14. Nervous system, motor units and reflexes

Question 1

What is the autonomic nervous system and which is it divided into?

Answer 1

it is the entire nervous system and can be divided into the central and peripheral nervous system

Question 2

What are efferent signals?

Answer 2

signals away from the CNS

Question 3

What are afferent signals?

Answer 3

signals towards the CNS

Question 4

What is somatic efferent?

Answer 4

motor fibres to skeletal muscle

Question 5

What is somatic afferent?

Answer 5

sensory fibres from skin and skeletal muscle

Question 6

What is the motor and sensory components of the autonomic nervous system divided into?

Answer 6

• enteric nervous system of the gut

- sympathetic and parasympathetic nervous system

Question 7

What is the main function of the autonomic nervous system?

Answer 7

• mediates output from CNS to the whole body, with exception of skeletal (voluntary) muscle

Question 8

What is output modulated by?

Answer 8

external and internal sensory input, often via reflexes involving negative feedback loops within PNS and CNS

Question 9

What are other functions of the autonomic nervous system?

Answer 9

regulates functions essential to human health and life that do not require conscious effort and that are largely involuntary

e. g.
- contraction and relaxation of vascular and visceral smooth muscle
- the heartbeat (including rate and force)
- all exocrine and certain endocrine secretions
- aspects of metabolism
- modulations of immune system processes

training allows a degree of conscious influence over the execution of some ANS reflexes