anatomy final

brain and spinal cord

• -cerebrum
• -corpus callosum
• -cerebellum
• -limbic system
• -brainstem

• -emergeges from the skull through the foramen magnum
• -courses through the vertebral foramen of the spinal column

• -contains nerve fibers that connect the CNS to the muscles and sense organs
• -housed outside of bone

• -under voluntary control
• -functional systems:
• -pyramidal
• -extrapyramidal

• -arises from motor strip
• -conscious initiation of movement

• -arises from pre-motor strip
• -provides muscle tone, background support for movement

• controls autonomic functions (internal organs and glands)
• -subsystems:
• -sympathetic system
• -parasympathetic system

• responds to stimulation through energy expenditure
• -"fight or flight"

responsible for quieting the body and conserving energy (undo-ing sympathetic stimulation)

• -largest structure of nervous system
• -flat sheet of cells
• -aka "gray matter"
• -white matter connects cerebrum to rest of nervous system
• -divided into right/left hemispheres
• -5 lobes
• -wrapped by 3 meningeal linings

• frontal
• parietal
• occipital
• temporal
• insular

• dura mater
• arachnoid mater
• pia mater
• -protect brain and hold structures in place

• -two layers of tough lining mostly attached to the skull
• -most superficial of meninges
• -extends away from skull to line major divisions of cerebrum

• -many blood vessels through this space
• -cerebrospinal fluid flows through this layer

• -thin fascia like covering
• -closely follows the contours of the brain

• -seperates 2 hemispheres of the cerebrum
• -mid-sagital division of cerebrum

seperates 2 hemispheres of the cerebellum

• -falx cerebri
• -falx cerebelli
• -tentorium cerebelli
• -diaphragma sella

horizontal dural shelf at the base of the skull that divides the cerebral and cerbellar regions

forms an anterior horizontal boundary between teh cerebrum and optic chasm

• surronds CNS
• -produced by the choroid plexus within each ventricle
• -flows through 4 ventricles in brain and arachnoid mater

• -Lateral ventricles (paired)
• -3rd ventricle
• -4th ventricle

composed of 4 spaces bounded superiorly by the corpus callosum and extending into each of the lobes of the cerebrum

located between the left and right thalami and hypothalami

• -diamond shaped
• -projects upward from the central canal of the spinal cored and lower medulla

• -cortex (gray matter)- 6 cell layers
• -divided into 2 halves
• -hemispheres connected by corpus callosum (white matter)
• -divided into 5 lobs

• -pyramidal cells
• -nonpyramidal cells
• -glial cells

involved in motor function

• small and star-shaped
• sensory or intercommunicative in function

• provide nutrition and waste disposal
• provide blood-brain barrier

• -Molecular- contains glial cells and axons from lower layers & receives input from other cortical areas
• - external granular- contains many small pyramidal cells & receives input from other cortical layers
• -external pyramidal- contains medum sized pyramidal neurons which send outputs to other cortical areas
• -internal granular- receives input from thalamus and other cortical areas
• -internal pyramidal- contains largest pyramidal cells which send output to motor centers beyond the cerebrum
• -multiform- consists of pyramidal cells that send info to the thalamus

• frontal
• parietal
• occipital
• temporal
• inular
• (and limbic systme)

• deep to frontal, parietal and temporal
• beneath lateral sulcus/fissure
• involved with maintaining the body and with emotion

• deep structures under cerebrum
• integration pts for info to/from cerebrum and cerebellum to brainstem
• basal ganglia-motor
• hippocampus- memory
• thalamus-sensory

divides temporal lobe form the frontal and anterior parietal lobes

seperates frontal and parietal lobes

• -most cognitive functions
• -initiation and inhibition of activity
• -anterior frontal lobe damage can have effects on personality and motivation
• -posterior frontal lobe damage can lead to speech disorders and paralysis/paresis in limbs

• frontal operculum (brocas area)
• orbital region
• precentral gyrus (motor strip)
• supplementary motor area (SMA)

important for speech motor planning

• region overlying eyes
• memory, emotion, motor inhibition, intellect

site of initiation of voluntary motor movement

motor strip n SMA give rise to corticospinal tract, that innervates sympathetic nervous system

• -things close to each other in the body are close to each other in brain
• -org is contralateral
• -org is inverted

• location for somatic (body) sensory reception
• sensory integration from all sensory areas
• -posterior to motor strip
• -anterior/superior to occipital lobe
• -superior to temporal lobe
• contralateral org

• postcentral gyrus (somatosensory cortex)
• association areas
• supramarginal gyrus and angular gyrus

• -sensory counterpart to motor strip
• org in same way

vision, audition, and somatic sense

involved in reading and writing

• site of auditory reception
• key landmarks:
• -heschl's gyrus (area 41)-all auditory info processed here
• -area 42- higher order processing region for auditory stimualtion
• -Wernicke's area (area 22)-damage here results in language damage

region responsible for receiving visual stimulation and higher-level visual processing

• next to subcortex
• basic body maintenance and emotion

• -the part of the pathway between the sensory and motor structures and the cerebrum where info is integrated
• -basal ganlia
• -hippocampus
• -thalamus

• primitive part of the brain involved in basic autonomic survival functions and in "low-level" details of movement
• -cerebellum
• -brainstem

• -paired structure
• -control/coordination of movement and initiation of movement
• -connections to thalamus, motor cortex, and somatosensory cortex
• -substructures:
• -caudate nucleus
• -putamen
• -globus pallidus

• paired structure
• -implicated in memory function
• -communicated with thalamus and temporal lobe

• -paired structure
• -final, common relay station for sensory info directed toward cerebral cortex
• -all sensation except olfaction passes through it

• -automatic motor coordinating center
• -controls balance, posture, and synergy of voluntary movement
• -3 lobes: anterior, middle, flocculonodular
• -3 layers of cells: molecular, purkinje, granular

controls muscle tone operating against gravity

coordinates fine motor adjustments

communicates with the vestibular system and coordinates body position in space

connect within cerebellum

project to nucleii and out of cerebellum

• connects to brainstem through three penducles:
• superiro, middle, and inferior
• -4th ventricle occupies space between the cerebellar peduncles and the brainstem

• -controls basic body functions like heart rate and breathing
• -connects brain to spinal cord

• -of brainstem
• -consists of transmission pathways
• -pyramidal tract
• -pyramidal decussation

carries signals to muscles from cortex

motor commands from one hemisphere cross to serve the opposite side of the body (juncture for contralateral organization

• -brainstem
• -connects motor planning centers of brain to cerebellum

• -brainstem
• -connecting link between lower and higher brain centers
• -connects cerebellum to cerebrum and basal ganglia
• -relays auditory and visual info

-vascular supply for the brain arises from two arteries: carotid and vertebral

• divides cerebrovascular system into the right and left internal carotid arteries
• -L/R internal arteries feed into the circle of Willis
• -provide blood to brain

• divied cerebrovascular system into right and left branches, and feeds into the basilar artery in posterior brain
• -L/R arteries combine and become the basilar artery which feed into circle of Willis

• series of junctures between arteries that completely encircles the optic chasm
• -provides redundant pathways for blood flow to regions of cerebral cortex

goes directly to olfactory areas

found at the level of the midbrain

are at the level of the pons

are found in medulla

incoming general sensory info for somatic system

incoming special sensory ifo for hearing and vision

incoming general sensory info for visceral system

incoming special sensory info for taste and smell

outgoing autonomic muscle control (for digestion and glands

innervation of skeletal musculature

innervation of musculature for mastication and deglutition

• special visceral afferent nerve
• -not a true cranial nerve because it reaches brain w/out passing through thalamus first
• -contains sensory fibers
• -mediate sense of smell

• optic nerve
• -special afferent nerve
• -sensory fibers that merge at the optic chiasm
• -enters brainstem at midbrain
• -processes visual info

• occulomotor
• -contains motor fibers for eye movements(general somatic efferent)
• -serves extrinsic ocular muscles ipsilaterally
• -also for pupil constriction and focus

• trochlear
• -general somatic efferent
• -contains motor fibers for eye movements
• -innervates superior oblique muscle contralaterally
• -turns eye down and in/out

• abducens
• -general somatic efferent
• -contains motor fibers for eye movements
• -abductor muscle
• -motor innervation to the lateral rectus ocular muscle

• trigeminal
• -3 major branches (tri-geminal)
• -motor supply to the muscles of matication and tensor veli palatini
• -transmits sensory info form the face
• -general somatic afferent

• facial
• -contains both sensory and motor fibers
• -supplies muscles of the face and the stapedius in middle ear
• -serves salivary glands
• -provides taste for anterior 2/3 of tongue

• vestibulocochlear
• -primarily sensory
• -special somatic afferent
• -carries nerves for hearing and balance
• -efferent portion serves cochlear hair cells that are involved in actively tuning hearing

• contains sensory and motor fibers
• -serves the face, tongue and phayrnx
• -posterior tongue and soft palate taste receptors
• - touch, temp, and pain sense from posterior tongue, faucial pillars, upper pharynx

• -glossopharyngeal
• -innervation of stylopharyngus and superior pharyngeal constrictor (special visceral efferent)
• -innervation of parotid gland for salivaiton (general visceral efferent)

• -vagus
• "wandering nerve"
• -runs throughout chest and abdomen
• -mix of sensory and motor fibers
• -supplies more visceral structures than any other cranial nerve

• superior laryngeal nerve
• recurrent laryngeal nerve
• pharyngeal branch

-external branch-innervates cricothryroid muscles for pitch control, special visceral

efferent-internal branch- sensory for the tongue and mucosa of the supralaryngeal area, general visceral afferent

• supplies all of the intrinsic laryngeal muscles, except cricothyroid (sve)
• supplies subglottal laryngeal muscosa (GVA)

• -taste (SVA) and sensation (GVA) from base of tongue and upper pharynx
• -innervation of upper and middle pharyngeal constrictors, plalopharyngeus, lev

• accessory
• -contains only motor fibers
• -SVE
• -serves muscles of pharynx, soft palate, and neck

• hypoglossal
• -motor nerve that supplies:
• all intrinsic tongue muscles
• most of extrinsic tongues muscles
• infrahyoid muscles
• -GSE
• -contralateral innervation