Ch14

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

How does the Parasympathetic nerve affect: -SA node -AV node -atrial muscle -ventricular muscle

-Decreased rate of diastolic depolarization; decreased cardiac rate -decreased conduction rate -no significant effect -no significant effect

Regulation of cardiac rate is controlled by _______ _______ of the ______ _____

-cardiac center -medulla oblongata

What are the three variables that regulate stroke volume?

-end diastolic volume -arterial blood pressure -contractility

How does the Sympathetic nerve affect: -SA node -AV node -atrial muscle -ventricular muscle

-increased rate of diastolic depolarization; increased cardiac rate -increased conduction rate -increased strength of contraction -increased strength of contraction

What is auto regulation and how is it accomplished in cerebral circulation?

-local intrinsic mechanisms regulate cerebral blood flow -achieved by myogenic regulation and metabolic mechanisms

Extrinsic control of contractility: -Sympathetic _________ and adrenal ______ can increase ______ by making more Ca2+ available to sarcomeres; which also ________ HR -Parasympathetic ________ will decrease heart rate which will ________ _______ --> increase ______ strength --> increase _____ _______ ; but not significantly so cardiac output _____

-norepinephrine; epinephrine; contractility -acetylcholine, increase EDV; contraction; stroke volume; decreases

These factors affect venous return: (6)

-pressure difference between arteries and veins -pressure difference in venous system -sympathetic nerve activity t stimulate smooth muscle contraction -skeletal muscle pumps -pressure difference in abdominal and thoracic cavities -blood volume

____ ____ occurs at the SA node when HCN channels open, allowing __ in

-spontaneous depolarization -Na+

4 conditions of peripheral resistance

-sum of all vascular resistance in systemic circulation -blood flow to organs runs parallel to each other; change in resistance to one organ doesn't effect others -vasodilation in a large organ may decrease total peripheral resistance and mean arterial pressure -increased cardiac output and vasoconstriction elsewhere make up for this

Blood flow to the heart: -blood flow is restricted during ___ ; cardiac tissue has ____ to store oxygen during ___ to be released in systole

-systole; myoglobin; diastole -

What are the dangers of hypertension

-vascular damage within organs -ventricular overload to eject blood due to hypertrophy which can lead to arrhythmia and cardiac arrest -contributes to the development of atherosclerosis

Why is the return of fluids not 100%?

10-15% remains in the interstitial spaces

How many liters of filtrate are moved across glomeruli a day? how much is actually removed as urine? what happens to the rest?

180 L; 1.5 L ; reabsorbed

How much of the total blood volume is in the veins?

2/3

How much body water is found in the cells? How much is in interstitial space? Blood plasma?

2/3 -80% -20%

Normally, ______ of the EDV is ejected, this is known as the ___ ____

60%, ejection fraction

If someone's heart has a stroke volume of 70 ml and a heart rate of 90 beats/min, the cardiac output equals _____________. A) 6.3 L/min B) 0.77 L/min C) 70 ml/min D) 1.28 ml/min

A) 6.3 L/min

___________ is a polypeptide vasodilator produced by the sweat glands. A) Bradykinin B) Histamine C) Seratonin D) Endorphin

A) Bradykinin

Cardiac control centers in the medulla oblongata receive input from baroreceptors located in some of the arteries. A) True B) False

A) True

Cerebral blood flow remains fairly constant at about 750 ml/min, in spite of changes in brain activity, blood pressure, and blood flow to other organs. A) True B) False

A) True

Decreased osmolality of the blood leads to decreased secretion of ADH. A) True B) False

A) True

In spite of the fact that the systemic vessels cover substantially more total length than the pulmonary vessels, the same amount of blood must flow through both of these systems at a given time. A) True B) False

A) True

Stroke volume is directly proportional to end-diastolic volume. A) True B) False

A) True

Low blood pressure stimulates the secretion of the Mineralocorticoid ______________. A) aldosterone B) angiotensin II C) vasopressin (ADH) D) atrial natriuretic peptide (ANP)

A) aldosterone

Veins are said to have a higher ____ than arteries because they expand more easily and a higher ___________ because they contain more blood. A) compliance; capacitance B) compliance; elasticity C) elasticity; capacitance D) elasticity; compliance

A) compliance; capacitance

The SA node depolarizes more frequently under the influence of ____________. A) norepinephrine B) acetylcholine C) the vagus nerve D) the medulla oblongata

A) norepinephrine

The enzyme that converts angiotensinogen into angiotensin I is _____________. A) renin B) angiotensin-converting enzyme (ACE) C) atrial natriuretic peptide (ANP D) vasopressin (ADH)

A) renin

Frictional resistance in the arteries; also called______; how does this relate to stroke volume?

Arterial blood pressure -afterload -inversely related to stroke volume

All of the fluid filtered by the capillaries of the kidneys is ultimately excreted as urine. A) True B) False

B) False

All parasympathetic nerve fibers to the heart innervate the SA node. A) True B) False

B) False

If a person has an arterial blood pressure of 102/62, the mean arterial pressure would equal 82mmHg. A) True B) False

B) False

Since the veins contain most of the body's blood at any one time, they have a higher blood pressure than any other type of vessel. A) True B) False

B) False

The arteries that supply blood to the organs are generally in a series with each other than in parallel with each other. A) True B) False

B) False

The heart's contractility is adjusted so that normally each ventricle expels all the blood contained in it, leaving none behind in the chamber. A) True B) False

B) False

The net filtration pressure of the capillaries is equal to the hydrostatic pressure of tissue fluid outside the capillaries. A) True B) False

B) False

According to the classic view of the Starling forces, capillaries usually tend to absorb fluid ________________. A) at the arteriolar end B) at the venular end C) only when the precapillary sphincters are open D) at neither end; they filter fluid and it is up to the lymphatic vessels to absorb it

B) at the venular end

Stroke volume is regulated by all of the following except ____________. A) end-diastolic volume B) cardiac output C) contraction strength D) mean arterial pressure

B) cardiac output

Any mechanism that increases heart rate is said to have a positive ______ effect. A) feedback B) chronotropic C) inotropic D) cholinergic

B) chronotropic

The contractility of heart muscle is its _______________. A) contraction strength at any length B) contraction strength at any given fiber length C) contraction frequency, which determines heart rate D) ability to contract, which is restored after the refractory period

B) contraction strength at any given fiber length

During systole, the ventricular myocardium gets its oxygen supply mainly from _______. A) hemoglobin B) myoglobin C) its high density of blood capillaries D) its high density of mitochondria

B) myoglobin

The Frank-Starling law of the heart describes the relationship between ___________. A) stroke volume and cardiac output B) stroke volume, end-diastolic volume, and contraction strength C) stroke volume and total peripheral resistance D) the left and right ventricles

B) stroke volume, end-diastolic volume, and contraction strength

Cardiac output may drop when one goes from lying to a standing position because of ________________. A) the baroreceptor reflex B) venous pooling C) orthostatic hypertension D) sinus tachycardia

B) venous pooling

Of all the factors that can affect blood flow to a particular organ, the most effective and easiest to control from moment to moment is _____________. A) blood viscosity B) vessel radius C) vessel length D) pressure differential

B) vessel radius

What is Poiseuille's Law?

Blood flow= ΔPr4(π)/ηL(8)

How does the skin help control body temperature in a changing environment? What mechanisms are used?

By regulating blood flow (thermoregulation) -increased blood flow to capillaries to release heat -sweat to aid in heat loss -bradykinins in sweat glands stimulate vasodilation

Contraction of the left ventricle of the heart at rest normally expels about ______ of the blood contained in the chamber. A) 10(--)15% B) 25(--)33% C) 60(--)70% D) 98(--)100%

C) 60(--)70%

Edema could be caused by all of the following except ______________. A) high arterial blood pressure (hypertension) B) leakage of plasma proteins into the tissue fluid, as in inflammation and allergy C) an elevated level of albumin in the blood plasma D) an obstruction of the lymphatic drainage

C) an elevated level of albumin in the blood plasma

Intrinsic control of blood flow refers to the ________________. A) way in which blood flow is determined by cardiac output B) blood flow in all places other than the heart itself C) control of blood flow by metabolic products of the tissues D) control of blood flow by the nervous and endocrine systems

C) control of blood flow by metabolic products of the tissues

Arteriovenous anastomoses are found mainly in the ___________________. A) renal circulation B) mesenteries of the abdominal cavity C) dermis of the skin D) cerebral circulation

C) dermis of the skin

The preload acting on a ventricle is equivalent to that chamber's _____________. A) contractility B) stroke volume C) end-diastolic volume D) ejection fraction

C) end-diastolic volume

A positive inotropic agent is something that _______________. A) reduces the heart rate in a positive feedback loop B) increases the heart rate in a positive feedback loop C) increases the contractility of myocardial fibers D) decreases the contractility of myocardial fibers

C) increases the contractility of myocardial fibers

Myxedema is a disease caused by hypothyroidism, which causes production of excessive amounts of glycoprotein in the Interstitial spaces. The effect of this on capillary fluid dynamics would be to cause ________________. A) precapillary sphincters to shut off blood flow to affected tissues B) vasodilation of the capillaries C) reduced osmotic return of fluid and thus accumulation of fluid in the tissues resulting in edema D) increased transfer of tissue fluid into the blood stream, resulting in hypertension

C) reduced osmotic return of fluid and thus accumulation of fluid in the tissues resulting in edema

A severe infection could decrease blood pressure by causing _____________. A) cardiogenic shock B) anaphylactic shock C) septic shock D) hypovolemic shock

C) septic shock

What intrinsic metabolic control mechanisms enhance vasodilation

CO2, K+, paracrine regulators

Baroreceptors are specialized pressure receptors found in the ____________. A) vena cava B) descending aorta C) medulla oblongata D) aortic arch

D) aortic arch

The amount of blood pumped by each ventricle in one minute is called _____________. A) stroke volume B) end-diastolic volume C) ejection fraction D) cardiac output

D) cardiac output

Atrial natriuretic peptide (ANP) helps to lower blood pressure and is secreted by the _____________. A) hypothalamus B) kidneys C) adrenal cortex D) heart

D) heart

During exercise, the cardiac output may rise to five times the resting value. In most people this is due mainly to an increase in ______________. A) stroke volume B) ejection fraction C) end-diastolic volume D) heart rate

D) heart rate

Osmoreceptors regulating the release of ADH are found in the _______________. A) kidneys B) right atrium of the heart C) aortic arch and carotid sinuses D) hypothalamus

D) hypothalamus

Pulmonary edema, shortness of breath, and fatigue are most likely to result from _________________. A) cardiogenic shock B) anaphylactic shock C) right-sided congestive heart failure D) left-sided congestive heart failure

D) left-sided congestive heart failure

A sphygmomanometer is used for __________. A) correcting orthostatic blood pressure B) reducing tachycardia C) restoring blood volume D) measuring blood pressure

D) measuring blood pressure

Production of angiotensin II indirectly ____________. A) causes vasodilation of arterioles and muscular arteries B) inhibits the sense of thirst C) stimulates excretion of excess sodium by the kidneys D) raises the blood volume

D) raises the blood volume

The hydrostatic pressure of blood in a capillary is 19 mmHg and that of the tissue fluid is 1 mmHg, while the colloid osmotic pressure of the blood is 23 mmHg and that of the tissue fluid is 0 mm Hg, at this particular portion of the capillary, fluid is being _______ with a net force of __________. A) given off; 5 mmHg B) given off; -3 mmHg C) taken up; 3 mmHg D) taken up; -5 mmHg

D) taken up; -5 mmHg

Why must the most active regions of the brain receive increased blood flow?

Due to arteriole sensitivity to metabolic changes

increased EDV results in increased contractility and increased stroke volume

Frank-Starling Law of the Heart

How does the baroreceptor reflex work?

Increased blood pressure stretches the receptors, increasing action potentials to the vasomotor and cardiac control centers in the medulla

What happens (baroreceptor reflex) when there is a fall in blood pressure

Increased sympathetic and decreased parasympathetic activity, resulting in increased heart rate and total peripheral resistance.

This sound is produced by the flow of blood in the brachial artery when the blood pressure cuff is on

Korotkoff

This is the hydrostatic pressure of the blood in the capillaries minus the hydrostatic pressure of the fluid outside the capillaries

Net filtration pressure

The difference of colloid osmotic pressure in blood plasma and interstitial fluid? -What is this value?

Oncotic pressure -25mmHg

What controls the movement of water between interstitial spaces and capillaries affecting blood volume?

Osmotic forces

This is a combination of hydrostatic pressure and oncotic pressure the predicts movement of fluid across capillary membranes

Starling forces

What are the effects of dehydration on urine and blood volumes?

Stimulation of osmoreceptors produces sensations of thirst, leading to increased water intake and an increase in the amount of ADH released from the posterior pituitary. ADH stimulates water reabsorption from the filtrate. A smaller volume of urine is thus excreted as a result of the action of ADH. - This raises the blood volume and, in the process, dilutes the blood plasma to lower its previously elevated osmolality. The rise in blood volume that results from these mechanisms is extremely important in stabilizing the condition of a dehydrated person with low blood volume and pressure.

why would a person in hypovolemic shock have a fast pulse, and cold clammy skin?

There is a decreased blood flow, so the skin would be cold, and a fast heart rate because the baroreceptor reflex is activated.

What Is congestive heart failure? and what are compensatory responses that occur?

When the cardiac output is insufficient to maintain the blood flow required by the body. Can lead to other things -increase in cardiac rate, contraction of ventricles, constriction of arterioles, urine secretion reduced, salt and water retention.

According to the Frank-Starling law of the heart, the strength of ventricular contraction is a. directly proportional to the end-diastolic volume. b. inversely proportional to the end-diastolic volume. c. independent of the end-diastolic volume. d. All of these are correct

a. directly proportional to the end-diastolic volume.

If a vessel were to dilate to twice its previous radius, and if pressure remained constant, blood flow through this vessel would a. increase by a factor of 16. b. increase by a factor of 4. c. increase by a factor of 2. d. decrease by a factor of 2.

a. increase by a factor of 16.

parasympathetic regulation of blood flow

acetylcholine- vasoconstriction (digestive, genitalia, and salivary glands)

Where is ADH secreted from ? Why is it secreted? What regulates it?

adrenal cortex; blood volume and pressure are reduced; renin-angiotensin-aldosterone system

This is released to stimulate vasodilation and decrease vascular resistance during exercise

adrenal epinephrine

Starling forces predict the movement of fluid out of the capillaries at the _______ end and into the capillaries at the ____ end

arteriole; venule

This shunts blood from arterioles directly to venules

arteriovenous anastomoses

This is activated by increased venous return to: stimulate reflex tachycardia, inhibit ADH release; stimulate secretion of atrial natriuretic peptide (excretion of more salts and water in urine)

atrial stretch reflexes

Which of these statements about arteriovenous shunts in the skin is true? a. They divert blood to superficial capillary loops. b. They are closed when the ambient temperature is very low. c. They are closed when the deep-body temperature rises much above 37° C. d. All of these are true.

b. They are closed when the ambient temperature is very low.

Both ADH and aldosterone act to a. increase urine volume. b. increase blood volume. c. increase total peripheral resistance. d. produce all of these effects.

b. increase blood volume.

Blood flow in the coronary circulation a. increases during systole. b. increases during diastole. c. remains constant throughout the cardiac cycle. d. decreases during diastole.

b. increases during diastole.

This is activated by changes in blood pressure detected by baroreceptors I the aortic arch and carotid sinuses?

baroreceptor reflex

How does the stroke volume increase during exercise despite a shorter time available for the heart chambers to fill with blood?

because the venous return is aided by the improved action of the skeletal muscle pumps and by increased respiratory movements of the diaphragm during exercise

Baroreceptors are most sensitive to drops in ___?

blood pressure

This is affected by blood volume/stroke volume, total peripheral resistance, and cardiac rate

blood pressure

These stimulate smooth muscle relaxation

bradykinin, nitric oxide, and prostaglandin I2

Which of these statements about interstitial fluid is false? a.It contains the same glucose and salt concentration as plasma. b. It contains a lower protein concentration than plasma. c. Its colloid osmotic pressure is greater than that of plasma. d. Its hydrostatic pressure is lower than that of plasma.

c. Its colloid osmotic pressure is greater than that of plasma.

The greatest resistance to blood flow occurs in a. large arteries. b. medium-size arteries. c. arterioles. d. capillaries.

c. arterioles.

Total blood flow in the cerebral circulation a. varies with systemic arterial pressure. b. is regulated primarily by the sympathetic system. c. is maintained constant within physiological limits. d. increases significantly during exercise.

c. is maintained constant within physiological limits.

The pulse pressure is a measure of a. the number of heartbeats per minute. b the sum of the diastolic and systolic pressures. c. the difference between the systolic and diastolic pressures. d. the difference between the arterial and venous pressures.

c. the difference between the systolic and diastolic pressures.

The volume of blood pumped per minute by the left ventricle is a. greater than the volume pumped by the right ventricle. b. less than the volume pumped by the right ventricle. c. the same as the volume pumped by the right ventricle. d. either less or greater than the volume pumped by the right ventricle, depending on the strength of contraction.

c. the same as the volume pumped by the right ventricle.

The sounds of Korotkoff are produced by a. closing of the semilunar valves. b. closing of the AV valves. c. the turbulent flow of blood through an artery. d. elastic recoil of the aorta.

c. the turbulent flow of blood through an artery.

Hypertension can increased risk of ?

cardiac diseases, kidney diseases, and stroke

The volume of blood pumped each minute by each ventricle

cardiac output

Arterial blood pressure =

cardiac output x total peripheral resistance

What is the formula for cardiac output? -average heart rate? -average stroke volume? -average cardiac output?

cardiac output= stroke volume x heart rate -70bpm -70-80 ml/beat -5,500 ml/minute

This is primarily controlled by intrinsic mechanisms and is relatively constant; cannot tolerate variation in blood flow

cerebral flow

What activates sympathetic vasoconstriction of the skin

cold temperatures

This is due to proteins dissolved in fluid

colloid osmotic pressure

Veins have a high ___; stretch more at a given pressure than arteries

compliance

Strength of ventricular contraction; how does this relate to stroke volume

contractility -increased contractility, increased stroke volume

this is primarily controlled by extrinsic mechanisms and shows the most variation; can handle low rates of blood flow

cutaneous flow

Which of these is a paracrine regulator that stimulates vasoconstriction? a. Nitric oxide b. Prostacyclin c. Bradykinin d. Endothelin-1

d. Endothelin-1

Which of these organs is able to tolerate the greatest reduction in blood flow? a. Brain b. Heart c. Skeletal muscles d. Skin

d. Skin

An increase in blood volume will cause a. a decrease in ADH secretion. b. an increase in Na+ excretion in the urine. c. a decrease in renin secretion. d. all of these.

d. all of these.

In the absence of compensations, the stroke volume will decrease when a. blood volume increases. b. venous return increases. c. contractility increases. d. arterial blood pressure increases.

d. arterial blood pressure increases.

Angiotensin II a. stimulates vasoconstriction. b. stimulates the adrenal cortex to secrete aldosterone. c. inhibits the action of bradykinin. d. does all of these.

d. does all of these.

Vasodilation in the heart and skeletal muscles during exercise is primarily due to the effects of a. alpha-adrenergic stimulation. b. beta-adrenergic stimulation. c. cholinergic stimulation. d. products released by the exercising muscle cells.

d. products released by the exercising muscle cells.

Local vasodilation is controlled by changes in: (6)

decreased oxygen concentrations from increased metabolism -increased co2 -decreased tissue pH -release of K+ and paracrine signals -reactive hyperemia -active hyperemia

These two events cause arteriole dilation of the cerebral circulation:

decreased pH of CSF -active neurons release K+, adenosine, NO and other chemicals

How is mean arterial pressure calculated

diastolic pressure + 1/3 pulse pressure

Blood pressure is lowest in a. arteries. b. arterioles. c. capillaries. d. venules. e veins.

e veins.

Edema may be caused by a. high blood pressure. b. decreased plasma protein concentration. c. leakage of plasma protein into the interstitial fluid. d. blockage of lymphatic vessels. e. all of these.

e. all of these.

Volume of blood in the ventricles at the end of diastole; also called ____; how does this effect stroke volume?

end diastolic volume -preload -increased EDV, increase stroke volume

What is essential hypertension? Secondary?

essential- a result of complex and poorly understood processes secondary- a symptom of another disease like kidney disease

what causes an increase in plasma osmolarity?

excessive salt intake; dehydration

Myogenic regulation: when blood pressure __ , cerebral vessels automatically __. and vice versa

falls, dilate

Fluid movement is proportional to:

fluid out - fluid in

What structure in the kidneys filters fluid to form urine?

glomeruli

What is felt when taking a pulse?

heart rate: increased blood pressure in that artery at systole

what causes Edema? (6)

high arterial blood pressure -venous obstruction -leakage of plasma proteins into interstitial space -myxedema -decreased plasma protein concentration obstruction of lymphatic drainage

What is hypertension

high blood pressure

Blood flows from ____ pressure to _______ pressure

higher; lower

What causes the opening of the HCN channels at the end of the preceding action potential

hyperpolarization

Where is ADH produced? Released? When is it stimulated? what does it do?

in the hypothalamus; posterior pituitary; when osmoreceptors detect increased plasma osmolality ; stimulates water reabsorption

This causes constriction of vessels of the cerebral circulation:

increased pH of CSF

What may be involved in causing essential hypertension

increased salt intake -increased sympathetic nerve activity -responses to paracrine regulators from endothelium -increased total peripheral resistance

What does atrial natriuretic peptide do?

increases excretion of salt and water from kidneys to reduce blood volume

What is used by some organs to promote constant blood flow when there is fluctuation of blood pressure? What's another name for this?

intrinsic regulation; autoregulation

Why is the mean arterial pressure significant?

it is the difference between mean arterial pressure and venous pressure that drives the blood into the capillaries

What organ can control blood volume and, in effect, stroke volume?

kidneys

Contraction of the myocardium squeezes the coronary arteries so, blood flow in the coronary vessels is ____ during systole than diastole

less

Treatments for hypertension (6)

lifestyle modification: limit salt intake, limit smoking and drinking, lose weight, exercise -K+ supplements -diuretics to increase urine formation -beta blockers to decrease cardiac rate -ACE inhibitors to block angiotensin II production -angiotensin II receptor blockers inhibit actions of angiotensin II

How does the Renin-angiotensin-aldosterone system work?

low blood pressure stimulates the kidneys to secrete renin, renin converts angiotensinogen to angiotensin I, angiotensin I is converted to angiotensin II by angiotensin converting enzyme (ACE)

What is the average pressure in the arteries in one cardiac cycle?

mean arterial pressure

cardiac tissue has lots of __ and ____ ___ making it very metabolically active.

mitochondria, and respiratory enzymes

Intrinsic Control of contraction strength: -due to ________ stretch -increased ___ stretches the myocardium which increases contraction strength -due to increased ____ and ___ overlap and increased sensitivity to Ca2+ in cardiac muscle cells -increased __________ resistance will _________ stroke volume -more blood will remain in ventricles so _______ increases -ventricles are stretched more with increased ____ so they ___ more strongly

myocardial -EDV -myosin, actin -peripheral; decrease -EDV - EDV, contract

vascular smooth muscle responds to changes in arterial blood pressure

myogenic control mechanisms

________ _____ _______ decreases the rate of pace EX:

negative chronotropic effect -parasympathetic acetylcholine

The sympathetic nerve fibers release what to stimulate vasoconstriction ; which in turn raises vascular resistance at rest

norepinephrine

Sympathetic control of blood flow?

norepinephrine released to smooth muscles of arterioles of skin to stimulate vasoconstriction; blood is diverted to skeletal muscles during 'fight or flight' -adrenal epinephrine - beta adrenergic receptors for vasodilation

This opens K+ channels and slows the heart rate

parasympathetic acetylcholine

____ ______ _____ increases the rate of pace EX:

positive chronotropic effect -

While veins may hold more blood than arteries they maintain a lower?

pressure

What is the difference between blood pressure at systole and at diastole?

pulse pressure

How is septic shock produced?

septic shock is a dangerously low blood pressure that may result from bacteria entering the blood circulation

Stretch receptors in the aortic arch and carotid sinus a. stimulate secretion of atrial natriuretic peptide. b. serve as baroreceptors that affect activity of the vagus and sympathetic nerves. c. serve as osmoreceptors that stimulate the release of ADH. d. stimulate renin secretion, thus increasing angiotensin II formation.

serve as baroreceptors that affect activity of the vagus and sympathetic nerves.

What organ can tolerate the greatest fluctuations in blood flow?

skin

What is the instrument used to measure an instrument

sphygmomanometer

Pulse pressure is a reflection of __ ____

stroke volume

These keep the HCN channels open, and increase heart rate

sympathetic norepinephrine and adrenal epinephrine

How does hyperventilation cause dizziness?

the arterial CO2 falls below normal and the vessels constrict

How do blood pressure cuffs work?

the cuff is inflated to beyond systolic blood pressure to pinch off an artery, as pressure is released, the first sound is heart at systole and reading is taken

The rate of blood flow is proportional to:

the differences in pressure

what is edema?

the excessive accumulation of interstitial fluids

What is the role of the sympathetic nervous system on the kidneys?

the kidney arterioles dilate, increasing blood flow and increasing urine production in order to decrease blood volume

At high pressure, vasoconstriction occurs in the brain, why?

to protect small vessels from damage and stroke

What factors affect venous return?

total blood volume and venous pressure

How is cardiac output distributed to different organs? Why?

unequally; unequal resistance to blood flow

There is little sympathetic control to blood flow to the brain unless what?

unless mean arterial pressure becomes very high

How does the skin keep heat in the body when ambient temperatures are low

vasoconstriction of arterioles

Angiotensin II has many effect to raise blood pressure: -__________ of small arteries and arterioles to _______ peripheral resistance -stimulates ______ center in hypothalamus -stimulates production of _______ in adrenal cortex

vasoconstriction, increase -thirst -aldosterone

Intrinsic metabolic controls enhance what during exercise

vasodilation

This is stimulated by both adrenal epinephrine and sympathetic acetylcholine

vasodilation

How does atrial natriuretic peptide regulate blood volume?

when the atria stretch due to high volume, salt and water excretion in urine is promoted, ADH secretion is inhibited

When is the last korotkoff sound and what is the average blood pressure ?

when the pressure in the cuff reaches diastolic pressure ; 120/80

What are the values of hydrostatic pressure -at arteriole end; venue end -interstitial fluid What about net filtration pressure at arteriole end and venule end?

- 37mmHg; 17mmHg -1mmHg -36mmHg; 16mmHg


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