Speech and Hearing Anatomy
Terms
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- thalamus
-
-collection of nuclei grouped together, largely grey matter
-thalamic adhesion connects -
-*relays sensorimotor info to the cortex*
-may contribute to some speech and language functions
-Medial border = third ventricle
-Lateral border = internal capsule - hypothalamus
-
-consists of many nuclei with different jobs
-clustered above the pituitary gland
-in the point of the optic recesses of the 3rd ventricle
-various autonomic and endocrine functions - interacts with the pituitary gland
-sends info where it needs to go (like the cortex) to integrate functions - basal ganglia
-
-a set of subcortical nuclei
-one in each hemisphere
-motor function and tone
-constributes to posture
-control or initiation of movement
-connects to thalamus and basal ganglia
-example problem: Parkinson's - caudate nucleus
-
-large c-shaped nucleus
-long curved tail
-runs along lateral ventricle
-head pushes into the lateral ventricle
-tail curves around back of thalamus, enters inferior horn
-ends at amygdala - putamen
-
-half-moon shaped
-posterior and lateral to the head of the caudate nucleus
-connected to the head by a strip of grey matter lying outside the putamen - claustrum
-
-part of the basal ganglia
-lies outside the putamen
-connects putamen to the head of the caudate nucleus
-grey matter - globus pallidus
-
-more medial than the putamen
-wedge shaped bunch of grey matter
-in between is the internal capsule - semi-permeable membrane
-
-outside of the neuron
-separates intercellular dextrocellular fluid
-both fluids have electrolytes - Salt conductors
- Potassium, sodium, chloride
- passive transports
- + and - ions are attracted
- control balance
-
-sodium potassium pump
-active transport, pushes K+ back in, goes against current
-potassium in, sodium out - resting membrane potential (RMP)
-
-neuron is at balance
- -70 MV is the resting charge
-stimulus will cause a change in RMP
-changes intracellular to +
- -70 MV -> 50 MV
-more + charges inside - action potential
-
-sodium gates open
- + inside, - out along axon
-K+ let in
-1 millisecond - saltatory conduction
-
-node -> node
-telodendrite synaptic buttons
-vessicle release neurotransmitters
-out into synaptic cleft stimulation for next neuron - post synaptic
- fire or not based on extrocellular fluid
- All or Nothing Principle
-
-Neurons either fire or don't fire
-Must be +50 MV - absolute refractory period
- when depolarized can't fire until -70 MV
- Order of firing
-
RMP
AP
ARP
RRP - relative refractory period
- partially recovered, and with enough stimulation, will fire again
- propogation
- electrical chemical wave
- resting state
-
- -70 MV - K+ leaks and some NA+ getting in
-in order for change, sodium comes in fast
- +50 MV - threshold reached - depolarizing firing to axon - astrocytes
-
-very structural
-keep things where they're supposed to be
-confines activities
-form blood/brain barrier
-neurons need oxygen which comes from blood, but not the toxins - these deliver the nutrients
-neurons - shield neural tissue from toxins - aligodendrocytes
-
-supportive
-insulate
-surrounding of the cell bodies
-form the myelin in the CNS
-neural pathways which connect the brain - Schwann Cells
-
-supportive
-insulate
-form myelin in the PNS
-actual cranial and spinal nerves - commissural pathways
-
-neural pathways in the CNS
-tracts that go from a location in 1 hemisphere to a corresponding location in the other hemisphere
-exp: corpus callosum - associational fibers
-
-connects in 1 hemisphere
-may be short or long
-can be lobes
-stay in the same hemisphere - arcuate fasciculus
- -tract that runs from Wernicke's to Broca's
- cingulum
- above the corpus callosum - frontal -> parietal -> occipital with limbic system and each other
- projection pathways (fibers)
-
-run to and from cortex
-connect cortex to other areas
-info in and out of cerebrum - corona radiata
- fibers
- internal capsule
-
-where fibers get closer together
-into brainstem - brain stem
-
-connects diencephalon to the spinal cord
-exits through the foramen magnum, then is the spinal cord
-bulbar region
-surrounded by projection fibers
-grey matter
-reticular formation -maintains life function
-coordinates CNS/PNS - midbrain/mesencephalon
-
-where fibers enter the brainstem
-crossover - pons
- serves as a bridge to and from the cerebellum - gray matter regulates facial movement and sensation
- medulla
- base of the brain stem, regulates basic life functions, like heart rates, respiration, phonation control
- cerebellum
- spaghetti looking, grey cortex outside, inside white with grey pockets - coordinates and regulates balance, posture, skilled movements
- vermis
- connects two hemispheres of the cerebellum
- peduncles
- bundles of connective white matter
- superior cerebellar peduncle
- leaving cerebellum, opp. motor cortex, offers corrective feedback
- dentate nucleus
- R & L - synapse happens here, message travels along
- middle cerebellar peduncle
- collection of fibers, info back into cerebellum from the cerebrum
- inferior cerebellar peduncle
- info in form nearby structures like the medulla and spinal cord
- spinal cord
-
-protected by vertebrae and meninges
-pia mater adheres to spinal cord surfac
-fibers longitudinal
-projection pathway all the way down, stops at the synapse
-pair of spinal nerves at each vertebrae
-31 spinal nerves, sensorimotor
-spinal ganglion - reflex arc
-
-a reflexive movement does not go all the way to the brain, goes to the ganglion and outt
-feelin goes all the way through the brain - cranial nerves
-
-work like spinal nerves
-synapse in the grey matter
-travels out motor component of nerve
-sensory acts the same way, receptor out at skin, cranial nerve V, trigeminal ganglion, synapses, message in basal ganglia, brain, thalamus
-outside cerebrum, brain, spinal
-every cranial nerve has a nucleus - sensorimotor nerves
-
-mixed nerves
-all spinal are this
-some cranial are too - anterior
- toward the front
- posterior
- toward the back
- superior
- upper/above
- inferior
- lower/below
- ventral
- away from the backbone
- dorsal
- toward the backbone
- caudal
- toward the tail
- rostral/cranial/cephalad
- toward the head
- lateral
- away from the axis or midline
- medial
- toward axis or midline
- proximal
- toward the body or root of extremity
- distal
- away from the body or root of extremity
- external
- toward the outer surface
- internal
- toward the inner surface
- central
- pertaining to or situated at the center
- peripheral
- pertaining to or toward the outer surface
- sagittal
- body plane divides right from left
- coronal/frontal
- body plane dividing front from back
- transverse
- body plane dividing upper from lower
- parasagittal
- not right on the midline
- cross-section
- tranverse cut through a tube, etc.
- afferent
- toward a structure
- efferent
- away from a structure
- cell
- organized system of protoplasm, contains nucleus, cytoplasm
- 5 types of tissues
-
-epithelial
-muscle
-connective
-nervous
-vascular - epithelial tissues
- covers and lines different vessels and different cavities of the body
- muscle
- made of contractile material, has an origin (fixed) and insertion (mobile)
- striated muscle
- long, voluntary muscles
- smooth muscle
- shorter, involuntary
- cardiac
- both long and short - voluntary and involuntary
- connective tissue
- loose and dense - special's primary goal is structure
- cartilage
- desiged to maintain shape
- bone
- osseous - most dense CT - provides support and structure
- tendon
- non-elastic, binds muscle to bone or muscle to cartilage
- ligament
- binds bone to bone, bone to cartilage, cartilage to cartilage
- aponeurosis
- broad and flattenedmatterial, tendenous, connects muscle to bone and muscle to muscle
- fasciae
- tissue fibers in a sheath, separate one muscle from another - layer of cartilage
- nervous
- highly specialized cells, conduct signals to and from brain
- vascular tissue
- fluid like blood, transports nutrients
- skull
- encases brain, allows for attachments of muscles and ligaments
- cranium
- 8 bones, where brain is housed
- frontal bone
- houses frontal sinus, surface of forehead, 1 bone
- parietal bone
- contributes to roof and sides of the skull - 2
- temporal bone
- contribute to lateral walls and base of skull - 2 bones
- occipital
- leaf shaped, forms the back of the cranium and the base of the skull - 1
- ethmoid bone
- "5th bone of the cranium" - inferior and posterior to the frontal lobe - surface of cranial floor - framework for nose and eyes - contains lateral labyrinths with nasal conchae
- nasal conchae
- little spaces covered with muscous membrane - nerve ending for smell - forms nasal septum
- sphenoid
- joins anteriorly with the ethmoid and posteriorly with the occipital - supports temporal and frontal lobes - pharyngeal structure
- sutures
- only in the skull - only immobile joints
- lamboidal
- separates occipital from temporal and parietal
- cerebrum
-
-2 hemispheres divided by the longitudinal fissure
-consists of many lobes - precentral gyrus
- before central sulcus, primary motor cortex, moves muscles on opposite side of the body
- Broca's area
- motor sperech production
- parietal love
-
-central sulcus
-integrates symbols/info together - postcentral gyrus
- -sensory function, primary sensory cortex
- occipital lobe
- visual interpretation, recognition
- temporal lobe
- -in both hemispheres, largely responsible for auditory reception
- limbic lobe/system
- center of the brain - composed of several structures - around the center of the brain - feeding, fleeing, fighting, arousal
- corpus callosum
- messages back and forth from left to right
- Isle of Reil
- visceral (gut reaction) actions - "old brain" - relays some info from one place to another
- cortex
- 6 layers of different types of neurons
- gray matter
- where cell bodies are located
- white matters
- myelinated axons
- midbrain
- links brain stem to cerebrum - visual and auditory reflexes
- meninges
- layers of membrane, cover and protect the CNS by holding structures together - some cushioning from membranes, other from fluids within - framework for blood vessels
- dura mater
-
-tough
-2 layers fused
-adheres, 1 side to skull, other to arachnoid
-protects and separates - falx cerebri
- -dura mater tissue that comes down from both sides above corpus callosum
- falx cerebelli
- around the cerebellum between those hemispheres - kept separate from cerebrum
- arachnoid
-
-thin
-web-like, lacy
-bridges over sulci
-holds stuff together
-on the gyri
-blood vessels and nerves pass through
-projects through dura mater - arachnoid granulations
- -reabsorbs fluid into granulations, puts into blood stream
- superior sagittal sinus
- major site of arachnoid granulations
- pia mater
-
-thin
-adheres one side to the arachnoid, other to brain/spinal tissues
-down in all of the sulci
-extremely vascular
-epithelial tissue
-merges to form choroid plexus - subdural space
- -between dura mater and arachnoid
- subarachnoid space
-
-between arachnoid and pia mater
-arteries, nerves, fluid - lateral ventricles
- -2, one left, one right - front is anterior horn, back is posterior horn
- septum pellucidum
- separates 2 lateral ventricles
- interventricular foramen
- hole, tube, L-R, leads into 3rd ventricle
- septume pelucidium
- if removed, you could see the anterior horn of the lateral ventricle - space b/w cerebrum and brain tissue - horns separated by this membrane
- cerebrospinal fluid
- produced in the meninges - lines the spaces - epithelial tissue
- choroid plexus
-
-tufts of tissue
-spongy
-in every ventricle
-along floor of lateral ventricle
-along the ceiling of the 3rd ventricle
-along the wall of the 4th ventricle - glial cells
- supportive cells around the neurons
- axon hillock
- junction between cell body and process of axon
- dendrites
- info to cell body
- axon
- info away from cell body
- node of Ranvier
- junction between the myelin - leaves part of the axon exposed to fluid outside the neuron
- synaptic cleft
- when adequate neural stimulation, neuron fires - when it reaches the synaptic button, neurotransmitters are released into this