Nervous system Flashcards
divisions of nervous system
sensory (afferent)
- somatic (conscious)
- visceral (unconscious)
motor (efferent)
- somatic (conscious)
- autonomic (unconscious)
lobes of the cerebrum
frontal - decision making, abstract thought
parietal - proprioception, touch
occipital - visual processing
temporal - smell hearing
insula - taste, cardiovascular homeostasis
gyri and sulci
gyri (hills)
- precentral gyrus (primary motor cortex)
- postcentral gyrus (primary somatosensory cortex)
sulci (valleys), deep ones are fissures
- longitudinal cerebral fissure
- central sulcus
increase convolutions, increase surface area of brain, increase cognition
white vs grey matter
white matter - myelinated axons
grey matter - cell bodies
brain: white deep to grey
spinal cord: white superficial to grey
voluntary movement process
intention to move starts in the motor association area
intention to move is finalised in the primary motor cortex
impulse travels from upper motor neuron to lower motor neuron (corticospinal tract), brainstem, spinal cord, muscle
left PMC controls voluntary movement in right of the body due to decussation of corticospinal tract in the brainstem
sensory information process
impulse from spinal cord passes through brainstem and reaches thalamus, thalamus processes and selects information to be passed on to PSC, information processed at PSC
sensory information from the left on the body is processed at the right PSC, due to decussation of sensory pathways
this leads to CONSCIOUS sensory awareness
importance of corpus callosum
right and left cerebral hemispheres are not functionally identical
largest white matter tract in brain allows for coordination and communication between 2 hemispheres, synchromises activity, decerases competition
cerebellum
coordination of movement
balance and posture
stores memories for movement patterns
mood regulation
right and left control right and left (ipsilateral)
brainstem
divided into midbrain, pons, medulla oblongata, contains many cranial nerve nuclei
midbrain: sleep/wake cycle regulation
pons: relays signals between cerebrum, cerebellum, spinal cord
medulla oblongata: heart rate, blood pressure, rate and rhythm of breathing, coughing, vomiting, sneezing, swallowing
thalamus
receives and processes sensory info, selectively relays it to PSC
coordinates movement by relaying signals from cerebellum and cerebrum
hypothalamus
commands autonomic nervous system and endocrine system
secretion of hormones
thermoregulation
hunger and thirst
limbic system
process and experience emotions
- thalamus
- hypothalamus
- hippocampus
- amygdala
- septum
- olfactory bulb
3 meninges layers
dura mater: thick, fibrous, opaque, innervated with sensory nerves
arachnoid mater: web of collagen and elastin fibres, contains and circulates CSF
pia mater: thin layer of areolar CT
surround, protect, nourish brain and spinal cord
ventricular system arrangement
2 lateral ventricles in each hemisphere
interventricular foramen
3rd ventricle
cerebral aqueduct
4th ventricle extends to spinal cord
how is CSF produced
produced by ependymal cells in the choroid plexus of the ventricles
CNF function
provides buoyancy for brain
shock absorber
provides nutrients removes waste from CNS
how is CSF removed from brain
reabsorbed by arachnoid granulations
superior sagittal sinus
internal jugular vein
brain blood supply
2 veins, 4 arteries
anterior circulation: internal carotid arteries
posterior circulation vetebral arteries
CN I Olfactory nerve
olfactory sensation from nose to brain, bypasses thalamus
CN II Optic nerve
visual info from retina to brain
CN III Oculomotor nerve
Moves upper eyelid
dilates constricts pupil
makes lens more spherical
CN IV Trochlear nerve
Moves eye inferiorly and laterally
CN V Trigeminal nerve
Touch, temperature, pain from face
mastication and biting
V1 V2 sensory, V3 mixed
CN VI Abducens nerve
moves eye laterally
