Flashcards in Chapter 20 Deck (234)
Vessel walls are compose of 3 ___ (layers) surround a lumen
opening through a vessel
the inner most layer of a blood vessel
tunica interna (intima)
This tunic is composed of an inner enothelium (simple squamous ET)
tunica interna (intima)
This tunic is surrounded by the sub-enothelium (areolar CT)
tunica interna (intima)
The middle layer or tunic of the blood vessel
this layer of the blood vessel is composed of smooth muscle
the outtermost layer of the blood vessel
this layer of the blood vessel is composed of dense irregular connective tissue
Very large vessels contain blood flow to tunica externa through a network of small arteries called the ___.
Arteries have thicker tunica ____, veins have thicker tunica _____.
Veins have a larger ___ than arteries and contain valves.
Arteries contain more collage and elastic fibers and so can withstand a higher range of ______.
blood pressure (40-100 mm Hg)
Veins can withstand a blood pressure from __ to ___ mm Hg.
_____ are strong, elastic vessels adapted for carrying blood away from the heart under high pressure.
The largest arteries are called ___. or ______.
elastic or conducting arteries
Elastic arteries contain large amounts of elastic fibers through ____.
all three tunics
Elastic arteries allow for stretching of arteries during _____ and recoiling during ______.
The elastic arteries include the aorta, pulmonary trunk, brachiocephalic, common carotid, subclavian, and ____ arteries.
common iliac arteries
Lumen diameters of elastic arteries range from 2.5 to ___ centimeter.
Elastic arteries branch into ____ arteries.
Muscular arteries are also called ____ arteries because the distribute blood to specific body regions and organs.
Muscular arteries have thicker tunica ___.
In muscular arteries the elastic fibers are confined to two Circumscribed sheets: _____ and _____.
internal elastic lamina
external elastic lamina
separates the tunica media from the tunica intima
internal elastic lamina
separates the tunica media from the tunica externa
external elastic lamina
A relatively greater amount of muscle gives muscular arteries a greater ability to _____ and ______ than elastic arteries.
vasoconstrict and vasodate
Muscular arteries include the brachial, anterior tibial, and ____.
The lumen diameter range of muscular arteries is ___ to ___.
1 centimeter to 0.3 millimeters
The smallest of the arteries are _______.
Arterioles are not ____.
The lumen diameter of arterioles range from 0.3 millimeters to ____ micrometers
Larger arterioles contain all three tunics with very little smooth muscle while the smallest arterioles contain just a ____ and a single layer of _____ around it.
Smooth muscle in arterioles are always contracted slightly causing ______.
Arterioles play a significant role in blood pressure regulation and _____
_____ connect arterioles to venules, 1 mm in length and only 8-10 micrometers in diameter.
There are three types of capillaries: continuous, fenestrated, and ____.
The most common type of capillaries
Continuous capillaries contain a continuous _____ layer and basement membrane.
Continuous capillaries have ____ between cells that allow for small substances (glucose, ion, amino acids) to move between blood plasma and tissues.
____ capillaries are found in muscle, skin, lungs, and CNS.
____ capillaries are composed of continuous endothelial lining and basement membrane, but the endothelial cells contain fenestrations (pores)
Fenestrated capillaries allow for small plasma proteins to move between plasma and _____.
Fenestrated capillaries allow for greater fluid transport between blood and ___ fluid.
Fenestrated capillaries are found in the _____ and assist in nutrient absorption.
Fenestraed capillaries are found in the ___ of eye an assist in aqueous humor production.
Fenestrated capillaries are found in the ____ of the brain in CSF production.
choroid plexus of the brain
Fenestrated capillaries are found in the ___ .
Fenestrated capillaries are found in the ____ and help filter blood.
___ capillaries are also called discontinuous capillaries.
Sinusoid capillaries have an ____ endothelial lining with large openings and either no basement membrane or a _____ one.
____ capillaries allow for larger substances (such as formed elements) between blood plasma and tissues.
Sinusoid capillaries are found in ____, the liver, and spleen, and _____.
red bone marrow
some endocrine glands
Capillaries do not function independently; rather, a group of capillaries (10 to 100) function together and form a ____.
A capillary bed is fed by a _____, a branch from arterioles and are continuous with venules by way of a thoroughfare channel.
True capillaries branch from _____.
Blood flow into true capillaries is controlled by _____ located between the metarteriole and the capillaries.
The precapillary sphincters go through cycles of contracting and relaxing at a rate of about 5 to 10 cycles per minute. These cycles process is called ____.
____ are vessels which are adapted to carrying blood back to the heart under low pressure.
Capillaries merge to form ___.
The smallest of veins are called ____ and have lumen in diameter ranging from 8-100 micrometers.
Venules are companions with ____.
Venules merge to form small to medium sized veins which merge to form _____.
Small/medium veins companion with ____ arteries (have similar structure).
Large veins companion with _____ (have similar structure).
Why do arteries contain more collagen and elastic fibers than veins?
to be able to withstand a greater amount and variance of blood pressure
The flow from elastic arteries to large veins.
What type of blood vessel has the greatest influence on blood pressure?
Valves in the veins have anatomic structure similar to ____ valves.
The largest percentage of blood, 70%, is within the ____ circulation.
55% of blood distribution at rest is found in the ____.
systemic veins (blood reservoirs)
At rest __% of blood is found within the pulmonary circulation.
At rest ___% of blood found within the heart.
Venoconstriction shifts blood in systemic veins back into circulation when needed such as ___.
Simple pathways contain only one artery, called an ___, one capillary bed, and one vein. (spleen)
_______ pathways contain various pathway combinations which include differing number of arteries, capillary beds, and veins.
Three types of alternative pathways are designated as _____ (the joining together of blood vessels) One type is designated as the ____.
Two or more arteries converging to supply one body region
i.e. superior/inferior gastric or coronary arteries
Two or more veins draining one body region
i.e. basilic, brachial, and cephalic
carry blood from artery directly to vein
arteriovenous anastomosis (shunts)
i.e. fingers, toes, palms, ears
blood flows through two capillary beds connected by portal vein
Two coronary anastomosis
right and left coronary arteries
The coronary artery that feeds lateral wall of right ventricle and posterior wall of both ventricles
right coronary artery
The coronary artery that feeds lateral wall of left ventricle and anterior wall of both ventricles
left coronary artery
The coronary arteries form an arterial anastomosis but more accurately, due to the fact the arteries do not cover the same areas of the heart, they form _______.
functional end arteries
____ is the narrowing or occluding of coronary arteries
Atherosclerosis (coronary artery disease)
____ is the pain in the chest, arm, shoulder from decreased blood supply to the heart.
____ results from sudden and complete occlusion of a coronary artery causing death of heart tissue due to lack of blood supply.
Myocardial infarction (heart attack)
Symptoms of a heart attack include: angina pectoris, weakness, shortness of breath, nausea, vomiting, anxiety, and ____.
When a coronary artery is narrowed or blocked, nearby arteries can branch out to carry blood to teh area this affected
When a coronary artery is narrowed and collateral circulation occurs it might let ____ recover and function properly if done quickly enough.
____ cannot regenerate, thus scar tissue fills teh damaged area (instead of muscle) if blood flow is not restored quickly)
_____ surgically inserts a vein to allow oxygenated blood to bypass teh occluded artery and reach teh affect myocardium
coronary bypass surgery
Blood is drained from the digestive organs and spleen into a ___, which takes the blood to the liver before it drains to the inferior vena cava.
hepatic portal vein
The hepatic portal system allows the ___to process blood coming from digestive organs before it returns to the heart and is pumped to the rest of the body. (rids blood of harmful substances such as alcohol, and toxins)
The hepatic portal system allows the liver to recycle components of the ____ broken down in the spleen.
The hepatic portal system has three branches: splenic vein, ___ vein, and ___ vein.
All three branches (splenic, inferior/superior mesenteric) plus the ___ veins drain into the hepatic portal vein.
Hepatic portal vein takes the blood to the liver, blood then drains from the liver through hepatic veins to the _____.
inferior vena cava
___ vein brings oxygen and nutrient rich blood from the placenta through the ductus venosus, past the liver, to the IVC, where the ____ blood mixes with the _____ blood. Then the SVC an IVC empty into the right atrium. Due to the lungs not being functional, blood pressure in teh right side of the heart is greater than the ____ side.
In fetal circulation, high blood pressure in the right side of the heart causes most of the blood to be ___ from the right atrium to the left atrium through the ____ and then into the left ventricle where it is then pumped in to the aorta. Blood that made it to the right ventricle (didn't go through the foramen ovale) is pumped into the pulmonary trunk where the blood is then shunted into teh aorta through the ____.
The aorta carries mixed blood to teh body. Within the body, fetal vessels contain many ___, directeing blood away from organs not yet functional to function organs. Deoxygenated blood returns to the _____ through umbilical arteries.
Postnatal Circulation Changes:
Babies first breath drops the pulmonary pressure, allowing ____ to dilate.
Postnatal Circulation Changes:
Pressure on the right side of heart deceases, as pressure on left side of heart increases, leading to ____.
Postanatal Circulation Changes:
All fetal cardiovascular structures turn into ligaments except the foramen ovale, which turns into the _____.
The postnatal structure for the ductus arteriosus
The postanatal structure for ductus venosus
The postnatal structure for foramen ovale
The postnatal structure for umbilical arteries
medial umbilical ligaments
The postnatal structure for umbilical vein
round ligament of liverligamentum teres
Why is the pressure greater on the right side of the fetal heart but greater on the left side after birth?
Blood can’t flow into closed vessels to the lungs thus right side of heart harder to pump blood (blood has to go through one of two shunts to get to the aorta).
Birth causes the opening of the pulmonary blood vessel with the first breath, decreasing how hard the right side has to pump, putting the pressure now on the left side to pump the blood to the body.
____ area is the diameter of vessel's lumen.
____ area estimates the lumen diameters in all of a single type of vessel (artery, capillary)
Total cross-sectional area and blood flow velocity have an ____ relationship
Increasing cross-sectional area ___ blood flow velocity (less pressure)
Functional significance to slower rate of blood flow through capillaries
In capillary exchange oxygen, some hormones and nutrients move by ____ from the blood (higher) into the interstitial fluid (lower)
In capillary exchange carbon dioxide and wastes ___ from tissues (higher) back into teh blood (lower)
In capillary exchange certain hormones (such as insulin) and fatty acids, transported from blood to interstitial fluid (or vice versa) through ____.
uses pinocytosis to move substance from one side of endothelial cell to other side
the movement of large amounts of fluids and tehir dissolved substances in one direction down a pressure gradient.
is the movement of fluid, by bulk flow, out of the capillary and into the interstitial fluid (occurs on arterial end of capillary)
Reabsorption is the movement of fluid, by bulk flow, into the blood from the interstitial fluid (occurs on venous end of capillary)
Not all fluid filtered out gets reabsorbed, leaving fluid in tissues…
The physical force exerted by a fluid on a structure
force exerted by blood against vessel wall
Blood hydrostatic pressure (HPb)
force of interstitial fluid on external surface of blood vessel
Interstitial fluid hydrostatic pressure (HPif)
HPb promotes filtration from ____
The ‘pull’ of water into an area by osmosis due to the higher concentration of solutes
colloid osmotic pressure
force that draws fluid back in to the blood due to proteins in blood (opposed HPb)
blood colloid osmotic pressure
~ force that draws fluid back into the interstitial fluid due to solute concentration
Intersitial fluid colloid osmotic pressure
COPb promotes ______
Difference between the net hydrostatic pressure and the net colloid osmotic pressure.
NFP = (HPb – HPif) – (COPb – COPif)
(+) results indicate filtration (fluids from blood to tissue)
(-) results indicate reabsorption (fluids from tissue to blood)
When total cross-sectional area increases, what happens to blood flow velocity? Which blood vessel has the greatest TCA?
It decreases (slows), capillaries
What's the difference between filtration and absorption?
Filtration is the movement of fluid and ions OUT of the blood
Reabsorption is the movement of fluid and ions INTO the blood
Hydrostatic pressure promotes __________ while colloid pressure promotes ___________.
What does this equation tell you?
NFP = (HPb – HPif) – (COPb – COPif)
How much net filtration or net reabsorption occurred between a particular tissue and the blood
The process by which a tissue itself, regulates or controls its local blood flow, in response to its changing metabolic needs
If a tissue is not receiving enough blood:
Oxygen and nutrient levels _____ in the tissue.
Carbon dioxide, lactate, H+ and K+ levels ____ in the tissue. Changes in these concentrations act as local vasodilators on the __________opening capillaries to the affected tissue
~ local blood flow is restored to the affected tissue, but with a marked increase in blood flow
Additional blood required to resupply oxygen and nutrient levels and rid tissue of wastes
The force per unit area that blood exerts against the inside wall of a vessel
Blood pressure changes from one end of the blood vessel to the other
blood pressure gradient
BP highest in _____, as heart is forcing blood into arteries with each ventricular contraction
BP lowest in ____, as blood flow velocity decreases as it goes through the capillaries
maximal stretching of arteries due to ventricular systole
maximal recoil of arteries, occurs during ventricular diastole
A normal blood pressure reading
amount of pressure change between ventricular relaxation and contraction
Measure of the elasticity and recoil of arteries
systolic bp - diastolic bp
pulse presse less than 40 mm Hg
poor heart function
pulse pressue of 40 mm hg
pulse pressure greater than 60 mm Hg
~ average measure of the blood pressure forces on the arteries
Mean arterial pressure
MAP = Diastolic BP + 1/3 Pulse pressure
Mean arterial pressure provides a numberical value for how well body tissues and organs are ____.
Diastolic BP lasts ___ than systolic BP
MAP of 60 or lower
insufficient blood flow
MAP of 70 - 110
MAP of 110 or high
too much blood flow and causes edema
What does pulse pressure measure?
The elasticity and recoil of the arteries
______ Assists in the movement of blood within limbs
skeletal muscle pump
_______ contract, squeezing blood through the veins and towards the heart
Exercise utilizes the ____ to get blood back to heart more quickly and efficiently
skeletal muscle pump
inactivity causes blood ____ in leg veins leading to deep vein thrombosis (DVT, blood clots within veins)
____ can be fatal if embolus breaks off and ends up inlungs
Assists movement of blood within thoracic cavity
Diaphragm contracts as we ____, expanding the thoracic cavity. This causes the intrathoracic pressure to ____, allowing blood vessels to open
Flattening of diaphragm compresses the abdominopelvic cavity ____ intra-abdominal pressure. This squeezes the abdominal vessels, moving the blood up to the _____.
Diaphragm relaxes when we ____, compressing thoracic cavity. This causes intrathoracic pressure to increase causing compression of ______ to empty into the heart
Abdominopelvic cavity _____, decreasing intra-abdominal pressure
This allows abdominal veins to _____ and fill from legs and organs.
Amount of friction the blood experiences as it is transported through the blood vessels
Peripheral resistance is affect by blood vessel radius, _____ and _____.
blood vessel length
thickness of blood
Greater blood viscosity leads to ___ resistance to flow
An anemic person has ____ viscosity thus a ____ resistance.
Longer vessels ___ resistance.
Greater friction fluid experiences as it travels through ___ vessels.
Gaining weigh ___ vessel length causing ___ resistance.
Greater vessel ___ leads to less resistance to flow
Vasoconstriction and dilation occur in all vessels, but the most influential is in teh ______ and ___.
muscular arteries and arterioles
size of lumen - has the biggest influence on peripheral resistance
blood vessel radius
Blood vessels are only innervated by the ____ division of the ANS.
Vasoconstriction/ dilation are dependent upon receptors in ____ of teh tunic media.
smooth muscle cells
Name four hormones that regulation blood pressure.
Angiotensin II, Aldosterone, ADH, ANP
Which three hormones decrease urine output?
Angiotensin II, Aldosterone, ADH
Which hormone increases urine output?
Which hormone is released from the heart?
What is needed to convert angiotensinogen into angiotensin I? And where is it produced?
Renin, in the kidneys
Vasocontriction/dilation dependent upon receptors in smooth muscle cells of _______.
Receptors are specific to their location of blood vessels in body..
_____receptors cause vasoconstriction in response to NE. _____ receptors cause vasodilation in response to EPI.
Activation of sympathetic division causes increased peripheral resistance, larger circulating blood volume, and ______.
redistribution of blood flow
more blood vessels constricted than dilated increasing blood pressure
increased peripheral resistance
venoconstriction increases venous return to heart thus increasing blood pressure
larger circulating blood volume
greater flow to heart and skeletal muscles
redistribution of blood flow
____ is the amount of blood that moves through the cardiovascular system per unit time. It is influenced by both blood pressure gradient and peripheral resistance.
total blood flow
total blood flow =
MAP / Resistance (of blood as it moves through vessels)
Blood flow is directly related to the pressure gradient. Pressure gradient _____, blood flow increases.
Blood flow is indirectly related to peripheral resistance. Resistance _______, blood flow decreases.
Increased cardiac output increases the ________, thus increases blood flow (directly related).
Vasodilation _______ peripheral resistance, thus increasing blood flow (indirectly related).
Decreased ______ decreases the pressure gradient, thus decreases blood flow.
Vasoconstriction _____ peripheral resistance, thus decreasing blood flow.
What's the difference between the skeletal muscle pump and the respiratory pump?
Skeletal muscle pump is the contraction/relaxation cycle of the muscles that moves the blood through the venous system
Respiratory pump is the changing pressures within the thoracic and abdominal cavities that moves the blood through the venous system
What are the three things that effect peripheral resistance?
Blood viscosity, blood vessel length and radius
Blood vessels are only controlled by the ___________ division of the ANS.
Beta-2 receptors cause ____________ while alpha-1 receptors cause ______________.
If cardiac output increased, what would happen to total blood flow?
It would increase
If peripheral resistance is increased due to clogged blood vessels, what would happen to total blood flow?
It would decrease
Why is total blood flow important?
It effects how quickly our body cells can receive nutrients and oxygen needed for energy production and growth. As well as riding the body cells of wastes which can build up and cause electrolyte or acid/base imbalances
Blood pressure must be high enough to maintain adequate perfusion of all ___.
Regulation of blood pressure is cardiac output, peripheral resistance and _____.
Regulation of blood pressure is controlled in the short term by the ____.
Regulation of blood pressure is controlled in the long term by the ________.
Sensory receptors that respond to stretch (as in the blood vessel walls)
Two main baroreceptors located in tunica externa of the ______and carotid sinuses (internal carotid artery).
Aortic arch receptors transmit signal to cardiovascular center (in medulla oblongata) through the ____.
Carotid sinus receptors transmit signal through _______ nerve
Activated response to changes in stretch of the blood vessel wall. Leads to increased blood pressure.
If blood pressure_____ baroreceptors decrease frequency of nerve signals to cardiovascular center.
If blood pressure _____ signals thru sympathetic pathways increase and decrease thru parasympathetic pathways. Leads to increased blood pressure.
If blood pressure _____ HR and SV increase = increase in CO, vasoconstriction increases peripheral resistance as well as venous return. Leads to increased blood pressure.
if blood pressure _____ Baroreceptors increase frequency of nerve signals to cardiovascular center. Leads to decreased blood pressure.
If blood pressure _____ signals thru sympathetic pathways decrease and increases thru parasympathetic pathways. Leads to decreased blood pressure.
If blood pressure ____ HR and SV decrease = decreases CO, vasodilation decreases peripheral resistance and shifts more blood into the venous reservoirs. Leads to decreased blood pressure.
Although ____ are more important in regulating respiration, are also secondarily involved in regulating blood pressure.
When ____ are stimulated, they initiate chemoreceptor reflexes. (negative feedback loops)
The two main chemoreceptors are the _____ located int eh arch of the aorta and and carotid body located at the bifurcation of the common carotid arteries.
Chemoreceptors send the aortic signal through CN X and carotid signals through ____.
Chemoreceptors are stimulated by increased ___ levels, decreased pH or very decreased ___ levels.
Once chemoreceptors are stimulated increase frequency of stimulation to vasomotor centers which ___ signals to sympathetic pathways. Blood vessels constrict causing increase resistance and more blood entering the circulation from the venous reservoirs
This causes increased blood pressure, which increases blood flow to lungs with allows for an increase in respiratory gas exchange
Liver produces angiotensinogen (inactive hormone) constantly
Kidneys releases renin (enzyme) when blood pressure is low
Renin converts angiotensinogen to angiotensin I
Angiotensin I is then converted to angiotensin II by angiotensin-converting enzyme (ACE) (found in high concentrations in the pulmonary capillary endothelium)
Functions of ANgiotensis II
Decreases urine formation
Stimulates release of aldosterone and antidiuretic hormone
Released from adrenal cortex
Increases absorption of sodium and water in kidney
Released from posterior pituitary
Increases absorption of water in kidneys, stimulates thirst center, in extreme cases can cause vasoconstriction
Antidiuretic hormone (ADH)
Angiotensin II, aldosterone and ADH ____ urine output to maintain blood volume and blood pressure
Angiotensin II and ADH (in high doses) _____ resistance and blood pressure