Divisions of the Nervous System Flashcards
What is the SNS?
Branch of PNS
Controls skeletal muscle, conscious control
Control from upper motor neurons in primary motor cortex
What is the ANS?
Branch of PNS
Controls visceral effectors
Coordinates system functions
Control from visceral motor nuclei in hypothalamus
Divided into sympathetic and parasympathetic
What does the sympathetic NS do?
Increases alertness, metabolic rate and muscular abilities
What does the parasympathetic nervous system do?
Reduces metabolic rate
Promotes digestion
What is the difference between efferent neurons of the somatic and autonomic nervous system?
SNS
- Long myelinated motor fibres leave the ventral root and innervate skeletal muscles
ANS
- Short preganglionic myelinated fibres leave the ventral root and synapse with an unmyelinated postganglionic fibre at the autonomic ganglion
What is a nerve plexus?
A network of intersecting nerve fibres which serve same part of body
What does the sacral plexus supply?
Motor and sensory nerves for posterior thigh, most of lower leg and foot
What is the largest peripheral nerve in the body?
Sciatic nerve
What does the sciatic nerve do?
Sensory AND motor
Mediated motor function of knee and below
Includes tibial nerve which controls foot
From which part of the germ layer does the nervous system develop?
The ectoderm
What are the first brain areas to be formed?
Prosencephalon
Mesencephalon
Rhombencephalon
