Nervous System 3

Question 1

reflexes

Answer 1

• fast, involuntary, unplanned response to changes to changes in the environment (internal or external) that helps maintain homeostasis
• functions - maintenance of homeostasis eg. protection / movement

reflexes can be:

• somatic (skeletal muscle) or automatic (smooth muscle, cardiac muscle, glands)
• spinal or cranial
• monosynaptic or polysynaptic

Question 2

reflex arc

Answer 2

neural pathway linking receptor and effector which produces a reflex

5 functional components:
1. receptor 
2. sensory neuron 
3. CNS (integrating centre) 
4. motor neuron 
5 effector

Question 3

reflexes examples

Answer 3

• stretch reflex
• pupillary reflex
• salivation reflex
• babinski reflex

Question 4

flexor (withdrawal) reflex

Answer 4

prevents injury

• step on nail - pain fibres send signal to spinal cord
• interneurons branch to different spinal cord segments
• motor fibres in several segments are activated
• more than one muscle group activated to lift foot of tack