Blood vessels Word Scramble
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Question | Answer |
arteries | carry blood away from heart; high pressure |
veins | carry blood back to heart; low pressure |
capillaries | connect smallest arteries to veins; intermediate pressure |
tunica interna | endothelium= simple squamous epithelium over a BASEMENT MEMBRANE & loose connective tissue, secretes VASODILATORS & VASO CONSTRICTORS, produce cell-adhesion molecules (for leukocytes) |
tunica media | smooth muscle, collagen, and elastic tissue; provides strength; VASOMOTION= smooth muscle changes blood vessel DIAMETER and affecting PRESSURE |
tunica externa | loose connective tissue that BINDS vessel to adjacent structures & anchors nerves, small vessels; VASA VASORUM= blood supply to large vessels! |
elastic (conducting) arteries | have internal and external ELASTIC LAMINA; recoil during diastole which lessens fluctuations in blood pressure, absorb PRESSURE DIFFERENCES |
muscular (distributing) arteries | distributes blood to SPECIFIC ORGANS, smooth muscle is THICK |
arterioles | control AMOUNT of blood to various organs, smooth muscle is THICK, minimal tunica externa |
aneurysm | a weak point in an artery or the heart wall; forms bulging sac that may burst; causes= atherosclerosis and hypertension |
arterial sense organs= | carotid sinuses, carotid bodies/ aortic bodies |
baroreceoptors | carotid sinuses; in walls of internal carotid artery; INCREASE blood pressure --> DECREASE heart rate & vasodilation |
chemoreceptors | carotid bodies/ aortic bodies; adjust respiratory rate to stabilize pH, CO2, O2; adjust heart rate to deliver blood to lungs |
capillary layers | only have the TUNICA INTIMA: (endothelium & basement membrane) |
continuous capillaries | Most common, Very NARROW intercellular clefts allow substances to diffuse in/out of capillary, Pericytes act as stem cells and may regulate diameter |
fenestrated capillaries | small holes pass through plasma membrane; important in organs engaging in absorption/ filtration |
sinusoids | LARGE GAPS between cells, Large fenestrae, Proteins and cells can pass through, Found in liver, bone marrow, lymphatic tissue |
capillary beds | network of capillaries, supplied by single metarteriole |
profusion | filling of capillary beds w/ blood |
veins properties | Great capacity for blood; thinner walls, flaccid, less muscular and elastic tissue ; collapse when empty, expand easily ; subjected to relatively low blood pressure (~10 mm Hg) |
movement of blood in veins via.... | skeletal muscle pump, respiratory pump, vasomotion, gravity |
skeletal muscle pump | localized pressure moves blood; one-way valves (ensure movement toward heart) |
respiratory pump | negative pressure in thoracic cavity when inhaling draws blood into heart |
vasomotion | smooth muscle contracts to increase VENOUS PRESSURE |
veins: postcapillary venules | porous & allow white blood cells to pass through; no smooth muscle |
muscular venules | receive blood from postcapillary venules; some muscle present |
medium veins | Travel with muscular arteries and drain individual muscles and organs |
large veins | Veins that lead into heart; Smooth muscle in all 3 tunics |
most common circulatory route | heart --> arteries --> arterioles --> capillaries --> venules --> veins |
portal system | blood flow through TWO consecutive capillary networks before returning to heart |
anastomosis | merging of 2 blood vessels |
blood flow depends on.... | depends on pressure gradients (PRESSURE DIFFERENCE) and is diminished by resistance (F=P/R) |
blood pressure= | the force that blood exerts against a vessel wall |
pulse pressure | difference between systolic and diastolic pressure; important measure of stress exerted on arteries |
mean arterial pressure (MAP): | average blood pressure that most influences risk level for edema, aneurysm, etc. |
diastolic pressure | minimum arterial BP taken during ventricular relaxation (diastole) between heart beats |
systolic pressure | peak arterial BP taken during ventricular contraction (ventricular systole) |
hypertension | high blood pressure; resting BP > 140/90. consequences= can weaken small arteries and cause aneurysms |
hypotension | chronic low resting BP; caused by blood loss, dehydration, anemia |
3 factors influencing blood pressure | cardiac output, peripheral resistance, blood volume |
factors of peripheral output | blood viscosity (albumin, RBC count, dehydration), vessel length & vessel radius (friction w/ blood vessel walls) longer vessels= more friction, smaller radius= more friction |
vasomotion | powerful way of altering blood pressure & flow; 1. local control 2. neural control 3.hormonal control |
local control (3 factors) | autoregulation, vasoactive chemicals, angiogenesis |
autoregulation | =ability of tissue to adjust its own blood supply via vasomotion or angiogenesis; “metabolic theory of autoregulation” describes that the accumulation of WASTES stimulates VASODILATION; ↓wastes → vasoconstriction |
vasoactive chemicals | substances SECRETED by platelets, endothelial cells, and perivascular tissue stimulate VASOMOTION |
angiogenesis= | growth of new blood vessels |
neural control of blood flow | Medullary ischemic reflex, chemoreceptors, baroreceptors |
medullary ischemic reflex | Medulla monitors its own O2 levels; When low, peripheral VASOCONSTRICTION and heart rate are INCREASED |
chemoreceptors | for blood pH, CO2; Coordinated effects with respiratory system ↑CO2 (hypercapnia)/↓pH (acidosis) stimulate vasoconstriction except in lungs |
baroreceptors | provide info on blood pressure; DECREASE blood pressure= VASOCONSTRICTION; INCREASE= VASODILATION |
vasoactive hormones | ANGIOTENSIN II= kidneys detect low BP; NE, E: baroreceptors (carotid sinus) respond to changes in BP via VESSEL RADIUS |
hormones regulating water balance | ANP: heart detects high pressure/volume; Aldosterone: adrenal cortex detects ↓Na +; ADH: hypothalamus detects ↑Na+; RESPOND VIA BLOOD VOLUME CHANGE |
what moves across capillaries? | water nutrients (O2, glucose, amino acids, lipids), wastes (CO2, creatin, urea, ammonia), ions/minerals, antibodies, hormones |
fluid filtered out of ________ and reabsorbed at ___________ | filtered out of ARTERIAL end of capillary & reabsorbed @ VENOUS end |
net filtration pressure= | NET HYDROSTATIC PRESSURE (drives fluid out of capillary) + NET OSMOTIC PRESSURE (drives fluid into capillary) |
capillaries reabsorb _______% of fluid they filter | 85% |
remaining 15% reabsorbed by.... | LYMPHATIC SYSTEM and returned to the blood |
edema | occurs when fluid filters into a tissue faster than it is absorbed; causes=increased capillary filtration, reduced capillary reabsorption, obstructed lymphatic drainage |
circulatory shock | 1. cardiogenic 2. Low Venous Return (LVR) Shock |
low venous return shock | Hypovolemic Low volume Obstructed venous return, Tumors, clots, etc., Venous pooling, Failure of blood to leave limbs |
excess of CO2 in blood= | hypercapnia |
Created by:
kpan
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