Anatomy Ch. 18, Brain and Cranial Nerves

hrdcorhrvivor's version from 2017-04-20 05:27

Section 1

Question Answer
brain is derived fromectoderm that forms neural tube
telencephaloncerebrum and lat ventricles
diencephalonthalamus, hypothalamus, epithalamus, third ventricle
mesencephalonmidbrain, cerebral aqueduct
metencephalonpons and cerebellum, part of fourth ventricle
myelencephalonmedulla oblongata, part of fourth ventricle
brain stemcontinuation of spinal cord, medulla oblongata, pons, midbrain
cerebellumsecond largest part of brain
cerebrumlargest part of brain
cranial meninges dura mater: two layers in cranial dura. arachnoid mater. pia mater: forms sheath around BVs. no epidural space. continuous with spinal meninges
dura materextensions of the dura mater separate parts of the brain
falx cerebriseparates two cerebral hemispheres
falx cerebelliseparates two cerebellar hemispheres
tentorium cerebelliseparates cerebrum from cerebellum
cerebrospinal fluid CSFclear, circulates through ventricles in brain, central canal of spinal cord, subarachnoid space
functions of CSFabsorbs shock and protects brain/spinal cord (mechanical protect). transports nutrients and wastes from blood and nervous tissue (circulation). maintains favorable chemical environment (chemical protection)
formation of CSFformed in choroid plexus: capillaries in walls of ventricles. theyre lined with ependymal cells, form blood CSF barrier. plasma from choroid plexus goes through these cells into ventricles to form CSF
ventricles of the brainlateral: in cerebral hemisphere. third: along midline. cerebral aqeuduct: midbrain. fourth: brainstem and cerebellum
CSF circulation1. formed in lat vents, leaves choroid plexus via intervent foramina. 2. third vent 3. cerebral aqueduct 4. fourth vent, exits via median and lat apertures 5. subarachnoid space 6. central canal of spinal cord. reabsorbed by arachnoid villi
hydrocephalyabnormal buildup of CSF in ventricles of brain, fluid increases pressure and can compress and damage brain in adults, children's skulls conform

Section 2

Question Answer
brain blood flowbrain received 20% of total blood supply, int carotid and vert arteries, circle of willis, int jugular veins
blood brain barrier BBBprotects brain from harmful substances, composed of tight junctions in cap endothelium w thick basement membrane
3 components of brainstemmedulla oblongata, pons, midbrain
medulla oblongatabreathing rhythm, heart rate, vomiting, swallowing
decussation of pyramidspyramids: buldges on ant side of medula, 90% of axons from right pyramid cross to the left and vice versa
cardiovascular centernuclei that regulate heart rate and BV diameter
respiratory centernuclei that adjust basic breathing rhythm
ponssup to medulla, connects brain parts and relays signlas related to skeletal muscle from cerebral cortex to cerebellum
pontine respiratory group control respiration
midbraincontains cerebral aqueduct, vision, hearing, motor control, sleep/wake
cerebral peduclestracts with axons that conduct nerve impulses from motor areas to spinal cord
sup colliculicoordinates eye movements
inf colliculiauditory stimuli, startle reflex
substantia nigradarkly pigmented, control subconscious muscle, neurons release dopamine
red nucleuscontrol voluntary movements of limbs
mesencephalic nucleusonly nucleus in CNS thats not a synaptic relay station, proprioceptive info to brainstem to control skeletal muscles of head
cerebellumcheck how well consciously initiated movements are carried out, send feedback to the cortex
cerebellum 2 hemispheres and vermiscontrol subconsious aspects of skeletal movement or equilibrium and balance
cerebellar cortexgray matter that form parallel folds called folia
arbor vitaetracts of white matter
cerebellar peduncles3 pairs, conduct impulses between cerebellum and other parts of brain
flocculonodular lobecontributes to equlibrium and balance

Section 3

Question Answer
thalamusrelays sensory info to cerebral cortex, all senses except smell go thru thalamus
ant nucleus of thalamusemotions, alertness, memory
medial nuclei of thalamusemotions, learning, awareness, cognition
lat group of thalamusemotional expression, sensory info integration
ventral group: lat geniculate nucleussends visual impulses to primary visual area
ventral gorup: med geniculate nucleussends auditory impulses to primary auditory area
intralaminar nuclei of thalamuspain perception, awakeneing
hypothalamus4 regions. mammillary: mammilary bodies, tuberal: median eminence and infundibulum, supraoptic: sup to optic chiasm, preoptic: regulates certain autonomic funx
infundibulumconnects hypothalamus to pit gland
median eminencesecretions collect here before entering portal sys
mammillary bodiesrelay info from amygdala and hippocampus to thalamus
functions of hypothalamuscontrol ANS, production of hormones, regulation of emotional and behavioural patters, eating and drinking, body temp, circadian rhythms
epithalamuspineal gland, secretes melatonin
cerebrumprovides us with all cognitive functions
cerebral cortexouter layer of cerebrum, gray matter folds
gyrifolds in cortex
sulcishallow grooves
fissuresdeep grooves
cerebral hemispheresseparated by longitudinal fissure connected by corpus callosum
frontal lobe sensationsbehavior, learning, voluntary movement
parietal lobe sensationssensation, perception, integrating sensory input
temporal lobe sensationsprocessing sensory input, primary auditory cortex
occipital lobe sensationsvisual processing center, primary visual cortex

Section 4

Question Answer
commissural tractsconduct impulses from gyri one hemisphere to corresponding gyri in opposite hemisphere
associated tractsconduct nerve impulses between gyri in same hemisphere
projection tractsconduct nerve impulses to and from thalamus, brain stem, spinal cord to cerebrum
basal nuclei (ganglia)masses of gray matter in each cerebral hemisphere. globus pallidus, putamen, caudate nucleus
functions of basal nucleihelp initiate and terminate movements, suppress unwanted movements, regulate muscle tone
limbic systemring of structures on the inner border of cerebrum and floor of diencephalan
hippocampuslong term memory
amygdalaintense emotion, aggression and fear, memory and emotion
olfactory bulbinvolved in olfaction
cingulate gyrusinfluential in linking behavioural outcomes to motivation
dentate gyrusthought to be involved in memory formation and depression
lobotomiescutting away most of the connections to and from the prefrontal cortex and the ant part of frontal lobes. reduce the symptoms of mental disorder, at the expense of person's personality and intellect
primary somatosensory areapostcentral gyrus
primary visual areaoccipital lobe
primary auditory areatemporal lobe
primary gustatory areaparietal lobe
primary olfactory area temporal lobe
primary motor areaprecentral gyrus
broca's speech areafrontal lobe, left hemisphere, planning and production of speech
wernicke's arearecongition of spoken language, left temporal and parietal lobes

Section 5

Question Answer
CN 1 (I)olfactory nerve, smell
CN 2 (II)optin nerve, vision
CN 3 (III)oculomotor nerve, eye and upper eyelid movement
CN 4 (IV)trochlear nerve, eye movement
CN 5 (V)trigeminal nerve, sensory: pain, touch, temp. motor: mastication. largest cranial nerve
CN 6 (VI)abducens nerve, eye movement abduction
CN 7 (VII)facial nerve, sensory: taste buds. motor: facial expressions
CN 8 (VIII)vestibulocochlear nerve, hearing, vestibular branch: equilibrium, cochlear branch: hearing
CN 9 (IX)glossopharyngeal nerve, sensory: taste buds, motor: release of saliva
CN 10 (X)vagus nerve, sensory: proprioception and stretch, motor: swallowing and vocalization
CN 11 (XI)accessory nerve, sternocleiomastoid and trapezius to coordinate head movements
CN 12 (XII) hypoglossal nerve, nerve impulses for speech and swallowing