A&P LECTURE CH. 19-21 LEARNING OUTCOMES

A blockage of which branch of the aortic arch would interfere with blood flow to the left arm?

A blockage of the left subclavian artery would interfere with blood flow to the left arm.

Briefly describe the general patterns of blood vessel organization.

(1) the peripheral distributions of arteries and veins of the body's left and right sides are generally identical except near the heart where the largest vessels connect to the atria or ventricles, ( 2) a single vessel may have several names as it crosses specific anatomical boundaries making accurate anatomical descriptions possible, (3) tissues and organs are usually serviced by several arteries and veins

Neural and endocrine regulatory mechanisms influence which factors?

Neural and endocrine regulatory mechanisms influence heart rate, stroke volume, peripheral resistance, and venous pressure.

Which of these is correct regarding the permeability of a specific capillary type?

Red blood cells are too large to exit any capillary type. Red blood cells normally do not exit a vessel unless it is damaged.

Name the arterial structure in the neck region that contains baroreceptors.

The arterial structure in the neck region that contains baroreceptors is the carotid sinus.

Identify the branches of the external carotid artery.

The branches of the external carotid artery are the superficial temporal, maxillary, occipital, facial, lingual, and external carotid arteries.

Identify two veins that carry blood away from the stomach.

The left and right gastroepiploic veins carry blood away from the stomach.

Identify the major branches of the inferior vena cava.

The major branches of the inferior vena cava are the lumbar, gonadal, hepatic, renal, adrenal, and phrenic veins.

The plantar venous arch carries blood to which three veins?

The plantar venous arch delivers blood to the anterior tibial, posterior tibial, and fibular (personeal) veins.

Describe the distribution of total blood volume in the body.

The systemic venous system and systemic arterial system contains 64 and 13 percent of the total blood volume, respectively. The remaining volume in contained in the heart (7%), pulmonary circulations (9%), and systemic capillaries (7%).

Name the three branches of the internal carotid artery.

The three branches of the internal carotid artery are the ophthalmic, anterior cerebral, and middle cerebral arteries.

Identify the three veins that merge to form the hepatic portal vein.

The three veins that merge to form the hepatic portal vein are the superior mesenteric, inferior mesenteric, and splenic veins.

Name the two arteries formed by the division of the brachiocephalic trunk.

The two arteries formed by the division of the brachiocephalic trunk are the right common carotid artery and the right subclavian artery.

Compare the oxygen content in the two circulatory circuits.

The two circulatory circuits of the cardiovascular system are the pulmonary circuit and the systemic circuit. The pulmonary circuit carries deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium. The systemic circuit carries oxygenated blood to the organs and tissues of the body and returns deoxygenated blood to the right atrium.

Name the two large veins that collect blood from the systemic circuit.

The two large veins that collect blood from the systemic circuit are the superior vena cava and the inferior vena cava.

Identify the two types of capillaries with a complete endothelium.

The two types of capillaries with a complete endothelium are continuous capillaries and fenestrated capillaries.

List the unpaired branches of the abdominal aorta that supply blood to the visceral organs.

The unpaired branches of the abdominal aorta that supply blood to the visceral organs are the celiac trunk, superior mesenteric artery, and inferior mesenteric artery.

Identify the veins that combine to form the brachiocephalic vein.

The veins that combine to form the brachiocephalic vein are the external jugular, internal jugular, vertebral, and subclavian veins.

Calculate the mean arterial pressure for a person whose blood pressure is 125/70.

Using the formula MAP = diastolic pressure + (pulse pressure)/3, MAP equals 70 + (125-70)/3, which equals 70 + 18.3, or 88.3 mm Hg.

What factors are involved in the formation of varicose veins?

Varicose veins are sagging, swollen superficial veins in the thighs and legs. They result from the pooling of blood due to gravity and the failure of venous valves.

How does the kidney respond to vasoconstriction of the renal artery?

Vasoconstriction of the renal artery would decrease both blood flow and blood pressure at the kidney. In response, the kidney would release EPO and renin. EPO increases the rate of red blood cell formation, which leads to an increase in blood volume. The release of renin would lead to an increase in the level of angiotensin II. The angiotensin II would bring about increased blood pressure and increased blood volume.

All the vessels of the systemic arterial system originate from the:

aorta

Fenestrated capillaries:

are found in the choroid plexus of the brain and the capillaries of the hypothalamus.

List the five general classes of blood vessels.

arteries, arterioles, capillaries, venules, and veins

The heart pumps blood, in sequence, through the

arteries, capillaries, and veins of the pulmonary and systemic circuits

In the capillaries, hydrostatic pressure (HP) is exerted by __________.

blood pressure blood pressure is the driving force for filtration

Blood pressure would INCREASE as a result of a DECREASE in __________.

blood vessel diameter Decreases in blood vessel diameter increase blood pressure because blood has more difficulty flowing through small vessels than large vessels. In other words, a decrease in blood vessel diameter increases total peripheral resistance. Assuming cardiac output remains constant, the increased total peripheral resistance would increase blood pressure. Or perhaps more intuitively, if cardiac output is to remain constant, blood pressure must increase.

The following activities and body conditions affect blood pressure by changing one of the two listed factors. Drag the appropriate physiological changes to their respective bins.

blood volume-- blood donation excessive sweating total peripheral resistance high altitude living growth smoking increased sympathetic activity

The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________.

capillary; interstitial fluid the capillary hydrostatic pressure (HPC; caused by blood pressure) is much higher than the interstitial hydrostatic pressure (HPI). The interstitial fluid is forced out of the capillaries.

Where are chemoreceptors located?

carotid bodies and aortic bodies and on the ventrolateral surfaces of the medulla oblongata.

Where are the sensors for the arterial baroreceptor reflex located?

carotid sinus and aortic arch the sensors are the arterial baroreceptors themselves, located at the carotid sinus and aortic arch. They detect changes in blood pressure by the degree of stretch on the blood vessel.

An unpaired branch of the abdominal aorta is the __________.

celiac trunk

Describe the structure and function of the cerebral arterial circle.

cerebral arterial circle (also known as the circle of Willis) is a ring-shaped anastomosis that encircles the infundibulum of the pituitary gland. Its anatomical arrangement creates alternate pathways in the cerebral circulation, so that if blood flow is interrupted in one area, other blood vessels can continue to perfuse the entire brain with blood.

Angiogenesis

is the growth of new blood vessels from preexisting vessels.

Trace the path of a drop of blood from the left ventricle to the right hip joint

left ventricle --> ascending aorta --> aortic arch --> thoracic aorta --> abdominal aorta --> right common iliac --> right external iliac --> right femoral --> right deep femoral --> right hip joint

Which net pressure draws fluid into the capillary?

net osmotic pressure the proteins exert colloid osmotic pressure, which draws fluid into the capillary.

Which wall layer is thicker in the artery than in the vein?

tunica media

Blood returns from the placenta in the single:

umbilical vein

Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary?

venous because the hydrostatic pressure of blood (which favors filtration out of the capillary) is lowest in the venous end of the capillary.

A blood clot that blocks the popliteal vein would interfere with blood flow in which other veins?

A blockage of the popliteal vein would interfere with blood flow in the tibial and fibular (peroneal) veins (which form the popliteal vein) and the small saphenous vein (which joins the popliteal vein).

Describe a capillary.

A capillary is a small blood vessel, located between an arteriole and a venule, whose thin wall permits exchange between blood and interstitial fluid by diffusion.

Besides containing valves, cite another major difference between the arterial and venous systems.

A major anatomical difference between the arterial and venous systems is the existence of dual (superficial and deep) venous drainage in the neck and limbs.

How is blood pressure maintained in veins to counter the force of gravity?

Assisted by the presence of valves in the veins, which prevent backflow of the blood, the contraction of the surrounding skeletal muscles squeezes venous blood toward the heart.

Explain the function of baroreceptor reflexes.

Baroreceptor reflexes respond to changes in blood pressure. The baroreceptors - located in the walls of the carotid sinuses and aortic arch - monitor the degree of stretch at those sites. When blood pressure increases, the cardiac centers decrease cardiac output and the vasomotor center if inhibited, resulting in vasodilation; when blood pressure decreases, the cardiac centers increase cardiac output and the vasomotor center is stimulated, resulting in vasoconstriction.

Define edema.

Edema is an abnormal accumulation of interstitial fluid in peripheral tissues.

Distinguish among efferent vessels, afferent vessels, and exchange vessels.

Efferent vessels (arteries) carry blood away from the heart, afferent vessels (veins) carry blood to the heart, and exchange vessels (capillaries) exchange nutrients, dissolved gases, and wastes between the blood and interstitial fluid.

Describe the plot of pressure versus flow rate.

It was linear, and the flow rate increased with increased pressure.

Which of the following changes would produce the greatest change in total peripheral resistance?

10%% change in vessel diameter The main determinant of total peripheral resistance is the diameter of the small arterioles. As blood vessel diameter increases, resistance goes down, and vice versa. Resistance is inversely proportional to the fourth power of the blood vessel radius. Radius is one-half of the vessel diameter. This means any change in vessel diameter will affect resistance by a factor of 1/r41/r4 where r is the radius. For example, a doubling of the vessel diameter will have a 2*2*2*2 or 16-fold reduction in resistance.

Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary?

34 mm HG HPc (35 mm Hg) - HPI (1 mm Hg) = 34 mm Hg, which is the net hydrostatic pressure at the arterial end. The hydrostatic pressure of the blood is much higher at the arterial end of the capillary, thus favoring filtration.

What effect does an increase in the respiratory rate have on CO2 levels?

An increase in the respiratory rate reduces CO2 levels.

Which would reduce peripheral resistance: an increase in vessel length or an increase in vessel diameter?

An increase in vessel diameter would reduce peripheral resistance. (An increase in vessel length would increase peripheral resistance.)

Identify the conditions that would shift the balance between hydrostatic and osmotic forces.

Any condition that affects either blood pressure or osmotic pressures in the blood or tissues will shift the balance between hydrostatic and osmotic forces.

Which is greater: arterial pressure or venous pressure?

Arterial pressure is much higher than venous pressure because it must push blood a greater distance and through progressively smaller and thinner vessels.

Choose the correct statement regarding blood flow.

Blood flow is slowest in the capillaries.

Define blood flow, and describe its relationship to blood pressure and peripheral resistance.

Blood flow is the volume of blood flowing per unit of time through a vessel of group of vessels; it is directly proportional to arterial pressure (increased pressure results in increased blood flow) and inversely proportional to peripheral resistance (increased resistance results in decreased blood flow.)

What are blood islands, and from which cells do they form?

Blood islands are aggregations of embryonic cells scattered within the yolk sac that form blood vessels and blood cells. During embryonic development, these islands give rise to hematopoietic stem cells and hemangioblasts.

the force of the blood against the vessel wall.

Blood pressure

the friction red blood cells encounter when moving past each other.

Blood viscosity:

Compression of Olivia's inferior vena cava causes her feet to swell due to which of the following alterations in capillary exchange?

Capillary hydrostatic pressure is increased

the volume of blood pumped out by one ventricle each minute.

Cardiac output

Describe autoregulation as it relates to cardiovascular function.

Cardiovascular autoregulation involves local factors changing the pattern of blood flow within capillary beds in response to chemical changes in interstitial fluids.

What is the function of chemoreceptor reflexes?

Chemoreceptor reflexes respond to decreasing pH and oxygen levels and to increasing CO2 levels in the blood and cerebrospinal fluid (CSF) by adjusting cardiovascular and respiratory activity. These reflexes stimulate responses by the cardiovascular centers to increase blood pressure through vasoconstriction and increased cardiac output and stimulate responses by the respiratory centers to increase the respiratory rate, which increases pH and oxygen levels and decreases CO2 levels.

Describe circulatory shock, progressive shock, and irreversible shock.

Circulatory shock occurs when blood loss exceeds about 35 percent of the total blood volume. Circulatory shock involves a series of positive feedback loops that are initiated after homeostasis has been disrupted. Progressive shock is the next stage after circulatory shock. It, too, is a series of positive feedback loops that accelerate tissue damage. Irreversible shock is the fatal stage that occurs if the positive feedback loops initiated during progressive shock are not broken.

Identify the compensatory mechanisms that respond to blood loss.

Compensatory mechanism that response to blood loos include an increase in cardiac output, a mobilization of venous blood reservoir, peripheral vasoconstriction, and the release of hormones that promote the retention of fluids and the maturation of erythrocytes.

The following physiological changes either increase or decrease blood pressure. Drag the appropriate factors to the respective bins.

Decreases blood pressure - Increase blood vessel diameter Increases blood pressure - Increase cardiac output - Increase blood vessel length - Increase blood volume - Increase total peripheral resistance - Increase blood viscosity

Describe the pattern of fetal blood flow to and from the placenta.

Deoxygenated blood flows from the fetus to the placenta through a pair of umbilical arteries, and oxygenated blood returns from the placenta in a single umbilical vein. The umbilical vein then drains into the ductus venosus within the fetal liver.

Describe the changes in cardiac output and blood flow during exercise.

During exercise, cardiac output increases, and blood flow to skeletal muscles increases at the expense of blood flow to less essential organs. Unless compensatory vasoconstriction occurs in "less essential" organs, such as those of the digestive system, vasodilation in skeletal muscles would cause a potentially dangerous decrease in blood pressure and blood flow throughout the body during exercise.

Describe the pulmonary circuit.

Ejects blood into the pulmonary trunk Powered by the right side of the heart short, low pressure

Identify the hormones responsible for short-term regulation of decreasing blood pressure and blood volume.

Epinephrine and norepinephrine from the adrenal medullae provide short-term regulation of decreasing blood pressure and blood volume.

Describe the roles of the natriuretic peptides.

Excessive stretching of the right atrium during diastole causes the release of atrial natriuretic peptide (ANP). Excessive stretching of the ventricles during diastole causes the release of brain natriuretic peptide (BNP). The roles of these peptides are to trigger responses whose combined effects act to crease blood volume and blood pressure. As blood volume and blood pressure decrease, natriuretic peptide production ceases.

At what sites in the body are fenestrated capillaries located?

Fenestrated capillaries are located where solutes as large as small peptides move freely into and out of the blood. These sites include endocrine glands, the choroid plexus of the brain, absorptive areas of the intestine, and filtration areas of the kidneys.

Under what general conditions would fluid move into a capillary?

Fluid moves into a capillary (reabsorption) whenever blood colloid osmotic pressure (BCOP) is greater than capillary hydrostatic pressure (CHP).

What is the function of hemangioblasts?

Hemangioblasts remodel blood islands first into capillary networks and then into larger arterial and venous networks.

Why are valves located in veins but not in arteries?

In the arterial system, pressures are high enough to keep the blood moving away from the heart and through arteries and capillaries. In the venous system, blood pressure is too low to keep the blood moving back toward the heart. Valves in veins prevent blood from flowing backward whenever the venous pressure drops.

Olivia's tachycardia is probably a result of

Inhibition of baroreceptors

In a healthy person, where is blood pressure greater: in the aorta or in the inferior vena cava? Explain.

Inn a healthy person, blood pressure is greater in the aorta than in the inferior vena cava. If the pressure were higher in the inferior vena cava than in the aorta, blood would flow in the reverse direction.

Grace is in an automobile accident, and her celiac trunk is ruptured. Which organs will be affected most directly by this injury?

Rupturing the celiac trunk would most directly affect the stomach, inferior portion of the esophagus, spleen, liver, gallbladder, and proximal portion of the small intestine.

The compression of Olivia's inferior vena cava will decrease cardiac output, because

The decrease in venous return will lower stroke volume

Explain the equation R ∝ 1/r4.

The equation R ∝ 1/r^4 states that resistance (R) is inversely proportional to the fourth power of the vessel radius (r). This means that a small change in vessel diameter results in a large change in resistance,.

Name the first two branches of the common iliac artery.

The first two branches of the common iliac artery are the internal iliac artery and the external iliac artery.

Describe the function of the hepatic portal system, and name its primary vessel.

The function of the hepatic portal system is to carry blood with absorbed nutrients from the digestive organs to the liver for processing. The primary vessel of the hepatic portal system is the hepatic portal vein.

Name the immediate and long-term problems related to hemorrhage.

The immediate, short-term problem during hemorrhage is to maintain adequate blood pressure and peripheral blood flow; the long-term problem is to restore normal blood volume.

Which vessel collects most of the venous blood inferior to the diaphragm?

The inferior vena cava collects most of the venous blood inferior to the diaphragm.

Name the veins that drain the dural sinuses of the brain.

The internal jugular veins drain the dural sinuses of the brain.

Identify the largest artery in the body.

The largest artery in the body is the aorta.

Describe the respiratory pump.

The respiratory pump is a mechanism by which a reduction of pressure in the thoracic cavity during inhalation assists venous return to the heart.

identify the six structures that are vital to fetal circulation but cease to function at birth, and describe what becomes of these structures.

The six structures vital to fetal circulation are two umbilival arteries, one

Whenever Thor gets angry, a large vein bulges in the lateral region of his neck. Which vein is this?

Thor's bulging vein is his external jugular vein.

Define tissue perfusion.

Tissue perfusion is blood flow to tissues that is sufficient to deliver adequate oxygen and nutrients.

the amount of friction blood encounters during flow through blood vessels.

Total peripheral resistance

List the factors that contribute to total peripheral resistance.

Total peripheral resistance reflects a combination of vascular resistance, vessel length, vessel luminal diameter, blood viscosity, and turbulence.

During exercise, cardiac output may increase by more than 170%% to meet the body's increased O2O2 demands. This increase in cardiac output increases blood pressure. But the accompanying increase in arterial pressure is relatively small—only about 40%%. What limits this increase in blood pressure so that it doesn't reach dangerously high levels during exercise?

Vasodilation causes arterial diameter to increase in the exercising skeletal muscle. During exercise, total peripheral resistance decreases. This is primarily due to an increase in the diameters of arterioles supplying the exercising muscles. Vasodilation of the blood vessels increases blood flow, providing the oxygen and nutrients necessary to support increased muscle metabolism. In addition, vasodilation of the arterioles in the skin also allows for greater blood flow to the skin for evaporative cooling.

Compare a ventricular septal defect with tetralogy of Fallot.

Ventricular septal defect (VSD) and tetralogy of Fallout are heart defects ailment. The defects results from a gap in the ventricular septum. Ventricular septal defect (VSD) and tetralogy of Fallout are heart defects ailment The defects result from a gap in the ventricular septum (Corno, 2009). The gap lets oxygenated blood to combine with the non-oxygenated blood in the heart chambers (Abdulla, 2011). The two defects affect the functioning of the heart and are prevalent among infants. tetralogy of Fallot is distinguished by four heart malfunctions. The malfunctions are the overriding aorta, ventricular septal defect, and right ventricular hypertrophy

Why is it beneficial for capillary pressure to be very low?

Very low capillary pressure is beneficial because it allows time for diffusion between the blood and the surrounding interstitial fluid.

A decrease in blood pressure at the arterial baroreceptors would result in which of the following?

an increase in heart contractility sympathetic nervous system activity would be increased because of the low blood pressure. Sympathetic fibers go to the ventricles of the heart and increase their contractility. An increase in contractility would increase stroke volume which would lead to an increase in cardiac output and blood pressure.

Stimulation of the adrenal medulla would result in which of the following?

an increase in heart rate and contractility epinephrine and norepinephrine are released from the adrenal medulla and act as part of the sympathetic nervous system, increasing heart rate and contractility. Epinephrine and norepinephrine have other effects that would also increase blood pressure.

Which of these organs contains only continuous capillaries, not fenestrated capillaries?

cerebrum The thyroid gland, kidneys, and intestinal tract all need to pass larger amounts of substances into or out of the blood. The cerebrum, on the other hand, needs to be protected from toxins and pathogens, so it has only continuous capillaries.

Which of the following would cause vasodilation of arterioles?

decreased activity of the sympathetic nervous system a decrease in the activity of the sympathetic nervous system would result in decreased activity of vasomotor fibers, resulting in vasodilation.

Describe the systemic circuit.

ejects blood into the aorta, systemic arteries, and arterioles(small arteries). powered by the left side of the heart long high friction circulation rest of body

Arterioles __________.

have a poorly defined tunica externa

The hepatic portal vein forms from the fusion of all of the following veins except the:

hepatic vein

Which of the following result(s) in an increase in fluid flow rate?

increase in pressure and increase in radius diameter

If blood pressure is increased at the arterial baroreceptors, what would happen with the activity level of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS)?

increased PNS activity and decreased SNS activity the PNS activity would increase and the SNS activity would decrease in an attempt to lower blood pressure.

Turbulence __________.

increases resistance

In this activity, we changed the pressure delivered by the left beaker. This is analogous to _______.

increasing the force of contraction of the heart

Which of the following arteries normally supply blood to the anterior half of the cerebrum?

internal carotids

Which vessel supplies the urinary bladder, the internal and external walls of the pelvis, and the external genitalia?

internal iliac artery

Blood is drained from the various venous sinuses within the cranium by the:

internal jugular veins.

The colloid osmotic pressure in the capillary is caused by __________.

proteins in the blood , the non-diffusible proteins in the plasma exert the colloid osmotic pressure, which pulls fluid into the capillary

The right ventricle pumps blood to the __________.

pulmonary circuit

Trace the path of a drop of blood from the right forearm to the right atrium.

right forarm --> right brachial --> right axillary --> right subclavian --> right brachiocephalic --> superior vena cava --> right atrium

Which chamber of the heart receives blood from the systemic circuit?

right strium

The brachiocephalic trunk branches to form which of the following?

right subclavian artery and right common carotid artery

Trace a drop of blood through the lungs, beginning at the right ventricle and ending at the left atrium.

right ventricle --> right and left pulmonary arteries --> pulmonary arterioles --> alveolar capillaries --> pulmonary venues --> pulmonary veins --> left atrium

Where is the majority of blood volume located during rest?

systemic venous system

Which of these structures does NOT help limit the flow of blood through capillary beds?

thoroughfare channel Thoroughfare channels do not have smooth muscle in their walls and are therefore unable to change their diameter to alter blood flow.