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Mechanisms of capillary exchange

By: HWC, Views: 7892

■ 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...

Neurotransmission at chemical synapses & Excitory and inhibitory potentials

By: HWC, Views: 7670

• A series of events occur at chemical synapses in order to communicate with the adjacent cell. • The action potential arrives at the presynaptic membrane. • The depolarization phase of the action potential opens voltage gated Ca+ channels. • increased inflow of Ca+' into the cyto...

Osmosis - water transport

By: HWC, Views: 7865

Osmosis is the flow of water down its concentration gradient, across a semi-permeable membrane. Osmosis is an example of diffusion, which is when molecules tend to distribute themselves evenly in a space. what is a semi-permeable membrane? It is a membrane or barrier that allows some molec...

Type of Cell Junctions - Desmosome, Hemidesmosomes and Gap Junctions

By: HWC, Views: 8091

Cell Junctions: Cell junctions are found in some multi-cellular organisms. They exist of complexes and are found between cells and between cells and other structures. The junctions provide a way for cells to connect and exchange signals. What are tight junctions, desmosomes, and gap junctions...

Covalent bonds - role in the body

By: HWC, Views: 7722

A covalent bond is formed when atoms share one or more pairs of electrons. This is opposed to an ionic bond, where electrons are actually transferred from one atom to another. Formation • Atoms fill up the outer orbital by sharing electrons. • Two oxygen atoms sharing electrons form on...

How Broken Bones Repair Themselves

By: Administrator, Views: 404

Bone healing, or fracture healing, is a proliferative physiological process in which the body facilitates the repair of a bone fracture. Generally bone fracture treatment consists of a doctor reducing (pushing) displaced bones back into place via relocation with or without anaesthetic, stabili...

Medullary osmotic gradient: countercurrent multiplier, urea recycling & vasa recta countercurrent exchange

By: HWC, Views: 8449

▪ The primary cause of the medullary osmotic gradient is the active transport of solutes. • In the ascending limb of the loop, active transport of Na+ ions drives passive reabsorption of Cl- ions. • Addition of these ions to the interstitial fluid of the medulla increases its osmolarity...

What are the Parts of a Plant Cell?

By: HWC, Views: 6794

Every chloroplast in a plant cell is packed with stacks of flattened sacs called thylakoids. The thylakoid membranes contain chlorophyll, as well as most of the other components required for the light reactions of photosynthesis. The chlorophyll-containing structures within the membranes are c...

Types of Transport - Uniport, Antiport and Symport (Glucose and Na+K+ Transporters)

By: HWC, Views: 7411

Some transport proteins bind and transport molecules very selectively. Uniport is the transport of one solute molecule. Symport is the transports of two solute molecules in the same direction. Antiport is the transports of two solute molecules in opposite directions. 1. Glucose bin...