Chapter 19 (Lecture) Flashcards by Abby Hassett

hardening of the arteries

arteriosclerosis

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deposition of material in the walls of arteries to form plaques

atherosclerosis

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causes of atherosclerosis

wearing out over time, pathological due to smoking, high cholesterol, fat consumption, autoimmune disease, genetics

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made up of endothelia and a basement membrane of CT
blood flows smoothly along this layer

tunica intima

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the middle layer, contains smooth muscle arranged circularly for regulating blood flow
can be regulated to constrict or dilate the lumen
supplied with sympathetic nerve endings (exception being clitoris and penis)

tunica media

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decreases blood supply

vasoconstriction

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increases blood supply

vasodilation

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have thicker walls than veins due to more smooth muscle
carry blood away from the heart
have more elasticity

arteries

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classes of arteries

elastic
muscular
arterioles

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blood containing space of the blood vessel

lumen

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a system of tiny blood vessels that nourish the more external tissues of the blood vessel wall

vasa vasorum

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the volume of blood flowing through a vessel or organ

blood flow

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the force per unit area that blood exerts on a vessel

blood pressure

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opposition to flow in a blood vessel
most important effector of both blood pressure and flow

resistance

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change in blood pressure / resistance

blood flow equation

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factors that impact flow and pressure

blood viscosity
blood vessel length
blood vessel diameter

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how to calculate blood vessel diameter

R = 1/(r)^4

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what anastamose to form brachocephalics

subclavians and internal jugulars

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supplies the ascending the transverse colons, and most of the small intestine

superior mesenteric artery

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supplies the descending and sigmoid colons and rectum

inferior mesenteric artery

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paired branches of the abdominal aorta

renal
suprarenal
gonadal
iliacs

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unpaired branches of the abnominal aorta

celiac trunk
mesenteric

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composed of blood from two different sources: internal carotids and vertebrals

circle of willis

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all systemic arteries can be traced back to

the left ventricle

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true or false: arteries run superficial and deep

false ## Footnote arteries only run deep

which pathways are more interconnected and variable

venous pathways

which systems have distinct drainage systems

brain and digestive system

causes vasoconstriction

excess oxygen and nutrients

contains the endothelium (made up of simple squamous epithelium)

tunica intima

inhibits fibrinolysis by competing w/ plasminogen and may contribute to the formatin of atherosclerotic plaques

lipoprotein

a vessel that is an intermediate between the arteriole and the capillary bed

metarteriole

reduction in the lumen diameter of a blood vessel as the smooth muscle contracts

vasoconstriction

thick-walled, large vessels near the heart that conduct blood continuously away from the heart

elastic arteries

smallest of the vessels that lead into capillary beds

arterioles

smaller vessels that distribute blood to specific body organs

muscular arteries

vessel layer that has a direct role in vasoconstriction

tunica media

what is the correct sequence of layers in the vessel wall from outside to inside

tunica externa --> tunica media --> tunica intima

which vessels have a tunica media with relatively more smooth muscle than elastic tissue, and an elastic membrane on each face of the tunica media

muscular arteries

which blood vessels have the proportionally thickest tunica media of all vessels

distributing arteries

which layer of the artery wall is regulated by the sympathetic nervous system and many hormones

middle layer

blood flows directly from .... into capillary beds

arterioles

the endothelium is composed of

simple squamous epithelium

prefix meaning blood vessels

vaso-

prefix meaning osmosis or osmotic

osmo-

prefix meaning layer of tissue

tunic-

prefix pertaining to hair

capill-

prefix meaning artery

arterio-

innermost layer of blood vessels made of endothelial tissue

tunica intima

blood flow into a capillary bed is regulated by

the precapillary sphincter

reduction in the diameter of a blood vessel is called ... and typically results in ...

vasoconstriction; an increase in blood pressure

the pressure of nondiffusable molecules pulling water to them

colloid osmotic pressure

small arteries that are dilated or constricted to control peripheral resistance, and thus blood pressure

arterioles

only found in arteries to help absorb the shock of the heartbeat and return the vessel to its natural size

elastic membranes

supply the lungs

pulmonary blood vessels

* supply all of the body except the lungs * are distensible * contain a large proportion of the blood volume

systemic veins

why are veins called capitance vesses or blood reservoirs

because they contain can hold more blood than corresponding arteries

pathway of capillaries

1. terminal arteriole 2. metaarteriole 3. postcapillary venule

types of capillaries

* continuous capillary * fenestrated capillary * sinusoid capillary

* least permeable in most common * abundant in skin, muscles, and CNS * intercellular clefts between endothelial cells (exception in the brain) * pinocytotic vesicles

continous capillary

* have large fenestrations (pores) that increase permeability * occur in areas of active filtration or absorption, and areas of endocrine hormone secretion

fenestrated capillary

* the most permeable capillaries that occur in limited locations (liver, bone marrow, spleen, and adrenal medulla) * have large intercellular clefts, fenestrations, few gap junctions, incomplete basement membranes * irregularly shaped, have larger lumens than other capillaries * allow large molecules to pass through

sinusoid capillary

what happens when the precapillary sphincters open

blood flows through true capillaries

what happens when the precapillary sphincters are closed

blood flows through the metarteriole--throroughfare channel and bypasses true capillaries

factors that impact blood flow and blood pressure

* blood viscosity * blood vessel length * blood vessel diameter

resistance is caused by

vasoconstriction and vasodilation mainly of arteries

what units are blood pressure measured in

mmHg

what unit is blood flow measured in

mL/min

how do we calculate total resistance in the body

Cardiac Output = BP / R

true or false: systemic blood pressure drops over distance from the heart

true

pulse pressure (PP) =

systolic BP - diastolic BP

mean arterial pressure =

diastolic pressure (DP) + (pulse pressure / 3)

why is mean arterial pressure highly skewed

to reflect that the heart spends more time in diastole than in systole

why does mean arterial pressure vary

depends on whether you are sitting, standing, or reclining

most systemic capillaries have an arterial pressure between

35-45 mmHg

* is due to fluid pressing against a wall * "pushes" fluid out of capillary into interstitial fluid and vice versa

hydrostatic pressure (HP)

by the time blood is returned to veins it has a blood pressure between

5-15 mmHg

how is it possible for venous return to equal cardiac output?

* structural modifications * respiratory pump * muscular pump * gravity

change in blood pressure =

cardiac output x resistance

when the ventricles contract (~120 mmHg)

systolic bp

when the heart relaxes (~80 mmHg)

diastolic bp

systemic blood pressure is normally

120/80 mmHg

why is the difference in presures necessary

to keep moving from areas of higher to lower pressure

aortic pressure =

100 mmHg

arterial capillary pressure =

30 mmHg

as blood travels farther from the heart,

its flow is greater and its pressure drops

if resistance goes down,

blood flow increases

if resistance goes up,

blood flow decreases

* very superficial on the medial side of the leg and empties into the femoral vein * often used as a graft in coronary artery bypass grafts (CABG)

greater saphenous vn

superficial vein on the lateral side of the leg

small saphenous vn.

superficial veins of the lower limb

* greater saphenous vn * smaller saphenous vn

deeper veins of the lower limb

* digital veins * venous arches * fibular, anterior and posterior tibial vein * femoral vein * external iliac vein

venous pathway of the deeper lower limb veins

1. digital veins 2. venous arches 3. fibular, anterior and posterior tibial vein 4. femoral vein 5. external iliac vein

hepatic veins empty into

the inferior vena cava

a specialized vascular system that begins and ends with a capillary bed

portal system

which veins join to form the hepatic portal vein

mesenteric veins, gastric veins, and splenic veins

drains blood from the small and large intestines, pancreas, spleen, and stomach

hepatic portal vein

what happens to blood when it is in the liver sinusoids

it detoxifies and removes nutrients before releasing the blood via the hepatic veins

what does the ascending lumbar veins empty into

the hemiazygos vein

what are the paired veins of the abdomen and where do they empty into

* renals, gonadals, adrenals * empty into ivc

what is the pelvis drained by

internal iliac (joins common iliac and forms IVC)

which two veins join on the posterior of the chest wall and empty into the SVC

azygos and hemiazygos veins

the site of blood draws

median cubital vein

venous pathway of the superficial veins of the upper limb

1. cephalic 2. median cubital vein 3. basilic vein 4. axillary vein 5. subclavian vein

venous pathway of the deep veins of the upper limb

1. radial and ulnar veins 2. brachial veins 3. axillary vein 4. subclavian vein

venous pathway of the hand

1. digital veins 2. palmar arches 3. basilic vein 4. axillary vein 5. subclavian vein

drains posterior head and neck superficially and empties into subclavian veins

external jugular veins

left and right drain into the SVC

brachiocephalic veins

join the subclavians to form the brachiocephalic veins

internal jugular veins

drain into internal jugulars

venous sinuses

drain blood from the heart wall

cornonary sinus

drain the abdomen, pelvis, and lower limbs

inferior vena cava

drain the head, neck, thorax, upper limbs

superior vena cava

when is pressure created

when flow is opposed by resistance

peak pressure generated by ventricular contraction

systolic bp

resting pressure of blood in the arteries when the ventricles relax

diastolic bp

what is the MAP in large arteries

~90-93 mmHg

by the time blood reaches the terminal arterioles the pressure has dropped to

35-45 mmHg due to resistance

what would too high of a pressure do to thin capillary membranes

damage

blood pressure pushing filtrate out

hydrostatic pressure

arteries are primarily named for

the regions they serve

when the external iliac crosses the inguinal line, it becomes

the femoral artery

arterial pathway of the lower limb

1. femoral artery 2. popliteal artery 3. ant. and post. tibial artery 4. fibular artery

the anterior tibial artery becomes what on the dorsum of the foot

dorsal pedis artery

the common iliacs become

the internal and external iliacs

become the arteries of the lower limb

external iliac artery

supplies the pelvic organs, bladder, and rectum

internal iliac artery

the abdominal aorta terminates as

the right and left common iliac arteries

unpaired branches of the abdominal aorta

celiac trunk (hepatic a., gastric a., and splenic a.), and mesenterics

supply blood to the intestines

superior and inferior mesenteric arteries

branches of the thoracic aorta

* bronchial arteries * posterior intercostals

blood pressure ranges from what to what in the venous end of the capillary

0-20 mmHg

what occurs in the venous end of the capillaries

* fluid is returned vial blood colloid osmotic pressure (i.e. oncotic pressure) * very little hydrostatic prssure at this end * about 90% of the plasma that leaves at the arterial end is returned at the venous end

what is the net filtration pressure out of the arterial end

10 mmHg

what is the net filtration pressure into the venous end

-8 mmHg

what are structural modifications to venous blood pressure

large lumens and valves to prevent backflow

what is meant by a respiratory pump in relation to venous blood pressure

abdominal pressure increases during breathing and squeezes veins, forcing blood upward through valves toward the heart

above the heart, what plays an important role in venous return?

gravity

what is meant by the muscular pump in relation to venous blood pressure

as skeletal muscles contract and expand, they squeeze surrounding veins and "milk" the blood up through the valves

hormonal regulators of blood pressure

* adrenal medulla hormones (NE, Epi) * angiotensin II * ADH * ANH * NO

what affect do adrenal hormones (NE, Epi) have on blood pressure

increase blood pressure

what is the effect of angiotensin II on blood pressure

increases blood pressure

what is the effect of ADH

increases water retention and increases blood pressure

what is the effect of ANH

increases water loss and decreases blood pressure

a major vasodilator, mainly in vessels leading to genitalia; localized hormone-like substance, acts as a major vasodilator to decrease BP

nitrous oxide

nervous system regulators of blood pressure

* vasomotor centers * sympathetic innervation of blood vessels * baroreceptors

responsible for smooth motor tone in many blood vessels

vasomotor centers in brainstem

where does blood spend the majority of its time

systemic veins and venules

what will increase tone in most blood vessels

increasing sympathetic output

vasomotor center steps

* brain (vasomotor center) * sympathetic nervous system * vasomotor tone * NE controls tone in most blood vessels

located in arteries near the heart

baroreceptors

what does increased BP cause

parasympathetic stimulation to decrease HR

decreased blood pressure does what

activates sympathetic nerves and increases HR and SV

arterial pathway of the upper limb

1. subclavian a. 2. axillary a. 3. brachial a. 4. radial and ulnar a. 5. superficial and deep palmar arches 6. terminal digital a.

where does the brachial artery bifurcate

above the antecubital fossa

the division of something into two branches or parts

bifurcation

* essentially a backup system composed of internal carotids and vertebrals

circle of willis

right and left vertebrals fuse into the

basilar artery

the basilar artery splits to become the

posterior cerebral arteries

the internal carotids give off what that anastomose with the basilar artery

posterior communicating arteries

the internal carotids also give off the ..., which join the anterior communicating to finish the circle

anterior communicating arteries

splits into the right subclavian, and right common carotid

brachiocephalic trunk

splits into the external and internal carotids

common carotid arteries

supplies superficial face and head

external carotid artery

supplies deeper structures of the head and brain

internal carotid artery

supplies the shoulder and upper arm

subclavian artery

what is the order in which the arteries come off of the aortic arch

1. brachiocephalic 2. left common carotid 3. left subclavian

what is the first branch at the base of the aorta (ascending)

coronary arteries

arteries that extend from the aortic arch

brachiocephalic trunk, left common carotid, left subclavian

abdominal aorta terminates as the

common iliac arteries

branches of the descending aorta

thoracic and abdominal

what causes the kidneys to reabsorb more water and raise volume and pressure

decreased blood pressure and/or blood volume

activates the Renin-angiotensin-aldosterone mechanism

decreased blood pressure and/or blood volume

what is the goal of the renin-angiotensin mechanism

increase blood pressure

an enzyme secreted by the kidneys when blood pressure drops

renin

myogenic regulators of blood flow

* increased stretch (pressure) in blood vessel walls will cause vessels to constrict and reduce flow into a tissue or organ * reduced stretch (pressure) in blood vessel walls will cause vessels to dilate and increase blood flow to an organ

cause a relaxation of precapillary sphincters and increase blood flow to the tissue

increases in vasodilator substances such as CO2, lactic acid, prostaglandins, histamine, nitrous oxide

an extremely powerful vasodilator that is released by many endothelial cells

nitric oxide

cause precapillary sphincters to contract and reroute the blood to other more needy tissues

increases in vasodilators (O2 and endothelins)

tissue perfusion is essential for

* delivery of oxygen to tissues * gas exchange in the lungs * absorption of nutrients in the digestive tract * proper urine formation

during physical activity, blood flow is directed away from which region and goes where

* away from digestive and urinary functions * into skeletal muscles and heart

metabolic factors in blood flow

* increase in vasodilators * increase in vasoconstrictors

renin converts angiotensinogen in the plasma into

angiotensin I

what converts angiotensin I to angiotensin II

ACE (angiotensin converting enzyme) in the lungs

* a powerful vasoconstrictor that raises blood pressure * stimulates aldosterone release by the adrenal glands so that more sodium and water will be reabsorbed in the kidneys, thus increasing BP

angiotensin II

when aldosterone is released,

bp increases

characteristic of veins but not arteries

large internal diameter

# true or false: arteries always carry oxygen-rich blood away from the heart

false

Varicose veins seen in the superficial veins of the legs are unsightly and are often treated by surgical removal. However, even without these veins being present, the return of all blood toward the heart from the legs is not diminished. This is primarily because

blood can still return via the deep veins

As the kidneys filter blood, it is necessary for both fluid and dissolved chemicals in the plasma to be rapidly removed without the removal of larger proteins or cells. Which capillary would be best suited for this filtration

fenestrated capillaries

most common capillaries in the body

continuous capillaries

factors that aid venous return

* venous valves * pressure changes in the thorax * activity of skeletal muscles

what would decrease total peripheral resistance to blood flow

decreasing hematocrit

Blood flow is __...______ proportional to the difference in blood pressure. Blood flow is ____...____ proportional to the total peripheral resistance

directly; inversely

which vessels sustain a drop in pressure from approx 35 mmHg to around 17 mmHg

capillaries

systolic bp - diastolic bp =

pulse pressure

possible consequences of low blood pressure on capillary function

* MAP would not be high enough for adequate capillary exchange to occur * tissues become ischemic because of lack of adequate perfusion

effect of atrial natiuretic peptide (ANP)

decreases bp (decreases blood volume) by reducing sympathetic vasomotor response

# true or false: decreased output from the vasomator center allows arterioles and veins to constrict

false ## Footnote Decreased output from the vasomotor center allows arterioles and veins to dilate (not constrict). The vasomotor center uses the sympathetic nervous system to stimulate contraction of vascular smooth muscle, which results in constriction of arteries (vasoconstriction) and veins (venoconstriction). While increased output from the vasomotor center results in constriction of these vessels, decreased output results in dilation

A muscle that is being regularly contracted during exercise will attract blood flow by dilating arterioles. Which factor would contribute to this effect?

increased levels of CO2

# true or false: osmotic pressure is fairly constant along the entire length of a capillary bed

true

For a special (mesenteric) capillary, each true capillary, where it branches from the metarteriole, is surrounded by a precapillary sphincter. These sphincters are controlled only by

local chemical conditions

expected responses to a drop in MAP

* increased thirst * secretion of aldosterone * release of renin from the kidneys

how would baroreceptor reflexes respond to a fall in blood pressure

vasomotor center would increase sympathetic output to arterial smooth muscle to increase TPR (total peripheral resistance)

which organs experience a decrease in blood flow during exercise

kidneys and GI tract ## Footnote directed toward muscles, heart, and skin

reduction in the concentration of albumin in blood plasma would alter capillary exchange by

decreasing colloid osmotic pressure and edema will occur

which vessels will return oxygenated blood to the left atrium of the heart to complete the pulmonary circuit

pulmonary vein

a blood clot in the first branch of the aorta would affect the blood flow to the

right side of the head and neck and right upper arm

# true or false an obstruction in the SVC would decrease the flow of the blood from the head and neck to the heart

true

# true or false: Arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of its proximity to the heart.

false

the abdominal aorta splits into which vessels

R and L common iliac arteries

* consists of a vein connecting two capillary beds together * its major vesssels are the S. mesenteric, I. mesenteric, and splenic veins * carries nutrients, toxins, and microorganisms to the liver for processing

hepatic portal system

from what artery does the right common carotid arise

brachiocephalic trunk ## Footnote found only on the right side of the body, and it splits to form the right common carotid artery and the right subclavian artery. These two arteries arise independently from the aorta on the left side of the body.

originates on the medial foot and empties into the femoral vein

great saphenous vn

Chapter 19 (Lecture) Flashcards

(215 cards)