Biopsychology : Structure and Function of Neurons

Question 1

Whats a neuron?

Answer 1

Nerve cells part of the nervous system. 80% are in the brain(others in spinal cord, peripheral nervous system and gut)

Question 2

How do they transmit information?

Answer 2

Electrically – through action potential
Chemically – using neurotransmitters

Question 3

Structure of neurons - What do they all consist of?

Answer 3

Dendrites, cell body, axon, myelin sheath, axon terminal

Question 4

Structure of neurons - dendrites

Answer 4

protrude from the cell body, carry nerve impulses from neighboring neurons towards the cell body

Question 5

Structure of neurons - cell body

Answer 5

a nucleus, contains genetic material of the cell

Question 6

Structure of neurons - axon

Answer 6

carries impulses away from the cell body down the length of the neuron

Question 7

Structure of neurons - myelin sheath

Answer 7

fatty coating that protects the axon and speeds up electrical transmission of the impulse. Segmented by gaps called nodes of ranvier (speed up transmission by forcing it to ‘jump’ across the gaps)

Question 8

Structure of neurons - axon terminal

Answer 8

where the vesicles are, communicates with the next neuron

Question 9

What disease results from degeneration of the myelin sheath?

Answer 9

Multiple Sclerosis - chronic autoimmune disorder where the immune system attacks the myelin sheath in the CNS, including the brain and spinal cord, causing slowing of neurotransmission, resulting in symptoms such as fatigues numbness, weakness, vision problems, difficulty with coordination and balance, and cognitive issues.

Question 10

Types of neurones - Sensory neuron (afferent)

Answer 10

• long dendrites, short axons. Located in spinal cord
• carry from sense receptors in PNS to CNS
• ‘Afferent neurons’ - incoming, take sensory info from environment and sends signal to the brain

Question 11

Types of neurones - Motor neuron

Answer 11

• short dendrites, long axons. Located in spinal cord.
• the fibre (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands
• take messages from CNS to effectors (muscles and glands)
• ‘Efferent neurons’ – outgoing, communicate info from brain to tissues and organs throughout the body (movement)

Question 12

Types of neurones - Relay neuron

Answer 12

• short dendrites, short axons. Located in the brain and spinal cord – 97% of all neurons.
• connect the sensory neurons to the motor or other relay neurons. They allow motor and sensory neurons to communicate with each other.
• ‘Interneuron’ – transmit info between sensory and motor neuron. Key role in learning, memory and planning