What are 2 main circulations?
the circulation that runs from the heart to the lungs, back to the heart?
what is the long loop to all parts of the body and back to the heart?
Do arteries carry blood towards or away from the heart?
veins carry blood, toward or away from the heart?
What do capillaries do?
contact tissue cells and directly serve cellular needs
what type of blood do veins carry in the pulmonary circulation?
what type of blood do veins carry in the systemic circulation?
what type of blood do arteries carry in the systemic circulation?
what type of blood do arteries carry in the pulmonary circulation?
what are the three layers of veins and arteries?
tunica intima, tunica media, and tunica externa
what is a lumen?
central blood containing space
what are capillaries?
endothelium with sparse basal lamina
what is the most internal layer of an artery or vein called?
what type of tissue lines the lumen of all vessels in the tunica intima?
what type of texture lines the tunica media?
smooth muscle and sheets of elastin
what controls vasoconstriction and vasodilation of vessels in the tunica media?
sympathetic nerve fibers
what type of fibers line the tunica externa?
what is another name for the tunica externa?
what are the 3 types of arteries?
what type of artery has large thich walls with elastin in all three tunics?
what are the smallest arteries?
what leads to cappilary beds?
what is the name of microscopic blood vessels?
capillaries allow how many RBC to pass through at a time?
a single RBC
capillaries are found in all tissues except for what?
cornea and lens of eye
what are the functions of capillaries?
exchange of gases, nutrients, wastes, hormones and etc
what are the 3 structural types of capillaries?
which type of capillarie is abundant in skin and muscles?
which type of capillary is the most permeable?
where are sinusoidal capillaries found in?
liver, bone marrow and spleen
what type of capillary is found in the endocrine glands, kidneys and small intestines?
what has thinner walls, but larger lumens?
is blood pressure lower in arteries or veins?
what are known as the blood reservoirs?
how much blood do the veins contain?
what causes resistance of blood flow?
total blood vessel length
blood vessel diameter
what are the 2 constant factors of resistance?
blood vessel length
which type of blood pressure is more accurate?
what is the unit of measurement for blood pressure?
what is blood pressure?
force per unit area exerted on the wall of a blood vessel by the blood.
(how much pressure blood puts on vessel)
why is resistance more important in influencing local blood flow?
because it is easily changed by altering blood vessle diameter
what is systemic blood pressure?
the pumping action of the heart generates blood flow
systemic pressure is highest where?
what is the mmHg in the right atrium?
where does the steepest drop occur in systemic blood pressure?
systemic pressure declines throughout what?
what type of cooperation is needed to maintain blood pressure?
coperation of the heart, blood vessels and kidneys. Also needs supervision by the brain.
what 2 factors come into play with the arterial blood pressure of the arteries close to the heart?
elasticity (compliance or distensibility)
volume of blood forced into them at any time.
blood pressure nea the heart is?
systolic pressure is pressure exerted during ventricular __________.
diastolic pressure is __________ level of arterial pressure.
pulse pressure is what?
difference between systolic and diastolic pressure.
what is mean arterial pressure?
MAP- pressure tha tpropels the blood to the tissues.
how do you figure up MAP?
MAP= diastolic pressure + 1/3 pulse pressure.
pulse pressure and MAP _________ with increasing distance from the heart.
what is the range of capillary blood pressure?
15-35 mm Hg
high blood pressure in capillaries cause what?
would rupture fragile, thin walled capillaries.
Are capillaries permeable?
most are permeable.
Why are most capillaries permeable?
low pressure forces filtrate ito interstitial spaces.
Which type of blood pressure changes little during the cardiac cycle?
venous blood pressure
what is the pressure gradient of venous blood pressure?
small pressure gradient of about 15 mm Hg
what is the pulse?
pressure wave caused by the expansion and recoil of arteries.
what type of pulse is routinely used?
radial pulse (taken at wrist)
how is systemic arterial blood pressure measured?
measured indirectly by the ausculatory method usig a sphygmomanometer.
pressure is increased in the cuff until it exceeds systolic pressure in the brachial artery.
what is the examiner of blood pressure listening for when he is releasing pressure and listening with a stethoscope?
when sounds disappear when the artery is no longer constricted and blood is flowing freely, this is known as what?
blood pressyre cycles over a __ period?
24 hour period
when do BPs peak?
in morning due to levels of hormones
what factors can help determine blood pressure?
age, sex, weight, race, mood, and posture may vary blood pressure.
what is hypotension?
low blood pressure
what is the range of systolic pressure for hypotension?
systolic below 100 mm Hg
what is hypotension often associated with?
long life and lack of cardiovascular illness
what is orthostatic hypotension?
temporary low blood pressure and dizziness when suddenly rising from sitting or reclining position.
chronic hypotension is a hint of what 3 things?
poor nutrition, Addison's disease or hypothyroidism.
what is an important sign of circulatory shock?
what are 3 transient adaptations of blood pressure?
fever, physical exertion and emotional upset
what are secondary hypertension factors?
identifiable disorders, including kidney disease
endocrine disorders such as hyperthyroidism and cushing's syndrome.
what is blood flow involved in? (5)
delivery of oxygen and nutrients, removal of wastes from tissue cells, gas exchange (lungs)
absorption of nutrients(digestive tract)
the rate of low is prescisely what?
the right amount to provide for proper function.
velocity of blood flow changes as it travels through the systemic circulation. (true or false)
Blood flow is the ______ in the aorta, _______ in the capillaries, increases again in veins.
slow capillary flow allows what?
adequate time for exchange between blood and tissues.
what happens during ventricular systole? (3)
coronary vessels are compressed, myocardial blood flow ceases and stored myoglobin supplies sufficient oxygen.
at rest, control is probably ______?
coronary vessles dilate in response to local accumulation of vasodilators during when?
when does blood flow increase up to 3-4 times the normal rate?
during strenuous exercise
blood flow through capillaries is known as what?
what is vasomotion?
slow and intermittent flow (because of the small size of capillaries)
what does vasomotion reflect?
the on/off opening and closing of precapillary sphincters