Nervous System Flashcards
Cerebellum function
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Cerebrum function
…
What are the three properties of a neuron?
- excitability
- conductivity
- secretion
What type of neurons are sensory neurons?
Unipolar
What type of neurons are motor neurons?
Multipolar
Where does the visceral sensory division send signals from?
Viscera od the thoracic and abdominal cavities
Where does information from the somatic sensory division come from?
Skin, muscles, bones and joints
What do Astrocytes do?
Forms a supportive framework between neurons and blood vessels
What do oligosendrocytes do?
Produces myelin sheath in the CNS
What do ependymal cells do?
Line central cavities of the brain and spinal cord, produce CSF
What do Schwann cells do?
Form myelin sheath in the PNS
What do Satellite cells do?
Provide support and nutrition to cell bodies in ganglia
What tissue is nervous tissue formed from?
Ectoderm
What does the hollow part of the neural tube become?
Central canal and ventricles of brain
When does neuralation begin?
Day 19
What forms from neural crest cells?
PNS
Frontal lobe
- abstract thoughts
- ## mood and motivation
Parietal lobe
- taste
- somatic sensation
- sensory integration
- language processing
Occipital lobe
- visual awareness
- visual processing
Temporal lobe
- hearing
- smell
- learning
- emotion
Thalamus function
Processes input prior to regulating to cerebrum
Hypothalamus function
- controls centre for endocrine and ANS
- thermoregulation
- food and water intake
Cerebellum function
- posture
-locomotion - ## fine motor control
Medulla function
- cardiac, respiratory, vomiting and vasomotor centres
Where do cranial nerves 1 and 2 arise from?
Cerebrum
Where do nerves 3-12 arise from?
Brain stem
What are the divisions of the spinal cord?
- cervical
- thoracic
- lumbar
- sacral
- coccygeal
Number of spinal nerves in each region
8 12 5 5 1
Where is CSF found in the brain?
Sub arachnoid space + ependymal cells
Somatosensory primary and association areas
- primary: parietal lobe
- Association: immediately dorsal
How is sensation detected?
- modality
- intensity
- duration
- location
What two neurons are involved in motor contraction?
Upper motor neuron
Lower motor neuron
What is the parasympathetic neurotransmitter?
- acetylcholine - adrenergic receptors
What are the sympathetic neurotransmitters?
- adrenaline and noradrenaline
What are the receptors for adrenaline and noradrenaline?
Muscarinic (excitatory or inhibitory)
Nicotinic (excitatory)
What is a tract?
A bundle of axons in the CNS
What is a nerve?
A bundle of axons in the PNS
What are the layers of meninges?
- dura
- arachnoid
- Pia
What are the 3 functions of cerebrospinal fluid?
- buoyancy and cushioning: the brain is so heavy that if it was not suspended in CSF the pressure of its weight against the bones of the skull would destroy nervous tissue
- protection: helps to prevent the brain from striking the cranium when the head is jolted
- chemical stability: has a circulatory function for removal of wastes and regulation of chemical environment
Explain how hydrocephalus can occur and why it’s presentation can manifest differently in infants and adults.
- CSF is constantly produced
- if it’s circulation or drainage is blocked the resulting build up of pressure causes abnormal growth in infants whose skull bones have not fused yet
- in adults pressure is put on the brain and it’s blood vessels, causing headaches, come and death if not treated
- treatment involves putting a shunt from the ventricles to a vein in the neck
How does the diameter of the fibre affect the speed of transmission?
- signal conduction occurs along the surface of the fibre
- large fibres have a larger surface area that small fibres, therefore signals travel faster along large fibres
Speed of signals in myelinated fibres
Up to 120m/sec
Speed of transmission in unmyelinated fibres
Up to 2m/sec
How many neurons are in the sensory pathway?
3
Which region is associated with the patella reflex?
Lumbar
Sensory pathway
1st order neuron cell body: dorsal root ganglion
2nd order neuron cell body: medulla
3rd order cell body: thalamus
Where does the sensory pathway decussate? Which neuron is it?
- medulla
- 2nd order neuron
Motor pathway
Upper motor neuron cell body: pre central gurus of frontal lobe
Lower motor neuron cell body: ventral horn of spinal cord
Where does the motor pathway decussate? Which neuron?
- medulla
- upper motor neuron
