NERVES/NEURONS/SPINAL REFLEXES

Question 1

DEFINITION: NEURONS

Answer 1

• Specialized (nerve) cells
• Receive, Transmit and Process information around the body
• 3 types: SENSORY, MOTOR AND INTERNEURON

Question 2

2 X NERVES

Answer 2

CRANIAL NERVES:

• Connect/link directly to the brain
• Allow sensory and motor information to travel directly to ORGANS, MUSCLES, and GLANDS

SPINAL NERVES:
- Connect from CNS to the PNS, for muscles, organs, and glands.

Question 3

STRUCTURE OF A NEURON

Answer 3

• DENDRITES
• A structure that receives incoming messages/signals from the pre-synaptic neurons
• Contain recpetor sites
• SOMA
• Known as the cell body
• Contains the nucleus
• NUCLEUS (Contains DNA: Genetic material)
• AXON
• A long nerve fibre
• Transmits electrical impulses away from the soma, to the terminal buttons.
• MYELIN SHEATH
• Insulates the axon
• Accelerates neural transmission as well as protects the axon.
• TERMINAL BUTTONS/AXON TERMINALS
• Located at the end of a neuron (nerve fibre ending)
• Forms junctions with other nerve cells

Question 4

SENORY NEURON

Answer 4

• Nerve cells that detect sensations
• Afferent Neurons
• Primarily located in the PNS
• PNS (glands, etc) to the Brain

Question 5

MOTOR NEURON

Answer 5

• Efferent Neurons
• Initiating a response through movement.
• CNS to the PNS
• Primarily located in the PNS

Question 6

INTERNEURON

Answer 6

• Nerve cells that carry information directly between sensory and motor neurons
• Involved in reflex actions
  Locate in the spinal cord

Question 7

SPINAL CORD/SPINAL REFLEXES

Answer 7

Spinal Reflex: OR Spinal arc

• Unconscious response, meaning it bypasses the brain
• It is a simple response
• Activated by an intense sensation, creating a simple stimulus-response behavior pattern.

Question 8

SPINAL REFLEXES X2

Answer 8

Monosynaptic:
- Involves the transmission from a sensory neuron to the appropriate motor neuron across ONE single synapse
- Example: Reflex action (Knee jerk)
Polysynaptic:
- Involves an electrical impulse being transferred from a sensory neuron to a motor neuron via at least one interneuron (Transmitting information across multiple synapses)
- Example: Withdrawal actions

Question 9

SYNAPSE

Answer 9

• A synaptic cleft

- The space between two neurons

Question 10

SYNAPTOGENESIS

Answer 10

• Process: when a new synapse is formed in the CNS