Chapter 19

What is the function of hemangioblasts?

They remodel blood islands fist into capillary networks and then into larger arterial and venous networks

Where are chemoreceptors located?

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

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

Because it allows time for diffusion between the blood and the surrounding interstitial fluid

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

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

External jugular vein

Identify the veins that combine to form the brachiocephalic vein

External jugular, internal jugular, vertebral, and subclavian veins

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

It reduces CO2 levels

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

epinephrine and norepinephrine

Neural and endocrine regulatory mechanisms influence which factors?

heart rate, stroke volume, peripheral resistance, and venous pressure

Identify the compensatory mechanisms that respond to blood loss

increase in cardiac output, mobilization of venous blood reservoir, peripheral vasoconstriction, and the release of hormones that promote the retention of fluids and the maturation of erythrocytes

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

Identify the major branches of the inferior vena cava

lumbar, gonadal, hepatic, renal, adrenal, and phrenic veins

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

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

Identify the branches of the external carotid artery

superficial temporal, maxillary, occipital, facial, lingual, and external carotid arteries

List the factors that contribute to total peripheral resistance

vascular resistance, vessel length, vessel luminal diameter, blood viscosity, and turbulence

Name the three branches of the internal carotid artery

Opthalmic, anterior cerebral, and middle cerebral arteries

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

The left subclavian artery

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 because it must push blood a greater distance through smaller and thinner vessels

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 is inhibited, resulting in vasodilation; when blood pressure decreases, the cardiac centers increase cardiac output and the vasomotor center is stimulated, resulting in vasoconstriction.

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 or group of vessels; it is directly proportional to arterial pressure and inversely proportional to peripheral resistance

Define tissue perfusion

Blood flow to tissues that is sufficient to deliver adequate oxygen and nutrients

Describe circulatory shock, progressive shock, and irreversible shock

Circulatory shock occurs when blood loss exceeds about 35% 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 is also 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 two types of capillaries with a complete endothelium

Continuous capillaries and fenestrated capillaries

Under what general conditions would fluid move into a capillary?

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

Why are valves located in veins but not in arteries?

In arteries, pressures are high enough to keep the blood moving away from the heart and through arteries and capillaries. In veins, 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

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

Increase in vessel diameter

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

Superior mesenteric, inferior mesenteric, and splenic veins

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

Superior vena cava and inferior vena cava

Compare the oxygen content in the two circulatory circuits

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.

Describe the roles of natriuretic peptides

The roles of these peptides are to trigger responses whose combined effects are to decrease blood volume and decrease blood pressure.

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

This 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. This would bring about increased blood pressure and increased blood volume

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

This would most directly affect the stomach, inferior portion of the esophagus, spleen, liver, gallbladder, and proximal portion of the small intestine

Describe the systemic circuit

Transports blood through the arteries, capillaries, and veins of the body from the left ventricle to the right atrium.

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

Two umbilical arteries, one umbilical vein, the ductus venosus, the foramen ovale, and the ductus arteriosus. After birth, the foramen ovale closes and persists as the fossa ovalis, a shallow depression; the ductus arteriosus persists as the ligamentum arteriosum, a fibrous cord; and the umbilical vessels and ductus venosus persist throughout life as fibrous cords.

Briefly describe general patterns of blood vessel organization

1) the peripheral distributions of arteries and veins on 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

Describe a capillary

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

Define edema

Abnormal accumulation of interstitial fluid in peripheral tissues

Describe auto regulation as it relates to cardiovascular function

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

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 venous 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

Identify the largest artery in the body

aorta

What factors are involved in the formation of varicose veins?

Pooling of blood due to gravity and the failure of venous valves

Identify two veins that carry blood away from the stomach.

The left and right gastro-epiploic veins

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.

Describe the distribution of total blood volume in the body

The systemic venous system and systemic arterial system contain 64% and 13% of the blood volume, respectively. The remaining blood volume is contained in the heart (7%), pulmonary circulation (9%), and systemic capillaries (7%).

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

The tibial and fibular veins, and the small saphenous vein

At what sites in the body are fenestrated capillaries located?

They 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

Describe the pulmonary circuit

Transports blood from the right ventricle through the pulmonary arteries, capillaries in the lungs and pulmonary veins and returns it to the left atrium

List the five general classes of blood vessels.

arteries, arterioles, capillaries, venules, and veins

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 Exchange vessels (capillaries): exchange nutrients, dissolved gases, and wastes between the blood and interstitial fluid.

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

It is assisted by the presence of valves in the veins, which prevent back flow of the blood, the contraction of the surrounding skeletal muscles squeezes venous blood toward the heart.

What is the function of 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 increase pH and oxygen levels and decreases CO2 levels.

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

Right atrium

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

Right common carotid artery and the right subclavian artery

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

Right ventricle-->pulmonary trunk-->right and left pulmonary arteries-->pulmonary arterioles-->alveoli-->pulmonary venules-->pulmonary veins-->left atrium

The plantar venous arch carries blood to which three veins?

The anterior tibial, posterior tibial, and fibular (peroneal) veins

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

The aorta. If the pressure were higher in the inferior vena cava than in the aorta, blood would flow in the reverse direction

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

The carotid sinus

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

The celiac trunk, superior mesenteric artery, and inferior mesenteric artery

Describe the structure and function of the cerebral arterial circle

The cerebral arterial circle 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

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

The existence of dual (superficial and deep) venous drainage in the neck and limbs

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

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

Name the immediate and long term problems related to hemorrhage

The immediate 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

Name the first two branches of the common iliac artery

The internal iliac artery and the external iliac artery

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

The internal jugular veins

Compare a ventricular septal defect with tetralogy of Fallot.

Ventricular septal defects are abnormal openings between the left and right ventricles. Tetralogy of Fallot includes a ventricular septal defect plus three other heart defects: a narrowing of the pulmonary trunk, a displaced aorta, and an enlarged right ventricle with corresponding thickened right and left ventricles