Term
|
Definition
microscopic vessels that usually connect arterioles and venues - permit exchange of nutrients and waste
-found near very cell in body
-distribution varies with metabolic activity in the tissue |
|
|
Term
| Structures that lack capillaries |
|
Definition
| cornea, lens, epithelium, and cartilage |
|
|
Term
|
Definition
| flow of blood through capillaries - regulated by smooth muscle sphincters in the walls |
|
|
Term
|
Definition
| composed of single layer of cells (endothelium) and a basement membrane |
|
|
Term
| Capillary network throughout the tissues |
|
Definition
| increase surface area- allow rapid exchange of large quantities of materials |
|
|
Term
|
Definition
| rings of smooth muscle fibers that regulate blood flow through true capillaries |
|
|
Term
|
Definition
| continuous, fenestrated, sinusoids |
|
|
Term
|
Definition
| plasma membrane forms complete tube interrupted by small intercellular gaps - found in muscle and connective tissue |
|
|
Term
|
Definition
| "window" plasma membrane has small pores - choirod plexus, villi, kidneys |
|
|
Term
|
Definition
| large fenestrations and gaps in the basement membrane - red bone marrow, liver, and spleen |
|
|
Term
|
Definition
little veins- formed from the union of several capillaries
-merge to form veins
-drain blood from capillaries |
|
|
Term
|
Definition
consist of same three tunics as arteries- but thinner
-less elastic tissue and smooth muscles
-contain valves to prevent back flow of blood |
|
|
Term
|
Definition
| veins with very thin walls with NO smooth muscle to alter their diameters - coronary sinus of the heart |
|
|
Term
|
Definition
| weak valves can lead to this- causes=congenital, standing, pregnancy, aging |
|
|
Term
|
Definition
| union of branches of two or more arteries supplying the same region- alternate blood pathways to get to the same region - collateral route of blood (alternate) |
|
|
Term
|
Definition
| blockage in arteries that dont have anastomoses (end arteries) - arteries die |
|
|
Term
|
Definition
| Largest portion of the blood is in systemic veins and venules (64%) - collectively called ___ - they store blood and can move it if the body needs it |
|
|
Term
|
Definition
| diffusion, transcytosis, bulk flow |
|
|
Term
|
Definition
most important method of capillary exchange- 0c, C02, flucose, amino acids, hormones, and others diffuse down concentration gradient
-small proteins diffuse
-plasma solutes diffuse across capillary walls
-brain-blood-brain barrier exists |
|
|
Term
|
Definition
| moves large lipid insoluble molecules across the capillary walls by enclosing substances within tiny vesicles that enter cells by endocytosis and exit by exocytosis -insulin |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
-interstitial fluid & blood --specific to capillary beds
passive flow of water and solutes in one direction driven by pressure (up pressure to down pressure)
-more important for determining the relative volumes in the blood stream and the interstitial fluid space
-dependent upon hydrostatic and osmotic pressure |
|
|
Term
| Starlings law of capillaries |
|
Definition
balance between two filtration pressures of moving material out and bringing it back in
-hydrostatic pressures and osmotic pressures |
|
|
Term
|
Definition
| between ateriole and venules - certain amount of fluid will filter out of the begining capillary and 85% of that fluid will be reabsorbed |
|
|
Term
|
Definition
C.O./ min - mL/min
-how much of the cardiac output is distributed to a tissue depends on the interplay of the pressure differences that drives the blood flow and the resistance to blood flow through that tissue |
|
|
Term
|
Definition
| is the pressure exerted on the walls of a blood vessel |
|
|
Term
| Factors that affect blood pressure |
|
Definition
cardiac output=increase
blood volume=increase
viscosity=increase
resistance=increase
elasticity of arteries=maintains bp rather than increase |
|
|
Term
|
Definition
| the opposition to blood flow as a result of friction between blood and the walls of blood vessels |
|
|
