Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Blood vessels
| 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
Popular Anatomy sets