Chapter 20 vessels
87. What facilitates venous return?
(1) BY VALVES WITHIN THE VEINS (2) TWO PUMPS---SKELETAL MUSCLE PUMP AND RESPIRATORY PUMP
61. What are 3 factors that help determine the amount of blood delivered to a specific organ or tissue? Describe each.
(1) DEGREE OF VASCULARIZATION: EXTENT OF BLOOD VESSEL DISTRIBUTION WITHIN A TISSUE DETERMINES THE POTENTIAL ABILITY OF BLOOD DELIVERY. (2) REGULATORY FACTORS: CHANGES IN METABOLIC ACTIVITY TISSUE DAMAGE PART OF DEFENSE SYSTEM VASOACTIVE CHEMICALS (3) TOTAL BLOOD FLOW: AMOUNT OF BLOOD TRANSPORTED THROUGHOUT THE ENTIRE VASCULAURE IN A GIVEN PERIOD OF TIME
105. What does activation of the vasomotor center and increased nerve signals along sympathetic pathways produce?
(1) INCREASED PERIPHERAL RESISTANCE (2) LARGER CIRCULATING BLOOD VOLUME & (3) REDISTRIBUTION OF BLOOD FLOW
47. Give specific examples of materials that are exchanged through diffusion in the capillaries.
(1) WITHIN SYSTEMIC CAPILLARIES, SUBSTANCES SUCH AS OXYGEN, HORMONES, AND NUTRIENTS MOVE BY DIFFUSION FROM HIGH CONCENTRATION IN BLOOD INTO INTERSTITIAL FLUID AND THEN INTO TISSUE CELLS. (2) CARBON DIOXIDE AND WASTES DIFFUSE FROM HIGHER CONCENTRATION IN TISSUE CELLS TO LOWER CONCENTRATION IN BLOOD. (3) VERY SMALL SOLUTES (E.G., OXYGEN, CARBN DIOXIDE, GLUCOSE, IONS) AND FLUIDS MAY DIFFUSE VIA ENDOTHELIAL CELLS OR INTERCELLULAR CLEFTS (4) LARGER SOLUTES (SUCH AS SMALL PROTEINS) MUST PASS THROUGH FENESTRATIONS OR GAPS IN SINUSOIDS.
19. What is the typical size of a capillary?
1 MM IN LENGTH WITH A DIAMETER OF 8-10 MICROMETERS, JUST SLIGHTLY LARGER THAN THE DIAMETER OF A SINGLE ERYTHROCYTE.
28. At any given time how much of the capillary beds are open? What percent of blood is moving through the capillaries at any given moment?
25% of capillary beds 5% of the total blood volume
85. What is blood pressure on the arterial end of the capillary compared to the venous end of the capillary?
40 MM Hg ON ARTERIAL END, <20 MM Hg ON VENOUS END
25. Describe the relationship of a metarteriole, thoroughfare channel, postcapillary venule, true capillaries, and precapillary sphincter.
A CAPILLARY BED IS FED BY A METARTERIOLE, WHICH IS A VESSEL BRANCH OF AN ARTERIOLE. THE PROXIMAL PART OF THE METARTERIOLE IS ENCIRCLED BY SCATTERED SMOOTH MUSCLE CELLS, WHEREAS THE DISTAL PART (CALLED THE THOROUGHFARE CHANNEL) HAS NO SMOOTH MUSCLE CELLS. THE THOROUGHFARE CHANNEL CONNECTS TO A POSTCAPILLARY VENULE WHICH DRAINS THE CAPILLARY BED. VESSELS CALLED TRUE CAPILLARIES BRANCH FROM THE METARTERIOLE AND MAKE UP BULK OF CAILLARY BED. AT THE ORIGIN OF EACH TRUE CAPILLARY, A SMOOTH MUSCLE RING CALLED THE PRECAPILLARY SPHINCTER CONTROLS BLOOD FLOW INTO TRUE CAPILLARIES.
104. What are the 2 primary receptors associated with the smooth muscle within the wall of each blood vessel? How does each work? Where is each found?
ALPHA RECEPTORS: MORE COMMON IN BODY VESSELS CONTRACT IN RESPONSE TO SYMPATHETIC STIMULATION, RESULTING IN VASOCONSTRICTION. BETA RECEPTORS: BLOOD VESSELS IN SKELETAL MUSCLE AND THE CORONARY VESSELS VESSELS RELAX IN RESPONSE TO EPINEPHRINE, RESULTING IN VASODILATION
88. To what does circulatory shock refer?
ANYSTATE IN WHICH THERE IS INSUFFICIENT BLOOD FLOW FOR ADEQUATE PERFUSION OF THE BODY'S TISSUES, TYPICALLY DUE TO IMPAIRED PUMPING OF THE HEART OR TO LOW VENOUS RETURN
107. What are the 2 main baroreceptors for the cardiovascular system? What is their specific role? Where is each found? Through which nerve are nerve impulses from each carried back to cardiovascular system?
AORTIC ARCH BARORECEPTORS: IMPORTANT IN REGULATING SYSTEMIC BLOOD PRESSURE LOCATED IN TUNICA EXTERNA OF AORTIC ARCH VAGUS NERVE CAROTID SINUSES: IMPORTANT IN MONITORING BLOOD PRESSURE CHANGES IN THE HEAD AND NECK LOCATED IN TUNICA EXTERNA OF EACH INTERNAL CAROTID ARTERY
1. Which blood vessels convey blood away from the heart to the capillaries? Which microscopic, relatively porous blood vessels are where exchange of substances between blood and tissues occurs? Which blood vessels drain blood from the capillaries, transporting blood back to the heart?
ARTERIES, CAPILLARIES, VEINS
31. With what are venules companion vessels?
ARTERIOLES
44. What is the sequence of vessels in a portal system?
ARTERY, CAPILLARY BED, PORTAL VEIN, CAPILLARY BED, AND VEIN
14. What is a progressive disease of the elastic and muscular arteries characterized by the presence of an atheroma (or atheromatous plaque) which leads to thickening of the tunica intima and narrowing of the lumen?
ATHEROSCLEROSIS
108. When activated what do baroreceptors initiate?
AUTONOMIC REFLEXES
65. What is the process by which a tissue itself regulates or controls its local blood flow in response to its changing metabolic needs?
AUTOREGULATION
106. What are specialized sensory nerve endings that respond to the stretch in blood vessel walls?
BARORECEPTORS
43. What is a portal system? Give 2 examples.
BLOOD FLOWS THROUGH TWO CAPILLARY BEDS, WITH THE TWO CAPILLARY BEDS SEPARATED BY A PORTAL VEIN. EXAMPLES: (1) HYPOTHALAMO-HYPOPHYSEAL PORTAL SYSTEM THAT EXTENDS BETWEEN THE HYPOTHALAMUS & THE ANTERIOR PITUITARY. (2) HEPATIC PORTAL SYSTEM
54. What is the force exerted by unit area by the blood as it presses against the vessel wall? What does this pressure promote?
BLOOD HYDROSTATIC PRESSURE (HPb) OR SIMPLY BLOOD PRESSURE. IT PROMOTES FILTRATION FROM THE CAPILLARY.
70. What is the force per unit area that blood exerts against the inside wall of a vessel?
BLOOD PRESSURE
90. What are some factors which affect peripheral resistance?
BLOOD VISCOSITY, BLOOD VESSEL LENGTH, AND THE SIZE OF THE LUMEN OF BLOOD VESSELS
112. What are the two main peripheral chemoreceptors? What is their specific role? Where is each found? Through which nerve are nerve impulses from each carried back to cardiovascular system?
BOTH SEND SENSORY INOUT TO CARDIOVASCULAR CENTER AORTIC BODIES: LOCATED IN ARCH OF AORTA VAGUS NERVE CAROTID BODY: LOCATED WITHIN EACH EXTERNAL CAROTID ARTERY GLOSSOPHARYNGEAL NERVE
49. What is the movement of large amounts of fluids and their dissolved substances in one direction down a pressure gradient?
BULK FLOW
10. Which vessel is unique in that it only contains the tunica intima composed of an endothelium and its underlying basement membrane there is no subendothelial layer. For what does having only the tunica intima account?
CAPILLARY ALLOWS FOR RAPID GAS AND NUTRIENT EXCHANGE BETWEEN THE BLOOD IN CAPILLARIES AND THE TISSUES.
98. What are the three primary variables that blood pressure is dependent on?
CARDIAC OUTPUT, RESISTANCE, AND BLOOD VOLUME
101. What are the 2 regulatory nuclei housed within the cardiac center?
CARDIOACCELERATORY CENTER AND CARDIOINHIBITORY CENTER
79. What is excess interstitial fluid in the brain called?
CEREBRAL EDEMA
80. What is a thrombus?
CLOT
56. What is the pull of water back into a tissue by the tissue's concentration of proteins (colloid)?
COLLOID OSMOTIC PRESSURE (COP)
8. What are arteries and veins that supply the same body region and tend to lie next to one another? Compare the structure of the two. What does the difference account for in an artery and a vein? Also see Table 20.1.
COMPANION VESSELS; ARTERIES HAVE A THICK TUNICA MEDIA, A NARROWER LUMEN, AND MORE ELASTIC AND COLLAGEN FIBERS THAT IT VENOUS COMPANION. ARTERIAL WALLS CAN SPRING BACK TO SHAPE, AND ARE MORE RESILIENT AND RESISTANCE TO CHANGES IN BLOOD PRESSURE THAN ARE VEINS. VEINS HAVE A THICKER TUNICA EXTERNA, A LARGER LUMEN, AND LESS ELASTIC AND COLLAGENOUS FIBERS THAN ITS COMPANION ARTERY.
13. What are conducting arteries and distributing arteries called?
CONDUCTING ARTERIES ARE ELASTIC ARTERIES DISTRIBUTING ARTERIES ARE MUSCULAR ARTERIES.
22. Where do you find examples of continuous capillaries, fenestrated capillaries, and sinusoids?
CONTINUOUS CAPILLARIES: FOUND IN MUSCLE, THE SKIN, LUNGS, AND CENTRAL NERVOUS SYSTEM FENESTRATED CAPILLARIES: SMALL INTESTINE FOR NUTRIENT ABSORPTION CILIARY PROCESS TO PRODUCE AQUEOUS HUMOR CHOROID PLEXUS TO PRODUCE CEREBROSPINAL FLUID ENDOCRINE GLANDS TO FACILITATE ABSORPTION OF HORMONES INTO BLOOD KIDNEY FOR FILTERING OF BLOOD SINUSOIDS: BONE MARROW FOR ENTRANCE OF FORMED ELEMENTS INTO 3 BLOOD AND TISSUES LIVER AND SPLEEN FOR REMOVING AGED ERYTHROCYTES FROM CIRCULATION AND SOME ENDOCRINE GLANDS FOR FACILITATING MOVEMENT OF HORMONES INTO BLOOD.
21. Distinguish between continuous capillaries, fenestrated capillaries, and sinusoids.
CONTINUOUS CAPILLARIES: MOST COMMON LINING OF ENDOTHELIAL IS COMPLETE BASEMENT MEMBRANE COMPLETE INTERCELLULAR CLEFTS PREVENT MOVEMENT OF LARGE SUBSTANCES INCLUDING FORMED ELEMENTS AND PLASMA PROTEINS, WHILE ALLOWING MOVEMENT OF FLUID CONTAINING SMALL SUBSTANCES SUCH AS GLUCOSE, AMONO ACIDS, AND IONS. FENESTRATED CAPILLARIES: SAME AS CONTIUOUS, EXCEPT ALSO CONTAIN FENESTRATIONS THAT PREVENT FORMED ELEMENTS BUT ALLOW SOME SMALLER PLASMA PROTEINS TO PASS. SINUSOIDS: LINING OF ENDOTHELIAL CELLS IS INCOMPLETE AROUND LUMEN BASEMENT MEMBRANE IS INCOMPLETE FORMED ELEMENTS, LARGE PLASMAPROTEINS, AND PLASMA CAN PASS.
57. Distinguish between COPb and COPif.
COPb is the force that draws fluid back into the blood due to the proteins in bloodCOPif is low because few proteins are present in interstitial fluid.
103. What is the result of increased parasympathetic motor output from cardioinhibitory center?
DECREASES HEARTRATE AND SLOWS THE CONDUCTION OF ELECTRICAL SIGNALS THROUGH THE HEART'S CONDUCTING SYSTEM, DECREASING CARDIAC OUTPUT
46. Give 3 examples of processes of how exchange takes place in the capillaries.
DIFFUSION, VESICULAR TRANSFER, AND BULK FLOW.
75. When is the lowest blood pressure generated in arteries, and how is it recorded?
DURING VENTRICUAR DIASTOLE DIASTOLIC PRESSURE
73. When is the highest blood pressure generated in arteries, and how is it recorded?
DURING VENTRICULAR SYSTOLE SYSTOLIC PRESSURE
11. Distinguish between elastic arteries, muscular arteries, and arterioles.
ELASTIC ARTERIES: HAVE THE LARGEST DIAMETER (2.5-1 CM) AND THE GREATEST PROPORTION OF ELASTIC FIBERS IN THEIR WALLS. MUSCULAR ARTERIES: MEDIUM-SIZED ARTERIES (DIAMETER FROM 1 CM-0.3 MM) WITH MORE SMOOTH MUSCLE ANDFEWER ELASTIC FIBERS TO ENSURE VASOCONSTRICTION HAVE PROPORTIONALLY THICKER TUNICA MEDIA. ELASTIC FIBERS CONFINES TO 2 CIRCUMSCRIBED SHEETS. ARTERIOLES: SMALLEST ARTERIES (DIAMETER FROM .3 MM - 10 MICROMETERS) TUNICA MEDIA 2 COMPOSED OF SIX OR FEWER LAYERSOF SMOOTH MUSCLE CELLS
12. Identify each of the following as elastic arteries or muscular arteries: aorta, pulmonary trunk, brachiocephalic, common carotid, subclavian, common iliac, brachial, anterior tibial, coronary, and inferior mesenteric artery.
ELASTIC: AORTA, PULMONARY TRUNK, BRACHIOCEPHALIC, COMMON CAROTID, SUBCLAVIAN, COMMON ILIAC. MUSCULAR: BRACHIAL, ANTERIOR TIBIAL, CORONARY, INFERIOR MESENTERIC ARTERY
20. What does the term "rouleau" refer to with respect to erythrocytes?
ERYTHROCYTES MUST TRAVEL IN A SINGLE FILE THROUGH EACH CAPILLARY
50. What is the movement of fluid by bulk flow out of the blood through the openings in the capillaries (e.g., fenestrations, intercellular clefts)? Where does it occur?
FILTRATION THE ARTERIAL END OF A CAPILLARY
63. What is angiogenesis? What is an example of this occurring with regard to skeletal muscle? What is the return to the previous state called?
FORMATION OF NEW BLOOD VESSELS IN TISSUES THAT REQUIRE THEM STIMULATION OF SKELETAL MUSCLE IN RESPONSE TO AEROBIC TRAINING REGRESSION IS THE RETURN TO THE PREVIOUS STATE.
23. What forms the blood-brain barrier?
FORMED BY MODIFIED CONTINUOUS CAPILLARIES THAT HAVE THICKENED BASEMENT MEMBRANES AND NO INTERCELLULAR CLEFTS.
37. What is the structure of valves in veins? To which heart valves are they similar?
FORMED PRIMARILY OF TUNICA INTIMA AND STRENGTHENED BY ELASTIC AND COLLAGEN FIBERS SIMILAR TO SEMILUNAR VALVES OF HEART
53. What is the physical force exerted by a fluid on a structure?
HYDROSTATIC PRESSURE (HP)
52. What are the two opposing forces at the capillary level that determine the direction of movement?
HYDROSTATIC PRESSURE AND COLLOID OSMOTIC PRESSURE
110. Describe the following: hypertension, hypotension, arteriosclerosis, orthostatic hypotension
HYPERTENSION: CHRONICALLY ELEVATED BLOOD PRESSURE HYPOTENSION: CHRONICALLY LOW BLOOD PRESSURE ARTERIOSCLEROSIS: THICKENED ARTERIOLE WALLS WITH REDUCED LUMINAL DIAMETER ORTHOSTATIC HYPOTENSION: OR POSTURAL HYPOTENSION A DROP IN BLOOD PRESSURE WHEN AN INDIVIDUAL SUDDENLY CHANGES POSITION
84. With regard to distance to heart, where are pulse pressure and mean arteria pressure the highest?
IN ARTERIES CLOSEST TO THE HEART, SUCH AS THE AORTA
102. What is the result of increased sympathetic motor output from cardioacceleratory center?
INCREASES BOTH HEARTRATE AND FORCE OF CONTRACTION, INCREASING CARDIAC OUTPUT
81. In what individuals is a DVT more likely? What is the most common site for a deep vein thrombosis (DVT)? What are initial signs of DVT? What is the most serious complication of DVT?
INDIVIDUALS WITH HEART DISEASE OR THOSE WHO ARE INACTIVE OR BEDRIDDEN DVT MORE LIKELY IN VEINS IN CALF (SURAL) REGION. INITIAL SIGNS OF DVT INCLUDE FEVER, TENDERNESS AND REDNESS IN AFFECTED AREA, SEVERE PAIN AND SWELLING IN AREAS DRAINED BY AFFECTED VEIN, AND RAPID HEARTBEAT MOST SERIOUS COMPLICATION IS PULMONARY EMBOLUS, IN WHCH A BLOOD CLOT BREAKS FREE AND TRAVELS TO THE LUNG
67. What is the condition that occurs when local blood flow is also regulated when vasoactive chemicals are released from damaged tissues, leukocytes, and platelets in response to tissue damage?
INFLAMMATION
55. What is the force of the interstitial fluid on the external surface of the blood vessel?
INTERSTITIAL FLUID HYDROSTATIC PRESSURE (HPif)
(Page 779) 42. What is an anastomosis? Distinguish between 3 types and include examples.
JOINING TOGETHER OF BLOOD VESSELS ARTERIAL ANASTOMOSIS: INCLUDES 2 OR MORE ARTERIES CONVERGING TO SUPPLY SAME BODY REGION. EX: SUPERIOR AND INFERIOR EPIGASTRIC ARTERIES THAT SERVE ABDOMINAL WALL. VENOUS ANASTOMOSIS: INCLUDES 2 OR MORE VEINS DRAINING THE SAME BODY REGION. EX: VEINS THAT DRAIN UPPER LIMB INCUDING BASILIC, BRACHIAL, AND CEPHALIC. ARTERIOVENOUS ANASTOMOSIS: SHUNT TRANSPORTS BLOOD FROM AN ARTERY DIRECTLY INTO A VEIN, BYPASSING THE CAPILLARY BED. EX: PRESENT IN FINGERS, TOES, PALMS, AND EARS AND ALLOW THESE AREAS TO BE BYPASSED IF THE BODY IS BECOMING HYPOTHERMIC (COLD)
60. What is the blood delivered to the capillaries of a specific tissue and is measured in milliliters per minutes?
LOCAL BLOOD FLOW
83. What is the average measure of the blood pressure forces on the arteries? Because diastolic pressure usually lasts slightly longer than systolic pressure, how is it calculated? Why is it clinically significant?
MEAN ARTERIAL PRESSURE (MAP) MAP= DIASTOLIC PRESSURE + 1/3 PULSE PRESSURE MAP PROVIDES A NUMERICAL VALUE FOR HOW WELL BODY TISSUES ARE PERFUSED.
62. What are examples of organs that are highly vascularized? What are examples of some with little vascularization?
MUCH VASCULARIZATION: ORGANS THAT ARE VERY ACTIVE METABOLICALLY, SUCH AS THE BRAIN, SKELETAL MUSCLE, HEART, & LIVER. LITTLE VASCULARIZATION: TENDONS & LIGAMENTS
58. What is the difference between the net hydrostatic pressure (difference between the blood and interstitial fluid hydrostatic pressures) and the net colloid osmotic (difference between the blood and the interstitial fluid colloid osmotic pressures) pressure? What is the formula (which is a variation of Starling's Law) for NFP?
NET FILTRATION PRESSURE (NFP) = (HPb - HPif) - (COPb - COPif)
7. What is the vasa vasorum?
NETWORK OF SMALL ARTERIES THAT SUPPLY BLOOD TO VERY LARGE VESSELS
24. Do capillaries function independently? If not, how?
NO, A GROUP OF CAPILLARIES (10-100) FUNCTION TOGETHER AND FORM A CAPILLARY BED
48. Describe how vesicular transport occurs and include examples of materials exchanged in this way.
OCCURS WHEN ENDOTHELIAL CELLS USE PINOCYTOSIS TO FUSE FLUIDFILLED VESICLES WITH PLASMA MEMBRANE CERTAIN HORMONES (LIKE INSULIN) AND FATTY ACIDS TRANSPORTED IN THIS WAY
59. How much of the fluid is typically reabsorbed at the venous end of the capillary? What happens to the rest?
ONLY ABOUT 85% LYMPHATIC SYSTEM IS RESPONSIBLE FOR PICKING IT UP AND RETURNING IT TO THE VENOUS CIRCULATION.
17. What is an aneurysm? Where are they most likely to occur?
PART OF ARTERIAL WALL THINS AND BALLOONS OUT, MAKING THE WALL MORE PRONE TO RUPTURE, WHICH CAN CAUSE MASSIVE BLEEDING AND MAY LEAD TO DEATH. MORE COMMONLY OCCUR IN THE ARTERIES AT THE BASE OF THE BRAIN OR IN THE AORTA.
29. What is the specific amount of blood entering capillaries per unit time per gram of tissue?
PERFUSION
38. Compare the blood distribution of the body at rest with regard to pulmonary circulation, the heart, and the systemic circulation.
PULMONARY CIRCULATION ~18% HEART ~12% SYSTEMIC CIRCULATION ~70%4
74. What is the rhythmic throbbing of an arterial wall as blood is being pumped through it? Why is its recording significant clinically?
PULSE (1) ALLOWS US TO INDIRECTLY DETERINE THE RATE OF HEARTBEAT(2) IT CAN INFORM ABOUT BLOOD PRESSURE (3) ITS ABSENCE TO DETERMINE IF BLOOD FLOW TO A PART IS LACKING
77. What is the additional pressure placed on the arteries from when the heart is resting to when the heart is contracting? How is it recorded? Why is it significant?
PULSE PRESSURE. PULSE PRESSURE IS THE DIFFERENCE BETWEEN THE SYSTOLIC AND DIASTOLIC BLOOD PRESSURE. SIGNIFICANT BECAUSE IT IS A MEASURE OF THE ELASTICITY AND RECOIL OF ARTERIES.
76. How is arterial blood pressure expressed? What is an average recording?
RATIO OF SYSTOLIC BLOOD PRESSURE TO DIASTOLIC BLOOD PRESSURE 120/80 MM Hg
51. What is the movement of fluid by bulk flow in the opposite direction, back into the blood? Where does it occur?
REABSORPTION THE VENOUS END OF A CAPILLARY
40. This relatively large amount of blood within veins allows veins to function as blood ____.
RESERVOIRS
89. What is the amount of friction the blood experiences as it travels through the blood vessels? What causes this?
RESISTANCE CARDIAC OUTPUT, RESISTANCE, AND BLOOD VOLUME
111. Are chemoreceptors more important in regulating respiration or blood pressure? How do they work with regard to regulating blood pressure?
RESPIRATION INITIATE CHEMORECEPTOR REFLEXES, WHCH ARE NEGATIVE FEEDBACK LOOPS
41. Distinguish between simple or alternative pathways of blood vessels.
SIMPLE: USE ONE MAJOR ARTERY, ONE CAPILLARY BED, AND ONE MAJOR VEIN TO DELIVER BLOOD TO A REGION. ALTERNATIVE: DIFFER IN NUMBER OF ARTERIES, CAPILLARY BEDS, OR VEINS THAT SERVE AN ORGAN OR REGION MAY INCLUDE ANASTOMOSES AND PORTAL SYSTEMS
34. Distinguish between small, medium-size, and large veins.
SMALL AND MEDIUM-SIZED VEINS ARE COMPANION VESSELS WITH MUSCULAR ARTERIES, WHEREAS THE LARGEST VEINS TRAVEL WITH ELASTIC ARTERIES.
18. What is meant by vasomotor tone and what regulates it? Do arterioles have a significant role in regulating systemic blood pressure and blood flow to different areas of the body?
SMOOTH MUSCLE IN THE ARTERIOLES USUALLY IS AT LEAST PARTIALLY CONSTRICTED REGULATED BY VASOMOTOR CENTER IN BRAINSTEM YES, ARTERIOLES PLAY A SIGNIFICANT ROLE.
26. How does sphincter relaxation and sphincter contraction differ?
SPHINCTER RELAXATION PERMITS BLOOD FLOW INTO TRUE CAPILLARIES, WHEREAS SPHINCTER CONTRACTION CAUSES BLOOD TO FLOW DIRECTLY FROM METARTERIOLE AND THOROUGHFARE CHANNEL INTO THE POSTCAPILLARY VENULE WITH BLOOD BYPASSING THE CAPILLARY BED
109. Are baroreceptors more effective in sudden, short-term changes or to long-term or chronic blood pressure regulation?
SUDDEN, SHORT-TERM
39. What is the breakdown of systemic circulation for the body at rest with regard to systemic veins, systemic capillaries, and systemic arteries?
SYSTEMIC VEINS 55% SYSTEMIC CAPILLARIES 5% SYSTEMIC ARTERIES 10%
71. What is a blood pressure gradient?
THE CHANGE IN BLOOD PRESSURE FROM ONE END OF A BLOOD VESSEL TO ITS OTHER END
69. How is total blood flow related to cardiac output?
THEY ARE EQUAL. IF CARDIAC OUTPUT INCREASES, TOTAL BLOOD FLOW INCREASES
78. What happens to the arteries as they age or become diseased?
THEY LOSE THEIR ELASTICITY AND EXPAND AND RECOIL LESS READILY, MAKING IT MORE DIFFICULT FOR THE HEART TO PUMP BLOOD
45. What is the function of capillaries?
TO ALLOW FOR THE EXCHANGE OF SUBSTANCES (E.G., RESPIRATORY GASES, NUTRIENTS, WASTES, AND HORMONES) BETWEEN THE BLOOD AND THE SURROUNDING TISSUES
35. Is blood pressure in veins typically low or high?
TOO LOW TO OVERCOME FORCE OF GRAVITY
6. What is the outermost layer of the vessel wall and its tissue makeup? What is its role?
TUNICA EXTERNA COMPOSED OF AREOLAR CONNECTIVE TISSUE THAT CONTAINS ELASTIC AND COLLAGEN FIBERS HELPS ANCHOR VESSEL TO OTHER STRUCTURES
3. What is the innermost layer of a blood vessel wall? Describe its tissue structure. Is it continuous with the endocardium?
TUNICA INTIMA OR TUNICA INTERNA COMPOSED OF AN ENDOTHELIUM (SIMPLE SQUAMOUS EPITHELIUM THAT FACES LUMEN AND THIN SUBENDOTHELIAL MADE UP OF AREOLAR CONNECTIVE, YES
4. What is the middle layer of the vessel wall and it tissue makeup?
TUNICA MEDIA COMPOSED PREDOMINANTLY OF CIRCULARLY ARRANGED LAYERS OF SMOOTH MUSCLE CELLS THAT ARE SUPPORTED BY ELASTIC FIBERS
2. What are the layers of blood vessel walls called? What is the inside space of the vessel, through which blood flows?
TUNICS, LUMEN
16. What is angioplasty?
USED IN TREATMENT OF AN OCCLUDED (BLOCKED) ARTERY BALLOON-TIP CATHETER IS INSERTED INTO ARTERY, BALLOON INFLATED AND STENT IS PLACED IN VESSEL
5. What is vasoconstriction, and what accounts for it? What is vasodilation, and what accounts for it?
VASOCONSTRICTION: NARROWING OF VESSEL LUMEN DUE TO CONTRACTION OF SMOOTH MUSCLE CELLS IN THE TUNICA MEDIA VASODILATION: WIDENING OF VESSEL LUMEN DUE TO RELAXATION OF SMOOTH MUSCLE
68. Which of the following cause vasodilation and/or vasoconstriction? aldosterone, angiotensin II, antidiuretic hormone (ADH), atrial natriuretic peptide (ANP), bradykinin, endothelins, epinephrine, histamine, nitric oxide, norepinephrine, prostaglandins, thromboxanes
VASODILATION: HISTAMINE, BRADYKININ, EPINEPHRINE, NITRIC OXIDE, AND ANP. VASOCONSTRICTION: PROSTAGLANDINS, THROMBOXANES, ENDOTHELINS, ANGIOTENSIN II, ALDOSTERONE, ADH, AND NOREPINEPHRINE
64. Distinguish between two groups of vasoactive chemicals.
VASODILATORS: SUBSTANCES THAT BOTH DILATE ARTERIOLES AND RELAX PRECAPILLARY SPHINCTERS, SO THERE 6 IS INCREASED BLOOD FLOW INTO A CAPILLARY BED. VASOCONSTRICTORS: SUBSTANCES THAT BOTH CONSTRICT ARTERIOLES AND CAUSE CONTRACTION OF PRECAPILLARY SPHINCTERS TO DECREASE BLOOD FLOW INTO A CAPILLARY BED
27. What is the cyclical process of the precapillary sphincters contracting and relaxing at a rate of about 5-10 cycles per minute called?
VASOMOTION
82. What are varicose veins? What are hemorrhoids?
VEINS BECOME DILATED AND TORTUOUS AS VALVES BECOME NONFUNCTIONAL, CAUSING BLOOD TO POOL IN ONE AREA. HEMORRHOIDS ARE VARICOSE VEINS IN THE ANORECTAL REGION.
72. Of what is blood flow pulsing, or pulsatile, in arteries a consequence?
VENTRICLES CONTRACTING AND RELAXING
30. What are the smallest veins and their dimensions?
VENULES MEASURE FROM 8 -100 MICROMETERS IN DIAMETER.
33. When does a venule become a vein?
WHEN ITS DIAMETER IS GREATER THAN 100 MICROMETERS
66. What is reactive hyperemia? Give an example.
WHEN THERE IS A MARKED INCREASE IN BLOOD FLOW TO AN AFFECTED TISSUE. EX: WHEN YOU ENTER A WARM ROOM AFTER BEING OUTSIDE IN THE COLD, CHEEKS TURN RED
9. Can an artery remain patent even without blood in it?
YES, AN ARTERY CAN REMAIN OPEN EVEN WITHOUT BLOOD IN IT.
36. Do veins have valves? If so, what is their significance?
YES, MOST VEINS HAVE VALVES WHICH PREVENT BLOOD FROM POOLING IN THE LIMBS.
