Irene Gold Spinal Anatomy

Endoderm (epithelium of respiratory tract and GI tract), mesoderm (everything else) and ectoderm (epidermis, hair, retina, anterior pituitary, CNS, PNS, adrenal medulla)

brain, spinal cord, ventricles, retina, posterior pituitary

Sympathetics, Schwann cells, Melanocytes, Meninges, Brachial arches, Adrenal medulla, Dorsal root ganglion, Meissner's plexus, Auerbach's plexus "SM SM BAD MA"

Proencephalon (forebrain --> Telencephalon and Diencephalon), Mesencephalon (midbrain --> Mesencephalon), Rhombencephalon (hindbrain --> Metencephalon and Myelencephalon) "Tel Di Mes Met My"

cerebrum, lateral ventricles, septum pellucidum, caudate and lenticular nuclei

Thalamus, epithalamus, hypothalamus, hypophysis, infundibulum, optic chiasm, 3rd ventricle, mammillary body

midbrain, cerebral peduncles, aqueduct of sylvius

Pons and cerebellum

Medulla oblongata, 4th ventricle

astrocyte (support blood brain barrier), microglia (macrophage of brain, from mesenchyme), ependymal (lines ventricles and makes CSF), oligodendrocytes (makes myelin in CNS), Schwann cells (makes myelin in the PNS)

T1 to L2, fight or flight (visceral motor, autonomic, not thinking), vasoconstriction of central arteries and vasodilation of arterioles of muscles and capillaries of skin, arector pili, sweat glands

IML (intermediate lateral cell nucleus) in the spinal cord) leave the cord via white (myelinated) rami communicates (preganglionic type B fibers), synapse on Sympathetic chain ganglion then leave via grey (unmyelinated) rami communicantes (postganglionic type C fibers), Norepinephrine and epinephrine are released

fiber to the adrenal medulla

gray color cell tumor which causes hypertension (HTN) by secreting excess epinephrine

above C4 pupil dilation

C4 to C5

C6 to C8

C8 to T1, merger between inferior sympathetic chain ganglion and upper thoracic ganglion

ptosis, meiosis, anhydrosis

• CN III --> ciliary ganglion --> pupil constriction
• CN VII --> superior salvitory nucleus --> sphenopalantine (pterygoplatine - motor --> lacrimal gland) and sphenomandibular (submandibular) --> geniculate nucleus and salivary glands
• CN IX --> Inferior salvitory nucleus --> otic ganglion --> parotid glands
• CN X --> Baroreceptors in carotids and pneumotaxic center (hering brewer reflex) (stretch receptors/lung say "lungs are full" - apneustic center inhibits pneumotaxic center
• S2 to S4

• Intellect and association
• Frontal lobe - motor
• Parietal lobe - sensory
• Occipital lobe - sight
• Temporal lobe - hearing

relay station, sensory fibers

hunger, thirst, temperature regulation, sex, rage, fear

balance and equilibrium, involuntary coordination

vasomotor, cardiac center, autonomic NS

collection of cell bodies that lie within the white matter of the cerebrum, plan and coordinate voluntary movement - putamen (large, dark, lateral), globus pallidus (small, pale, medial), caudate nucleus, amygdala, substantia nigra, subthalamic nucleus

putamen + globus pallidus, becomes damaged in Wilson's disease

putamen and caudate nucleus - primary control of involuntary movement and posture

association (connect regions of the same hemisphere), commississural (carry impulses across the corpus callosum), projection (send impulses from below to the cortex

flocculondoular for equilibrium, anterior and posterior for coordination (all work ipsilaterally)

climbing fibers (afferent input from inferior olivary nucleus), pontocerebellar fibers (pass through middle cerebellar peduncle) (mossy fibers), spinocerebellum tract

fastigial (balance), globus (2), emboliform, dentate

go to thalamus, red nucleus, vestibular nucleus (only efferent/motor aspect of cerebellum - done by purkinje fibers)

cerebellum accelerates, basal ganglia brakes

• Superior cerebral vein --> superior sagittal sinus (drains superior) --> confluence of sinuses (level of EOP)
• Inferior sagittal sinus and great cerebral vein --> straight sinus (drains middle) --> confluence
• Occipital sinus (drains posterior) --> confluence
• Confluence --> right and left transverse sinuses --> sigmoid sinus
• Sphenoparietal --> cavernous --> superior petrosal --> sigmoid sinus
• Sigmoid sinus and inferior petrosal --> internal jugular vein (drains the brain)

Choroid plexus in the lateral ventricles makes the CSF (ependymal cells) --> foramen of monroe (interventricular foramen) --> 3rd ventricle --> cerebral aqueduct (aqueduct of sylvius) --> 4th ventricle --> foramen of magendie (medial) and lushka (lateral) --> subarachnoid space and central canal (reabsorbed in arachnoid villi in the superior sagittal sinus

Laberinthine arteries, pontine arteries, superior cerebellar arteries and posterior cerebral arteries

Inferior cerebellar artery and anterior and posterior spinal artery

voluntary movement

voluntary movement to distal extremities

flexors of proximal upper limb

posterior musculature above T6 and anterior musculature below T6

mediates equilibrium

medial extensor muscles of the back

reflexes from vision and hearing to turn the head

touch, pressure

pain and temperature

unconscious proprioception from upper extremity

unconscious proprioception from lower extremity

Gracilis from lower extremity and cuneatus from upper extremity - conscious proprioception, vibration, two point discrimination, position sense

in the medulla not the spinal cord, merger of the posterior columns and spinothalamic tracts in the medulla

Incoming dorsal roots - DRG (ganglion nerve cell body outside CNS), 1st synapse for all sensory nerves except for reflexes and pain (V), pain and temperature

Substantia gelatinosa - incoming dorsal axons, edits sensory of superior colliculus, mechanoreceptors synapse here, presynaptic pain inhibition

Nucleus propius - for touch and pressure - receives from IV, V, VI

Basal spinal nucleus - post synaptic pain inhibition, endorphins and enkephalins from periaqueductal gray from aqueduct of sylvius, nucleus propius for touch and pressure - recieves from IV, V, and VI

Corticospinal --> V, VI and VII, at posterior horn, pain synapses

Primary sensory neurons

T1 to L2, intermediolateral cell column (IML) - intermediate between dorsal an dventral nerve supply for sympathetic reflex (flight or flight) (vasodilation, sweating, controlling blood supply), dorsal nucleus of clarke makes up part of lateral horn

Descending tracts - at anterior horn, termination of ventral fibers (vestibule), alpha motor neurons to extrafusal fibers of muscle, controlled by precentral gyrus (frontal lobe)

Large motor neurons - lamina to limb plexuses, gamma motor neurons to intrafusal fibers for muscle tone, controlled by dentate nucleus (cerebellum)

Gray commissure - surrounds central canal (small interneurons), decussating axons

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal (31 total)

anterior is disc and body, posterior is articular facets, superior is superior pedicle, inferior is inferior pedicle

Occulomotor --> ciliary ganglion --> pupillary constrictor

Trigeminal --> Gasserian ganglion (motor and sensory)

• facial --> superior salvitory nucleus
• 1. --> sphenopalantine (motor) --> lacrimal gland
• 2. --> submandibular --> salivary glands --> geniculate --> taste

Glossopharyngeal --> inferior salvitory nucleus --> otic ganglion --> parotid gland

motor --> nucleus ambiguus --> muscles of pharynx and larynx

vagus dorsal motor nucleus --> parasympathetic to 2/3 of the transverse colon

spinal accessory --> innervates SCM and trapezius

• Anterior cavity - anterior chamber (cornea to iris - filled with aqueous humor, produced by ciliary epithelium) and posterior chamber (iris to lens - filled wiht aqueous humor) - communicate by way of the pupil
• Posterior cavity - lens to retina - filled with vitreous humor

the area of most acute vison found in the center of the macula

rods and cones --> bipolar cells --> ganglion cells

ganglion axons make up the optic nerve --> optic chiasm (optic chiasm lesion --> bitemporal hemianopsia) --> optic tract --> lateral geniculate body (in the thalamus - all sensory info except smell goes here) --> optic radiation --> visual cortex in occipital lobe

cochlear nerve --> trapezoid body --> superior olivary nucleus --> inferior colliculus --> tectospinal pathway --> cervical muscles

Lateral geniculate/thalamus - for reflex of eyes with neck movement

Medial geniculate/thalamus - for reflex of ears with neck movement

hearing and balance

perilymph: External Auditory Meatus --> tympanic membrane --> malleus --> incus --> stapes --> oval window --> cochlea (contains organ of corti for sound perception), spiral ganglion of corti --> cranial nerve VIII (cochlear nucleus)

ventral fibers detect loudness and timing of sound and go to the secondary neurons (trapezoid body) and the dorsal fibers which detect quality of sound go to the superior olivary nucleus

via Lateral lemniscus to the Inferior colliculus to the Medial geniculate body of the thalamus then auditory radiation to the superior gyrus in temporal lobe "SLIM"

endolymph: semicircular canals (detection by the christa ampullaris determines rotation and angular acceleration), utricle (responsible for static equilibrium), sacule (responsible for linear acceleration, thickening of utricle in sacule where hair cells is located is called macula)

sensory neuron --> cribiform plate --> olfactory bulb (mitral cells) -->Uncus (associated with the rhinecephalon and hippocampus

uncus of the parahippocampus, dentate gyrus of the hippocampus, fornix, amygdaloid

superior (posterior ethmoid air cells open here) middle (maxillary and frontal sinuses drain here), inferior (nasolacrimal duct drains here)

Axillary (C5 - from posterior cord), Musculocutaneous (C6 - from lateral cord), Radial (C6-T1 - serves all extensors - from posterior cord), Median (C6-T1 - from medial and lateral cords), Ulnar (C8-T1 - from medial cord)

obturator (L2-4 - adductors of thigh), femoral (L2-4 - leg extensors), sciatic (L4-S3 - leg flexors), deep peroneal (medial leg and foot), superficial peroneal (lateral leg and lateral foot), tibial (posterior leg)

• ALL (anterior longitudinal ligament in front of the vertebral bodies --> anterior atlanto-occipital from atlas to occiput) (limits extension)
• PLL (posterior longitudinal ligament in back of vertebral bodies, anterior portion of canal --> tectoral membrane from C2 to occiput) (wider in cervicals, thinner in lumbars, homonym of sacrococcygeal, limits flexion)
• IVD (intervertebral disc)

• LF (ligamentum flavum = yellow ligament) from lamina to lamina (posterior portion of canal) (high elastic fiber content, limits flexion) --> posterior atlantoaxial ligament from C2 to C1 --> posterior atlantooccipital ligament from C1 to occiput
• CL (capsular ligament) - articular process to articular process
• ITL (intertransverse ligament) - from TP to TP

• ISL (interspinous ligament) - between the spinous process
• SSL (supraspinous ligament) - from SP to SP
• Ligamentum nuchae - SS ligament from C7 to occiput

• TL (transverse ligament) - holds dens in fovea dentalis of atlas (fovea dentalis is on posterior side of anterior tubercle of atlas)
• CL (cruciate ligament) - runs from occiput to body of C2, includes transverse ligament, cross-shaped (transverse ligament across part of the cross and vertical portion from axis to occiput)
• AL (alar ligament or check ligament) - from sides of the dens to occipital condyles, limits rotation of C2
• AD (apical dental ligament) - from apex of dens to anterior aspcect of foramen magnum, limits flexion and extension of C2

Oblique capitus superior (TP of C1 --> occiput above the nuchal line, extension and lateral rotation of head), Oblique capitus inferior (SP of C2 --> TP of C1, rotation of C1 on C2), Rectus capitus posterior major (SP of C2 --> lateral nuchal line, extension and lateral rotation of head), Rectus capitus psoterior minor (posterior tubercle of C1 --> below nuchal line, extension of head)

C3 to T2 (cervical, largest at C6), T10 to T12 (lumbar)

Synarthrosis, Amphiarthrosis, Diarthrosis

syndesmosis (interosseous membrane, amphiarthrotic or slightly moveable), synostosis (sutures/skull, synarthroses or immovable), gomphosis (teeth, synarthrotic)

synchondrosis (temporary, epiphyseal plate, cartilage, synarthrotic), symphysis (IVD, pubic symphysis, fibrocartilage, amphiarthrotic)

Diarthrotic or freely moveable, ginglymus (hinge, ex. elbow), trochoid (pivot/rotary, ex. A/A joint, radius/ulnar), condlymus (ovoid, ellipsoidal ex. knee, TMJ, wrist), saddle (sellar, ex. thumb), spheroideal (ball and socket), gliding (articulatio plana, ex. vertebral facets, AC joint)

H-shaped gray area which contains the cell bodies, surrounded by an area of white matter which contains the axons that ascend the cord to the brain or descend from the brain

• Dorsal horn - ascending neurons and interneurons, relays incoming sensory information to higher centers
• Ventral horn - contains descending neurons and interneurons, controls motor functions of the muscles of the trunk and limbs
• Intermediate zone - autonomic pre-ganglionic neurons which control motor functioning of the viscera, also contain neurons (clarke's column) which send sensory information to the cerebellum

• Posterior funiculi - ascending axons which relay sensory information to the medulla oblongata
• Lateral funiculi - contain sensory, motor and autonomic axons
• Anterior funiculi - contain axons descending from the brain which relay motor information to the muscles

Bror Rexed subdivided gray matter into 10 laminae: Lamina I to VI are in the dorsal horn, Lamina VII are the intermediate zone, Laminae VIII and IX are the ventral horn, Lamina X is the gray matter surrounding the central canal

marginal zone, most superficial region of dorsal horn, important sensory relay for pain and temperature

substantia gelatinosa, receives afferent information from nonmyelinated fibers and integrates it with that from thinly myelinated afferent fibers that project to lamina I

contain the nucleus proprius, integrates sensory input with information that descends from the brain and the region of the base of the dorsal horn where many neurons which project into the brainstem are located

contains Clarke's nucleus or cell column only in the thoracic and upper lumbar segments, this relays information about limb postition and movement to the cerebellum; the intermediolateral nucleus or cell column also located in the thoracic and upper lumbar segments contains autonomic preganglionic neurons

contains interneurons that are important in regulating skeletal muscle contraction

receives afferent input similar to Lamina I and II

contains central branches of small diameter fibers

contains axons of propriospinal neurons that interconnect different regions of the spinal cord

Spinal cord (fasciculus gracilis and cuneatus) --> Nucleus Gracilis and Cuneatus --> Medulla oblongata --> Pons --> Midbrain --> ventral posterior lateral nucleus of the thalamus --> cerebral cortex

posterior funiculi, ascend the cord ipsilaterally until the medulla oblongata, where they decussate, at the cervico-medullary junction, at the level of T6 the columns divide to form two bundles --> gracile and cuneate fascicle

ascends medially and contains fibers from the ipsilateral sacral, lumbar and lower thoracic segments

ascends laterally and contains fibers from the upper thoracic and cervical segments

they continue traveling by way of the medial lemniscus to the VPL nucleus of the thalamus then to the posterior central gyrus of the parietal lobe, to the somatic sensory cortex (somesthetic cortex) for localization

discrimination touch, vibration, joint position sense, tested by rhomberg's test and touch

located in the anterolateral column, contains fibers from ascending pathways which originate in different laminae of the dorsal horn of the spinal cord, decussates segmentally and ascends the cord contralaterally, terminates in the brainsterm, hypothalamus and thalamus

Spinothalamic (lateral and ventral), spinoreticular, and spinomesencephalic tracts

most prominant ascending nociceptive pathway in the spinal cord, carries information from neurons in laminae I and V to VII, terminates in the thalamus at the VPL nucleus, information goes from the thalamus to the somatic sensory cortex in the posterior central gyrus of the parietal lobe for locatlization

nociceptive information from the neurons in laminae VII and VIII, these axons terminate on neurons in the reticular formation of the medulla and pons, this information is then relayed onto the thalamus and other structures in the diencephalon

noxious and thermal sensations which are relayed to them from A-delta and C fibers, Lateral spinothalamic relays pain and temperature, ventral spinothalamic relays touch and pressure

spinotectal tract, contains information from nociceptive neurons in laminae I and V, terminates in the tectum (roof) of the midbrain, in the superior colliculus, also projects to the mesencephalic periaqueductal gray region, which surrounds the cerebral aqueduct (contains neurons that are part of a descending pathway that regulates pain trasmission

second major ascendign system for mediation of somatic sensation, relays pain, temperature, crude touch, tested by pinwheel, temperature of water in test tubes, randomly touching the patient

located in the lateral funiculi, relay information to the cerebellum regarding body position, position of body parts relative to each other (unconscious proprioception)

lower extremity info enters the posterior spinal cord and decussates immediately, tract travels witht he anterolateral system to the brain stem where it decussates back to side of origin, enters the superior cerebellar peduncle (brachium conjunctivum), info goes ot the floccular-nodular lobe of the cerebellum, ultimately the information reaches the somesthetic cortex of the parietal lobe, the rest of the cortex including the motor area and the vestibular nuclei

info from upper extremities ascends the cord, do NOT decussate in the cord, neurons are in Clarke's column, enter the inferior cerebellar peduncle (restiform body), info travels to the floccular-nodular lobe of the cerebellum, this info ultimately reaches the same areas as the ventral spinocerebellar tracts

originates in the motor cortex of the brain, most decussate at the level of the medullary pyramids and continue contralaterally down the spine as the lateral corticospinal tracts, those that do not decussate at the pyramids continue down the spine as the ventral corticospinal tracts, may decussate at the segmental cord level or remain ipsilateral

direct pathway for voluntary movement, function in voluntary, fine movement, innervate the fine flexors of the fingers and toes

originate primarily in the reticular formation of the mesencephalon, pons and medulla oblongata, have both excitatory and inhibitory connetions with spinal interneurons and motor neurons

descend to the cord both ipsilaterally as the homologue of the IML and contralaterally to terminate on the volunary extensor muscles of the posterior compartments of the limbs and the back

inhibit the action of the ipsilateral mesencephalic reticulospinal tracts

conscious postural maintenance and pain control

originate at the vestibular nuclei, there are 4 of these, the tract from the lateral vestibular nuclei (dieter's nucleus) descends the cord ipsilaterally as the lateral vestibulospinal tract to innervate all involuntary extensor or anti-gravity muscles of the back; the tracts from the superior, inferior and medial nuclei also descend the cord ipsilaterally and contralaterally, also ascend as the medial longitudinal fasciculus to end on cranial nerves III IV (mesencephalon) and VI (pons) to drive the eyes, function in posture/extensor muscles

originates in the magnocellular portion of the red nucleus in the midbrain, decussates immediately and descends through the medulla to the dorsal part of the lateral column of the spinal cord, inervates the voluntary flexor musculature of the limbs above T6 (some books say in the cervical spine only)