Which layer of the typical blood vessel is constructed from simple squamous epithelium? |
tunica intima |
Which layer of the typical vessel can be regulated via vasoconstriction or vasodilation? |
tunica media |
What is the outermost layer of the blood vessel wall for an artery or vein? |
tunica externa |
The aorta is an example of a(n) __________. |
elastic artery |
What type of tissue is found in the walls of the arteries but not in the walls of capillaries and venules? |
elastic tissue |
Which capillaries are the most common in the body? |
Continuous capillary |
Which of the following is NOT an important source of resistance to blood flow? |
total blood volume |
Calculate mean arterial pressure (MAP) if systolic blood pressure is 120 mm Hg and diastolic blood pressure is 70 mm Hg. |
87 mm Hg |
What blood vessel experiences the steepest drop in blood pressure? |
arterioles |
The pulse pressure is ________. |
systolic pressure minus diastolic pressure |
Factors that aid venous return include all except ________. |
urinary outpu |
Why is it important that blood pressure drop to lower levels as it reaches the capillary beds? |
Because capillaries are fragile and extremely permeable |
What is the value for the net filtration pressure (NFP) at the arteriolar end of the capillary? |
10 mm Hg |
Assume a person is experiencing a hemorrhage and the HPc has dropped to 23 mm Hg at the arteriole end of the capillary. Calculate net filtration pressure (NFP) at the arteriole end of the capillary. |
-2 mm Hg |
The adjustment of blood flow to each tissue in proportion to its requirements at any point in time is termed autoregulation. |
True |
In the capillaries, hydrostatic pressure (HP) is exerted by __________. |
blood pressure |
The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________. |
capillary, interstitial fluid |
Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary? |
34 mm Hg |
The colloid osmotic pressure in the capillary is caused by __________. |
proteins in the blood |
Which net pressure draws fluid into the capillary? |
b. net osmotic pressure |
Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary? |
venous |
Which vessel leaves the right ventricle of the heart to take oxygen-poor, dark red blood into pulmonary circulation? |
pulmonary trunk |
Which vessel(s) return(s) oxygenated blood to the left atrium of the heart to complete the pulmonary circuit? |
pulmonary vein |
Which vessel(s) of the pulmonary circuit transport(s) oxygen-rich blood? |
pulmonary veins |
From what artery does the right common carotid artery arise? |
brachiocephalic trunk |
Which artery branches off the subclavian arteries? Select from letters A-D. |
posterior auricular vein |
Which vein is the longest in the body and empties into the femoral vein? |
Great Saphenous vein. |
Blood from the lower limbs is returned to the heart via the _______ |
Inferior Vena Cava |
tunic media |
*smooth muscle cells and sheets of elastin |
vasoconstriction |
Decrease in the diameter of blood vessels |
vasodilation |
A widening of the diameter of a blood vessel. |
vasa vasorum |
A network of small blood vessels that supply large blood vessels |
3 layers of arteries, veins, and capillaries |
tunica intima tunic media tunic externa |
tunica intima |
Endolthelium * internal elastic membrain |
tunic externa |
elastic and collagen fiber covering, contains nerves(sympathetic ans) |
elastic arteries |
Arteries closest to the heart *Largest in diameter ranging in 2.5 cm to 1 cm * present in all three tunics but the most in tunic media * help hart pump blood |
Venous system |
*Veins carry blood toward hart |
arterial system |
carries blood away from the heart |
muscular arteries |
Also called distribution arteries *delivers blood to specific body organs *toward capularys has less elasticity * supply's blood to hart and brain |
arterioles |
* smallest arteries *range in size from 0.3 mm down to 10 um *tunic media is the chief smooth muscle with a few scattered elastic fibers |
capillaries |
* smallest blood vessels *, A tiny blood vessel that allows an exchange of oxygen, carbon dioxide, and nutrients between blood and cells in tissue |
three types of capillaries |
continuous, fenestrated, sinusoidal |
continuous capillaries |
Most common - skin, muscle |
intercellular clefts |
gaps of unjoined membrane *small holes most permeable |
blood brain barrier |
*small capillary in the brain that keep out everything except oxygen and nutrience *protect the brain |
fenestrated capillaries |
*oval pores large holes * permeable to fluid and small solutes then continues capillary are |
sinusoid capillaries |
*massive pores *Found in the liver, bone marrow, spleen, and medulla high permeability *allow large molecules and even blood cells to pass blood and tissue *produce or eliminate red blood cells |
sphincter open |
blood flows through true capillaries |
sphincter closed |
blood flows through metarteriole-thoroughfare channel and bypasses true capillaries |
capillary beds |
Interwoven networks of capillaries form the microcirculation between arterioles and venules |
venules |
Capillaries merged together *range from 8-100 in diameter *carry blood to the hart |
postcapillary venules |
smallest venules, composed of endothelium and a few pericytes |
veins are called |
capacitance vessels blood reserviors |
capacitance vessels |
the term for veins because they have the ability to stretch. they have a large diameter and are more distensible to hold more blood. this reduces stress on the heart. |
blood reserviors |
systemic veins that serve as storage depots for blood that can be moved to other parts of the body if needed *35% blood in arteries |
venous valves |
*found in lower limbs (legs) *tortuous and dilated because of incompetent (leaky) valves |
varicose veins |
Abnormally swollen veins that lost elasticity & cause decrease blood flow |
hemorrihoids |
inflamation of the anus; caused by pregnancy, aging and intercourse |
venous sinuses |
-flattened, dilated veins that serve as a channel for blood, lymph or CS *around the brain acts as a reserve and maintains blood pressure *supported by tissue that surrounds them *blood draining from the brain tough dura |
vascular anastomoses |
*around joints and supply's to joints organs receive blood from more than one arterial branch and arteries supply |
blood flow |
the volume of blood flowing through a vessel , an organ, or the entire circulation *picks up oxygen |
blood pressure |
Force exerted by blood in the arteries |
resistance |
opposition to flow and is a measure of the amount of friction blood encounters as it passes through vessels |
blood viscosity |
*resistance from flow of blood The internal resistance to flow that exists in all fluids and is related to the thickness or "stickiness" of a fluid. |
total blood vessel length |
*smaller the vessel more blood pressure rises the longer the vessel, the greater the resistance to flow |
blood vessel diameter |
changes frequently and significantly alters peripheral resistance, fluid close to wall flow slower than fluid in the center |
arterial blood pressure |
the measure of the pressure exerted by the blood as it pulsates through the arteries *how much elastic arteries close to the hart strech * volume of blood force into them at any time |
systolic pressure |
Pressure in artery blood flow * pressure in the aorta is higher than the pressure in the more distal vessels |
diastolic pressure |
Blood pressure that remains between heart contractions. *hart is relaxed |
pulse pressure |
*PULSE PRESSURE=diastolic-systolic the difference between diastolic and systolic pressure |
Mean arterial pressure |
MAP *diastolic usually last longer than systole MAP=diastolic pressure+(pulse pressure/3) |
capillary blood pressure |
Most very permeable, so low pressure forces filtrate into interstitial spaces |
venous blood pressure |
changes little during cardiac cycle, small pressure gradient about 15 mm Hg, low pressure due to cumulative effects of peripheral resistance |
three functional adaptations critically important to venous return |
muscular pump respiratory pump sympathetic venoconstriction |
muscular pump |
contraction of skeletal muscles "milk" blood toward the heart and valves prevent backflow |
respiratory pump |
Helps move blood back to heart, Pressure changes from breathing squeeze veins, move blood towards heart |
sympathetic venoconstriction |
Reduces the volume of blood in the veins layer of smooth muscle around the veins constrict under sympathetic control |
cardiac centers |
found in the medulla (brain stem) * controls hart rate and motor centers control blood pressure |
cardiovascular center |
medulla oblongata helps regulate heart rate and stroke volume |
baroreceptor reflexes |
*more blood vessels stretched the faster they go *blood pressure rises *located in the carotid sinuses *provide major blood supply to brain |
chemoreceptor reflexes |
*sends messages to the medulla of how many chemicals are in the blood (harder/faster) *carbon dioxide rises and PH falls or oxygen contents of the blood drop sharply *in aortic arch and large arteries that send impulses to the cardioaccerertory center * blood pressure rises and speed the blood to the hart and lungs |
caratid |
pulse location that can be taken on neck |
aortic bodies |
Name the stretch receptors located in the aortic arch: |
adrenal medulla hormones |
norepinephrine and epinephrine increase blood pressure |
angiotensin II |
1. stimulates the secretion of aldosterone and ADH *increase in blood pressure |
aterial natriuretic peptide |
ANP *released in atria * drop in blood pressure |
antiduretic hormones |
ADH *stimulate water conservation by the kidneys |
direct renal mechanism |
alters blood volume independently of hormones |
indirect renal mechanism |
blood pressure drops from hemerage *regulated by kidneys *kidneys release renin into blood *liver converts angiotensin I > ACE converts to angiotensin II (stablives blood) |
aldosterone |
"increases Na re absorption at expense of K secretion" |
basil dilation |
contract |
arterial tunic |
*main site for histological specialization in arteries *made of smooth muscle and elastic connective tissue *smallest capillary |
capillaries |
*deliver oxygen and nutrient to cell tissue * rid carbon dioxide and waste *go to every cell and tissue |
hyperventilation |
Breathing faster and deeper than necessary reduces carbon dioxide concentration resulting in respiratory alkalosis |
respiratory alkalosis |
Always due to hyperventilation, Deficiency is respiration such as slow or irregular shallow respirations can lead to an excessive accumulation of carbon dioxide in the blood which results in a condition called.. |
respiratory acidosis |
Decreased hydrogen (in PH) and below normal carbon dioxide (PCO2) level |