Neuroanatomy Exam 2 chapter5

Chapter 5

Spinal Cord housed in ?

housed in boney vertebral column

Spinal cord 5 sections (inferior to superior) or (superior to inferior)

cervical, thoracic, lumbar, sacral, and coccygeal sections (superior to inferior) head to feet

How many cervical spinal nerves?

thoracic spinal nerves

lumbar spinal

sacral spinal

coccygeal spinal

superior to inferior or inferior to superior

8

12

5

5

1

breakfast at 8, lunch at 12, dinner at 5 twice, and then a midnight snack at 1

superior to inferior

what is PNS and what is CNS

spinal nerves, spinal cord

spinal nerves - PMS

Spinal cord- CNS

higher the spinal cord injury the ____ and more ______

higher the spinal cord injury the worse and more deadly

SAME

Sensory afferent, motor efferent

-body to brain- S

-brain to body - M

Spinal cord moves information that is motor or efferent as well as sensory info

yup

Four fiber types spinal cord External Organization

• to skeletal muscles (somatic)-control

• to smooth muscle, heart, glands (visceral- gut can’t really control)

• from skin to brain - control

• from lungs and digestive tract- can;t

• GSE fibers: (———)

• GVE fibers: (———-)

• GSA fibers:

• GVA fibers:

Dorsal ramus

ventral ramus

spinal nerve

dorsal root

ventral root

dorsal horn

ventral horn

anterior median fissure

central canal

rammi communicantis

lateral funiculus

ventral funiculus

dorsal furniculus

Dorsal ramus (toward back

ventral ramus (toward front near nose anterior

RAMUS means branch

spinal nerve

dorsal root

ventral root

dorsal horn

ventral horn

anterior median fissure

spinal cord: internal organization Major landmarks

Dorsal funiculus (bundle of fibers)

lateral funiculus

ventral funiculus

funiculus (white matter)

left vs right ?

Spinal Cord Function

relaying efferent and afferent information between body and brain

Mediating reflexes through the reflex arc

Major motor tracts DON”T NEED TO KNOW TRACTS

Lateral corticospinal contralateral body movement

anterior (or ventral) corticospinal: trunk muscles

Rubrospinal: flexor tone

Vestibulospinal: extensor tone

Major sensory tracts of internal organization of spinal cord

Dorsal columns: fine touch, pressure, proprioception

Spinothalamic: regulates pain, temperature, crude touch

Spinocerebellar: helps with proprioception (sensation of knowing body in space)

Spinal Cord Disorders

• Spinal cord Injury, Spina Bifida, Myelitis, Peripheral Neuropathy

Spinal cord injury About and implications

About- Paresis (incomplete) or plegia (complete)

loss of sensation or movement

Implications- Loss of movement may

impact speech production

Vehicular accidents account for 40% of cases

Spina Bifida ( spinal cord or Brainstem?)

about and implication

Spinal cord

About- Neural tube defect occurring early in

development, causing lower limb paresis,

bowel and bladder issues

Implications- No direct speech or

language implications

possible paraparesis and bowel and bladder issues

Myelitis (spinal cord or Brainstem?)

about and implication

• inflammation of the spinal cord can be caused by virus, bacteria, fungi, parasites, and toxic agents (lead poisoning)

• Different types (Poliomyelitis - affects gray matter MOTOR LOSS

• Leukomyelitis- affects white matter SENSORY LOSS

• Transverse myelitis- affects both gray and white matter MOTOR AND SENSORY LOSS

No direct speech or

language implications

Peripheral Neuropathy (spinal cord or Brainstem?)

about and implication

Implications-

Inflammation of PNS, resulting in

degeneration of the spinal nerves. Caused

by toxic poisoning, infections, metabolic

disorders, and nutritional issues. Causes

loss of sensation. Leads to paresthesia or anesthesia

Implications-

No direct speech or

language implications.

The Brainstem: anterior external organization

what 3 parts does it consist of ?

Midbrain - most superior (closer to brain)

Pons - inferior to midbrain superior to medulla

Medulla - inferior to pons

Brainstem Functions

• Regulating major life functions (e.g., heart beat, respiration)

• Mediating head and neck reflexes (e.g., gag) via cranial nerves (see next slide)

• Regulating alertness and wakefulness

Where do most cranial nerves originate and which do not originate in the brain stem

medulla area and 1 and 2 do not originate in brain stem

First Cranial nerve

function and pathologies

Olfactory

• Origin = Olfactory bulb

• Fiber type = SVA

• Function(s) = Smell

• Problem(s) = Anosmia (lack of smell)

• afferent

Sensory

Cranial Nerve 2

Olfactory Nerve II

• Origin = Thalamus

• Fiber type = SSA

• Function(s) = Vision

• Problem(s) = Visual disturbances; loss of vision (blindness)

Sensory

Cranial nerve 3

• III. Oculomotor Nerve

• Origin = Midbrain

• Fiber type= GSE, GVE

• Function(s) = motor movement

  • GSE: Moves eyes left and right; controls eyelid

  • GVE: pupil constrictor

• Problem(s) = Loss of pupillary light reflex; papilledema; ptosis

MOTOR

Cranial nerve 4

• IV. Trochlear Nerve

• Origin = Midbrain

• Function(s) = Moves eyes up and down

• Problem(s) =Diplopia; nystagmus; difficulty moving eyes up and down

Motor

Cranial nerve 5

• V. Trigeminal Nerve DETAILS

• Origin = Pons

• Fiber type = SVE, GSA

• Function(s) = 

  • GSA: touch, pain, temp. and vibration for face, mouth, ant. 2/3 of tongue

  • GVE: Chewing muscles

  • SENSORY and MOTOR

• Problem(s) = Loss of above sensations; difficulty chewing; abnormal jaw-jerk reflex

TRI - THREE MAJOR BRANCHES- ophthalmic, maxillary branch, mandibular branch

Cranial Nerve 6

• VI. Abducens Nerve

  6 pack- abs- abducens

• Origin = Pons

• Fiber type = GSE

• Function(s) = Rotates eyes out

• Problem(s) = eye rotates in (strabismus) and diplopia; nystagmus

Motor

Cranial Nerve 7

• VII. Facial Nerve

• Origin = Pons

• Functional Category = SVE, GVE, GSA, SVA

• Function(s) =

  • SVE: Muscles of face

  • GSA: Sensation near ears

  • SVA: Taste in ant. 2/3 of tongue

  • GVE: Salivary glands

• Problem(s) = Facial paralysis/paresis; taste loss

smile, blink, squeeze face, puff cheeks, kiss

Motor and sensory

Cranial nerve 8

• VIII. Vestibulocochlear Nerve*

• Also known as auditory nerve

• Origin = Pons/medulla junction

• Fiber type = SSA

• Function(s) = Hearing and balance

• Problem(s) = Hearing loss; balance problems

Sensory

Cranial nerve 9

• IX. Glossopharyngeal Nerve

• Origin = Pons/medulla junction

• Fiber type = SVE, GVE, GVA, SVA

• Function(s) =

  • SVE: Pharyngeal movement

  • GVE: Parotid gland (salivation)

  • GVA: Middle ear, pharynx, post. 1/3 of tongue

  • SVA: Taste on post. 1/3 of tongue

  • Movement of pharynx, responsible for taste on back of tongue

    GLOSSO- sensory

  • Pharyngeal- motor

• Problem(s) = Absent gag and swallow reflex; loss of taste; loss of pharyngeal movement

MOTOR and Sensory

Cranial nerve 10

• X. Vagus Nerve

• Origin = Medulla

• Fiber type = SVE, GVE, GSA, GVA, SVA

• Function(s) =

  • SVE: Pharyngeal and laryngeal muscles

  • GVE: helps Heart, lungs; digestive tract

  • GSA: Tactile sensation to external ear canal

  • GVA: Pain from mucous membranes

  • SVA: Taste from epiglottis and pharynx

• Problem(s) = Absent gag and swallow reflex; loss of velar movement; loss of voice

Sensory and motor

Cranial nerve 11

• XI. Spinal Accessory Nerve

• Origin = Medulla, spinal cord

• Fiber type = SVE

• Function(s) = Neck and shoulder muscles

• Problem(s) = Droopy shoulder; movement of neck

Motor

Cranial nerve 12

• XII. Hypoglossal Nerve

• Origin = Medulla

• Fiber type = GSE

• Function(s) = Muscles of tongue

• Problem(s) = Loss of tongue movement; tongue fasciculations, tongue atrophy

• speech and swallowing

only for motor movement

Brainstem Disorders

Wallenberg Syndrome

location, about implication

-Medulla

-Usually caused by stroke affecting a vessel

leading to the brainstem.

-Ataxia, paralysis of

ipsilateral palate and vocal

fold, dysphagia. Violent

hiccups impacting

speaking, eating, and

sleeping.

Brainstem Disorders

locked in Syndrome

location, about implication

-pons

-Causes quadriplegia and cranial nerve

paralysis

-Inability to speak or

swallow

Brainstem Disorders

Webers syndrome

location, about implication

-Midbrain,

-Contralateral hemiplegia and ipsilateral

oculomotor paralysis with ptosis.

-Hemiparesis affects the

lower face muscles and

tongue

Brainstem Disorders

Benediktis syndrome

location, about implication

-midbrain

-Contralateral hemiparesis and ataxic

tremor

-Hemiparesis affects the

lower face muscles and

tongue

Brainstem Disorders

Cerebellar Hemispheral syndrome

location, about implication

-Cerebellum

-Caused by stroke, tumor, and multiple

sclerosis. Affects ipsilateral limbs causing

tremor, dysmetria, and

dysdiadochokinesia, Holmes’ rebound

affect.

-No direct speech or

language implications

Brainstem Disorders

Vermal syndrome

location, about implication

-Cerebellum

-Damage of the vermis resulting from

stroke, tumor, MS, and other degenerative

disorders. Affects trunk muscles with

symptoms such as unsteadiness , tremor,

postural issues, and gait ataxia

-No direct speech or

language implications

Brainstem Disorders

Friederichs Ataxia

location, about implication

-Cerebellum

-Inherited, progressive neurological disorder

of autosomal recessive pattern. Causes

progressive muscle weakness in limbs, loss

of coordination, curvature of the spine,

vision problems.

-Dysarthria, hearing issues

Brainstem Disorders

Cerebellar Agenesis

location, about implication

-Cerebellum

-No cerebellum

-No direct speech or

language implications

Cranial nerves

-1 gave wif - sensory nerve - olfactory is the way

-second nerve helps me see right - central peripheral sight central peripheral sight sensory nerve for eye Optic nerve is the way

-pupils constricting, third nerve eyes are moving, prevents eyelid drooping oculomotor nerve baby

-the trochlear nerve works the superior oblique this is the fourth nerve. Hard to look down if it’s weak

-trigeminal nerve works mastificaiton, deals with sensory and motor, deals with face sensation

-abducent is the sixth, does eye abduction, motor nerve for motion, helps prevent double vision

-facial is the 7th, does facial expression, it’s sensory and motor, 2/3 of taste sensation

-Vestibulocochlear is the 8th, body balancer, used for the ear, sound sensor

-Glossopharyngeal nerve, senses taste from the 1/3 back of the tongue, the 9th it helps us swallow hey

-tenth nerve is vagus, lets us speak and say stuff, it’s sensory and motor, baby

Accessory nerve - is the 11th, so shrug your shoulders, and test head resistance

-the hypoglossal nerve, is the twelfth nerve, deals with tongue movement,

major cerebellar pathways and functions

Vestibulocerebellar

Vermal spinocerebellar

Paravermal spinocerebellar

Pontocerebellar

Vestibulocerebellar- overall body posture and balance; coordination of eye movements

Vermal spinocerebellar -trunk and girdle muscle tone and posture

Paravermal spinocerebellar - distal muscle group tone and posture

Pontocerebellar- planning, initiating and timing of volitional motor activity

Functions of Cerebellum

Motor and Linguistic

• Motor:

  • Helps in planning, monitoring, and correction of motor movement using sensory feedback

  • Coordinates fine motor activity

  • Monitors head and body position

  • Participates in learning of new motor skills

• Linguistic:

  • Perception of speech/language, verbal working memory, verbal fluency, grammar processing, writing, and reading

Testing the cerebellum

-finger to nose test

-Diasochokinesia (pat-ta-ka)

-uncoordinated sloppy movement may indicate cerebellar damage

Damage to Cerebellar may lead to symptoms

• ataxia

• dysmetria

• Dysdiadochokinesia

• Nystagmus

• Ataxic dysarthria

• Hypotonia

• ataxia - Discoordinated, clumsy movements

• dysmetria- over-or undershooting touching a mark

• Dysdiadochokinesia- inability to perform rapid, alternating movements or hands or mouth

• Nystagmus - fast, involuntary eye movements either side to side or up and down

• Ataxic dysarthria -slurred or scanning (broken into syllables speech)

• Hypotonia- reduced muscle tone and reflexes, muscle tire