ORG exam 1 Flashcards

Question

Brain: frontal lobe BA SM

Answer 1

Broca's area-- l cerebral hem, part of inferior frontal gyrus, speech motor planning and programming SMA- supplementary motor area- left hemisphere , initiating and preparation of movt, including speech and thought- brodman 6

Answer 2

Primary sensory cortex- post central gyrus contralateral sensation- interpret touch, pain, temp somatotopic map

Answer 3

projection fibers- aff and eff upper motor neurons corticospinal- brain to spine, corticobulbar brain to head upper sensory neurons

Answer 4

Cortex--> Corona Radiata - large radiation of projections fibers just below cerebral cortex Internal Capsule - projection fibers converge tightly into band of white matter – through basal ganglia Cerebral Peduncles/crus cerebri - down thru to brainstem and SC musculature below – midbrain level --corticobulbar tracts synapse in brainstem nuclei and innervate CN --corticospinal tracts continue down to --Pyramids - crossing/decussations of corticospinal fibers in medulla leading to SC where synapse on motoneurons in ventral horns

Answer 5

also called corpus striatum =caudate+putamen should be called “nuclei”- looks like blue tooth includes 1) caudate - bilateral, long tailed structure which ends at the amygdala 2) lenticular nucleus - nut-shaped structures at front of caudate; consists of ---putamen ---globus pallidus - two segments (internal, external) function: ---involved in integrating complex motor activity such as walking, posture, balance, and of course, speech; ---regulating size direction etc i.e. inhibiting unwanted motor activity

Answer 6

sensory relay and integration center- does not control movt directly but can affect if damaged walnut-sized oval masses deep within each cortex; more mesial than BG each consists of many different nuclei specialized for different functions e.g. memory, language, sensory, motor, attention and arousal -the two can be connected to one another subthalamic nuclei -less apparent nuclei below thalamus that are involved in motor system

Answer 7

substantia nigra - just deep to peduncles – dark gray/black, important for providing dopamine to basal ganglia directly above red nucleus - round nucleus that is another structure involved in motor activity via cerebellum cerebral peduncles - anteriorly – white matter, continuation of internal capsule so important motor pathway to SC

Answer 8

posterior inferior part of brain; more, smaller convolutions divided into two hemispheres with cortex of gray matter and interior regions of gray and white matter fn: integrates and coordinates smooth, synergistic limb movts, balance, posture, and gait (wide-based gate); timing * ipsilateral control*

Answer 9

anterior hump at top of brainstem fibers connect to the cerebellum ventral portion - contiguous with cerebral peduncles to pyramids dorsal portion - brainstem nuclei of some CN that exit at pons, nuclei of reticular formation, and ascending and descending sensory and motor tracts

Answer 10

lowermost portion of brainstem contiguous with SC below contains *pyramids - decussation *dorsal portion of medulla ---nucleus cuneatus and nucleus gracilis -cell bodies for sensory tracts coming up from SC *upper posterior medulla ---inferior cerebellar peduncles - carrying info to cbl *reticular formation- cardiac and vasomotor life fn centers of MO (HB, respiration, wake)--coma

Answer 11

2 UMN branches corticobulbar tract: to cranial nerves corticospinal tract: to spinal nerves origin - pyramidal cells in primary motor cortex, but also cells in premotor cortex and primary sensory cortex (topographic organization along the strip) path: corona radiata> internal capsule> cerebral peduncles (aka crus cerebri)> to Brainstem/corticobulbar (contra or ipsi) > CN OR to SC/corticospinal- (decuss=contra)> ventral part of SC (motor neurons) function: critical for voluntary, skilled, discrete, rapid movts-- including speech movts

Answer 12

second source of input to LMNs/final common pathway multiple synapses along its pathway origin - cortex - motor, premotor, and sensory cortex Reticular pathways: --1. corticoreticulo fibers: cortex down to reticular formation nuclei in brainstem --2. cerebelloreticular --3. reticulospinal fibers: brainstem down to motoneurons probably involved in muscle tone, some fibers are actually inhibitory to muscle activity

Answer 13

corticorubral fibers: cortex to red nucleus rubrospinal tract: red nucleus to spinal motor neurons important for flexion activity probably also in speech muscles

Answer 14

``` vestibulospinal fibers: vestibular nuclei in brainstem down to SC **function overall regulates reflexes (so certain reflexes don’t occur), muscle tone resulting from a certain amount of input at all times- must be in balance and the upper pathway inhibits, posture so that direct pathway can accomplish its goals ```

Answer 15

decorticate posture - lesion of upper portion of indirects/directs - corticoreticular/rubral pathways - allow fibers from rubral/reticular/vestibular to fire uninhibited leading to extensor activity in the legs and flexion activity in the arms (BROCA arm) decerebrate posture - lesions from midbrain to medulla now ends the flexion activity and see arm extensor activity as well (floppy) - localized reflexes unmodified from input above - Speech problems not language- dysarthria not aphasia

Answer 16

1) “direct activation pathway” - pyramidal system - upper motor neuron UMN 2) “indirect activation pathway” - extrapyramidal system 3) “cerebellar control circuit”- coordination/timing 4) “basal ganglia control circuit”- size of movt 5) “final common pathway” - lower motor neuron LMN

Answer 17

no direct contact with motoneurons below; exert their influence in integration/regulation and coordination of movt via complex interactions among cortical/subcortical structures Circuits, excitatory and inhibitory: *cortico-striato-pallido-thalamo-cortical loop --sub-circuit 1: striatonigral (putamen-substantia nigra-putamen) *dopamine (inhibitory) --sub-circuit 2: subthalamic nucleus - globus pallidus Should be a balanced system: neurotransmitter activity in striatum is critical-- acetylcholine (excit) and dopamine (inhib), also gaba (inhib) function: critical for normal muscle contraction and posture allowing for voluntary movts to proceed smoothly --regulate amplitude, velocity, and initiation of movts --regulates intended movts, dampen unwanted movts --in speech, the basal ganglia circuit actually seems to “dampen” movts

Answer 18

hemispheres control movts on ipsilateral sides of body-because info goes from L cbl up to R cortex which controls L body corticocerebellar loop: primary motor and premotor to cbl cbl via red nucleus and thalamus back to cortex (cortico-[pons]-cerebellar-rubro-thalamo-cortical) fn in speech: role in anticipating intended speech movts and providing feedback from periphery temporal regulation of sensory and motor info inhibitory role in movt to refine poorly formed cortical movts, smoothing and coordinating movts ipsilateral control of movt

Answer 19

12 pairs of CN and their ganglia 31 pairs of spinal nerves and their ganglia; dorsal and ventral roots nerve = collection of nerve fibers aff - carry impulses from sensory structure toward CNS eff - carry impulses from CNS to end structure e.g. muscle mixed - some have both types of nerve fibers

Answer 20

emphasis on CNs of speech designated by roman numerals in order of which they leave brainstem from top to bottom motor CN - cell bodies in brainstem nuclei sensory CN - cell bodies in ganglia at sensory organ

Answer 21

largest CN; complex, important nerve for our interests ”trigeminal” because has 3 main branches bilateral innervation Sensory and motor- bilateral Sensory: face, mouth and lower jaw, *anterior 2/3 of tongue (Dentist blocks CN 5) Motor: muscles of mastication: medial and lateral pterygoids, masseter, buccinator muscles of soft palate - tensor veli palatini (pulls down) tensor tympani - in middle ear suprahyoid muscles: mylohyoid, anterior belly digastric

Answer 22

large, complex sensory-motor nerve important for aspects of speech and swallowing upper facial muscles - bilateral cortical input lower facial muscles - uni/contralateral cortical input *speech* sensory: **anterior 2/3 of tongue - taste, touch - skin around ear Motor: stapedius muscle in middle ear posterior belly digastric stylohyoid muscles surrounding eye muscles of face and nose buccinator, orbicularis oris, lower lip muscles, platysma also motor input to mucuous membrane glands of nose and palate

Answer 23

bilateral sensory input > heschl’s gyrus cochlear portion: arises from cells in spiral ganglion of cochlea, enter brainstem at lateral most pontomedullary junction, courses up to temporal cortex of brain via a number of bilateral synapses Lesions of: LSN - unilateral deafness e.g. acoustic neuroma/schwannoma USN - no symptoms because of bilateral activation of cortex by cochlear nerve vestibular portion: equilibrium and balance, fibers arise in vestibular labyrinths of the inner ear lesions: vertigo - sense that the world is rotating nystagmus - spasmodic eye movements nausea and vomiting common with these

Answer 24

``` bilateral innervation motor: stylopharyngeus muscle and superior constrictor eff to parotid (salivary) gland part of middle pharyngeal constrictor Sensory: **tactile sensation posterior 1/3 of tongue, **taste - posterior 1/3 of tongue external ear skin internal tympanic membrane mucous membrane of pharynx, soft palate, posterior tongue mediates pharyngeal gag reflex **but not all people will have one contributes to initiating swallow reflex ```

Answer 25

``` latin for wandering - as in vagabond bilateral innervation Motor Pharyngeal branch: muscles of pharynx (except stylopharyngeus) palatoglossus muscle of tongue levator veli palatini ``` Superior laryngeal branch: cricothyroid (pitch changing) tense thin elongate Recurrent laryngeal branch: innervates all other muscles of larynx- PHONATION arytenoids, etc glands of pharynx, larynx, thoracic and abdominal viscera *left recurrent loops under aorta

Answer 26

``` Sensory larynx, trachea, esophagus and thorax, and abdominal viscera skin at back of ear and ext aud meatus external tympanic membrane pharynx involved in palatal gag reflex Cough, clear throat ```

Answer 27

bilateral innervation motor - spinal portion Levator veli palatini?? Sternocleidomastoid- turn head Trapezius- shrug shoulders

Answer 28

primarily motor nerve all intrinsic and extrinsic tongue muscles except palatoglossus also some strap muscles of neck **contralateral innervation - i.e. right cortex controls left tongue muscles and vice versa

Answer 29

extends from C1 to about T11 inferior portion - ends as conus medullaris cauda equina -Sen N at bottom fan outward looking like a tail transverse section: gray matter center dorsal horns - aff or sensory neurons into SC ventral horns - associated with eff motor neurons from SC to muscles SC enlarged in two regions: cervical and thoracic where many neurons involved in supplying muscles of upper and lower limbs white matter surrounding tracts of aff and eff fibers running to other parts of SC or up toward brain e.g. pyramidal tract - continuation of the corticospinal motor tract from all the way up at motor cortex

Answer 30

31 pairs formed by merging of dorsal and ventral roots divide into dorsal and ventral ramus - which has both afferent and efferent fibers motor fiber cell bodies - in ventral horn of spinal cord sensory fiber cell bodies - in ganglia at sensory organ 8 cervical (c 1-4 phrenic nerve-- diaphragm) (C5-8 and T1 -brachial plexus -chest & upper limb) 12 thoracic (intercostal nerves - from T1-11 -innervate muscles of the ribs; T6-12 supply abdominal muscles) 5 lumbar 5 saccral 1 coccygeal

Answer 31

alpha motoneurons - influenced by the pyramidal system gamma motoneurons - influenced by the extrapyramidal system muscle spindle afferent - afferent fiber back to the motoneuron to complete a reflex arc this interaction is the way certain reflexes can occur based on feedback from the afferent fiber to the motoneuron Sensory in, motor out

ORG exam 1 Flashcards

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