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Mechanisms of capillary exchange

By: HWC, Views: 6761

■ The primary role of capillaries is to permit the exchange of nutrients and wastes between the blood and tissue cells (via interstitial fluid). ■ Oxygen and nutrients move from the blood to the cells. ■ Carbon dioxide and other wastes move from the cells to the blood. The three ba...

Mechanisms of capillary exchange (transcytosis & bulk flow)

By: HWC, Views: 6289

■ This method of capillary exchange is mainly used to transport small amounts of large, lipid-insoluble (water soluble) molecules, such as large proteins. ■ Substances, packaged in vesicles, move through endothelial cells via endocytosis and exocytosis. ■ This method of exchange is th...

Coronary Heart Disease Animation

By: Administrator, Views: 9907

Arteriosclerotic heart disease occurs when arterial vessels are marked by thickening, hardening, and loss of elasticity in arterial walls. Course of cardiovascular disease accelerates due to: Reduced blood flow Rlevated blood lipids Defective endothelial repair

Cytotoxic T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 6995

• Most cells which have CD8 on their surface become cytotoxic T cells (Tc cells). • CD8 T cells recognize a foreign antigen when it is presented in conjunction with the protein, MHC-I. • Nearly all nucleated cells in the body express MHC-I molecules. • T cells that recognize self-pe...

Types of synapses - electrical & chemical

By: HWC, Views: 6694

• Neurons communicate with one another or effector cells via synapses that allow information to be filtered and integrated. • The two types of synapses are: • electrical • chemical. • Electrical synapses, also known as gap junctions, contain many ion channels (connexons) conne...

Non-polar compounds - insolubility

By: HWC, Views: 6688

• A non-polar molecule has uniform distribution of electrons. • Non-polar compounds like fatty acids in lipids have a high proportion of carbon and hydrogen. • Lipids possess no charge or partial charge. • Lipids are not attracted to water molecules. • Lipids are not soluble in...

Lipid absorption - end products & transport mechanism

By: HWC, Views: 6180

• The end products, fatty acids and monoglycerides, depend on bile salts for absorption. • Bile salts form micelles (tiny spheres), which ferry fatty acids and monoglycerides to epithelial cells. • Free fatty acids, monoglycerides, and some phospholipids and cholesterol molecules, dif...

Molecules, Membrane Permeability and Structure

By: HWC, Views: 6147

Organisms are not isolated system at equilibrium and need to intake nutrients and electrolytes as remove wastes. Similarly Cells within an organism must also exchange compound by passing them through membrane. The permeability of a membrane is the rate of passive diffusion of molecules th...

Resting membrane potential - electrical polarity and maintenance requirements

By: HWC, Views: 6450

• A resting membrane potential exists when there is a buildup of: 1. positive ions outside the membrane. 2. negative ions inside the membrane. • Membranes with opposing charges are said to be polarized. • The difference in charge applies only to the small distance across the membran...