Biopsychology(neurons and structure)

Question 1

What are neurons?

Answer 1

Neurons are specialised cells which are used to carry neural information throughout the body.

Question 1

What do neurons mostly consist of?

Answer 1

Mostly consist of cell body, dendrites and an axon.

Question 2

Process of dendrites to cell body -

Answer 2

Dendrites are located at one end of the neurone and receive signals from other neurons or sensory receptors. These are connected to the cell body.

Question 3

Process of cell body to axon to axon terminals -

Answer 3

Cell body is the control centre of the neuron. From the cell body the impulse is carried along the axon and terminates at the axon terminal.

Question 4

The myelin sheath -

Answer 4

This is found in many nerves including those in the brain and spinal cord, it acts as an insulating layer around the neuron. The myelin sheath allows the nerve impulse to transmit more rapidly. If damaged the impulse slows.

Question 5

Length of neuron -

Answer 5

Can vary from a few millimetres to a metre.

Question 6

The three types of neuron -

Answer 6

Sensory neuron, relay neuron and motor neuron.

Question 7

Sensory neuron -

Answer 7

Carry nerve impulses from sensory receptors (vision, touch and taste). Carried to the brain and spinal cord. These sensory receptors which connect to this specific neuron are found in eyes, tongue, ears and skin. When these impulses reach the brain they are translated into sensations. For example visual input, heat, pain. So the organism reacts appropriately. Not all sensory information travels as far as the brain but still the CNS in terms of the spinal cord where it is terminated. This allows reflex actions to occur quickly without the delay of impulses to the brain.

Question 8

Relay neuron -

Answer 8

Lie somewhere between the sensory input and the motor output, these neurons allow sensory and motor neurons to communicate with each other. These relay neurons are only located wholly in the CNS.

Question 9

Motor neuron -

Answer 9

The motor neuron conduct signals from the CNS to effector organs such as muscles. Their cell bodies may be located in the CNS but their axon run and forms part of the PNS. Motor neurons form synapses with muscles which control their contractions. When stimulated the neuron releases neurotransmitters that bind to receptors on the muscle leading to a trigger of a response on the muscle. When the axon of which muscle it forms a synapse with contracts. The strength of the muscle contraction depends on the firing rate of the axons of motor neuron that control it.