

resistance to blood flow imposed by the force of friction between blood and the walls of its vessels

Answer 29

peripheral resistance

Question 30

factors that influence peripheral resistance:

Answer 30

- blood viscosity | - diameter of arterioles

Question 31

blood viscosity is determined mainly by the proportion of ______, but also partly by the number of ______.

Answer 31

red blood cells (hematocrit), protein molecules

Question 32

arterial blood pressure tends to vary directly with ____.

Answer 32

peripheral resistance

Question 33

_____ is caused by viscosity and small diameter of arterioles and capillaries

Answer 33

friction

Question 34

_____ have a muscular coat that allows them to constrict or dilate and change the amount of resistance to blood flow

Answer 34

arterioles

Question 35

controls changes in the diameter of arterioles; it plays a role in maintenance of the general blood pressure and in distribution of blood to areas of special need

Answer 35

vasomotor control mechanism

Question 36

controls changes in the diameter of arterioles; it plays a role in maintenance of the general blood pressure and in distribution of blood to areas of special need

Answer 36

vasomotor control mechanism see slide 24 for more info

Question 37

local mechanism produce vasodilation in localized areas

Answer 37

hyperemia

Question 38

amount of blood returned to the heart by veins

Answer 38

venous return

Question 39

____ occurs when a change in blood pressure causes a change in vessel diameter (because of elasticity) that accommodates the new pressure and thereby keeps blood flowing

Answer 39

the stress-relaxation effect

Question 40

the pull of gravity on venous blood while sitting or standing tends to cause a decrease in venous return

Answer 40

orthostatic effect

Question 41

facilitate venous return by increasing the pressure gradient between the peripheral veins and the venae cavae

Answer 41

venous pumps

Question 42

facilitate venous return by increasing the pressure gradient between the peripheral veins and the venae cavae

Answer 42

venous pumps: - respirations - skeletal muscle contractions

Question 43

inspiration increases the pressure gradient between peripheral and central veins by decreasing central venous pressure and also by increasing peripheral venous pressure

Answer 43

respirations

Question 44

promote venous return by squeezing veins through a contracting muscle and milking the blood toward the heart

Answer 44

skeletal muscle contractions

Question 45

changes in ________ change the amount of blood returned to the heart

Answer 45

total blood volume

Question 46

The _____ the total volume of blood, the greater the volume of blood returned to the heart

Answer 46

greater

Question 47

the mechanisms that change total blood volume most quick;y, making them most useful in maintaining constancy of blood flow, are:

Answer 47

those that cause water to move quickly: - into plasma - out of the plasma

Question 48

the ______ system recovers the fluid not recovered by the capillary and returns it to the venous blood before it is returned to the heart

Answer 48

lymphatic

Question 49

reduces amount of water lost by the body by increasing the amount of water the kidneys reabsorb from urine before the urine is excreted from the body this mechanism is triggered by input from baroreceptors and osmoreceptors

Answer 49

the anti-diuretic hormone (ADH) mechanism

Question 50

renin is released when blood pressure in the kidneys is low - leads to increased secretion of aldosterone which simulates retention of sodium - angiotensin II is an intermediate compund that causes vasoconsriction this complements volume-increasing effects of renin and promotes an increase in overall blood flow

Answer 50

Renin-Angiotensin-Aldosterone System (RAAS)

Question 51

adjusts venous return from an abnormally high level by promoting the loss of water from plasma, thereby causing a decrease in blood volume increase urine sodium loss

Answer 51

Atral-Natriuretic-Hormone (ANH) mechanism

Question 52

Arterial blood pressure is measured with the aid of a _______ and ______.

Answer 52

sphygmomanometer and stethoscope

Question 53

force of the blood pushing against artery walls as ventricles contract

Answer 53

systolic blood pressure

Question 54

force of the blood pushing against artery walls when ventricles are relaxed and during isovolumetric ventricular contraction

Answer 54

diastolic blood pressure

Question 55

difference between the systolic and diastolic blood pressures

Answer 55

pulse pressure

Question 56

average blood pressure in the arteries for the perfusion of tissues

Answer 56

mean arterial pressure (MAP)

Question 57

a mercury-filled pressure sensor used in clinical and research settings to measure the arterial blood pressure quickly and accurately

Answer 57

sphygmomanometer

Question 58

volume of blood circulating through the body per minute

Answer 58

minute volume of blood

Question 59

_____ Law: minute volume = pressure gradient / resistance the minute volume of blood is determined by the magnitude of the blood pressure gradient and peripheral resistance

Answer 59

Poiseulle's Law

Question 60

______ mechanism: reveals important information about the cardiovascular system, blood vessels, and circulation expansion stores energy released during recoil, conserving energy generated by the heart and maintaining relatively constant blood flow

Answer 60

pulse mechanism

Question 61

each pulse starts with ventricular contraction and proceeds as a wave of expansion throughout the arteries it gradually dissipates as it travels, disappearing in the capillaries

Answer 61

pulse wave

Question 62

the ____ can be felt where ever an artery lies near the surface and over a bone or other firm background

Answer 62

pulse

Question 63

detectable pulse exists only in large veins, most prominently near the heart; this pulse is not clinically important

Answer 63

venous pulse

Question 64

Where pulse can be felt (7)

Answer 64

- radial artery: at the wrist - temporal artery: in front of the ear or on the outer side of the eye - common carotid: anterior edge of the SCM muscle - facial artery: lower margin of the lower jawbone - brachial artery: bend of the elbow, along inner margin of the biceps muscle - femoral artery: middle of groin - popliteal artery: behind the knee

Question 65

occurs when force exerted by the arterial blood vessel exceeds 140/90 mmHg

Answer 65

hypertension HTN

Question 66

lower than normal blood pressure. Acute or chronic.

Answer 66

hypotension