Chapter 20 Flashcards
Vessel walls are compose of 3 ___ (layers) surround a lumen
tunic
opening through a vessel
lumen
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
tunica media
this layer of the blood vessel is composed of smooth muscle
tunica media
the outtermost layer of the blood vessel
tunica externa
this layer of the blood vessel is composed of dense irregular connective tissue
tunica externa
Very large vessels contain blood flow to tunica externa through a network of small arteries called the ___.
vasa vasorum
Arteries have thicker tunica ____, veins have thicker tunica _____.
media
externa
Veins have a larger ___ than arteries and contain valves.
lumen
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.
0-20
_____ are strong, elastic vessels adapted for carrying blood away from the heart under high pressure.
elastic arteries
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 ______.
ventricular systole
ventricular diastole
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.
1
Elastic arteries branch into ____ arteries.
muscular
Muscular arteries are also called ____ arteries because the distribute blood to specific body regions and organs.
distributing
Muscular arteries have thicker tunica ___.
media
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 ____.
coronary arteries
The lumen diameter range of muscular arteries is ___ to ___.
1 centimeter to 0.3 millimeters
The smallest of the arteries are _______.
arterioles
Arterioles are not ____.
named
The lumen diameter of arterioles range from 0.3 millimeters to ____ micrometers
10
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.
tunica interna
smooth muscle
Smooth muscle in arterioles are always contracted slightly causing ______.
vasomotor tone
Arterioles play a significant role in blood pressure regulation and _____
blood flow
_____ connect arterioles to venules, 1 mm in length and only 8-10 micrometers in diameter.
Capillaries
There are three types of capillaries: continuous, fenestrated, and ____.
sinusoid
The most common type of capillaries
continuous
Continuous capillaries contain a continuous _____ layer and basement membrane.
endothelial
Continuous capillaries have ____ between cells that allow for small substances (glucose, ion, amino acids) to move between blood plasma and tissues.
gaps
____ capillaries are found in muscle, skin, lungs, and CNS.
Continuous
____ capillaries are composed of continuous endothelial lining and basement membrane, but the endothelial cells contain fenestrations (pores)
fenestrated capillaries
Fenestrated capillaries allow for small plasma proteins to move between plasma and _____.
tissues
Fenestrated capillaries allow for greater fluid transport between blood and ___ fluid.
interstitial
Fenestrated capillaries are found in the _____ and assist in nutrient absorption.
small intestines
Fenestraed capillaries are found in the ___ of eye an assist in aqueous humor production.
ciliary process
Fenestrated capillaries are found in the ____ of the brain in CSF production.
choroid plexus of the brain
Fenestrated capillaries are found in the ___ .
endocrine glands
Fenestrated capillaries are found in the ____ and help filter blood.
kidneys
___ capillaries are also called discontinuous capillaries.
sinusoid
Sinusoid capillaries have an ____ endothelial lining with large openings and either no basement membrane or a _____ one.
incomplete
discontinuous
____ capillaries allow for larger substances (such as formed elements) between blood plasma and tissues.
sinusoid
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 ____.
capillary bed
A capillary bed is fed by a _____, a branch from arterioles and are continuous with venules by way of a thoroughfare channel.
metarterioles
True capillaries branch from _____.
metarterioles
Blood flow into true capillaries is controlled by _____ located between the metarteriole and the capillaries.
precapillary sphincters
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 ____.
vasomotion
____ are vessels which are adapted to carrying blood back to the heart under low pressure.
veins
Capillaries merge to form ___.
venules
The smallest of veins are called ____ and have lumen in diameter ranging from 8-100 micrometers.
venules
Venules are companions with ____.
arterioles
Venules merge to form small to medium sized veins which merge to form _____.
large veins
Small/medium veins companion with ____ arteries (have similar structure).
muscular arteries
Large veins companion with _____ (have similar structure).
elastic arteries
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.
elastic arteries muscular arteries arterioles capillaries venule small/medium veins large veins
What type of blood vessel has the greatest influence on blood pressure?
arterioles
Valves in the veins have anatomic structure similar to ____ valves.
semilunar valve
The largest percentage of blood, 70%, is within the ____ circulation.
systemic
55% of blood distribution at rest is found in the ____.
systemic veins (blood reservoirs)
At rest __% of blood is found within the pulmonary circulation.
18%
At rest ___% of blood found within the heart.
12%
Venoconstriction shifts blood in systemic veins back into circulation when needed such as ___.
exercise
Simple pathways contain only one artery, called an ___, one capillary bed, and one vein. (spleen)
end artery
_______ pathways contain various pathway combinations which include differing number of arteries, capillary beds, and veins.
Alternative
Three types of alternative pathways are designated as _____ (the joining together of blood vessels) One type is designated as the ____.
anastomoses
portal system
Two or more arteries converging to supply one body region
arteriole anastomosis
i.e. superior/inferior gastric or coronary arteries
Two or more veins draining one body region
venous anastomosis
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
portal system
i.e. liver
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.
angina pectoris
____ 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 ____.
increased sweating
When a coronary artery is narrowed or blocked, nearby arteries can branch out to carry blood to teh area this affected
collateral ciruculation
When a coronary artery is narrowed and collateral circulation occurs it might let ____ recover and function properly if done quickly enough.
myocytes
____ cannot regenerate, thus scar tissue fills teh damaged area (instead of muscle) if blood flow is not restored quickly)
myocytes
_____ surgically inserts a vein to allow oxygenated blood to bypass teh occluded artery and reach teh affect myocardium
coronary bypass surgery
