BIO 360 - Exam 3 - Chapter 15 Summary Questions Flashcards
Blood flow through the cardiovascular system is an excellent example of ______ ______ in the body. Cardiac contraction creates high pressure in the ventricles, and this pressure drives blood through the vessels of the systemic and pulmonary circuits, speeding up cell-to-cell ______. Resistance to flow is regulated by ______ and ______ ______ ______ that act on arteriolar smooth muscle and help match tissue perfusion to tissue needs.
What is the homeostatic baroreceptor reflex?
Capillary exchange of material between the plasma and interstitial fluid compartments uses several transport mechanisms, including ______, ______, and ______ ______.
mass flow / communication / local / reflex control mechanisms
monitors arterial pressure to ensure adequate perfusion of the brain and heart.
diffusion, transcytosis, bulk flow
Homeostatic regulation of the cardiovascular system is aimed at?
maintaining adequate blood flow to the brain and heart.
Total blood flow at any level of the circulation is equal to the ______ ______.
cardiac output
Blood vessels are composed of layers of smooth muscle, elastic and fibrous connective tissue, and ______.
endothelium
______ ______ ______ maintains a state of muscle tone.
Vascular smooth muscle
The walls of the aorta and major arteries are both stiff and springy. This property allows them to?
AE
absorb energy and release it through elastic recoil
______ regulate blood flow through capillaries by contraction and dilation of p______ s______.
Metarterioles / precapillary sphincters.
______ and ______ ______ are the site of exchange between blood and interstitial fluid.
Capillaries / postcapillary venules
______ hold more than half of the blood in the circulatory system. Why?
Veins / Veins have thinner walls with less elastic tissue than arteries, so veins expand easily when they fill with blood.
______ is the process by which new blood vessels grow and develop, especially after birth.
Angiogenesis
The ventricles create high pressure that is the driving force for blood flow. The ______ and ______ act as a pressure reservoir during ______ ______.
aorta / arteries / ventricular relaxation
Blood pressure is highest in the ______ and decreases as blood flows through the circulatory system. At rest, desirable ______ ______ is 120 mm Hg or less, and desirable ______ ______ is 80 mm Hg or less.
arteries / systolic pressure / diastolic pressure
Pressure created by the ventricles can be felt as a ______ in the arteries. Pulse pressure equals..
pulse / systolic pressure minus diastolic pressure.
Blood flow against gravity in the veins is assisted by what two things?
(1) one-way valves
(2) respiratory and skeletal muscle pumps
Arterial blood pressure is indicative of the driving pressure for blood flow. Mean arterial pressure (MAP) is defined as
diastolic pressure +1/3 (systolic pressure - diastolic pressure)
Arterial blood pressure is usually measured with a sphygmomanometer. Blood squeezing through a compressed artery makes ______ sounds.
Korotkoff
Arterial pressure is a balance between ______ ______ and ______ ______, the resistance to blood flow offered by the arterioles.
cardiac output / peripheral resistance
If blood volume ______, blood pressure ______. If blood volume ______, blood pressure ______.
increases / increases / decrease / decrease
Venous blood volume can be shifted to the ______ if arterial blood pressure falls.
arteries
Arterioles regulate their own blood flow through my______ a______.
What two things does vasoconstriction do?
myogenic autoregulation
(1) increases the resistance offered by an arteriole
(2) decreases the blood flow through the arteriole
What is active hyperemia and reactive hyperemia?
Active hyperemia is a process in which increased blood flow accompanies increased metabolic activity.
Reactive hyperemia is an increase in tissue blood flow following a period of low perfusion.
Most systemic arterioles are under ______ ______ control.
______ causes ______.
Decreased sympathetic stimulation causes ______.
tonic sympathetic / Norepinephrine / vasoconstriction / vasodilation
Epinephrine binds to arteriolar ______ and causes ______.
Epinephrine on ______ found in the arterioles of the heart, liver, and skeletal muscle, causes ______.
a-receptors / vasoconstriction
b-receptors / vasodilation
Changing the resistance of the arterioles affects ______ ______ ______ and alters blood flow through the arteriole.
mean arterial pressure
The flow through individual arterioles depends on their resistance. How?
The higher the resistance in an arteriole, the lower the blood flow in that arteriole.
The reflex control of blood pressure resides in the ______ ______. ______ in the carotid artery and the aorta monitor arterial blood pressure and trigger the ______ ______.
medulla oblongata / Baroreceptors / baroreceptor reflex.
Efferent output from the medullary cardiovascular control center _________________.
Increased sympathetic activity _______________.
Increased parasympathetic activity _________________.
Increased sympathetic discharge at the arterioles ______ ______.
There is no significant parasympathetic control of arterioles.
goes to the heart and arterioles.
increases heart rate and force of contraction.
slows heart rate.
causes vasoconstriction.
Cardiovascular function can be modulated by input from higher brain centers and from the respiratory control center of the medulla.
The ______ ______ functions each time a person stands up. The decrease in blood pressure upon standing is known as o______ h______.
baroreceptor reflex / orthostatic hypotension
Exchange of materials between the blood and the interstitial fluid occurs primarily by ______.
diffusion
______ ______ have leaky junctions between cells but also transport material using transcytosis. Continuous capillaries with tight junctions form the ______- ______ ______.
Continuous capillaries / blood-brain barrier
______ ______ have pores that allow large volumes of fluid to pass rapidly.
Fenestrated capillaries
The velocity of blood flow through the capillaries is slow, allowing diffusion to go to equilibrium.
The mass movement of fluid between the blood and the interstitial fluid is ______ ______. Fluid movement is called ______ if the direction of flow is out of the capillary and ______ if the flow is directed into the capillary.
bulk flow / filtration / absorption
The osmotic pressure difference between plasma and interstitial fluid due to the presence of plasma proteins is the ______ ______ ______.
colloid osmotic pressure.
About 3 liters of fluid filter out of the capillaries each day. The lymphatic system returns this fluid to the circulatory system.
Lymph capillaries accumulate fluid, interstitial proteins, and particulate matter by bulk flow. Lymph flow depends on smooth muscle in vessel walls, one-way valves, and the skeletal muscle pump.
What is edema?
The condition in which excess fluid accumulates in the interstitial space is called edema. Factors that disrupt the normal balance between capillary filtration and absorption cause edema.
______ ______ is the leading cause of death in the United States. Risk factors predict the likelihood that a person will develop cardiovascular disease during her or his lifetime.
Cardiovascular disease
______ is an inflammatory condition in which fatty deposits called plaques develop in arteries. If plaques are unstable, they may block the arteries by triggering blood clots.
Atherosclerosis
______ is a significant risk factor for the development of cardiovascular disease.
Hypertension
