Organisation Of The Nervous System Flashcards
What is the nervous system
A system that allows the organism to:
- Sense info about its environment
- 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 make up the sensory afferent division
Somatic and visceral sensory neurons
What makes up CNS
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 muscle and glands aka autonomic nervous system
What are the 2 ANS divisions
Parasympathetic and sympathetic divisions
What are the 2 principal cell types of nervous system
Neurons (transmit electrical signal) and neuroganglia (support cells)
6 classes of neuroganglia
Astrocytes Microglia Oliodendrocytes schwann cells non ciliated ependymal cells ciliated ependymal cells
what does astrocyte do
form BBB
what does microganglia do
phagocytosis to fight infection
what does oliodendrocytes do
bind CNS neurons together and insulates axons
what do schwann cells do
myelin sheath
what do non-ciliated ependymal cells do
secrete cerebro spinal fluid
what does ciliated ependymal cells do
move cerebro spinal fluid around to keep it homogenous
what is white matter
bundles of axons each coated in mylein sheath
what is gray matter
masses of cell bodies and dendrites each covered with synapses
what does the brain and spinal cord consist of
grey and white matter
what is the reflex arc
- stimulus activates recetor
- activates senosry neuron and transmits signal to CNS
- CNS processes info and transmits signal to motor
- motor sends signal to muscles/glands for response
- response
what do poprioceptive senses do
detect stretch in tendons muscles joints and ligaments
where are visceral senses more common
digestive and urinary tract
reproductive organs
what are the peripheral sensory receptors
exteroceptors
enteroceptors
proprioceptors
what do entercoeptors do
detect stimuli from within i.e internal viscera
what do exteroceptors do
detect stimuli from outside the body
how may pairs of cranial nerves
12
where do cranial nerves serve
head and neck
which 2 cranial nerves don’t arise from the brains tem and pass through the foramine in the base of the skull
1 and 2
which 3 cranial nerves are purely senosry whilst the other 9 are mixed senosry and motor
optic -2
olfactory - 1
vestibulocochlear-8
what is cranial nerve 1
olfactory- for smell (info from nose) - senosry
what is cranial nerve 2
optic-visual (info from eyes)- sensory
what is cranial nerve 3
oculometer-eye movement, pupil constriction and lens shape-motor
what is cranial nerve 4
trochlear- eye movement- motor
what is cranial nerve 5
trigeminal- info from face, mouth; for chewing- mixed
what is cranial nerve 7
facial- for taste, tear, expressions and salivary glands-mixed
what is cranial nerve 8
vestibulochlear-hearing and equibrium-senosry
what is cranial nerve 9
glossopharyngeal-info from oral cavity; baro and chemoreceptors in blood vessels. for swallowing, salivary gland secretions- mixed
what is cranial nerve 10
vagus-info from and to sensory and efferents-mixed
what is cranial nerve 11
spinal accessory- oral cavity, neck and shooulder muscles moveemnt- motor
what is cranial nerve 12
hypoglossal-tongue muscles-motor
what is cauda equina
collection of nerve roots at inferior end of vertebral canal of the spine
what protects the spine
vertebrae
how many pairs of spinal nerves and how do they attach
31 pairs
attach through dorsal and ventral nerve roots
what 2 nervous systems is the peripheral nervous system divided to
ANS
SNS
role of autonomic nervous sytem
involuntary smooth muscle contractions
role of somatic nervous sytem
voluntary skeletal muscle contraction based on motor neurons at the NM junction
difference between sympathetic and parasympathetic system
neutrotransmitters are preganglionic and postganglionic
- sympathetic = Ach and Noradrenaline
- parasymp= Ach and Ach
only 2 exceptions to the SNS postganglionic fibre which doesn’t release NA
- the transmission of a signal to sweat glands releases ACh not NA
- transmission of a signal to the adrenal glands releases adrenaline not NA
what is used ot break down acetylcholine i the synamse to only result in one signal and not multiple ones
acetylcholinesterase
