biopsych - structure and function of neurons

Question 1

What is a terminal button (pre-synaptic membrane)

Answer 1

• end of the neuron
• send the information through to the next neuron - through the release of neurotransmitters

Question 2

What is the function of the dendrites (post-synaptic membrane)

Answer 2

• where the neurotransmitter receptors are found
• receptor and neurotransmitter bind –> new electrical impulse occurs

Question 3

What is the function of nodes of ranvier (the gap)

Answer 3

• speeds up transmission of impulse
• by forcing it to ‘jump’ across the gaps along the axon

Question 4

What is the function of the axon?

Answer 4

• Sends a nerve impulse through the neuron
• To transmit a message to the next neuron

Question 5

What is the function of myelin sheath?

Answer 5

• Protects the axon
• helps to speed up transmission of the message

Question 6

What the function of the cell body?

Answer 6

• contains nucleus (genetic material of cell)

Question 7

What are the 3 types of neurons?

Answer 7

• Sensory neuron
• Relay neuron
• Motor neuron

Question 8

Outline the structure and function of the nervous system

Answer 8

• split into two main parts: CNS and PNS
• CNS: made up of brain and spinal cord
• brain - responsible for higher mental functions
• spinal cord - responsible for reflex actions and transmitting info to and from the brain
• PNS - sub-divided into ANS and SNS
• ANS - responsible for involuntary functions e.g. breathing, digestion
• ANS - further subdivided into sympathetic branch (responsible for fight or flight) and parasympathetic branch (conserves and restores body energy when relaxed)
• SNS - responsible for voluntary movements e.g. walking and transmits info from the brain to skeletal muscles

Question 9

Where are sensory neurons located?

Answer 9

In the PNS in clusters known as the ganglia

Question 10

What is the function of sensory neurons?

Answer 10

• Sends information from the senses (PNS) towards the brain (CNS)
• Receptors found in eyes, skin, ears, tongue

Question 11

What is the structure of sensory neurons?

Answer 11

• Long dendrites
• Short axons

Question 12

Why do sensory neurons have long dendrites?

Answer 12

Covers a large SA

Question 13

Why do sensory neurons have short axons?

Answer 13

Only sends information from PNS to C

Question 14

What is one way of identifying sensory neurons?

Answer 14

Cell body found in centre

Question 15

Where are relay neurons located?

Answer 15

In the brain and the visual system

Question 16

What is the function of relay neurons?

Answer 16

• Found in CNS
• Carry nerve impulses between neurons -
• allowing sensory and motor neurons to communicate
• Involved in analysing the sensations from these neurons
  and deciding how to respond

Question 17

What is the structure of relay neurons?

Answer 17

• Short axons
• Short dendrites
• No myelin sheath

Question 18

Why do relay neurons have short axons?

Answer 18

Not too far for message to travel

Question 19

Why do relay neurons have short dendrites?

Answer 19

• Only attached to 1 sensory neuron
• So small SA to cover

Question 20

What is the function of motor neurons?

Answer 20

• Send info via long axons
• From CNS to effectors e.g. muscles/glands

Question 21

What is the structure of motor neurons?

Answer 21

• Short dendrites
• Long axons

Question 22

Why do motor neurons have short dendrites?

Answer 22

Only connected to one muscle

Question 23

Why do motor neurons have long axons?

Answer 23

Sends messages from CNS to effectors