C2.2 Neural Signalling

Question 1

Features of the nervous system

Answer 1

Central nervous system (CNS): Brain and spinal cord - protected by bone.
Receives and processes bodily information and activity.

Composed of cells called neurons. Neurons can carry rapid electrical impulses.

Peripheral nervous system: all non-CNS nerves. Connect the CNS to all organs, muscles and sensors.

Question 2

How do neurons interact

Answer 2

Communicate information by transmitting a nerve impulse which is an electrical signal.

Question 3

3 types of neurons

Answer 3

Sensory neurons: have long axons and transmit nerve impulses from sensory receptors to the CNS.

Motor neurons: have long axons and transmit nerve impulses from CNS to effectors (muscles and glands)

Relay neurons: a.k.a. connector/inter neurons. Much smaller cells, with many interconnections.

Question 4

Main structural regions of a neuron

Answer 4

Network of dendrites: highly branched fibres that extend from the cell body that receive information.

Cell body: contains the nucleus and the cell organelles.

Axon: a long extension from the cell body that conducts nerve impulses to the terminal knobs.

Axon terminal knobs: end of a nerve where impulse leaves from.

Question 5

Define resting membrane potential

Answer 5

When a neuron is at rest/unactivated. Outside fluid of membrane is positively charged and inside is negatively charged.

membrane potential measures the difference in electrical charge between the inside and outside of neurons.

Magnitude of -70mV.