A4 Nervous System 1

Question 1

Outline the general functions & anatomical divisions of the nervous system

Answer 1

Detection → Information processing/Integration → Response

Central nervous system: brain & spinal cord
Peripheral nervous system: cranial & spinal nerves

Question 2

Understand basic neuronal function and the means by which information transfer occurs within the nervous system

Answer 2

Detection - sensory (afferent)
Integration - CNS
Response - motor (efferent)

Sensory transmission info. peripheral → CNS “afferent”
Integration / processing in CNS
CNS → peripheral “motor”

Question 3

Describe the general structure of a neuron

Answer 3

• Very large cells
• axon - long cytoplasmic process, transmits impulses to other neurons
• dendrites - shorter processes, collect info. from neurons

Question 4

Distinguish between the different functional subclasses of neuron

Answer 4

Multipolar neuron - 2 or more dentrites
Unipolar neuron - one axon divides close to cell body
Bipolar neuron- one axon, one dendrite

Question 5

Describe the terms “ganglion” & “nucleus”

Answer 5

Ganglion = a group of nerve cell bodies OUTSIDE the CNS

Nucleus = a group of cell bodies INSIDE the CNS

Question 6

Describe the reflex arc

Answer 6

1. Impulse from sensory receptor
2. Transmitted in sensory neuron
3. Synapse between sensory neuron & somatic motor neuron
4. Impulse to muscle - contract

Question 7

Describe the structure of a typical peripheral nerve

Answer 7

• Axons surrounded by endoneurium
• Fascicles surrounded by perineurium
• Nerve surrounded by epineurium

Question 8

Understand the differences between grey & white matter

Answer 8

Grey matter = nerve cell bodies & supporting cells (brain)
White matter = nerve fibres & supporting cells (spinal cord)

Question 9

Define myelination and explain the significance

Answer 9

Electrical insulation of the axon
- increase the speed of action potential conduction

Question 10

List and describe the neuroglia of the CNS & PNS

Answer 10

neuroglia are non-neuronal supporting cells

CNS:
astrocytes - structural, metabolic exchange
microglia - phagocytes
Oligodendrocytes - produce myelin
Ependymal cells - fluid transport, secretion

PNS:
Schwann cells - wrap around axon
Satellite cells - stem cells

Question 11

Discuss the origin & function of cerebrospinal fluid

Answer 11

Produced in choroid plexus
Occupies the ventricles of brain & central canal of spinal cord

Functions:
- protection
- buoyancy
- transport (e.g. waste products & hormones)