front 1 Lumen | back 1 Central blood-containing space in the vessel |
front 2 Tunica Intima | back 2 innermost tunic, contains the endothelium (the simple squamous epithelium that lines the lumen of all vessels) |
front 3 tunica media | back 3 middle tunic, mostly circularly arranged smooth muscle cells and sheets of elastin |
front 4 Vasoconstriction | back 4 lumen diameter decreases as the smooth muscle contracts- allows more blood flow |
front 5 Vasodilation | back 5 lumen diameter increases as the smooth muscle relaxes - decreases blood flow |
front 6 tunica externa | back 6 outermost layer of a blood vessel wall, composed largely of loosley woven collagen fibers that protect and reinforce the vessel, and achor it to surrounding structure |
front 7 Vasa Vasorum | back 7 In larger vessels, the tunica externa contains a system of these tiny blood vessels |
front 8 Elastic Arteries | back 8 Thick-walled arteries near the heart (the aorta and its major branches) They are also known as pressure reservoirs aka: conducting arteries |
front 9 Muscular arteries | back 9 deliver blood to specific body organs (sometimes called distributing arteries) |
front 10 Arterioles | back 10 smallest of the arteries-lumen diameter ranging from 0.3mm down to 10 Um |
front 11 capillaries | back 11 smallest blood vessels |
front 12 pericytes | back 12 smooth muscle-like cells that stabilize the capillary wall and help control capillary permeability |
front 13 continuous capillaries | back 13 abudant in skin and muscles, these are the most common and have intercellular clefts (least permeable capillary) |
front 14 intercellular clefts | back 14 gaps of unjoined membrane that are large enough to allow limited passage of fluids and small solutes |
front 15 fenestrated capillaries | back 15 riddled with oval pores, or fenestrations and increase permeability (fenestra=window) |
front 16 sinusoid capillaries | back 16 highly modified, leaky capillaries found only in the liver, bone marrow, spleen, and adrenal medulla.most permeable capillary |
front 17 stellate macrophages | back 17 remove and destroy any bacteria (can be found in sinusoid capillaries) |
front 18 capillary beds | back 18 interweaving networks that connect arteriole and venule |
front 19 microcirculation | back 19 flow of blood from an arteriole to a venule (through a capillary bed) |
front 20 What are the two types of vessels that a capillary bed consists of? | back 20 1. Vascular Shunt
|
front 21 vascular shunt | back 21 short vessel that directly connects the arteriole and venule at opposite ends of the bed |
front 22 true capillaries | back 22 actual exchange vessels; number 10-100 per capillary bed |
front 23 terminal arteriole | back 23 an arteriole that divides into capillaries. |
front 24 metarteriole | back 24 vessel structurally intermediate between an ateriole and a capillary (continuous with the thoroughfare channel) |
front 25 thoroughfare channel | back 25 intermediate between a capillary and a venule (connects with the metarteriole) |
front 26 postcapillary venule | back 26 joins with the thoroughfar channel and then drains the capillary bed |
front 27 precapillary sphincter | back 27 surrounds the root of each true capillary at the metarteriole and acts as a valve to regulate blood flow into the capillary |
front 28 Venules | back 28 Capillaries unite to form venules; extremely porous (like capillaries) |
front 29 Veins | back 29 venules join to form veins; walls are always thinner and their lumens larger than those of corresponding arteries, however, veins are usually collapsed and their lumens appear slitlike |
front 30 capacitance vessels & blood reservoirs | back 30 AKA VEINS; with their large lumens,&thin walls, veins can accomodate a fairly large blood volume. |
front 31 How much blood supply can veins hold? | back 31 up to 65% of the body's blood supply at any time (although they are usually only partially filled) |
front 32 Venous Valves | back 32 formed from fold sof the tunica intima, prevent blood from flowing backward |
front 33 Varicose Veins | back 33 veins that are toruous and dilated because of incompetent (leaky) valves |
front 34 Venous sinuses | back 34 highly specialized, flattened veins with etremely thin walls composed only of endothelium |
front 35 anastomoses | back 35 coming together |
front 36 Vascular anastomoses | back 36 blood vessels that form special interconnections |
front 37 arterial anastomoses | back 37 most organs receive blood from more than one arterial branch, and arteries supplying the same territory often merge, forming arterial anastomoses |
front 38 What do anastomoses provide? | back 38 altenbate pathways, called collateral channels (helps blood to reach a given body region) |
front 39 arteriovenous anastomoses | back 39 meterteriole-thoroughfare channel shunts of capillary beds that connect arterioles and venules |
front 40 venous anastomoses | back 40 veins that interconnect much more freely than arteries, and are very common |
front 41 Blood flow | back 41 the volume of blood flowing through a vessel, or an organ |
front 42 Blood pressure (BP) | back 42 the force per unit area exerted on a vessel wall by the contained blood (exptressed in mm Hg) |
front 43 resistance | back 43 opposition to flow and is a measure o the amt of friction blood encounters as it passes through vessels |
front 44 Peripheral resistance | back 44 most friction is encountered in the peripheral (systemic) circulation, well away from the heart, this is the term we use |
front 45 Blood Viscosity | back 45 related to the thickness or "stickiness" of the blood |
front 46 Total Blood Vessel Length | back 46 relationship betwn total blood vessel length and resistance is straightforward: the longer the vessel, the greater the resistance |
front 47 Blood Vessel Diameter: | back 47 Blood vessel diameter changes frequently and significantly alters peripheral resistance (think of a river: water runs rapidy in the center, but slower on the sides) |
front 48 What is the relationship formula for Flow, Pressure, and Resistance? | back 48 F=∆P/R
|
front 49 systolic pressure | back 49 The pressure peak generated by ventricular contraction |
front 50 How much does the systolic pressure average in adults? | back 50 averages 120 mm Hg |
front 51 Diastolic Pressure | back 51 aortic valves close, preventing blood from flowing back into the heart. during this time aortic pressure drops to its lowest level |
front 52 What is the average diastolic pressure in healthy adults? | back 52 70 to 80 mm Hg |
front 53 Pulse Pressure | back 53 difference between the systolic and diastolic pressures |
front 54 Mean Arterial Pressure (MAP) | back 54 the pressure that propels the blood to the tissues.
|
front 55 What are the three functional adaptations that are critically important to venous return? | back 55 1. The muscular Pump
|
front 56 What vessel has the greatest drop in Blood pressure? | back 56 arterioles |
front 57 Muscular Pump | back 57 consists of skeletal muscle activity: as skeletal muscles surrounding the deep veins contract and relax, they "mil" blood toward the heart |
front 58 respiratory pump | back 58 moves blood up toward the heart as pressure changes in the ventral body cavity during breathing |
front 59 Sympathetic venoconstriction | back 59 reduces the volume of blood in the veins-the capacitance vessels |
front 60 Cardiovascular center | back 60 consists of the cardiac centers and the vasomotor center that controls the diameter of blood vessels |
front 61 Vasomotor center | back 61 controls diameter of blood vessels |
front 62 vasomotor fibers | back 62 vasomotor center transmits impulses at the fairly steady rate along sympathetic efferents |
front 63 Vasomotor tone | back 63 arterioles are almost always in a state of moderate constriction |
front 64 Baroreceptors | back 64 when arterial blood pressure rises, it activates baroreceptors. These inhibit (or bar) to the vasomotor and cardioacceleratory centers |
front 65 What are the threemechanisms that bring about a decrease in blood pressure? | back 65 1. Arteriolar Vasodilation
|
front 66 Arteriolar Vasodilation | back 66 decreased output from the vasomotor centers allows arterioles to dialte |
front 67 Venodilation | back 67 decreased output from the vasomotor center also allows veins to dilate, which shifts blood to venous reservoirs. This decreases venous return and CO (cardiac output) |
front 68 Decreased Cardiac Output | back 68 impulses to the cardiac centers inhibit sympathetic activity and stimulate parasympathetic activity, reducing heart rate and contractile force. |
front 69 Carotid Sinus Reflex | back 69 protects the blood supply to your brain (these are from baroreceptors) |
front 70 Aortic Refelx | back 70 helps maintain adequate blood pressure in your systemic circuit as a whole |
front 71 Adrenal medulla hormones | back 71 epinephrine, and norepinephrine goes to the blood; causing an increase in cardiac output and promoting generalized vasoconstriction |
front 72 Angiotensin II | back 72 When blood pressure or blood volume are low the kidneys release renin. Renin generates Angiotensin II which stimulates intense vasoconstriction, promoting a rise in systemic blood pressure. It stimulates release of aldosterone and ADH |
front 73 Atrial Natriuretic Peptide (ANP) | back 73 this leads to a reduction in blood volume and blood pressure (vasodilation) |
front 74 Antidiuretic hormone (ADH) | back 74 stimulates kidneys to conserve water. |
front 75 Direct Renal Mechanism | back 75 alters blood volume independently of hormones |
front 76 Renin-Angiotensin-aldesterone mechanism | back 76 through this the kidneys can also regulate blood pressure indirectly.Angiotensin converting enzyme (ACE) converts angiotensin I to angiotensin II. |
front 77 Aldosterone | back 77 a hormone that enhances renal reabsorption of sodium |
front 78 Vital Signs | back 78 this is how clinicians assess the efficiency of a person's circulation by measuring pule and blood pressure |
front 79 pulse | back 79 alternating expansion and recoil of arteries during each cardiac cycle allow us to feel a pressure wave |
front 80 pressure points | back 80 the pulse points on the body that are compressed to stop blood flow into distal tissues during hemorrhage |
front 81 auscultatory method | back 81 measure systemic arterial blood pressure indirectly in the brachial artery of the arm |
front 82 What is the instrument used to measure blood pressure by the auscultatory method? | back 82 Sphygmomanometer |
front 83 Hypertension | back 83 chronically elevated blood pressure |
front 84 Hypotension | back 84 low blood pressure (below 90/60 mm Hg) |
front 85 Primary and Secondary Hypertension | back 85 90% are Primary and only 10% are secondary. Primary hypertension is when there has been no underlying cause identified. Secondary Hypertension is when there is an identifiable condition. |
front 86 What could cause chronic hypotension | back 86 addison's disease, hypothyroidism, sever malnutirition |
front 87 Tissue Perfusion | back 87 Blood flow through body tissues |
front 88 What is tissue perfusion involved in? | back 88 1. delivering oxygen and nutrients to tissue cells & removing wastes
|
front 89 Autoregulation | back 89 this is how each organ or tissue manage to get the blood flow it needs. The automatic adjustment of blood flow to each tissue in proportion to the tissue's requirements at any instant. |
front 90 Nitric Oxide (NO) | back 90 powerful vasodilator which acts via a cyclic GMP second-messenger system. |
front 91 Endothelins | back 91 the endothelium also releases potent vasoconstrictors, called endothelins, which are among the most potent vasoconstrictors known. |
front 92 myogenic responses | back 92 fluctuations in systemic blood pressure would cause problems for individual organs were it not for the myogenic responses of vascular smooth muscle. |
front 93 Reactive Hyperemia | back 93 refers to the dramatically increased blood flow into a tissue that occurs after the blood supply to the area has been temporarily blocked |
front 94 Active or Exercise Hyperemia | back 94 when muscles become active, blood flow increases (hyperemia) in direct proportion to their greater metabolic activity |
front 95 Vasomotion | back 95 the on/off opening and closing precapillary sphincters in response to l local auto-regulatory controls |
front 96 Capillary Hydrostatic Pressure (HPc) | back 96 tends to force fluids through capillary walls (a process called filteration) leaving behind cells and most proteins. |
front 97 Interstitial fluid hydrostatic pressure (HPif) | back 97 blood pressure-which forces fluid out of the capillaries is opposed by the HPif acting outside the capillaries and pushing fluid in. |
front 98 Capillary colloid osmotic pressure (OPc) | back 98 abundant plasma proteins in capillary blood (primarily albumin molecules) develop this. |
front 99 New filteration pressure (NFP) | back 99 this considers all the forces acting at the capillary bed. |
front 100 Circulatory shock | back 100 any condition in which blood vessels are inadequately filled and blood cannot circulate normally. |
front 101 Hypovolemic Shock | back 101 the most common form of circulatory shock:which result from large-scale blood or fluid loss. |
front 102 Vascular Shock | back 102 blood volume is normal, but circulation is poor as a result of extreme vasodilation. |
front 103 Cardiogenic Shock | back 103 pump failure, occurs when the heart is so inefficient that it cannot sustain adequate circulation. (could be caused by heart attacks) |
front 104 Blood Islands | back 104 The endothelial lining of blood vessels is formed by mesodermal cells which collect in little masses |
front 105 What are the conducting arteries? | back 105 Elastic Arteries are sometimes called this. |
front 106 What are the distributing arteries? | back 106 muscular arteries |
front 107 Direct renal mechanism | back 107 alters blood volume independently of hormones |
front 108 angiotesin II acts in 4 ways to stabilize arterial blood pressure and extracellular fluid volume. What are those ways? | back 108 1. stimulates adrenal cortex to secrete aldosterone; also stimulates sodium reabsorption by kidneys
|
front 109 What is the major player in controlling local vasodilation? | back 109 NO (Nitric Oxide), often this overrides sympathetic vasoconstriction when tissues need more blood flow |
front 110 MAP is the same everywhere in the body. true/false? | back 110 true |
front 111 Are capillary density and blood flow greater in red fibers, or white fibers? | back 111 red (slow oxidative) fibers |
front 112 Blood will flow into occipital sinus into the ____ and turn into the brachialcephalic vein | back 112 external jugular |
front 113 blood in the circle of willis will flow into the _______ and then into the transverse sinus | back 113 cavernous sinus |
front 114 Blood in the cephalic vein flows into the ________ and then into the basilic vein | back 114 median cubital vein |
front 115 blood in the Great sa``phenous vein flows into the _____ and then into the iliac vein | back 115 femoral |