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Chapter 21: Blood Vessels and Circulation

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The layer of vascular tissue that consists of an endothelial lining and an underlying layer of connective tissue dominated by elastic fibers is the
tunica interna
Smooth muscle fibers in arteries and veins are found in the
tunica media
One of the major characteristics of the arteries supplying peripheral tissues is that they are
muscular
The only blood vessels whose walls permit exchange between the blood and the surrounding interstitial fluids are
capillaries
One of the primary characteristics of continuous capillaries is that they
prevent the loss of blood cells and plasma proteins
The unidirectional flow of blood in venules and medium-sized veins is maintained by
the presence of valves
The specialized arteries that are able to tolerate the pressure shock produced each time ventricular systole occurs and blood leaves the heart are
elastic arteries
Of the following blood vessels, the greatest drop in blood pressure occurs in the
arterioles
If the systolic pressure is 120mm Hg and the diastolic pressure is 90 mm Hg, the mean arterial pressure (MAP) is
100 mm Hg
The distinctive sounds of Korotkoff heard when taking the blood pressure are produced by
turbulences as blood flows past the constricted portion of the artery
The phenomenon that helps maintain blood flow along the arterial network while the left ventricle is in diastole is
elastic rebound
The most important factor in vascular resistance is
friction between blood and the vessel walls
Two factors that assist the low venous pressures in propelling blood toward the heart are
muscular compression of peripheral veins and the respiratory pump
From the following selections, choose the answer that correctly identifies all the factors that would increase blood pressure
increasing CO, increasing SV, increasing VR, increasing PR, increasing BV
The two major factors affecting blood flow rates are
pressure and resistance
For circulation to occur, the circulatory pressure must be sufficient to overcome the
total peripheral resistance
Atrial natriuretic peptide reduces blood volume and pressure by
blocking release of ADH, stimulating peripheral vasodilation, increased water loss by the kidneys
The circulatory-regulatory mechanisms that can assist in short-term and long-term adjustments are
endocrine responses
The regulatory mechnism that cause immediate, localized homeostatic adjustments is
autoregulation
The central regulation of cardiac output primarily involves the activities of the
autonomic nervous system
An increase in cardiac output normally occurs during
widespread sympathetic stimulation
Stimulation of the vasomotor center in the medulla causes ___________________ and inhibition of the vasomotor center causes _______________
vasoconstriction; vasodilation
Hormonal regulation by vasopressin, epinephrine, angiotensin II, and norepinephrine results in
increasing peripheral vasoconstriction
The three primary interrelated changes that occur as exercise begins are
increasing vasodilation, increasing venous return, increasing cardiac output
The only area of the body where the blood supply is unaffected while exercising at maximum levels is the
brain
The four large blood vessels, two from each lung, that empty into the left atrium, completely the pulmonary circuit, are the
pulmonary veins
The blood vessels that provide blood to capillary networks that surround the alveoli in the lungs are
left and right pulmonary veins
Other than near the heart, the peripheral distributions of arteries and veins on the left and right sides are
generally identical on both sides
As the external iliac artery leaves the body trunk and enters the lower limb, it becomes the
femoral artery
The link between adjacent arteries or veins that reduces the impact of a temporary or permanent occlusion of a single blood vessel is
an anastomosis
The three elastic arteries that originate along the aortic arch and deliver blood to the head, neck, shoulders, and arms are the
brachiocephalic, L. common carotid, left subclavian
The large blood vessel that collects most of the venous blood from organs below the diaphragm is the
inferior vena cava
The three blood vessels that provide blood to all of the digestive organs in the abdominopelvic cavity are the
celiac artery and the superior and inferior mesenteric arteries
The diaphragm divides the descending aorta into
superior thoracic aorta and inferior abdominal aorta
The three unpaired arteries originating from the abodominal aorta are the
L. gastric, splenic, and common hepatic arteries
Except for the cardiac veins, all the body's systemic veins drain into either the
superior or inferior vena cava
Blood from the tissues and organs of the head, neck, chest, shoulders, and upper limbs is delivered to the
superior vena cava
Blood from the lower limbs, the pelvis, and the lower abdomen is delivered to the
external iliac veins
Blood leaving the capillaries supplied by the celiac, superior, and inferior mesenteric arteries flows into the
hepatic portal system
The nutritional and respiratory needs of a fetus are provided by
diffusion across the placenta
In early fetal life, the foramen ovale allows blood to flow freely from the
right atrium to the left atrium
In the adult, the ductus arteriosus persists as a fibrous cord called the
lifamentum arteriosum
A few seconds after birth, rising O2 levels stimulate the constriction of the ductus arteriosus, isolating the
pulmonary and aortic trunks
The primary effect of a decrease in the hematocrit of elderly individuals is
a lowering of the oxygen-carrying capacity of the blood
In the heart, age-related progressive atherosclerosis causes
restricted coronary circulation
The systems responsible for modifying heart rate and regulating blood pressure are the
nervous and endocrine systems
The branches of the popliteal artery are
anterior and posterior tibial arteries
Intraveling from the heart to the peripheral capillaries, blood passes through
elastic arteries, muscular arteries, and arterioles
In general terms, blood flow (F) is directly proportional to
pressure
The goal of cardiovascular regulation is
maintenance of adequate blood flow through the peripheral tissues and organs
Along the length of a typical capillary, blood pressure gradually falls from about
30 to 18 mm Hg
In which of the following organs would you find fenestrated capillaries
filtration areas of the kidneys, absorptive areas of the intestine, endocrine glands
The average pressure in arteries is approximately
100 mm Hg
The effective pressure in the venous system is roughly
16 mm Hg
Net hydrostatic pressure forces water ______ a capillary; net osmotic pressure forces water _____ a capillary
out of; into
Of the following selections, the condition that would have the greatest peripheral resistance is
doubling the diameter of a blood vessel
The relationship F - P/R means
flow is directly proportional to the pressure gradient and inversely proportional to resistance
To increase blood flow to an adjacent capillary, the local controls that operate are
decreasing O2, increasing CO2, decreasing pH
The adrenergic fiber innervating arterioles are ______ fibers that release ______ and cause ______
sympathetic; norepinephrine; vasoconstriction
Two arteries formed by the bifurcation of the brachiocephalic artery are the
common carotid, subclavian
The artery that serves the posterior thigh is the
deep femoral
A major difference between the arterial and venous systems is that
there is dual venous drainage in the limbs
The large vein that drains the thorax is the
azygos vein
The veins that drain the head, neck, and upper extremities are the
brachiocephalics
The veins that drain venous blood from the legs and the pelvis are
common iliacs
The vein that drains the knee region of the body is the
popliteal
The large artery that serves the brain is the
internal carotid
The artery that links the subclavian and brachial arteries is the
axillary
The three arterial branches of the celiac trunk are the
L. gastric, splenic, and hepatic
The artery that supplies most of the small intestine and the first half of the large intestine is the
superior mesenteric
The artery that supplies the pelvic organs is the
internal iliac artery