Biology A2, F2144 module 1: communication & homeostasis

One is always good for the body and one is always bad

Negative feedback uses neurones and positive uses hormones

Negative reverses a change away from optimum. Positive enhances it.

Negative feedback is part of the autonomic nervous system. Positive feedback is part of the somatic

Small cell body at receptor, long dendron but short axon with numerous dendrites. Myelinated.

large cell body at Central Nervous System, long dendron with dendrites going to effectors. Non myelinated

large cell body at receptor, long dendrite, short axon but no dendron . Myelinated.

Large cell body at Central Nervous System and a long axon with dendrites. Myelinated.

the sodium/potassium pump begins pumping 2K+ into the cell and 2Na+ out.

the cell repolarises.

K+ ion channels open.

The cell depolarises

When ions diffuse into the cell and gather in a high conc. at the point at which they diffused in, causing them to diffuse to an area of low conc. further down the cell.

The way in which an action potential appears to "jump" between the nodes of ranvier along a myelinated neurone.

the slow, smooth, linear flow of an action potential in a non-myelinated neurone due to the high concentrations of ions diffusing in through voltage gated channels and diffusing down the neurone.

Where several action potentials join together to make one, larger one.

Sodium/potassium pump

acetyl choline receptors

sodium ion channel

calcium ion channel

Nor-adrenaline and Adrenelase

choline and cholinase

acetyl choline and acetylcholinesterase

acetate and acetatedecarboxylase

First messengers

Peptide

Hexose

Steroid

hormone

chemical

enzyme

second messenger

glycolysis

glycogenesis

gluconeogenesis

glycogenolysis

Family History

not being able to produce enough insulin

obesity

being of asian/afro-Caribbean origin

rise in blood pressure

rise in activity in the limbs

fall in blood pH

Adrenaline being released into the blood