explain: circle of willis
- brain gets blood from 2 internal carotid arteries + 2 vertebral arteries
⤷ all 4 connect at base of brain = circle of willis - branch off into smaller arteries that go to brain + cerebellum
- circle helps if one arteries has issues
⤷ others can pick up the slack
⤷ more cerebral security
name: divisions of the nervous system
CENTRAL NS
- brain
- spinal cord
SOMATIC NS = voluntary (mvt)
- cranial nerves
- spinal nerves
AUTONOMIC NS = involuntary
- sympathetic (fight flight)
- parasympathetic (rest digest)
- enteric
explain: afferent vs efferent
- afferent = towards brain + spinal cord
- efferent = away from brain
name: all cranial nerves in order
I - Optic
II - Olfactory
III - Oculomotor
IV - Trochlear
V - Trigeminal
VI - Abducens
VII - Facial
VIII - Vestibulocochlear
IX - Glossopharyngeal
X - Vagus
XI - Accessory
XII - Hypoglossal
name: divisions of spinal cord
- 31 total pairs of nerves
- 8 cervical (C1 - C8)
- 12 thoracic (T1 - T12)
- 5 lumbar (L1 - L5)
- 5 sacral (S1 - S5)
- 1 coccygeal
define: dermatome
- area of skin supplied by single spinal nerve
- symptoms from a dermatome can indicate which nerve is involved
explain: damage to each region of spinal cord
CERVICAL
- impairs function from neck down
- loss of function to thoracic, lumbar, and sacral
⤷ damage to all areas below
THORACIC
- impairs breathing + digestion
- loss of function to lumbar and sacral
LUMBAR
- impairs mvt. in legs and feet
- loss of function to sacral
SACRAL
- impairs bowels + bladder
- also affects sexual function + daily life
explain: complete vs incomplete injury
- of spinal cord
- complete = spinal cord is damaged across whole width
⤷ complete loss of sensation + musc. control - incomplete = injury spreads across part of spinal cord
⤷ some areas still intact + retain some function
name + explain: neuron types (func?) (3)
- sensory neurons
- bring info to CNS
- long axons bc carrying info far distance
- ex.
⤷ bipolar = retina
⤷ somatosensory = skin, musc. - interneurons
- associate sensory and motor activity
- lost of dendritic branching
- ex.
⤷ stellate = thalamus
⤷ pyramidal = cortex
⤷ purkinje = cerebellum - motor neurons
- send sig. from brain and spinal cord to musc.
- ex.
⤷ motor = spinal cord
quesiton: what is glia to neuron ratio?
- how proven to be less than 1:1
- originally thought to be 1 trillion glia to 100 billion neurons
⤷ 10:1 glia:neuron ratio
name; parts of brainstem (3)
- diencephalon
- midbrain
- hindbrain
explain: purpose of cerebellum
- motor coordination + motor skills
- posture + balance
- language processing
- working memory
- higher order thinking
explain: purpose of medulla
- part of hindbrain -> brainstem
- breathing + HR
⤷ damage to this area is often fatal
name: parts of hindbrain (3)
- pons
- reticular formation
- medulla
explain: purpose of reticular formation
- part of hindbrain -> brainstem
- controls general arousal
⤷ moving from unconscious to conscious - important in sleeping + waking
explain: purpose of pons
- part of hindbrain -> brainstem
- taking info to higher parts of brain
⤷ relay to and from brain
name: parts of midbrain (2)
- tectum
- tegmentum
explain: purpose of tectum
- part of midbrain -> brainstem
- superior colliculus = gets visual input
- inferior colliculus = gets auditory input
explain: purpose of tegmentum (parts?)
- part of midbrain -> brainstem
- red nucleus
⤷ involved in limb mvt. - substantia nigra
⤷ involved in approach/avoidance beha. - periaqueductal gray matter
⤷ around cerebral aquaduct
⤷ involved in pain resp.
name: parts of diencephalon (3)
THALAMUS (inner)
- relay station for sensory into
EPIHTHALAMUS (middle)
- has pineal gland (better sleep quality)
HYPOTHALAMUS (below)
- regulates bodily functions
⤷ eat, thirst, hormones
- mediates endocrine struc.
- thalamus connects info -> thalamus collects intro
name: relevant nuclei
- lateral geniculate body
- medial geniculate body
- ventrolateral posterior body
explain: parts of forebrain (3)
- basal ganglia
- limbic sys.
- neocortex
**basal ganglia and limbic sys are subcortical
explain: purpose of hippocampus
- part of forebrain
- memory + learning
explain: purpose of amygdala
- emotional meaning + money
- fear, reward
