The Brain Flashcards
what is the CNS composed of?
the brain and spinal cord
what is the PNS composed of?
cranial nerves and spinal nerves
afferent neuron
sensory neuron
efferent neuron
motor neuron
somatic sensory receptors
monitor the outside environment
visceral sensory receptors
monitor the internal environment
somatic nervous system
skeletal muscle
autonomic nervous system
sympathetic or parasympathetic ie smooth muscle , cardiac muscle
the 3 layers of the meninges
dura mater
arachnoid mater
pia mater
where is CSF formed?
choroid plexus of lateral ventricle
functions of CSF
- bathes brain and spinal cord
- protection
- nutrition for brain tissue
- blood-brain barrier
what are the 4 regions of the brain
- the cerebrum
- the diencephalon
- the cerebellum
- the brainstem
what connects the hemispheres of the cerebellum?
the corpus callosum
what is hemispheric lateralization?
each hemisphere specializes in certain activities
what are the lobes in the cerebellum?
frontal lobe, parietal lobe, occipital lobe and temporal lobe
where is the primary motor cortex located?
the frontal lobe of the cerebellum
what does the primary motor cortex do?
initiates voluntary movement of skeletal muscle on the opposite side of the body
what does the premotor cortex do?
coordinates learned activities
prefrontal cortex
frontal lobe, personality and thought processes
what are the upper motor neuron pathways
anterior and lateral
cerebellum function
smooth coordinated muscle movement
how does the cerebellum receive sensory info?
dorsal spinocerebellar tract via proprioceptors
cerebellar diseases
jerky uncoordinated movements
- intention tremor
- past pointing
- ataxia (clumsy gait)
function of the thalamus
relay nerve impulses from other brain regions to motor cortex
function of the basal nuclei
planning, programming and execution of voluntary movement
how do the basal nuclei control movement
with two way communication system with cerebral cortex can modify output from motor cortex
what type of impulses are predominant in basal nuclei
inhibitory
what does damage to the basal nuclei result in?
increased muscle tone, tremors, difficulty initiating movement
cause of parkinsons disease
lack of dopamine released by neurons of the substantia nigra which project up into putamen and caudate nucleus
symptoms of parkinsons disease
basal nuclei more active = resting tremor, bradykinesia and rigidity of muscles
cause of huntingtons disease
damage to caudate nucleus
symptom of huntingtons disease
jerky involuntary movements
what does the vestibular apparatus do?
equilibrium and balance, maintain posture
what is the vestibular apparatus composed of?
3 semicircular canals (anterior, posterior and lateral)
2 chamber - utricle and saccule
what do the utricle and saccule do?
linear acceleration
what do the semicircular canals do?
angular acceleration
what are the sensory receptors of the vestibular apparatus?
hair cells in the membranous labyrinth
what is a reflex?
an automated response to a stimulus mediated within the brain or spinal cord, reflex arc
what are muscle spindles?
stretch activated sensory receptors
what are hair cells composed of?
stereocilia and a kinocilium
what does bending of the hair cells in VA do?
depolarisation sets up action potentials in the vestibular portion of the the cranial nerve VIII
functions of hypothalamus
autonomic nervous system, hunger and thirst, emotional responses
