Chapter 21 Review Questions
Identify and discuss the factors that contribute to systemic vascular resistance.
1) Blood viscosity is dependent on the ratio of formed elements and proteins to plasma. In general, increased viscosity, via increased formed elements or decreasing plasma volume, increases resistance. 2) Total blood vessel length is directly proportional to resistance; thus, increasing length of circuit (by adding new blood vessels to serve added tissue) increases resistance. 3) Diameter/radius of blood vessels, which is primarily controlled by ANS, has a major effect on resistance. Increased vessel diameter decreases resistance, thus increasing flow. In general, changes in the diameter of small vessels (e.g. arterioles) have greater effect because more surface area is in contact with blood.
Normal blood pressure for a young adult male is
120/80
What general regions do the visceral and parietal branches of the thoracic aorta supply?
2 and 4
What would the pulse pressure and mean arterial pressure be for an individual with a blood pressure of 120/80?
40; 93.3
Know what a capillary is
??
Know what a precapillary sphincter look like
??
What arterial wall is composed of a simple squamous epithelium, a basement membrane and a layer of elastic tissue?
??
What does a capillary with an incomplete or absent basement membrane look like
??
What is a metarteriole?
??
What type of capillary is found in the kidneys, villi of the small intestine, choroid plexuses, and some endocrine glands?
??
Which arterial wall consists mainly of elastic fibers and smooth muscle fibers?
??
What is a portal vein? Describe the hepatic portal circulation.
A vein that carries blood from one capillary network to another is called a portal vein. The hepatic portal circulation carries venous blood from the gastrointestinal organs and spleen to the liver. It receives blood from GI organs and the spleen and delivers it to the liver. After a meal it is very rich in nutrients absorbed from the GI tract.
What category of hypertension drugs lower blood pressure by blocking formation of angiotensin II, which results in vasodilation and decreased aldosterone secretion?
ACE inhibitors
Describe the vessel wall characteristics of the five main types of blood vessels that blood travels through from the time it leaves the left ventricle until it returns to the right atrium.
Blood is carried away from the heart in arteries. All arteries have an outer tunica externa (mostly elastic and collagen fibers), an inner tunica media (mostly smooth muscle and elastic fibers) and a lining called the tunica interna (endothelial tissue). Large diameter arteries have more elastic fibers than smooth muscle in their walls and conduct blood to regions of the body, e.g. the subclavian artery carries blood toward the upper extremity. As arteries enter a body region, they branch and their diameters decrease. Their walls have proportionately more smooth muscle than elastic tissue. These arteries are called muscular or distributing arteries, e.g. the radial artery. Branching of the blood vessels continues until the vessels are nearly microscopic arterioles. Arterioles have little elastic tissue, but can change diameter quickly because of the smooth muscle in their wall. Thus, they are the major sites of regulation of blood pressure and distribution. Arterioles feed into capillary beds. Capillaries are the sites of exchange between the tissues and the blood. Venules drain the capillaries and begin the path back to the heart. Venules merge to form veins (and ultimately, vena cava) that carry the blood to the heart. Veins have much less smooth muscle than arteries. Vein also have valves that help prevent backflow of blood.
Veins
Blood vessels that carry blood from the tissues back to the heart
Arteries
Carry blood away from the heart to other organs
Which of the following would NOT result in an increase in systemic vascular resistance? A.Decreased diameter of systemic arterioles B.Increased blood viscosity C.Decreased length of the systemic circulatory route D.Increased vasoconstriction of systemic arterioles E.Increased red blood cell count
Decreased length of the systemic circulatory route
The cephalic, basilic, median, antebrachial, radial and ulnar veins originate in the head.
False
In fetal circulation, what is the opening between the right and left atria called?
Foramen ovale
Describe the route of an RBC traveling from the heart to the left elbow and back to the heart.
From the heart, the RBC will enter the ascending aorta and then the aortic arch. The RBC will exit the aorta through the left subclavian artery, continue on that route through the axillary artery and into the brachial artery. At the elbow, the blood cell will exit into one of the small distributing arteries, move into a capillary bed, and then into venules in the elbow region. The RBC will then probably enter the median cubital vein and move into either the basilic or the cephalic vein. The basilic vein drains into the brachial vein, which drains into the axillary vein. The cephalic vein drains directly into the axillary vein. From axillary vein, the RBC will travel into the subclavian and brachiocephalic veins before entering the superior vena cava. The SVC will take the RBC back to the heart.
________ is persistently high blood pressure.
Hypertension
This type of shock is due to decreased blood volume.
Hypovolemic
In a freak accident, an overheated and dehydrated roofer falls off the roof and onto a mirror that is being brought into a construction site. The mirror breaks and cuts several blood vessels, including the femoral artery. What will happen to the roofer's NFP in his capillary beds? Why?
If the roofer overheated, he probably had already lost a significant volume of body fluid through perspiration as his body tried to cool off. That loss would account for the dehydration. Loss of fluid without significant loss of solutes causes the blood colloidal osmotic pressure (BCOP) to increase. The cuts the roofer suffered would cause hemorrhaging and a loss of blood hydrostatic pressure (BHP). If the BHP goes down and the BCOP goes up, the net filtration pressure (NFP) should decrease because NFP = (BHP + IFOP) - BCOP. [IFOP is the interstitial fluid osmotic pressure, which is so much smaller than the BHP or BCOP that it usually doesn't change NFP.]
What is the main difference between the pulmonary and systemic circulations with respect to their autoregulatory response to changes in blood O2 level?
In systemic circulation, low O2 causes dilation of the blood vessel walls. This will lead to increase in O2 delivery to tissues. In pulmonary circulation, the opposite occurs in response to low levels of O2. The pulmonary vessels constrict to ensure blood only goes to those alveoli that are receiving rich O2 supply and avoids poorly ventilated sacs.
Which of the following vessels carries the venous blood from the lower body into the right atrium?
Inferior vena cava
Which of the following vessels drains blood from the head and neck?
Jugular vein
Which of the following vessels supplies blood to the intestines?
Mesenteric artery
Which of the following vessels is a pulse point found at the wrist?
Radial artery
Which of the following would NOT occur in response to hypovolemic shock?
Release of atrial natriuretic peptide (ANP)
Which of the following vessels supplies blood to the kidneys?
Renal artery
What category would an individual with a blood pressure of 145/95 be placed in?
Stage 1 hypertension
Which of the following effectors would NOT be activated as described below in response to hypovolemic shock? A.Adrenal cortex releases aldosterone. B.Kidneys conserve salt and water. C.Heart rate increases. D.Systemic arterioles vasodilate. E.Heart contractility increases.
Systemic arterioles vasodilate.
What do following arteries have in common: superficial temporal artery, brachial artery and common carotid artery?
They are all common pulse points.
Which of the following vessels drains blood from the lower leg?
Tibial vein
Systemic vascular resistance or total peripheral resistance refers to all of the vascular resistances offered by systemic blood vessels.
True
The arch of the aorta supplies the head and arms (upper part of the body).
True
Which layer of the arterial wall is primarily composed of elastic and collagen fibers?
Tunica externa
Which layer of the arterial wall is responsible for vasoconstriction?
Tunica media
When an artery or arteriole is damaged, its smooth muscle layer contracts producing
a vascular spasm
Which of the following types of tissues contains continuous capillaries? A.skeletal muscle B.smooth muscle C.connective tissue D.lungs E.all of these choices
all of these choices
What do the following chemicals have in common: potassium, hydrogen ions, lactic acid, nitric oxide, and adenosine?
all potent vasodilators
During embryonic development, blood vessels are formed by
angioblasts
This type of blood vessel plays a key role in regulating blood flow into capillaries
arterioles
Which of the following types of blood vessels have high pulsing blood pressure?
arterioles
Which of the following hormones would NOT stimulate changes that lead to an increase in arterial blood pressure? A.Atrial natriuretic peptide(ANP) B.Antidiuretic hormone(ADH) C.Aldosterone D.Angiotensin E.Epinephrine
atrial natriuretic peptide (ANP). ANP lowers blood pressure by causing vasodilation and by promoting the loss of salt and water in the urine, which reduces blood volume.
The largest driving force for pulling fluid from the interstitial spaces back into the capillaries is
blood colloid osmotic pressure
All of the following aid in venous return of blood to heart EXCEPT A.the skeletal muscle pump. B.the respiratory pump. C.blood viscosity. D.venoconstriction E.venous valves.
blood viscosity
Which of the following characteristics of blood depends mostly on the ratio of RBCs to plasma volume? A.total blood volume B.blood viscosity C.venous return D.clotting time E.immunoglobulin profile
blood viscosity
In which of the following types of blood vessels is blood pressure NOT pulsing? 1. Arteries 2. Capillaries 3. Arterioles 4. Venules
capillaries & arterioles
The volume of blood that circulates through the systemic (or pulmonary) blood vessels per minute is called
cardiac output (CO)
The alternate route of blood flow to a body part through an anastomosis is called
collateral circulation
When the umbilical cord is tied after birth, the umbilical arteries close by filling in with
connective tissue
When chemoreceptors in blood vessels detect high levels of carbon dioxide in the blood, they stimulate all of the following changes EXCEPT: A.increased vasoconstriction of arterioles. B.increased blood pressure. C.decreased respiratory rate. D.increased sympathetic stimulation of arterioles and veins. E.increased vasoconstriction of veins.
decreased respiratory rate
Which of the following is the most important method of capillary exchange? A.diffusion B.transcytosis C.bulk flow D.primary active transport E.secondary active transport
diffusion
Capillaries are also referred to as
exchange vessels
The pressure-driven movement of fluids and solutes from blood into interstitial fluid is called
filtration
Cardiac output is dependent on both
heart rate and stroke volume
Circulation time = ____________________
in a resting human is normally 1 minute.
The cardiovascular center is located
in the medulla oblongata
Which of the following would NOT result in an increase in arterial blood pressure? A.Increased blood volume B.Increased sympathetic stimulation C.Increased heart rate D.Increased stroke volume E.Increased arteriolar vasodilation
increased arteriolar vasodilation
All of the following changes are commonly observed in the cardiovascular system in response to aging EXCEPT A.decreased cardiac output. B.increased compliance of the aorta. C.loss of cardiac muscle strength. D.decline in maximum heart rate. E.increased systolic blood pressure.
increased compliance of the aorta
Which of the following would be a normal response of the cardiovascular system to a decreased frequency of action potentials arising from the baroreceptors? A.Increased systemic vascular resistance B.Increased parasympathetic stimulation C.Decreased heart rate D.Decreased stroke volume E.Decreased cardiac output
increased systemic vascular resistance
The myogenic response of smooth muscle results in
more forceful contractions when stretched
What general regions do the external and internal iliacs supply?
pelvis and lower limbs
Which branch(es) of the coronary arteries listed below supply the left ventricle? 1. Posterior interventricular branch of the right coronary artery 2. Marginal branch 3. Anterior interventricular branch of the left coronary artery 4. Circumflex branch of the left coronary artery
posterior interventricular branch of the right coronary artery, anterior interventricular branch of the left coronary artery, circumflex branch of the left coronary artery
Which of the following structures is used to control the flow of blood through a capillary bed? A.thoroughfare channels B.precapillary sphincters C.postcapillary sphincters D.venules E.valves in veins
precapillary sphincters
Elastic arteries function as
pressure reservoirs
Abnormal conditions such as atherosclerosis and patent ductus arteriosus cause an large increase in the
pulse pressure
The pulmonary trunk divides into ______________.
right and left pulmonary arteries.
The pulmonary circulatory route carries blood from the
right ventricle to the left atrium.
All the veins of the systemic circulation eventually drain into the
superior and inferior vena cava and coronary sinus
Which of the following structures are found in veins but NOT in arteries? A.tunica externa B.tunica media C.tunica interna D.valve E.lumen
valve
In resting individuals, these vessels serve as a large blood reservoir from which blood can be quickly diverted to other vessels as needed.
veins and venules