Nervous Tissue-12-1: Divisons of the Nervous system

Question 1

State the two anatomical divisions of the nervous system

Answer 1

– Central nervous system
– Peripheral nervous system

Question 2

what are the parts of the CNS

Answer 2

Brain and spinal cord

Question 3

What are the parts of the PNS

Answer 3

– Includes all nervous tissue outside CNS and ENS

Question 4

What are the functional divisions of the PNS?

Answer 4

– Afferent division
* Carries sensory information
* From receptors in peripheral tissues and organs to
CNS
– Efferent division
* Carries motor commands
* From CNS to muscles, glands, and adipose tissue
– Receptors
* Detect changes or respond to stimuli
* May be neurons or specialized cells
* May be single cells or complex sensory organs
(e.g., eyes, ears)
– Effectors
* Target organs that respond to motor commands

Question 5

What are the divisions of the Efferent part of the PNS

Answer 5

– Somatic nervous system (SNS)
* Controls skeletal muscle contractions
* Both voluntary and involuntary (reflexes)
– Autonomic nervous system (ANS)
* Controls subconscious actions, contractions of
smooth and cardiac muscle, and glandular
secretions
* Sympathetic division has a stimulating effect
* Parasympathetic division has a relaxing effect

Question 6

Describe the Enteric nervous system

Answer 6

100 million neurons in walls of digestive tract
* As many or more than in spinal cord
* Use the same neurotransmitters as the brain
– Initiates and coordinates visceral reflexes locally
* Without instructions from CNS
– Can be influenced by ANS