Anatomy: Midterm 2, Cns Spine, Brainstem, Cerebellum

Front 1

Rostral

Back 1

toward nose

Front 2

Caudal

Back 2

toward tail

Front 3

Spinal cord functions

Back 3

spinal nerves attach to spinal cord, involved with sensory/motor innervation of body below head, provides 2-way conduction pathway for signals b/w body and brain, major center for reflexes

Front 4

Spinal cord location

Back 4

runs through vertebral canal of vertebral column through vertebral foramina, extends from foramen magnum at base of skull to L3 in infants and L1/2 in children in adults

Front 5

Conus medullaris

Back 5

where inferior end of spinal cord tapers

Front 6

Filum terminale

Back 6

long filament of CT extending from conus medullaris which attaches to coccyx inferiorly, anchoring spinal cord in place

Front 7

Cauda equina

Back 7

collection of spinal nerve roots in inferior end of vertebral canal

Front 8

Cervical/lumbar enlargments

Back 8

where spinal cord nerves for upper/lower limbs arise

Front 9

Spinal nerves

Back 9

31 pairs (PNS) attach to spinal cord through dorsal/ventral nerve roots, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal, nerves lie in intervertebral foramina

Front 10

Spinal cord segments

Back 10

indicate the region of spinal cord where spinal nerve fibers emerge, located superior to there corresponding spinal nerves emerge (because spinal cord doesn’t extend to the end of spinal column), so segment T5 is located at level of T4

Front 11

Spinal cord deep grooves

Back 11

cord is wider laterally than anteroposteriorly, 2 grooves run length of cord and partly divide it into left/right halves (dorsal median sulcus, and ventral median fissure)

Front 12

White matter funiculi

Back 12

divides white matter into dorsal, ventral, and lateral funiculi (long ropes)

Front 13

Ascending white matter fibers

Back 13

carry sensory info from sensory neurons to brain

Front 14

Descending white matter fibers

Back 14

carry motor info from brain to spinal cord to stimulate muscle contraction/gland secretion

Front 15

Commissural white matter fibers

Back 15

carry info from one side of spinal cord to the other

Front 16

Commissure of white matter

Back 16

bundle of axons that crosses from one side of CNS to the other

Front 17

Gray commissure

Back 17

cross-bar of H, unmyelinated axons with narrow central cavity

Front 18

Dorsal horns of gray matter

Back 18

posterior arms of H, run as columns the entire length of spinal cord, contain cell bodies of motor neurons and interneurons

Front 19

Ventral horns of gray matter

Back 19

anterior arms of H, run as columns the entire length of spinal cord, contain cell bodies of motor neurons and interneurons, ventral are largest in cervical/lumbar segments, motor neurons send axons out of cord via ventral roots to supply muscles and glands

Front 20

Lateral horns of gray matter

Back 20

small columns in thoracic/superior lumbar segments of spinal cord

Front 21

Dorsal root ganglia of gray matter

Back 21

sensory neuron cell bodies outside spinal cord

Front 22

Dorsal roots of gray matter

Back 22

where sensory neuron axons reach spinal cord

Front 23

Dorsal horn interneurons of gray matter

Back 23

receive info from sensory neurons

Front 24

Somatic/visceral regions of gray matter

Back 24

[dorsal] somatic sensory, visceral sensory, visceral autonomic motor, somatic motor [ventral]

Front 25

Paresthesia

Back 25

loss of sensory function, damage to dorsal horn of sensory neuron cell bodies in dorsal root ganglia

Front 26

Paralysis

Back 26

damage to ventral horn or ventral motor roots destroys motor neurons

Front 27

Meninges

Back 27

3 CT membranes that lie external to brain/spinal cord, cover/protect CNS, enclose/protect blood vessels that supply CNS, contain cerebral spinal fluid, dura mater, arachnoide mater, pia mater

Front 28

Epidural space of meninges

Back 28

fat-rich cushioning space external to dura mater

Front 29

Dura mater

Back 29

strongest layer of meninges, single leathery layer of dense fibrous tissue, to level of S2

Front 30

Subdural space

Back 30

thin flui-filled space in between dira mater and arachnoid mater

Front 31

Arachnoid mater

Back 31

layer lies deep to dura mater, to level of S2

Front 32

Subarachnoid space

Back 32

filled with cerebral spinal fluid and large blood vessels that supply the neural tissue, spanned by web-like threads that anchor arachnoid mater to pia mater

Front 33

Pia mater

Back 33

innermost layer of meninges, clings tightly to spinal cord, delicate layer of CT richly vascularized with small blood vesels, extends to coccyx, has denticulate ligaments, clings to surface of brain and follows contours

Front 34

Denticulate ligaments

Back 34

lateral extensions of pia mater anchor spinal cord laterally to dura mater throughout length of cord

Front 35

Cerebrospinal fluid

Back 35

watery fluid that fills subarachnoid space and hollow cavities of brain/spinal cord, provides liquid cushion/buoyancy, nourishes, removes waste produced by neurons, carries chemical signals b/w parts of CNS

Front 36

Lumbar puncture/spinal tap

Back 36

needle is inserted b/w L4 and L5 vertebrae into subarachnoid space to obtain CSF or inject medicine

Front 37

Meningitis

Back 37

inflammation of meningeal tissues from infection

Front 38

Encephalitis

Back 38

inflammation of brain or spinal cord from infection

Front 39

Brain

Back 39

1500 grams, performs complex neural functions (intelligence, memory, sensory-motor integration, etc), controls/maintains ANS and endocrine system

Front 40

Embryonic development of brain, week 4

Back 40

brain arises from rostral part of neural tube, caudal portion of neural tube becomes the spinal cord, 3 primary brain vesicles emerge (prosencephalon, mesencephalon, rhombencephalon)

Front 41

Embryonic development of brain, week 5

Back 41

primary brain vesicles develop into 5 secondary vesicles, prosencephalon divides into telencephalon and diencephalon, mesencephalon remains undivided, rhombencephalon divides into metencephalon and myelencephalon

Front 42

Telencephalon

Back 42

cerebral hemispheres

Front 43

Diencephalon

Back 43

thalamus, hypothalamus, epithalamus

Front 44

Mesencephalon

Back 44

midbrain

Front 45

Metencephalon

Back 45

pons and cerebellum

Front 46

Myelencephalon

Back 46

medulla oblongata

Front 47

Organization of brain

Back 47

centrally located gray matter contains neuron cell bodies (brain nuclei) and interneurons that process info, external white matter has interneurons, cerebrum/cerebellum have additional gray matter called cortex which is external to white matter

Front 48

Ventricles of brain

Back 48

expansions of brain’s central cavity, filled with cerebrospinal fluid, lined with ependymal cells, continuous with each other and central canal of spinal cord: paired lateral ventricles (telencephalon), 3rd (diencephalon) and 4th (pons, cerebellum, medulla oblongata)

Front 49

Paired lateral ventricles

Back 49

in cerebral hemispheres, horseshoe-shaped from bending of hemispheres, each has anterior/inferior horns, anterior horn separated by septum pellucidum

Front 50

3rd ventricle

Back 50

diencephalon, connected anteriorly with lateral ventricles by interventricular formena

Front 51

cerebral aqueduct

Back 51

midbrain, connects 3rd and 4th ventricles

Front 52

4th ventricle

Back 52

in hindbrain brainstem, connects to central canal of inferior medulla and spinal cord, 3 openings in the walls (paired lateral apertures and median aperture), connect ventricles with subarachnoid space which allows cerebral spinal fluid to fill both ventricles

Front 53

choroid plexus

Back 53

lies in roof of 4th, 3rd, and lateral ventricles

Front 54

brain stem

Back 54

midbrain, pons, medulla oblongata, each 1 inch long, make up 2.5% mass, function = passageway for all fiber tracts running b/w cerebrum and spinal cord, innervation of face/head, 10 pairs of cranial nerves associated, generates autonomic behaviors necessary for survival

Front 55

medulla oblongata

Back 55

conical shaped, continuous with spinal cord at level of foramen magnum of skull, most caudal level of brain stem, part of 4th ventricle lies dorsal to rostral half of medulla, cranial nerves 8-12 attach to medulla (lie near 4th ventricle), CN 6 and 7 emerge from brainste, b/w medulla and pons

Front 56

inferior cerebellar peduncles

Back 56

fiber tracts connecting medulla and cerebellum

Front 57

olive of medulle

Back 57

contains inferior olivary nucleus

Front 58

inferior olivary brain nucleus

Back 58

large wavy fold of gray matter, relay station for sensory info travelling to cerebellum, especially for proprioceptive info ascending from spinal cord

Front 59

pyramids of medulla

Back 59

2 longitudinal ridges with lie on ventral surface, formed by pyramidal tracts that extend through brainstem and spinal cord carrying voluntary motor output from cerebrum to spinal cord

Front 60

decussation of pyramids

Back 60

in caudal part, most of pyramid fibers cross over to opposite side of brain to enable each hemisphere to control voluntary movements of opposite side of body

Front 61

CN 8, vestibulocochlear nerve

Back 61

attaches at junction of medulla/pons in dorsolateral portion of medulla, sensory vestibular nuclear complex and sensory cochlear nuclei

Front 62

CN 9, glossopharyngeal nerve

Back 62

nucleus ambiguous (motor) and solitary nucleus (sensory)

Front 63

CN 10, vagus nerve

Back 63

dorsal motor nucleus of vagus, nucleus ambiguous, solitary nucleus

Front 64

CN 11, accessory nerve

Back 64

spinal accessory, branch of vagus nerve, associated brain nuclei located on rostral portion of spinal cord

Front 65

CN 12, hypoglossal nerve

Back 65

hypoglossal nucleus (motor)

Front 66

Reticular formation

Back 66

loose cluster of brain nuclei that run through core of brainstem, stimulate cerebral alertness and regulates muscles, present in medulla, forms 3 columns that extend length of brainstem (midline raphe nuclei, medial nuclear group, lateral nuclear group), contain pontine nuclei in motor tracks

Front 67

Visceral motor nuclei of reticular formation

Back 67

cardiac center regulates force and rate of heart beat, vasomotor center regulates blood pressure, respiratory center regulates breathing, centers for hiccupping, sneezing, swallowing, coughing

Front 68

Pons

Back 68

bulge in brainstem, forms ventral bridge b/w brainstem and cerebellum, separated from cerebellum by 4th ventricle, contains nuclei of cranial nerves 5-7 (trigeminal nerve, abducens nerve, facial nerve), function = receive sensory impulses and initiate motor activity to structures of head, reticular formation, pontine nuclei, pyramidal motor tract, middle cerebellar peduncles

Front 69

Pontine nuclei

Back 69

relay brain nuclei in a path that connects a portion of cerebral cortex with cerebellum which contributes to coordination of voluntary movements, send axons to cerebellum in thick middle cerebellar peduncles

Front 70

Middle cerebellar peduncles

Back 70

carry info from cerebral cortex and pontine nuclei to cerebellum

Front 71

Midbrain

Back 71

b/w pons and diencephalon, central cavity = cerebral aqueduct, ventral surface = cerebral peduncles with pyramidal tracts (ventricle part of peduncle = crus cerebri), pair of superior cerebellar peduncles connect midbrain to cerebellum

Front 72

Periaqueductal gray matter of midbrain

Back 72

surrounds cerebral aqueduct, involved in sympathetic response, mediates visceral pain, most ventral part contains motor neuron cell bodies to CN 3 (oculomotor) nuclei and CN 4 (trochlear) nuclei (only CN that emerges from dorsal brainstem

Front 73

Corpora quadrigemina of midbrain

Back 73

largest brain nuclei in midbrain, make up tectum (roof) of dorsal midbrain and form 4 bumps on dorsal surface, divided into 2 superior (visual reflexes) and 2 inferior (reflexive response to sound) colliculi

Front 74

Substantia nigra of midbrain

Back 74

embedded in midbrain white matter, contain neuronal cell bodies with melanin, deep to pyramidal tracts of cerebral peduncle, functionally linked to basal nuclei and deep gray matter of cerebrum, degeneration of neurons contribute to parkinson’s

Front 75

Red nucleus of midbrain

Back 75

deep to substantia nigra, reddish hue due to rich blood supply and presence of iron pigment in neuron cell bodies, associated with cerebellum

Front 76

Cerebellum

Back 76

located dorsal to pons/medulla (separated by 4th ventricle), 11% mass, smoothes/coordinates body movements directed by other brain regions, helps maintain posture/equilibrium, 2 hemispheres connected by vermis, folded into ridges (folia) separated by grooves (fissures), each hemisphere subdivided into anterior/posterior/flocculonodular lobes

Front 77

Cortex of cerebellum

Back 77

outer gray matter which is neuron rich calculator that smoothes out body movements

Front 78

Arbor vitae of cerebellum

Back 78

internal white matter rich in axons which carry info to/from cortex

Front 79

Depp cerebellar nuclei

Back 79

deeply situated gray matter, gives rise to axons that relay instructions from cerebellar cortex to other parts of brain

Front 80

Info on equilibrium in cerebellar cortex

Back 80

relayed from receptors in inner ear through vestibular nuclei in medulla to flocculonodular lobe

Front 81

Info on current limb/trunk movements in cerebellar cortex

Back 81

from proprioceptors up spinal cord through olivary nuclei to medial portions of anterior/posterior lobes

Front 82

Info from cerebral cortex

Back 82

from cerebral cortex through pontine nuclei in pons to lateral portions of anterior/posterior lobes

Front 83

Superior cerebellar peduncles

Back 83

connect to midbrain and carry info away from cerebellum to cerebral cortex

Front 84

Middle cerebellar peduncles

Back 84

connect to pons and carry info into cerebellum from cerebral cortex through pontine nuclei

Front 85

Inferior cerebellar peduncles

Back 85

arise from medulla and carry fibers from vestibular nuclei and spinal cord through olivary nuclei into cerebellum

Front 86

Ipsilateral

Back 86

fibers to and from cerebellum

Front 87

Coordinating movement by cerebellum

Back 87

1) cerebellum receives info on movement from motor cortex, 2) cerebellum compares intended movement with body position, 3) cerebellum sends instructions back to cerebral cortex to continuously coordinate, adjust/fine tune motor commands to spinal cord

Front 88

Higher cognitive functions of cerebellum

Back 88

refines movements when learning new motor skill, motor memory, cognition of language, problem-solving, task planning

Front 89

Injury to cerebellum

Back 89

damage to anterior/posterior lobes = disorders in coordination, damage to flocculonodular lobe = disorders in equilibrium

Front 90

Diencephalon

Back 90

forms center core of forebrain, surrounded by hemispheres, 3 structures (thalamus, hypothalamus, epithalamus), borders 3rd ventricle, composed of gray matter

Front 91

Thalamus

Back 91

inner room, 80% of diencephalon, 12 major brain nuclei, relay station for incoming sensory info, gateway to cerebral cortex, afferent impulses from all conscious senses except olfaction converge here, nuclei organize/amplify or scale down signals

Front 92

Ventral posteriolateral nuclei of thalamus

Back 92

relay station for sensory info ascending to primary sensory areas of cerebral cortex

Front 93

Medial geniculate body of thalamus

Back 93

receives auditory input

Front 94

Lateral geniculate body of thalamus

Back 94

receives visual input

Front 95

Hypothalamus

Back 95

below thalamus, b/w optic chiasm and border of mammilary bodies, pituitary gland projects inferiorly from hypothalamus, 12 brain nuclei, main visceral control center of body, regulates sleep-wake cycles, some nuclei near mammillary body mediate arousal from sleep, functions = control of ANS, endocrine system, body temp, hunger/thirst (sense concentrations of nutrients/salts in blood), emotional responses, motivational behavior, memory (mammillary body)

Front 96

Feeding-initiating centers of hypothalamus

Back 96

in lateral part

Front 97

Feeding-inhibiting centers of hypothalamus

Back 97

in ventromedial part

Front 98

Suprachiasmatic nucleus of hypothalamus

Back 98

biological clock, regulates timing of circadian rhythms in response to daylight-dark cycles

Front 99

Preoptic nucleus of hypothalamus

Back 99

responds to suprachiasmatic nucleus to induce sleep

Front 100

Mammillary body of hypothalamus

Back 100

receives inputs from hippocampal formation

Front 101

Epithalamus

Back 101

dorsal part of diencephalon, roof of 3rd ventricle, one tiny group of brain nuclei, contains pineal gland (secretes melatonin, contributes to control of circadian rhythms)