Chapter 19 Blood Vessel Mastering A&P

A pregnant patient comes into a clinic and asks about a small dark bulge that is becoming more apparent on her leg. What is it and what caused it? An aneurysm, caused by a weakening of the vein due to chronic hypertension or arteriosclerosis. Phlebitis, which is typically caused by a bacterial infection or physical trauma. Hemorrhoids. The growing fetus puts downward pressure on the veins of the groin and restricts the return of blood to the heart, causing the valves in the peripheral veins to begin to fail. A varicose vein. The growing fetus puts downward pressure on the vessels of the groin and restricts the return of blood to the heart, causing the valves in the peripheral veins to begin to fail.

A varicose vein. The growing fetus puts downward pressure on the vessels of the groin and restricts the return of blood to the heart, causing the valves in the peripheral veins to begin to fail.

Due to the branching of arteries the type of arteries that would be most numerous would be ________. muscular arteries arterioles pulmonary arteries elastic arterie

Arterioles

How would an attack by a mugger affect blood pressure? What is the physiological basis for your answer? Blood pressure would decrease due to parasympathetic nervous system stimulation. Blood pressure would increase due to parasympathetic nervous system stimulation. Blood pressure would increase due to vagal nerve stimulation. Blood pressure would increase due to sympathetic nervous system stimulation. Blood pressure would decrease due to sympathetic nervous system stimulation.

Blood pressure would increase due to sympathetic nervous system stimulation.

Which of the following is likely during vigorous exercise? The skin will be cold and clammy. Blood flow to the kidneys increases. Capillaries of the active muscles will be engorged with blood. Blood will be diverted to the digestive organs.

Capillaries of the active muscles will be engorged with blood.

The outermost layer of a blood vessel is the tunica intima. T/F

False

Vasodilation is a widening of the lumen due to smooth muscle contraction. T/F

False

Which of the following is not true regarding fenestrated capillaries? Fenestrated capillaries form the blood-brain barrier. Fenestrated capillaries in endocrine organs allow hormones rapid entry into the blood. Fenestrated capillaries are essential for filtration of blood plasma in the kidney. Fenestrated capillaries in the small intestine receive nutrients from digested food.

Fenestrated capillaries form the blood-brain barrier.

A precapillary sphincter is a cuff of smooth muscle that regulates the flow of blood into the capillaries. T/F

True

The term ductus venosus refers to ________. a condition of the aged in which the arteries lose elasticity a special fetal vessel that allows umbilical blood to bypass the liver damage to the valves in the veins, leading to varicose veins a fetal shunt that bypasses the lungs

a special fetal vessel that allows umbilical blood to bypass the liver

Which of the following is the most significant source of blood flow resistance? blood vessel diameter blood viscosity blood vessels type total blood vessel length

blood vessel diameter

The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following? a decrease in oxygen levels an increase in oxygen levels changes in arterial pressure a decrease in carbon dioxide

changes in arterial pressure

Blood from the lower limbs drains into the __________ before returning to the heart. thoracic aorta inferior vena cava abdominal aorta superior vena cava

inferior vena cava The inferior vena cava returns blood from the lower limbs to the heart.

Cerebral blood flow is regulated by ________. ADH skin temperature intrinsic autoregulatory mechanisms the hypothalamic "thermostat"

intrinsic autoregulatory mechanisms

Which of the following would experience a decreased blood flow during exercise? skeletal muscles skin kidneys brain

kidneys The kidneys and the GI tract (i.e. the stomach and intestines) would have a decreased blood flow during exercise.

Which of the following is characteristic of veins but not arteries? elastic membranes larger internal diameter large muscular tunic vasa vasorum

larger internal diameter Veins have larger internal diameters than similar sized arteries.

Which of the following would take the longest time to regulate blood pressure? chemoreceptor-initiated reflexes renal regulation baroreceptor-initiated reflexes hormonal control of peripheral resistance

renal regulation Renal mechanisms mediate the long-term control of blood pressure by counteracting fluctuations in blood pressure by altering blood volume. For example, if blood pressure is too low, more water will be reabsorbed to the blood from the kidney, thus increasing blood volume and blood pressure.

The most permeable capillaries, which contain fenestrations and large intercellular clefts, are __________. sinusoid capillaries fenestrated capillaries arterioles continuous capillaries

sinusoid capillaries Sinusoid capillaries are the most permeable type of capillary due to large intercellular clefts among their endothelial cells. These capillaries allow large molecules--even blood cells--to pass into the surrounding tissue. Sinusoid capillaries are found in the liver, bone marrow, spleen, and adrenal medulla.

Factors that aid venous return include all except ________. pressure changes in the thorax urinary output venous valves activity of skeletal muscles

urinary output