Chapter 6

Question 1

Action Potential

Answer 1

A short term change in the electrical potential on the surface of a cell in response to stimulation, and then leads to the transmission of an electric impulse that travels across the cell membrane.

Question 2

Depolarisation

Answer 2

The reversal of the resting potential in excitable cell membranes when stimulated i.e. the tendency of the cell membrane potential to become positive with respect to the potential outside the cell.
A positive shift in a cells resting potential, thus making it numerically smaller and less polarised.

Question 3

Threshold potential

Answer 3

The minimum size of the stimulus required.

Question 4

Sensory Neuron

Answer 4

Carry information from the receptors to the CNS.

Question 5

Motor Neuron

Answer 5

Carry information away from the CNS to muscle cells/glands.

Question 6

Myelin Sheath

Answer 6

An insulating layer surrounding neurons, that dramatically increase the speed of conduction.

Question 7

Neurotransmitter

Answer 7

Chemical released by a neuron axon into the synaptic cleft between it and the target cell. It stimulates or inhibits the target cell.

Question 8

Synapse

Answer 8

Junction between two neurons.

Question 9

Neurohormone

Answer 9

Hormones released by the axon end of a neuron into the bloodstream.

Question 10

Osmoreceptors

Answer 10

Receptors in the hypothalamus that detect an increase in blood solutes: that is, a reduction of water in the blood.

Question 11

Toxin

Answer 11

Substances poisonous to an organism.

Question 12

Cerebrum

Answer 12

Largest part of mammalian brain, divided into left and right sides, which are connected by a thick band of nerves.