Chapters 18 and 19 Cardiovascular system and blood vessels, A&P II: Chapter 18 - The Heart Test Questions, CHAPTER 18- Heart Quiz+ Practice Questions, Chapter 18 Heart Multiple Choice, Chapter 19: The Cardiovascular System: Blood Vessels > Chapter Pr...

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Hypertension is defined physiologically as a condition of sustained arterial pressure of __________ or higher.

140/90

stroke volume:

(SV) volume of blood pumped out by one ventricle with one beat

risk factors involved in heart disease:

-Congestive heart failure -Coronary atherosclerosis -Persistent high blood pressure -Multiple myocardial infarcts -Dilated cardiomyopathy

Neural controls of blood vessels are directed primarily at:

1. altering blood distribution 2. maintaining adequate systemic blood pressure Under conditions of low blood volume, all vessels except those supplying the heart and brain are constricted.

The main factors influencing blood pressure are:

1. cardiac output 2. peripheral resistance 3. blood volume blood pressure = cardiac output X peripheral resistance Cardiac output (ml/min) = stroke volume (ml/beat) X heart rate (beats/min) Cardiac output is about 5.5L/min

The kidneys act directly and indirectly to regulate arterial pressure and provide long-term mechanism of blood pressure control:

1. direct - control water retention 2. indirect - release renin which results in the formation of angiotensin, a powerful vasoconstrictor.

Blood flowing through a terminal arteriole may take one of two routes:

1. through the true capillaries 2. through the shunt Blood flowing through true capillaries exchanges with tissue cells, whereas blood flowing through shunts bypasses the tissue cells. blood flowing into the true capillaries is regulated by vasomotor nerve fibers and local chemical conditions. The capillary beds may be flooded with blood or almost completely bypassed.

heart wall:

3 layers: outer epicardium(same as visceral pericardium) , middle myocardium(cardiac muscle , bulk of heart, layer that contracts its branching layers are connective tissue called fibrous skelteon of heart ), and inner endocardium(sheet of endothelium on inner heart surface, slick and reduces friction due to blood flow , is continuous with endothelium of blood vessels.) The heart has its own blood supply via coronary arteries.

heart chambers:

4 chambers(receives blood to heart, contract minimally and thin walled.): 2 superior atria (atrium and singular) 2 inferior ventricles separated by interatrial septum or interventricular septum external to atria are auricles that increase the atrial volume somewhat. Interatrial septum has a shallow depression , fossa ovalis is spot where opening(formen ovale) existed in fetal heart .

blood enters left atrium by:

4 pulmonary veins that transport blood from lungs back to the heart .

10) To auscultate the aortic semilunar valve, you would place your stethoscope in the ________. A) second intercostal space to the right of the sternum B) second intercostal space to the left of the sternum C) fifth intercostal space inferior to the left nipple D) fifth right intercostal space

13) Which of the following factors does not influence heart rate? A) skin color B) age C) gender D) body temperature

15) If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________. A) decreased delivery of oxygen B) a decrease in the number of available mitochondria for energy production C) a lack of nutrients to feed into metabolic pathways D) an inadequate supply of lactic acid

18) Which of the choices below reflects the balance (or imbalance) between the direction and amount of fluid that flows across the capillary walls? A) hydrostatic and osmotic pressure B) hydrostatic pressure only C) blood volume and viscosity D) plasma and formed element concentration

19) A foramen ovale ________. A) connects the two atria in the fetal heart B) is a condition in which the heart valves do not completely close C) is a shallow depression in the interventricular septum D) is a connection between the pulmonary trunk and the aorta in the fetus

2) Which of the events below does not occur when the semilunar valves are open? A) Ventricles are in diastole. B) Blood enters pulmonary arteries and the aorta. C) AV valves are closed. D) Ventricles are in systole

26) Select the correct statement about the function of myocardial cells. A) The entire heart contracts as a unit or it does not contract at all. B) Cardiac muscle cells are innervated by sympathetic, parasympathetic, and somatic nerve fibers so that the nervous system can increase heart rate. C) The refractory period in skeletal muscle is much longer than that in cardiac muscle. D) The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction

28) Compared to skeletal muscle, cardiac muscle ________. A) has gap junctions that allow it to act as a functional syncytium B) lacks striations C) has more nuclei per cell D) cells are larger than skeletal muscle cells

3) Hemorrhage with a large loss of blood causes ________. A) a lowering of blood pressure due to change in cardiac output B) a rise in blood pressure due to change in cardiac output C) no change in blood pressure but a slower heart rate D) no change in blood pressure but a change in respiration

30) Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer. A) tunica intima B) tunica media C) tunica externa D) tunica adventitia

30) The second heart sound is heard during which phase of the cardiac cycle? A) isovolumetric relaxation B) isovolumetric contraction C) ventricular ejection D) ventricular filling

31) If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________. A) threshold is reached more quickly and heart rate would increase B) potassium channels compensate and no change in heart rate would occur C) heart rate would decrease, but blood pressure would rise due to the excess sodium present D) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle

32) Select the correct statement about cardiac output. A) A slow heart rate increases end diastolic volume, stroke volume, and force of contraction. B) Decreased venous return will result in increased end diastolic volume. C) If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased. D) Stroke volume increases if end diastolic volume decreases

34) Isovolumetric contraction ________. A) refers to the short period during ventricular systole when the ventricles are completely closed chambers B) occurs while the AV valves are open C) occurs immediately after the aortic and pulmonary valves close D) occurs only in people with heart valve defects

4) The left ventricular wall of the heart is thicker than the right wall in order to ________. A) accommodate a greater volume of blood B) expand the thoracic cage during diastole C) pump blood with greater pressure D) pump blood through a smaller valve

8) Aldosterone will ________. A) promote an increase in blood pressure B) promote a decrease in blood volume C) result in a larger output of urine D) decrease sodium reabsorption

A heart murmur would be detected when blood is heard flowing from the _______ to the ___________. a. R. atrium/tricuspid valve b. R. atrium to left atrium/tricuspid valve c. L ventricle to left atrium; mitral valve d. L atrium to left ventricle; mitral valve

2. Which of the events below does NOT occur when the semilunar valves are open? A) Ventricles are in diastole. B) Blood enters pulmonary arteries and the aorta. C) Ventricles are in systole. D) AV valves are closed.

A) Ventricles are in diastole.

7. The condition where fluid compresses the heart and limits its ability to contract is called ________. A) cardiac tamponade B) myocardial infarction C) pericarditis D) angina pectoris

A) cardiac tamponade

16. Norepinephrine acts on the heart by ________. A) causing threshold to be reached more quickly B) blocking the action of calcium C) causing a decrease in stroke volume D) decreasing heart contractility

A) causing threshold to be reached more quickly

18. The foramen ovale ________. A) connected the two atria in the fetal heart B) is a condition in which the heart valves do not completely close C) is a connection between the pulmonary trunk and the aorta in the fetus D) is a shallow depression in the interventricular septum

A) connected the two atria in the fetal heart

10. The source of blood carried to capillaries in the myocardium would be the ________. A) coronary arteries B) coronary veins C) coronary sinus D) fossa ovalis

A) coronary arteries

14. If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________. A) decreased delivery of oxygen B) an inadequate supply of lactic acid C) a lack of nutrients to feed into metabolic pathways D) a decrease in the number of available mitochondria for energy production

A) decreased delivery of oxygen

6. Blood within the pulmonary veins returns to the ________. A) left atrium B) right atrium C) right ventricle D) left ventricle

A) left atrium

39. Exercise results in skeletal muscles compressing veins which encourages blood to return to the heart. In this scenario, which of the following is correct? A) preload increases B) venous return decreases C) stroke volume decreases D) end diastolic volume (EDV) decreases

A) preload increases

19. Which vessel(s) of the heart receive(s) blood from the right ventricle? A) pulmonary trunk B) aorta C) pulmonary veins D) venae cavae

A) pulmonary trunk

36. Which of the following transports oxygen-rich blood? A) pulmonary vein B) pulmonary artery C) pulmonary trunk D) superior vena cava

A) pulmonary vein

11. The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________. A) pumps blood against a greater resistance B) expands the thoracic cage C) sends blood through a smaller valve D) pumps a greater volume of blood

A) pumps blood against a greater resistance

32. Isovolumetric contraction ________. A) refers to the short period during ventricular systole when the ventricles are completely closed chambers B) occurs immediately after the aortic and pulmonary semilunar valves close C) occurs while the atrioventricular (AV) valves are open D) occurs only in people with heart valve defects

A) refers to the short period during ventricular systole when the ventricles are completely closed chambers

9. To auscultate the aortic semilunar valve, you would place your stethoscope in the ________. A) second intercostal space to the right of the sternum B) second intercostal space to the left of the sternum C) fifth right intercostal space D) fifth intercostal space inferior to the left nipple

A) second intercostal space to the right of the sternum

17. If the vagal nerves to the heart were cut, the result would be that ________. A) the heart rate would increase by about 25 beats per minute B) parasympathetic stimulation would increase, causing a decrease in heart rate C) the atrioventricular (AV) node would become the pacemaker of the heart D) the heart would stop, since the vagal nerves trigger the heart to contract

A) the heart rate would increase by about 25 beats per minute

All of these structures can be ID in the ventricles except a. trabeculae carneae b. papillary muscles c. pectinate muscles d. chordae tendinae

maintenance of systemic blood pressure:

Any fluid driven by a pump through a circuit of closed channels operates under pressure, and the nearer the fluid is to the pump, the greater the pressure. Blood flows through the blood vessels along a pressure gradient from high to low. Pressure results when flow is opposed by resistance. As the left ventricle contracts and expels blood into the aorta, it stretches the elastic walls of the aorta causing aortic pressure to reach its peak-the systolic arterial blood pressure and averages about 120 mm Hg. During diastole which occurs during ventricular relaxation, closure of the semilunar valve prevents blood flowing back into the heart, and the walls of the aorta recoil, maintaining continuous pressure on the reducing blood volume. During this time, aortic pressure drops to its lowest level (diastolic pressure). The difference between the systolic and diastolic pressures is the pulse pressure. It is felt as a throbbing pulsation in an artery during systole as the elastic arteries are expanded by the blood being forced into them by ventricular contraction.

Systemic Circuit -

Arterial portion - Aorta (largest artery in the body) is named by regions (ascending aorta, aortic arch, thoracic aorta, abdominal aorta. Branches off the aorta go to all body regions. For details, see the flowchart in Figure 19.21a.

general structure of arterial system:

Arteries can be divided into three groups: 1. elastic arteries 2. muscular arteries 3. Arterioles

Which of the following is true when comparing arteries and veins?

Arteries carry blood away from the heart; veins carry blood to the heart.

Atrial repolarization occurs during this period of time, seen on an ECG a. P wave b. QRS Complex c. T wave d. S-T Segment e. P-R interval

Atrial systole occurs ___________ firing of the SA node. a. before b. after

autoregulation of localized blood flow:

Automatic adjustment of blood flow to each tissue in proportion to its requirements at any point in time. Regulated by conditions and is independent of systemic factors. Since mean arterial pressure is identical throughout the body, changes in blood flow through individual organs are controlled by modifying the diameter of local arterioles feeding the capillaries. Thus organs regulate their own blood flow by varying resistance of their arterioles. Local physical factors are also important autoregulatory stimuli. Vascular smooth muscle responds directly to passive stretch and causes vasoconstriction. Reduced stretch promotes vasodilation. Such responses to changing volume entering an arteriole are called myogenic responses. Generally both chemical and physical factors determine the final autoregulatory response of a tissue. Autoregulation in the brain, heart, and kidneys is extraordinarily efficient. Adequate perfusion is maintained even in the face of fluctuating mean arterial pressure. The number of vessels in the region increases, and the existing vessels enlarge. This is common in the heart when a coronary vessel is partially occluded; it occurs throughout the body in people who live in high-altitude areas.

1) Normal heart sounds are caused by which of the following events? A) excitation of the SA node B) closure of the heart valves C) friction of blood against the chamber walls D) opening and closing of the heart valves

12) The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________. A) pumps a greater volume of blood B) pumps blood against a greater resistance C) expands the thoracic cage D) sends blood through a smaller valve

12) Which of the choices below explains why the arterioles are known as resistance vessels? A) Their prime function is the exchange of nutrients and wastes between the blood and tissue cells. B) The contraction and relaxation of the smooth muscle in their walls can change their diameter. C) They distribute blood to various parts of the body. D) They contain a large quantity of elastic tissue.

17) Blood flow to the skin ________. A) is controlled mainly by decreasing pH B) increases when environmental temperature rises C) increases when body temperature drops so that the skin does not freeze D) is not an important source of nutrients and oxygen for skin cells

18) If the vagal nerves to the heart were cut, the result would be that ________. A) the heart would stop, since the vagal nerves trigger the heart to contract B) the heart rate would increase by about 25 beats per minute C) the AV node would become the pacemaker of the heart D) parasympathetic stimulation would increase, causing a decrease in heart rate

20) Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation? A) tunica intima B) tunica media C) tunica externa D) tunica adventitia

20) Which vessel(s) of the heart receive(s) blood during right ventricular systole? A) venae cavae B) pulmonary trunk C) aorta D) pulmonary veins

21) The influence of blood vessel diameter on peripheral resistance is ________. A) the only factor that influences resistance B) significant because resistance is inversely proportional to the fourth power of the vessel radius C) significant because resistance is directly proportional to the blood vessel diameter D) insignificant because vessel diameter does not vary

23) In the dynamics of blood flow through capillaries, hydrostatic pressure ________. A) and osmotic pressure are the same B) is the same as capillary blood pressure C) generally forces fluid from the interstitial space into the capillaries D) is completely canceled out by osmotic pressure

23) The tricuspid valve is closed ________. A) while the ventricle is in diastole B) when the ventricle is in systole C) while the atrium is contracting D) by the movement of blood from atrium to ventricle

24) When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________. A) tracing out where the auricles connect B) noticing the thickness of the ventricle walls C) locating the apex D) finding the papillary muscles

29) During the period of ventricular filling ________. A) pressure in the heart is at its peak B) blood flows mostly passively through the atria and the open AV valves into the ventricles C) the atria remain in diastole D) it is represented by the P wave on the ECG

29) Which of the following are involved directly in pulmonary circulation? A) superior vena cava, right atrium, and left ventricle B) right ventricle, pulmonary artery, and left atrium C) left ventricle, aorta, and inferior vena cava D) right atrium, aorta, and left ventricle

3) Which statement best describes arteries? A) All carry oxygenated blood to the heart. B) All carry blood away from the heart. C) All contain valves to prevent the backflow of blood. D) Only large arteries are lined with endothelium.

33) During contraction of heart muscle cells ________. A) the action potential is initiated by voltage-gated slow calcium channels B) some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores C) the action potential is prevented from spreading from cell to cell by gap junctions D) calcium is prevented from entering cardiac fibers that have been stimulated

33) Modified capillaries that are lined with phagocytes are called ________. A) fenestrations B) sinusoids C) thoroughfare channels D) anastomoses

37) Mechanisms that do not help regulate blood pressure include ________. A) nervous control that operates via reflex arcs involving baroreceptors, chemoreceptors, and higher brain centers B) the dural sinus reflex C) renal regulation via the renin-angiotensin system of vasoconstriction D) chemical controls such as atrial natriuretic peptide

4) The most common type of blood capillary is the ________. A) sinusoidal capillary B) continuous capillary C) fenestrated capillary D) distributing capillary

43) The short-term controls of blood pressure, mediated by the nervous system and bloodborne chemicals, primarily operate via all but which of the following? A) reflex arcs involving baroreceptors B) altering blood volume C) reflex arcs associated with vasomotor fibers D) chemoreceptors

45) Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation? A) kidney B) lungs C) liver D) heart

46) Normal average blood pressure for a newborn baby is ________. A) 120/80 B) 90/55 C) 150/90 D) 130/80

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

7) Blood within the pulmonary veins returns to the ________. A) right atrium B) left atrium C) right ventricle D) left ventricle

7) The arteries that are also called distributing arteries are the ________. A) elastic arteries B) muscular arteries C) arterioles D) capillaries

8) The condition where fluid compresses the heart and limits its ability to contract is called ________. A) pericarditis B) cardiac tamponade C) myocardial infarction D) angina pectoris

9) The pulse pressure is ________. A) systolic pressure plus diastolic pressure B) systolic pressure minus diastolic pressure C) systolic pressure divided by diastolic pressure D) diastolic pressure plus 1/3 (systolic pressure plus diastolic pressure)

37. What is the expected heart rate when a heart is removed from a living body? A) 75 beats / minute B) 100 beats / minute C) 50 beats / minute D) the heart would immediately stop beating

B) 100 beats / minute

33. Given an end diastolic volume (EDV) of 120 ml / beat and an end systolic volume (ESV) of 50 ml / beat, the stroke volume (SV) would be ________. A) 170 ml / beat B) 70 ml / beat C) 120 ml / beat D) 50 ml / beat

B) 70 ml / beat

23. Select the correct statement about the heart valves. A) The mitral (bicuspid) valve separates the right atrium from the right ventricle. B) The atrioventricular (AV) valves prevent backflow of blood into the atria during ventricular contraction. C) Aortic and pulmonary semilunar valves control the flow of blood into the heart. D) The tricuspid valve divides the left atrium from the left ventricle.

B) The atrioventricular (AV) valves prevent backflow of blood into the atria during ventricular contraction.

25. Select the correct statement about the structure of the heart wall. A) Connective tissue in the heart wall aids in the conduction of the action potential. B) The myocardium is the layer of the heart that actually contracts. C) The fibrous cardiac skeleton forms the bulk of the heart. D) The heart chambers are lined by the endomysium.

B) The myocardium is the layer of the heart that actually contracts.

3. Hemorrhage with a large loss of blood causes ________. A) no change in blood pressure but a slower heart rate B) a lowering of blood pressure due to change in cardiac output C) no change in blood pressure but a change in respiration D) a rise in blood pressure due to change in cardiac output

B) a lowering of blood pressure due to change in cardiac output

5. The P wave of a normal electrocardiogram indicates ________. A) ventricular repolarization B) atrial depolarization C) atrial repolarization D) ventricular depolarization

B) atrial depolarization

4. Damage to the ________ causes heart block. A) sinoatrial (SA) node B) atrioventricular (AV) node C) atrioventricular (AV) bundle D) atrioventricular (AV) valves

B) atrioventricular (AV) node

27. During the period of ventricular filling ________. A) the aortic and pulmonary semilunar valves are open B) blood flows mostly passively through the atria and the open atrioventricular (AV) valves into the ventricles C) the atria remain in diastole D) pressure in the heart is at its peak

B) blood flows mostly passively through the atria and the open atrioventricular (AV) valves into the ventricles

1. Normal heart sounds are caused by which of the following events? A) friction of blood against the chamber walls B) closure of the heart valves C) opening of the heart valves D) excitation of the sinoatrial (SA) node

B) closure of the heart valves

28. The second heart sound is heard during which phase of the cardiac cycle? A) ventricular filling B) isovolumetric relaxation C) isovolumetric contraction D) ventricular ejection

B) isovolumetric relaxation

31. During contraction of heart muscle cells ________. A) all of the calcium required for contraction comes from storage in the sarcoplasmic reticulum B) some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores C) calcium is prevented from entering cardiac fibers that have been stimulated D) the action potential is prevented from spreading from cell to cell by gap junctions

B) some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores

15. If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________. A) contractions would last as long as the refractory period B) tetanic contractions might occur, which would stop the heart's pumping action C) pacemaker cells would cease to spontaneously depolarize D) it would be much longer before cardiac cells could respond to a second stimulation

B) tetanic contractions might occur, which would stop the heart's pumping action

13. Which of the following is NOT an age-related change affecting the heart? A) decline in cardiac reserve B) thinning of the valve flaps C) atherosclerosis D) fibrosis of cardiac muscle

B) thinning of the valve flaps

29. If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________. A) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle B) threshold is reached more quickly and heart rate would increase C) potassium channels compensate and no change in heart rate would occur D) heart rate would decrease, but blood pressure would rise due to the excess sodium present

B) threshold is reached more quickly and heart rate would increase

Blood being pumped out right ventricles enters the a. aorta b. coronary sinus c. left atrium d. pulmonary artery e. pulmonary vein f. venae cavae

structure and function of heart valves:

Blood flows through the heart in one direction. This one-way flow is enforced by 4 heart valves: one pair of atrioventricular valves(tri and bi cuspid) and one pair of semilunar valves(pulmonary and aortic ), which open and close in response to differing blood pressures on their two sides. The aortic and pulmonary semilunar valves guard the bases of the large arteries issuing from the ventricles and prevent backflow into the associated ventricles. Each of the semilunar valves has three pocket-like cusps. When the ventricles contract, the pressure in the ventricles are greater than the pressure in the aorta and pulmonary arteries and the valves are forced open. The blood exits the ventricle. When the ventricles relax and the blood begins to flow backward toward the heart, it fills the cusps and effectively closes the valves. In valvular stenosis (narrowing) the valves become stiff and the heart must contract more forcibly than normal.

structure and function of the venous system:

Blood is carried from the capillary beds toward the heart by veins. vessels increase in diameter, and their walls gradually thicken as they progress from venules to the larger and larger veins. Veins are usually collapsed, and their lumens appear slit-like in routine tissue preparations. The tunica media tends to be thin and there is little smooth muscle or elastin. In the vena cava, the tunica adventitia is further thickened by longitudinal bands of smooth muscle. With their large lumens and thin walls, veins can accommodate large blood volume. Up to 65% of the body's total blood supply is found in the veins. veins are normally only partially filled with blood.Blood pressure within the veins is low and some special adaptations that help return blood to the heart .The large diameter lumens are one structural adaptation. Another is the presence of valves that prevent blood from flowing backward. Valves are most abundant in the veins of the limbs. They are absent in veins of the ventral body cavity.

function of vascular system:

Blood is forced into the large arteries leaving its ventricles. It then moves into successively smaller arteries, finally reaching their smallest branches, the arterioles, which feed into the capillary beds of body organs and tissues. Blood draining from the capillaries is collected by venules-( small veins that merge to form larger veins that ultimately empty into the great veins converging on the heart. )

Blood pumped out of the left ventricles enters the a. aorta b. coronary sinus c. left atrium d. pulmonary artery e. pulmonary vein f. venae cavae

Ventricular filling (mid-to-late diastole) -

Blood returning from the circulation flows through the atria and the open AV valves into the ventricles. Following atrial depolarization (P wave), the atria contract to propel residual blood out of the atria and into the ventricles. Ventricles now have the maximal volume of blood.

1) Which of the following is not one of the three main factors influencing blood pressure? A) cardiac output B) peripheral resistance C) emotional state D) blood volume

11) The source of blood carried to capillaries in the myocardium would be the ________. A) coronary sinus B) fossa ovalis C) coronary arteries D) coronary veins

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

15) Peripheral resistance ________. A) decreases with increasing length of the blood vessel B) increases as blood vessel diameter increases C) increases as blood viscosity increases D) is not a major factor in blood pressure in healthy individuals

16) Brain blood flow autoregulation ________. A) is less sensitive to pH than to a decreased oxygen level B) causes constriction of cerebral blood vessels in response to a drop in systemic blood pressure C) is abolished when abnormally high CO2 levels persist D) is controlled by cardiac centers in the pons

16) If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________. A) it would be much longer before cardiac cells could respond to a second stimulation B) contractions would last as long as the refractory period C) tetanic contractions might occur, which would stop the heart's pumping action D) it would be less than 1—2 m

19) Which of the following is a type of circulatory shock? A) hypovolemic, caused by increased blood volume B) cardiogenic, which results from any defect in blood vessels C) vascular, due to extreme vasodilation as a result of loss of vasomotor tone D) circulatory, where blood volume is normal and constant

22) The form of circulatory shock known as hypovolemic shock is ________. A) the form of shock caused by anaphylaxis B) any condition in which blood vessels are inadequately filled and blood cannot circulate normally C) shock that results from large-scale loss of blood volume, or after severe vomiting or diarrhea D) always fatal

22) Which of the following is not part of the conduction system of the heart? A) AV node B) bundle of His C) AV valve D) SA node

24) Which of the following is the most significant source of blood flow resistance? A) blood viscosity B) total blood vessel length C) blood vessel diameter D) blood vessels type

26) Which of the choices below does not explain why low capillary pressures are desirable? A) Capillaries are fragile and high pressures would rupture them. B) Most capillaries are extremely permeable and thus even low pressures force solute-containing fluid out of the bloodstream. C) Low blood pressure is associated with longer life span than high blood pressure. D) Low capillary pressure reduces the load of drainage the lymphatic drainage must handle

31) The arteries that directly feed into the capillary beds are called ________. A) muscular arteries B) elastic arteries C) arterioles D) venules

35) Commotio cordis is heart failure due to a ________. A) mild electrical shock to the heart itself B) severe electrical shock to the body C) relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing D) loss of blood from an artery

35) Which of the following blood pressure readings would be indicative of hypertension? A) 120/80 in a 30-year-old man B) 140/90 in a 70-year-old woman C) 170/96 in a 50-year-old man D) 110/60 in a 20-year-old woman

41) Cerebral blood flow is regulated by ________. A) skin temperature B) ADH C) intrinsic autoregulatory mechanisms D) the hypothalamic "thermostat"

44) Secondary hypertension can be caused by ________. A) obesity B) stress C) arteriosclerosis D) smoking

47) If blood pressure is almost normal in a person who has lost blood, does that mean the tissues are receiving adequate blood flow? A) yes B) no C) not necessarily

30. Select the correct statement about cardiac output. A) If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased. B) Decreased venous return will result in increased end diastolic volume. C) A slow heart rate increases end diastolic volume, stroke volume, and force of contraction. D) Stroke volume increases if end diastolic volume decreases.

C) A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.

(True/False) Baroreceptors are effective in long-term regulation of blood pressure.

False

(True/False) If the net filtration pressure (NFP) is positive, then fluid is reabsorbed into the blood.

False

For which type of heart condition might a doctor prescribe calcium channel blockers? a. depressed heart rate b. heart irritability c. heart murmur d. weak heart rate

The hepatic portal system collects blood from the __________ and then routes it to the __________.

GI tract; liver

How would heart rate change with a new drug that inhibits opening of voltage-gated calcium ion channels? a. no change in HR b. HR would be slower c. HR will be faster d. HR will stop

If the cells of the SA node fail to function, how would the heart rate be affected? a. be faster b. be slower c. be irregular d. not change

effects of exercise on the cardiovascular system:

In response to regular exercise, the heart adapts to the increased demand by increasing in size and becoming a more efficient and more powerful pump. Also it clears fatty deposits from blood vessels walls, retarding atherosclerosis and coronary heart disease.

Hypotension:

Low blood pressure; systolic pressure below 100mm Hg. reflects individual variations and is no cause for concern. Often associated with long life and old age free of illness.

control of blood pressure:

Maintaining a steady flow of blood is vital for proper organ function. Blood pressure is regulated by neural, chemical and renal controls.

Nerve impulses are directly supplied to the papillary muscles by the a. SA Node b. purkinje fibers c. AV Node d. bundle of His

Of the following layers of heart wall, which consumes the most energy? a. epicardium b. myocardium c. endocardium d. visceral pericardium

Venous portion -

Peripheral veins merge and eventually return blood to either the inferior vena cava or superior vena cava, which returns blood to the heart. For details, see the flowchart in Figure 19.26

Predict the nature of an ECG recording when the atrioventricular node becomes the pacemaker. a. continue to be a normal sinus rhythm b. P wave would be much larger than normal c. the R-R interval rate would increase d. the T wave would be much smaller

Pulmonary Circuit -

Pulmonary trunk rt/lt pulmonary arteries lobar arteries pulmonary capillaries pulmonary veins

The heart

Pump that circulates blood via blood vessels. Size of fist and located in thorax in mediastenum cavity. Tips slightly to the left.

factors that affect it (CO):

The Cardiac Output increases when (SV)stroke volume increases or the HR increases or both. The critical factor controlling SV is preload (the degree to which cardiac muscle cells are stretched just before they contract). Stretching cardiac muscle cells leads to increases in contractile force. A slow heartbeat gives more time for ventricular filling. Exercise speeds venous return to the heart. SV can also be affected by increasing contractility (via hormones thyroxine, epinephrine). Afterload (back pressure on the semilunar valves by arterial blood) can be a factor in SV in hypertensive individuals because this pressure must be overcome for ventricles to eject blood

The amount of blood ejected with one heart beat is defined: a. cardiac output b. ejection fraction c. heart rate d. stroke volume

The bundle of His is located here. a. intreatrial septum b. inerventricular septum c. flood of the right atrium d. apex of the heart

principal events of the cardiac cycle:

The cardiac cycle is the blood flow through the heart during one complete heartbeat.

coronary circulation:

The cells of the heart receive no nutrients or oxygen from the blood flowing through the heart. Their blood supply provided right and left coronary arteries. coronary arteries branch and supply routes for blood delivery. there is a backup system when these arteries become occluded. Full occlusion of a coronary artery leads to tissue death and heart attack. After passing through the capillary beds of the myocardium, the cardiac veins join together forming an enlarged vessel-the coronary sinus, which empties into the right atrium.

The entire ventricular myocardium is depolarized during this time on an ECG a. S-T segment b. Q-T interval c. QRS complex d. Twave e. P wave f. RR interval

pathways of blood through the heart:

The heart is 2 side-by-side pumps with separate blood circuit. receives blood returning to the heart from body and sends it through lungs. In lungs the blood gives up waste carbon dioxide and takes on oxygen.

unique aspects of fetal circulation

The interatrial septum in the fetal heart is incomplete. The foramen ovale connects the two atria and allows blood entering the right heart to bypass the pulmonary circuit and the collapsed, non-functional fetal lungs. Another bypass, the ductus arteriosus connects the pulmonary trunk and aorta. The ductus venosus largely bypasses the liver. The umbilical vein and arteries circulate the blood between the fetal circulation and the placenta where gas and nutrient exchanges occur with the mother's blood.

intrinsic conduction system of the heart and how it relates to an electrocardiogram:

The intrinsic conduction system consists of noncontractile (non-muscular) cardiac cells specialized to initiate and distribute impulses throughout the heart, it depolarizes and contracts orderly manner. The heart has autorhythmic cells that have an unstable resting potential; these cells continuously depolarize until reaching a threshold and initiating an action potential. These electrical events are based on the flow of ions (sodium, potassium, and calcium) across the cell membranes.

pathways of blood through the heart:systemic circulation pump

The left side of the heart , receives oxygenated blood from the lungs and pumps it to body tissues via the arteries. longer/thicker and encounters 5 times as much friction.

The major ionic change that initiates the rising phase of the autorhythmic cell action potential is: a. influx of K ions b. influx of Ca ions c. influx of Na ions d. efflux of Ca ions e. efflux of K ions f. exit of calcium ions from the Sarcoplasmic reticulum

sounds of the heart and their clinical significance:

The normal heartbeat produces two sounds : (lub-dup)- -Thefirst sound happens when the AV valves close. -The second sound occurs as the semilunar valves close. Each lub-dup is separated by a pause which indicates heart relaxation. . (incompetent)-If a valve fails to close completely a swishing sound is heard. (stenosis)-If a valve fails to open completely it restricts blood flow through the valve .

The plateau portion of the action potential in contracile cardiac muscle cells is due to: a. influx of K ions b. influx of Ca ions c. influx of Na ions d. efflux of Ca ions e. efflux of K ions f. exit of calcium ions from the Sarcoplasmic reticulum

pathways of blood through the heart: pulmonary circuit pump

The right side of the heart ,pumps deoxygenated blood to the lungs. short/thinner and low-pressure.

true capillary

The terminal arteriole feeding the bed leads into a metarteriole which is continuous with the thorough fare channel. The channel joins the postcapillary venule that drains the bed. Typically, a cuff of smooth muscle (precapillary sphincter), surrounds the root of each true capillary at the metarteriole and acts as a valve to regulate the flow of blood into the capillary.

the structure of vessel walls

The three vessel types vary in length, diameter, and the relative thickness and tissue makeup of their walls. The walls of all blood vessels EXCEPT the capillaries are composed of three distinct layers, or tunics. The tunics surround lumen. The inner most tunic contacts with the blood- tunica intima. It contains the endothelium that lines the lumen of the vessel, and its cells fit together, forming a slick surface minimizing friction. The middle layer-tunica media, consists mostly of circularly arranged smooth muscle cells and elastic fibers. Since small changes in blood vessel diameter greatly influence blood flow and blood pressure, the activities of the tunica media are critical in regulating circulatory dynamics. The tunica media is usually the bulkiest layer in arteries. The outer most layer is the tunica adventitia and is composed of loosely woven collagen fibers that protect the vessel and anchor it to surrounding structures.

physiology of blood flow:

The velocity of blood flow changes as blood travels through the systemic circulation. It is fastest in the aorta and other large arteries and slowest in the capillaries. Velocity is inversely related to the cross-sectional areaof the vessel to be filled. Blood flows fastest where the total cross-sectional area is least. As the arterial system continues to branch the total cross-sectional area of the vascular bed increases, and velocity of blood flow declines proportionally.

general structure of vascular system:

There are three types of blood vessels: 1. arteries 2. capillaries 3. veins

vessels

There is about 60,000 miles of within the adult body.

Isovolumetric relaxation (early diastole) -

This phase following the T wave, is when the ventricles relax. The blood remaining in the chambers is called the end systolic volume. The falling pressure in the ventricles causes the blood in the large arteries to flow back,which closes the semilunar valves. During the time of ventricular contraction, the atria have been in relaxation and refilling with blood. When the ventricles finish contracting the pressure in the atria is now greater than in the ventricles, and the AV valves reopen.

Hypertension:

Transient elevations occur as normal adaptations during fever, physical exercise, and emotional upset. Although hypertension is usually asymptomatic for the first 10-20 years, it slowly strains the heart and damages the arteries (silent killer). defined physiologically as a condition of sustained elevated arterial pressure of 140/90 or higher. As a general rule, elevated diastolic pressures are more significant medically, because they always indicate progressive occlusion and/or hardening of the arterial tree. About 90% of hypertensive people have "primary or essential" hypertension which cannot be assigned to specific organic cause. Factors such as diet, obesity, heredity, race, and stress are believed to be involved. Clinical signs usually appear after the age of 40. Dietary factors :high sodium, saturated fat,and cholesterol and deficiencies in certain metal ions (potassium, calcium, magnesium). Factors that most accurately predict risk are the seventy of blood pressure elevation, blood cholesterol levels, cigarette smoking, presence of diabetes mellitus, and stress levels.

What do you think the HR would do if you stood on your head (think about other changes that might occur and how your body might use HR to compensate) a. no change b. decrease c. increase

What factor would cause an increase in the size of the ORS complex of an ECG recording? a. an increase in HR b. decrease in blood volume c. decrease in BP d. increase in heart size

What is happening during atrial diastole? a. ventricle diastole b. ventricle systole c. it switches

What is the purpose of the coronary circuit serve? a.. none b. delivers 1/20 of the body's blood supply to the heart muscle itself c. it delivers blood to the anterior lung surface for gas exhange d. it feeds the anterior thoracic wall

What prevents the AV valves from opening back into the atria? a. papillary muscles b. valve cusps c. moderator band d. chordae tendineae

structure and function of vascular anastomoses:

Where vascular channels unite or interconnect, they form anastomoses. Most organs receive blood from more than one arterial branch, and nearby arteries supplying the same territory often merge, forming arterial anastomoses, which permits free communication between vessels involved and provide alternate pathways for blood to reach a given body region. Arterial anastomoses are abundant in abdominal organs and around joints, where active movement may hinder blood flow through one channel. Veins interconnect much more freely than arteries, and as a result, occlusion of venous channels rarelyblocks blood flow or leads to tissue death.

Which layer is also considered the visceral pericardium? a. endocardium b. myocardium c. epicardium

Why is high BP damaging to the heart? a. blood would be more viscerous and harder to pump b. the HR slows does to dangerously low levels if BP is too high c. Due to the increased afterload, ventricle must contract more forcefully to expel the same amount of blood

lumen

a central blood-containing space

Chronic hypertension is

a common and dangerous disease that warns of 'increased peripheral resistance.

The sinoatrial (SA) node:

a small mass of cells in the right atrium that spontaneously depolarize (initiate a contraction) about 75 times a minute. the pacemaker of theheart. The rate of contraction can be altered by the sympathetic nervous system,hormones, and electrolytes depolarization wave spreads by gap junctions throughout atria and reaches the atrioventricular (AV) node . There is a 0.1 sec delay to give the atria time to contract before theventricles contract. The delay happens because the fibers are smaller & fewer gap junctions. After this step the impulses speed up again.

Secondary hypertension

accounts for 10% of cases, is due to identifiable disorders-arteriosclerosis, and endocrine disorders such as hyperthyroidism and Cushing's disease. Treatment is directed at the underlying disorder.

Arteries and veins

act simply as conduits for blood. Only the capillaries come into intimate contact with tissue cells and directly serve cellular needs.

cardiac output

amount of blood pumped out by each ventricle in 1 minute. product of heart rate (HR) and stroke volume .

Which of the following acts on the kidneys and blood vessels to raise blood pressure?

antidiuretic hormone

veins

are blood reservoir

arteries

are conduits

capillaries

are exchange sites

Baroreceptors (BP)

are mechanoreceptors that detect changes in arterial pressure.located in the carotidsinuses and the aortic arch & in nearly every large artery of the neck and thorax. When pressure rises and stretches these receptors, they send signals to the vasomotor center resulting in vasodilation and decline in pressure.

papillary muscles

are projecting and stalk-like and play a role in valve function.

arterioles

are resistance vessels

Blood flows directly from __________ into capillary beds.

arterioles

Ventricular systole -

atria relaxes, the ventricles begin contracting, the AV valves close; the ventricles are now in the isovolumetric contraction phase. Then the semilunar valves open, and blood is expelled from the ventricles to the aorta and pulmonary trunk (ventricular ejection phase)

When arterioles constrict blood :

backs up in the arteries and blood pressure increases. Blood pressure varies directly with the amount of blood in the vascular system. Blood volume varies with age and gender and is usually maintained at about 5 liters in adults.

Lungs:(Blood Flow)

blood flow through the lungs is unusual in many ways. The pathway is short, and the arteries and arterioles are similar to veins and venules in structure (thin walls, large lumens). There is little resistance to blood flow, and less pressure is needed. Arterial pressure in the pulmonary circulation is much lower (about 25/10 versus 120/80). The autoregulatory mechanism is exactly opposite that seen in most tissues (low oxygen causes vasoconstriction). When the air sacs of the lungs are flooded with oxygen-rich air, the pulmonary capillaries become flushed with blood and ready to receive the oxygen. If the air sacs are blocked, the oxygen content in those areas will be low, and blood will largely bypass those areas.

Vascular shock :

blood volume is normal and constant. Poor circulation results from extreme vasodilation that leads to an abnormal expansion of the vascular bed. The huge drop in peripheral resistance is revealed by rapidly falling blood pressure. The most common causes are loss of vasomotor tone due to failure of autonomic nervous system regulation and septicemia.

Primary hypertension

cannot be cured. Most can be controlled by diet, losing weight, and antihypertensive drugs.

Blood vessel diameter

changes often , important factor in altering peripheral resistance. Fluid close to the walls of a channel is slowed by friction as it passes along the wall-fluid in the center of the channel flows more freely and faster. smaller the tube=greater the friction because relatively more fluid contacts the tube walls. Because arterioles are small diameter vessels and can enlarge or constrict in response to neural and chemical controls, they are the major determinants of peripheral resistance.

forms of circulatory shock:

circulatory shock, hypovolemic shock, vascular shock, and cardiogenic shock

Coronary atherosclerosis -

clogging of coronary vessels with fatty buildup, impairs blood and oxygen delivery to cardiac cells

Blood pressure in the elastic arteries

close to the heart reflects two factors: 1. how much those arteries can be stretched 2. the volume of blood forced into them at any time . Blood pressure changes in a regular fashion in the elastic arteries near the heart, and blood flow within them is pulsatile.

Persistent hypertension is

common in obese people because of the total length of their blood vessels is relatively greater than that in thinner people.

Purkinje fibers:

complete the pathway to the apex and then turn superior to depolarize the contractile cells of both ventricles, which spread throughout the ventricles via gap junctions between cells. The ventricles then contract from inferior to superior forcing blood into arteries (pulmonary and aorta).

An electrocardiogram (ECG, EKG):

composite of all the action potentials generated by the intrinsic conduction system. It is made possible because the electrical currents generated in and transmitted through the heart spread throughout the body and can be detected. Atrial depolarization( by the SA node) - P wave. atrial depolarization complete, impulse is delayed at the AV node. Ventricular depolarization begins at the apex-QRS complex. During this time atrial repolarization occurs (restoration of ion distribution allowing another depolarization event) the wave is not visible, being drowned out by the large QRS wave. Ventricular depolarization is completed. Ventricular repolarization begins at the apex-T wave. After the T wave, ventricular repolarization is complete

Congestive heart failure -

condition where pumping efficiency (CO) of the heart is so low that blood circulation is inadequate to meet tissue needs

The vessels that exhibit the lowest level of permeability are the __________.

continuous capillaries

Systole:

contraction period of heart (forcing blood out of its chambers)

The nervous system (BP)

controls blood pressure and distribution by altering the diameter of arterioles.

Osmotic pressure:

created by the presence in a fluid of large nondiffusible molecules, such as plasma proteins. Such substances draw water toward them. Osmotic pressure does not vary form one end of the capillary bed to the other. At any point along a capillary, fluids will leave the capillary if net hydrostatic pressure is greater than net osmotic pressure, and fluids will enter if net osmotic pressure exceeds net hydrostatic pressure.

Multiple myocardial infarcts -

decreases pumping efficiency because dead heart cells are replaced by scar tissue

Function of arterial system Muscular arteries, (distributing arteries):

deliver blood to specific body organs and account for most of the named arteries. Their diameter ranges from that of a little finger to that of a pencil lead. They have the thickest tunica media of all vessels. Their tunica media contains smooth muscle and less elastic tissue. more active in vasoconstriction and are less distensible.

The sympathetic nervous system(BP)

enervates the smooth muscle layer of blood vessels (arterioles) via- a potent vasoconstrictor.

Fenestrated capillaries

essentially similar to the continuous variety except that some of the endothelialcells are riddled with oval pores/fenestrations (windows). The fenestrations are usually covered by a very delicate membrane , so this variety has greater permeability to fluids and small solutes. They are found where active capillary absorption occurs, (such as in the small intestines, and in endocrine organs) which allow hormones to gain rapid entry into the blood. Fenestrated capillaries with perpetually open pores occur in the kidneys, where rapid filtration is essential. Highly modified, leaky capillaries (sinusoids) connect the arterioles and venules in the liver, bone marrow, lymphoid tissues, and some endocrine glands.

Skeletal muscles:(blood flow)

extremely changeable, varies with the degree of muscle activity. Resting skeletal muscles receive about 1 liter of blood per minute, and only about 25% of their capillaries are open. During this time, myogenic and general neural mechanisms predominate. When muscles become active, blood flow increases in direct proportion to their greater metabolic activity (active or exercise hyperemia). During vigorous exertion, blood flow can increase tenfold or more, and virtually all capillaries are open. Autoregulation occurs almost entirely in response to the decreased oxygen concentration. Systemic adjustments occur to ensure that more blood reaches the muscles. Vasoconstriction of vessels in the digestive viscera and skin diverts blood away from these areas temporarily.

Hydrostatic pressure:

force exerted by fluid pressing against a wall. In capillaries, hydrostatic pressure is the same as capillary blood pressure -- pressure of blood against the capillary wall. Capillary hydrostatic pressure is also called filtration pressure because it forces fluids through the capillary walls. Hydrostatic forces dominate at the arterial end while osmotic forces dominated at the venous end. Thus, net fluid flows out of the circulation at the arterial ends of the capillary beds and into the blood stream at the venous end. More fluid enters the tissue spaces than is returned to the blood. This fluid and any leaked proteins are picked up by the lymphatic vessels

Blood Vessels

form the closed delivery system that begins and ends at the heart. They are dynamic structures that pulsate, constrict, and relax, and even proliferate.

Function of arterial system Arterioles:

have a lumen smaller than 0. 3 mm , smallest of the arterial vessels. The largest of the arterioles exhibit all three tunics, but the tunica media is chiefly smooth muscle with few elastic fibers. Blood flow into the capillary beds determined by alterations in arteriole diameter in response to changing neural stimuli and local chemical influences. When arterioles constrict the tissues served are largely bypassed. When arterioles dilate, blood flow into the local capillaries increases .

Dilated cardiomyopathy -

heart enlargement; ventricles stretch and have decreased contractility

Abnormal heart sounds:

heart murmurs-Unobstructed blood flows silently. If theres obstructions, the turbulence generates heart murmurs.

Systemic blood pressure

highest in the aorta and declines throughout the length of the pathway to finally reach 0mm Hg in the right atrium. The steepest change in pressure occurs in the arterioles, which offer the greatest resistance to blood flow. So long as a pressure gradient exits, blood flow continues until it completes the circuit back to the heart.

variations from normal blood pressure

hypotension and hypertension

The net result of autoregulation is:

immediate vasodilation of the arterioles serving the capillary beds of needy tissues, and blood flow to the area is temporarily increased. This is accompanied by relaxation of precapillary sphincters allowing blood to surge through the true capillaries.

covering of heart :

in order: double walled pericardium--> outer fibrous pericardium( protects heart and anchors to surrounding structures: diaphram , sternum, and great vessels)--> outer serous pericardium(parietal pericardium:fused to outer fibrous peri.)--> serous fluid(prevents friction damage as heart contracts)--> inner serous pericardium(visceral pericardium:covers hearts external surface)--> heart wall--> heart

Hypercalcemia (affects HR)

increases heart irritability, can lead to spastic heart contraction.

Blood flow would be increased by __________.

increasing cardiac output

Too much sodium(affects HR)

inhibits transport of calcium, thus blocking heart contraction.

Excess potassium (affects HR)

interferes with depolarization and may lead to heart block and cardiac arrest.

The activity of the vascular smooth muscle

is regulated by vasomotor fibers of the sympathetic system. Depending on the needs of the body, the vasomotor fibers can cause either vasoconstriction or vasodilation.

Venous blood pressure

is steady and changes very little during the cardiac cycle.

heart

is the pump

Sinusoids

large, irregularly shaped lumens, and are usually fenestrated. These modifications allow large molecules to pass between blood and surrounding tissues. Blood flows sluggishly through the sinusoid channels, allowing time for it to be processed or modified in various ways (absorbing nutrients, removing and destroying microbes).

Function of arterial system Elastic arteries

large, thick-walled vessels near the heart( ex.aorta and its major branches.) largest and most elastic in arterial system . Their large-diameter lumen allows them to serve as low-resistance conduits. The elastic arteries contain more elastin than any other vessel type. The abundance of elastin enables these arteries to withstand and smooth out large pressure fluctuations by expanding when the heart forces blood into them, and then recoiling to propel blood onward into the circulation when the heart relaxes. The alternating expansion and recoil of elastic arteries during each cardiac cycle creates a pressure wave called a pulse. The arterial pulse rate reflects heart rate.

Blood flows from the lungs to the __________ via the __________.

left atrium; pulmonary veins

The atrioventricular valves (AV):

located at the junctions of the atria and theyre respective ventricles and prevent backflow into the atria when ventricles are contracting. The right AV valve, the tricuspid, has 3 valve flaps/cusps. The left AV valve/mitral valve, the bicuspid, has two. Attached to AV valve flaps are tiny white collagen cords -chordae tendineae ("heart strings") that anchor the cusps to the papillary muscles protruding from the ventricular walls. When heart is relaxed, the AV valve flaps hang open. Blood flows through the atria into the ventricles. When the ventricles contract, pressure rises in the ventricle and forces blood against the valve flaps- closing the valve. The chordae tendineae and papillary muscles anchor the valve flaps in the closed position. If the cusps where not anchored in this manner, they would be blown upward into the atria.

atrioventricular (AV) node:

located in the inferior portion of the interatrial septum. the nerve fibers spread the depolarization wave through the atrioventricular bundle (bundle of His) . the AV bundle splits into right and left bundle branches which continue down the interventricular septum.

atrioventricular bundle(bundle of His):

located in the interventricular septum.

vessel length

longer the vessel= greater resistance. Since viscosity and vessel length are normally unchanging, these factors are constant.

Chronic hypotension

may hint at poor nutrition because the poorly nourished are often anemic and have inadequate levels of plasma proteins.

regulation of heart rate:

most important influences on heart rate are from autonomic nervous system. When the sympathetic nervous system is activated, norepinephrine is released causing the heart to beat faster and to contract more forcibly. Activation of the parasympathetic division opposes the sympathetic effects and reduces heart rate via the release of acetylcholine. Hormones such as epinephrine produces the same effects as norepinephrine. Thyroxine causes a slower but more sustained increase in heart rate when it is released in large quantities. Reduced blood levels of ionic calcium depress the heart. Other factors including age, gender, exercise, and body temperature also influence heart rate.

Heart:(blood flow)

movement of blood through the smaller vessels of the heart is influenced by aortic pressure and the pumping activity of the ventricles. When the ventricles contract, the coronary vessels are compressed, and blood flow stops. As the heart relaxes, the high aortic pressure forces blood through the circulation. Under resting conditions, blood flow through the heart is about 250ml/min. During strenuous exercise, the coronary vessels dilated in response to a local accumulation of ADP and carbon dioxide, and blood flow can increase 3 to 4 times. This increased blood flow is important because cardiac cells use as much as 65% of the oxygen carried to them in blood under resting conditions (most other tissue use 25%). Increased blood flow is the only way to make sufficient oxygen available

Cardiogenic shock is most likely to result from __________.

multiple heart attacks

Fluids would be likely to leave or filter out of the capillary if __________.

net hydrostatic pressure (HP) is greater than net osmotic pressure (OP)

Match the following terms to their correct descriptions. Choices: nitric oxide angiotensin II stretch of vascular smooth muscle sympathetic impulses Matches: hormonal control of blood flow nervous system control of blood flow metabolic control of blood flow myogenic control of blood flow

nitric oxide -- metabolic control of blood flow stretch of vascular smooth muscle -- myogenic control of blood flow sympathetic impulses -- nervous system control of blood flow angiotensin II -- hormonal control of blood flow

Cardiogenic shock, or pump failure :

occurs when the heart is so inefficient that it cannot sustain adequate circulation. It's usually cause is myocardial damage from numerous myocardial infarcts.

Peripheral resistance is

opposition to flow ,measure of the amount of friction the blood encounters passing through the vessels. Most friction is encountered in the peripheral circulation. There are three important sources of resistance: 1. blood viscosity 2. vessel length 3. vessel diameter

inferior ventricles:

pumps blood out of heart . The right ventricle pumps blood to pulmonary arteries carriying blood to the lungs. left ventricle ejects blood into aorta carrying blood to the body. Marking the internal ventricle walls are irregular muscle ridges called trabeculae carneae.

Venules

range are about 8-100μm in diameter, and are formed when capillaries unite. The smallest venules (postcapillaryvenules) consist entirely of endothelium around which a few fibroblasts congregate. The venules are extremely porous, and inflammatory fluid and WBC's move easily from the blood stream through their walls. Venules join to form veins, which usually have three distinct tunics, but their walls are always thinner and their lumens larger than those of corresponding arteries.

diastole:

relaxation period of heart (allowing its chambers to refill with blood)

Blood viscosity is

resistance to flow and related to the thickness/stickiness of a fluid. greater the viscosity, =less easily molecules pass one another.

blood enters the right atrium via three veins:

returns blood from body regions: superior vena cava- superior to diaphram inferior vena cava-inferior to diaphram coronary sinus-collects blood draining from myocardium

vascular shunt (metarteriole-thoroughfare channel) -

short vessel connects the arteriole and venule at opposite ends of the capillary bed.

Which of the following would experience increased blood flow during exercise?

skin

Blood from the brain is returned to the heart via the __________.

superior vena cava

Match the following terms to their correct descriptions. Choices: pulse pressure systolic pressure diastolic pressure mean arterial pressure Matches: lowest level of aortic pressure the difference between systolic and diastolic pressure peak of aortic pressure pressure that propels blood to the tissues

systolic pressure -- peak of aortic pressure diastolic pressure -- lowest level of aortic pressure pulse pressure -- the difference between systolic and diastolic pressure mean arterial pressure -- pressure that propels blood to the tissues

Blood flow is

the actual volume of blood flowing through a vessel, an organ, or the entire circulation in a given period of time. For the entire vascular system, blood flow is = to cardiac output.

Blood pressure is

the force per unit area exerted on the wall of a blood vessel by blood.Differences in pressure within the vascular system provide force that keeps blood moving through the system. The term blood pressure means- systemic arterial blood pressure in the largest arteries near the heart. in terms of millimeters of mercury.

Persistent high blood pressure -

the heart must work harder to pump the blood against the pressure exerted by arterial blood

Prolonged hypertension is

the major cause of heart failure, vascular disease, renal failure and strokes.Because the heart has to work harder, the myocardium enlarges, the heart weakens and its walls become flabby. The vessels also develop small tears 'in the endothelium and accelerate the progress of atherosclerosis. As the vessels become increasingly blocked, blood flow to the tissues becomes inadequate, and vascular complications of vessels 'in the brain, retinas heart and kidneys begin to appear.

Hypovolemic shock :

the most common form of shock. It results from large-scale blood loss such as might follow acute hemorrhage, severe vomiting or diarrhea, or extensive bums. If blood volume drops rapidly, heart rate increases, creating a weak, "thready" pulse. Intense vasoconstriction alsooccurs moving blood away from blood reservoirs into the major circulatory channels. Blood pressure is stable at first, but eventually drops if blood volume loss continues. The key to management is fluid replacement as quickly as possible.

Blood vessel diameter changes

the most important influence on pressure and blood flow patterns. Very small changes in diameter can produce substantial changes in resistance and blood pressure, because resistance varies inversely with the fourth power of vessel radius. if the radius of a vessel is doubled=resistance is then 1/16 as much

this valve is found between the right atrium and the right ventricle a. mitral b. bicuspid c. tricuspid d. semilunar

Brain:(blood flow)

total blood flow to the brain averages about 750 ml/min and is maintained at relatively constant levels. Cerebral blood flow is regulated by one of the most precise autoregulatory systems in the body and is tailored to local neuronal need. Brain tissue is exceptionally sensitive to declining pH and increased carbon dioxide. Oxygen deficits are much less potent stimulus for autoregulation. Greatly excessive carbon dioxide levels abolish autoregulatory mechanisms and severely depress brain activity. The brain also has myogenic mechanisms that protect it from possible damaging changes in blood pressure. Fainting occurs when mean arterial pressure falls below 60 mm Hg and cerebral edema is the usual result of pressures over 160mm Hg.

The vessel layer that has a direct role in vasoconstriction is the __________.

tunica media

When would the capillary beds surrounding the gastrointestinal organs be open?

when digesting a meal

24. Select the correct statement about the function of myocardial cells. A) The refractory period in skeletal muscle is much longer than that in cardiac muscle. B) Cardiac muscle cells are innervated by sympathetic, parasympathetic, and somatic nerve fibers so that the nervous system can increase heart rate. C) The entire heart contracts as a unit or it does not contract at all. D) The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.

C) The entire heart contracts as a unit or it does not contract at all.

8. The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________. A) pericarditis B) myocardial infarct C) angina pectoris D) ischemia

C) angina pectoris

22. When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________. A) tracing out where the auricles connect B) locating the base C) noticing the thickness of the ventricle walls D) finding the papillary muscles

C) noticing the thickness of the ventricle walls

34. When does the period of atrial repolarization occur? A) during the T wave B) ventricular contraction C) ventricular depolarization D) during the P wave

C) ventricular depolarization

21. The atrioventricular (AV) valves are closed ________. A) when the ventricles are in diastole B) while the atria are contracting C) when the ventricles are in systole D) by the movement of blood from atria to ventricles

C) when the ventricles are in systole

capillary structure:

Capillaries are the smallest blood vessels. Their thin walls consist of a thin tunica intima.The average capillary length is 1 mm and the average lumen diameter is 8-1 0 μm just large enough for RBC's to slip through. capillaries are ideally suited for their role in exchange of materials between the blood and interstitial fluid. Structurally, capillaries are classified as: 1. continuous 2. Fenestrated Continuous capillaries are abundant in the skin and muscles. They are continuous in the sense that their endothelial cells provide an uninterrupted lining.

capillary function:

Capillaries do not function independently; they tend to form interweaving networks called capillary beds. In most body regions, a capillary bed consists of two types of vessels: 1. vascular shunt (metarteriole-thoroughfare channel) 2. true capillary

blood flow through capillaries:

Capillaries: blood flow is slow and intermittent, rather than steady (vasomotion), and reflects the "on-off' opening and closing of the precapillary sphincters. Fluid movements: fluid (water + solutes) is forced out of the capillaries through the clefts at the arterial end of the bed, but most is returned at the venous end. In theory, blood pressure -- which forces fluid out of the capillaries -is opposed by hydrostatic pressure of the interstitial fluid (back pressure).

Cardiac muscle cells have several similarities with skeletal muscle cell. Which one is NOT a simularity? a. cells are each innervated by a nerve ending b. cells store Ca ions in sarcoplasmic reticulum c. cells contain sacromeres d. cells depolarize when Na ions enter cytoplasm

Hepatic portal system -

Carries nutrient-rich blood from the digestive organs to the liver where it can be processed before going to the rest of the body. Capillary beds of the intestines -mesenteric veins -hepatic portal vein (also receives input from splenic vein) -liver (sinusoidal capillaries) -hepatic veins -inferior vena cava

Circulatory shock:

Condition in which blood vessels are inadequately filled and blood cannot circulate normally. If this condition persists, cell death and organ damage occurs.

10) Which of the following signs of hypovolemic shock is a relatively late sign? A) cold, clammy skin B) increased heart rate C) rapid, thready pulse D) rapidly falling blood pressure

13) Which of the following is true about veins? A) Venous valves are formed from the tunica media. B) Up to 35% of total body blood is in venous circulation at any given time. C) Veins have a small lumen in relation to the thickness of the vessel wall. D) Veins are called capacitance vessels or blood reservoirs.

14) Which of the following is not an age-related change affecting the heart? A) atherosclerosis B) decline in cardiac reserve C) fibrosis of cardiac muscle D) thinning of the valve flaps

14) Which of the following processes provides a long-term response to changes in blood pressure? A) neural controls B) baroreceptor-initiated reflexes C) chemoreceptor-initiated reflexes D) renal regulation

17) Norepinephrine acts on the heart by ________. A) decreasing heart contractility B) causing a decrease in stroke volume C) blocking the action of calcium D) causing threshold to be reached more quickly

2) Which of the following chemicals does not help regulate blood pressure? A) ADH B) atrial natriuretic peptide C) angiotensin II D) nitric acid

21) Which of these vessels receives blood during ventricular systole? A) aorta only B) pulmonary arteries only C) pulmonary veins only D) both the aorta and pulmonary trunk

25) Select the correct statement about the heart valves. A) The mitral valve separates the right atrium from the right ventricle. B) The tricuspid valve divides the left atrium from the left ventricle. C) Aortic and pulmonary valves control the flow of blood into the heart. D) The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.

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

27) Select the correct statement about the structure of the heart wall. A) The fibrous skeleton forms the bulk of the heart. B) Connective tissue in the heart wall aids in the conduction of the action potential. C) The heart chambers are lined by the endomysium. D) The myocardium is the layer of the heart that actually contracts

27) Which of the choices below does not involve tissue perfusion? A) delivery of oxygen and nutrients to, and removal of wastes from, tissue cells B) gas exchange in the lungs C) absorption of nutrients from the digestive tract D) blood clotting

28) Which of the following do not influence arterial pulse rate? A) activity B) postural changes C) emotions D) the vessel selected to palpate

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

34) Factors that aid venous return include all except ________. A) activity of skeletal muscles B) pressure changes in the thorax C) venous valves D) urinary output

36) Select the correct statement about factors that influence blood pressure. A) An increase in cardiac output corresponds to a decrease in blood pressure, due to the increased delivery. B) Systemic vasodilation would increase blood pressure, due to diversion of blood to essential areas. C) Excess protein production would decrease blood pressure. D) Excess red cell production would cause a blood pressure increase.

38) The velocity of blood flow is ________. A) in direct proportion to the total cross-sectional area of the blood vessels B) slower in the arteries than in capillaries because arteries possess a relatively large diameter C) slower in the veins than in the capillaries because veins have a large diameter D) slowest in the capillaries because the total cross-sectional area is the greatest

39) Select the correct statement about blood flow. A) It is relatively constant through all body organs. B) It is measured in mm Hg. C) It is greatest where resistance is highest. D) Blood flow through the entire vascular system is equivalent to cardiac output.

40) A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to the ________. A) left side of the head and neck B) myocardium of the heart C) left upper arm D) right side of the head and neck and right upper arm

42) A patient with essential hypertension might have pressures of 200/120 mm Hg. This hypertensive state could result in all of the following changes except ________. A) increased work of the left ventricle B) increased incidence of coronary artery disease C) increased damage to blood vessel endothelium D) decreased size of the heart muscle

48) What do the ductus arteriosus and the foramen ovale become at birth? A) ligamentum teres; fossa ovalis B) fossa ovalis; ligamentum arteriosum C) ligamentum arteriosum; ligamentum teres D) ligamentum arteriosum; fossa ovalis

49) Which of the following would not result in the dilation of the feeder arterioles and opening of the precapillary sphincters in systemic capillary beds? A) a decrease in local tissue oxygen content B) an increase in local tissue carbon dioxide C) a local increase in histamine D) a local increase in pH

5) Damage to the ________ is referred to as heart block. A) SA node B) AV valves C) AV bundle D) AV node

5) Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________. A) arterioles B) arteries C) veins D) capillaries

50) Arteriolar blood pressure increases in response to all but which of the following? A) increasing stroke volume B) increasing heart rate C) rising blood volume D) falling blood volume E) all of these

6) The P wave of a normal electrocardiogram indicates ________. A) ventricular repolarization B) ventricular depolarization C) atrial repolarization D) atrial depolarization

6) Which of the following statements regarding the hepatic portal system is false? A) It carries nutrients, toxins, and microorganisms to the liver for processing. B) Its major vessels are the superior mesenteric, inferior mesenteric, and splenic veins. C) It consists of a vein connecting two capillary beds together. D) It branches off of the inferior vena cava.

9) The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________. A) ischemia B) pericarditis C) myocardial infarct D) angina pectoris

20. Which of the following is NOT part of the intrinsic conduction system of the heart? A) sinoatrial (SA) node B) atrioventricular (AV) node C) bundle branches D) atrioventricular (AV) valve

D) atrioventricular (AV) valve

26. Compared to skeletal muscle, cardiac muscle ________. A) has more nuclei per cell B) lacks striations C) cells are larger than skeletal muscle cells D) has gap junctions that allow it to act as a functional syncytium

D) has gap junctions that allow it to act as a functional syncytium

12. Which of the following factors does NOT influence heart rate? A) gender B) body temperature C) age D) skin color

D) skin color

38. While auscultating heart sounds during a checkup, Andy's doctor hears a high-pitched sound during ventricular contraction. Which type of valve could cause this? A) incompetent tricuspid valve B) deficient pulmonary semilunar valve C) insufficient mitral (bicuspid) valve D) stenotic aortic semilunar valve

D) stenotic aortic semilunar valve

35. During exercise, which of the following would occur on an electrocardiogram (ECG) compared to an individual at rest? A) the T wave would decrease B) the P-R interval would decrease C) the S-T segment would decrease D) the time from one R to the R of the next heartbeat would decrease

D) the time from one R to the R of the next heartbeat would decrease

Decreased Stroke volume will__________ cardiac output? a. increase b. decrease c. no change

During isovolumeteric relaxation, what opens the AV valves? a. contraction of ventricles b. ventricles stretching back to resting state c. blood flowing from ventricles to atria d. blood flowing from ventricles to great artery e. atrial pressure is greater than ventricle pressure f. ventricle pressure is greater then atrial pressure

blood flow in special areas:

Each organ has special functions revealed in its pattern of autoregulation.

orthostatic hypotension -

Elderly people are prone, temporary low blood pressure and dizziness when they rise suddenly from a reclining or sitting position. Blood pools in the lower extremities.

Chapters 18 and 19 Cardiovascular system and blood vessels, A&P II: Chapter 18 - The Heart Test Questions, CHAPTER 18- Heart Quiz+ Practice Questions, Chapter 18 Heart Multiple Choice, Chapter 19: The Cardiovascular System: Blood Vessels > Chapter Pr...

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