The organisation of the nervous system Flashcards
what is the nervous system?
a system that allows the organism to:
- sense info about its environment
- to respond rapidly and accordingly
what does the somatic sensory neuron detect?
- touch
- pain
- pressure
- vibration
- temperature
- hearing
- equilibrium
- vision
- smell
what does the visceral sensory neuron detect?
- stretch
- pain
- temperature
- chemical changes
- nausea
- hunger
- taste
- irritation
what neurons makes up the sensory afferent division.
the somatic and visceral sensory neurons
what makes up the central nervous system?
the cranial and spinal nerves
what does the somatic motor do?
-innervates skeletal muscles for movement
what does the visceral motor do?
-innervates smooth muscles, cardiac muscles and glands. aka autonomic nervous system (ANS)
what are the 2 ANS divisions?
parasympathetic and sympathetic divisions
what are the 2 principal cell types of the nervous system?
neurons (transmit electrical signal) and neuroglia (support cells)
6 classes of neuroglia?
- Astrocytes
- Microglia
- Oligodendrocytes
- Schwann cells
- Non ciliated ependymal cells:
- Ciliated ependymal cells
what does the astrocyte do?
form the blood brain barrier.
what does the microglia do?
phagocytosis to fight infection
what does the oligodendrocytes do?
bind the CNS neurons together and insulate the axons.
what does the schwann cells do?
myelin sheath
what does the non-ciliated ependymal cells do?
secrete cerebro spinal fluid.
what does the ciliated ependymal cells do?
move cerebro spinal fluid around to keep it homogenous
what is white matter?
-bundles of axons each coated with a myelin sheath
what is gray matter?
-masses of cell bodies and dendrites each covered with synapses
what does the brain and spinal cord consist of?
gray and white matter
what is the reflex arc?
- stimulus activates receptor
- this activates the sensory neuron and transmits signal to cns
- cns processes info and transmits signal to motor neuron
- motor neuron sends signal to muscles/glands for a response
- RESPONSE!!!