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355 Cards in this Set

  • Front
  • Back
name the cranial nn
I Olfactory
II Optic
III Oculomotor
IV Trochlear
V Trigeminal
V1 Ophthalmic
V2 Maxillary
V3 Mandibular
VI Abducens
VII Facial
VIII Vestibulocochlear
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal
name the types of afferents in cranial + spinal
General somatic afferent (GSA)
Touch, pain, temperature, proprioception

General visceral afferent (GVA)
Chemo-, mechano- stretch reception from viscera

Special afferent (SA)
Special senses (olfaction, vision, hearing, taste, balance)
****Taste is best categorized as
visceral afferent when interpreting
brain stem anatomy
name the types of efferents in cranial + spinal
General somatic efferent (GSE)
Motor to skeletal muscle

General visceral efferent (GVE)
Motor to smooth muscle, glands and cardiac muscle

Branchial efferent (BE)
Motor to skeletal muscle derived from pharyngeal arch mesoderm
name the 3 nn that special afferent (SA) only
I Olfactory
II Optic
VIII Vestibulocochlear
name the 4 nn that are efferent only
III Oculomotor (GSE, GVE)
IV Trochlear (GSE)
VI Abducens (GSE)
XII Hypoglossal (GSE)
Pharyngeal arch nerves
V Trigeminal (arch 1)
VII Facial (arch 2)
IX Glossopharyngeal (arch 3)
X Vagus, superior laryngeal (arch 4)
X Vagus, recurrent laryngeal (arch 6)
XI Accessory BE
Pharyngeal =

BE =

GSE in branchial arches
match the pharyngeal arch to its nerve
which part of the brain are the following nn associated?

CN I –
CNs III & IV –
CN I – Telencephalon
CN II – Diencephalon
CNs III & IV – Mesencephalon
CNs V-VIII - Metencephalon
CN IX-XII - Myelencephalon
what are the 2 exceptions of this rule:

A given nucleus generally contributes to only one nerve
both involve vagus)
Nucleus of the Solitary Tract: VII, IX and X
Nucleus ambiguus: IX and X
name the nuclei of CN III
all efferent (all efferent nerves are factors of 12---3, 4, 6, 12)

Oculomotor nucleus: motor to MR, IR, SR, IO and levator palpebrae (SOMATIC EFFERENT)

Edinger-Westphal nucleus: parasympathetics to eye, constrict pupil and accommodate lens (VISCERAL EFFERENT)
____ is the most ‘diffuse’ cranial nerve nuclei, because no matter what level of the brainstem you section, you will see some nucleus of it
CN V (trigeminal)
where is the motor trigeminal nucleus and the main sensory nucleus?
motor trigeminal nucleus is located in the mid-pons,

The best landmark is trigeminal nerve fibers running through the middle cerebellar peduncles. The fibers appear as a hand gripping a pale egg. The pale egg is the motor nucleus.
One of the nuclei of the trigeminal nerve

The spinal nucleus of V is easiest to see in the caudal medulla, although it extends throughout the entire medulla.
The adjacent spinal tract of V: pain afferents before they synapse.
For facial pain, temp, itch.
one of the nuclei of the trigeminal nerve

The mesencephalic nucleus is a thin ribbon of cells that runs along the fourth ventricle and cerebral aqueduct, just outside the periaqueductal grey.
Has cell bodies of stretch receptors for jaw proprioception,
The abducens nucleus along with the internal genu of the facial nerve make up the ________, a hump at the caudal end of the medial eminence on the dorsal aspect of the pons.
facial colliculus
the nuclei of the facial nerve?
SVE: Motor to muscles of facial expression and stapedius (Facial nucleus)

GVE: parasympathetics to submandibular and sublingual via chorda tympani (superior salivary)

SSA: taste from anterior 2/3 of tongue (nucleus of the solitary tract, rostral)

GSA: sensory from outer ear (spinal trigeminal)
what does the facial nerve wrap around?

what's the two bumps called?

what section is this?
Facial Genu: from nucleus, nerve wraps around the ABDUCENS nucleus
-the ‘bump’ is the Facial Colliculus

the pons
what's the intermediate nerve?

what does it carry?
distinct root of CN VII, sometimes referred to as the
“sensory root” despite having a visceral motor component (everything but somatic motor..)

-GVA from ear
-SVA from tongue
name the 2 nuclei here?

they both happen to carry what kind of info?
vestibular + cochlear
(carry special sensory)

Cochlear nucleus:
- Special sensory
- from organ of Corti
- Hearing

Vestibular nucleus:
- Special sensory
from semicircular ducts and
macculae of utricle and saccule
- Balance and acceleration
name the 4 nuclei of glossopharyngeal (CN IV) (medial to lateral)

Nucleus ambiguus:
- to stylopharyngeous

Inferior salivary nucleus:
- parasympathetics
parotid gland
- via otic ganglion

Nucleus of solitary tract:
- taste from post 1/3 of tongue
- via sup. ganglion of GP nerve

Spinal trigeminal nucleus:
ear, pharynx
- via sup. and inf. ganglia of GP nerve
nuclei of CN X? (4)
Nucleus Ambiguus:
Pharynx and larynx

Dorsal Motor Nucleus of Vagus:
viscera (heart, bronchi, gut) above
left colic flexure


Nucleus of the Solitary Tract
Caudal part: visceral sensory, such as gut distension
Rostral part of nucleus for taste
from pharynx

Spinal Trigeminal Nucleus:
Outer ear
where is the Accessory spinal nucleus:

what info does it carry

and what muscles does it innervate
- spinal cord (C1-C5)

- branchial motor
- to trapezius and sternocleidomastoid
hypoglossal nucleus
motor to tongue muscles

The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal.
nuclei of the parasymps?
Lens and pupil
Edi-Westphal and CN III

Lacrimal, submandibular, and sublingual glands
superior salivatory nucleus and CN VII – nervus intermedius

Otic ganglion to parotid gland
inferior salivatory nucleus and CN IX

Thoracic viscera, foregut and midgut
dorsal motor nucleus of the vagus and CN X
nerve dist of tounge
from VII (taste ant. 2/3 tongue) via geniculate ganglion and chorda tympani

from IX (taste post. 1/3) via petrosal ganglion

from X (taste epiglottis/tongue) via nodose ganglion
what nucleus is responsible?
nucleus ambiguous

Pharyngeal Elevators
NA helping coordinate
gag reflex?
summary of all nerves
CN I & II…don’t even count
CN IV: motor only, (trochelar n.)
CN VI: motor only, (abducens n.)
CN XII: motor only, (hypoglossal n.)

CN III has motor (occulomotor n.) and carries parasympathetics to eye (Edinger-Westphal n.)
CN VIII: sensory only (vestibular n. & cochlear n.)
CN XI: motor only, (cervical (C1-C5) & nucleus ambiguus)

CN V: sensory (spinal trigeminal n., main sensory n., mesencephalic n. ) and motor (motor trigeminal n.)
CN VII: motor (facial n.), sensory (N. of solitary tract) and parasympathetics (superior salivary n.), remember that the nervus intermedius carries the sensory portion of CN VII.
CN IV: sensory (N. of solitary tract), motor (N. ambiguus) and parasympathetics (inferior salivary n.)
CN X: sensory (N. of solitary tract), motor (N. ambiguus) and parasympathetics (dorsal n. of X)
all cranial nerves are ventral except

(its the only one that decussates too)
name the part of the brain each cranial nerve leaves from
four locations….
2 nerves: Olfactory and Optic
Within this you have 1 in the telencephalon and 1 in diencephalon

2 nerves: Oculomotor and trochlear

4 nerves: Trigem, Abducens, Facial, Vestibulocochlear

4 nerves: Glossopharyngeal, Vagus, Accessory, Hypoglossal

So moving caudally, it is 2,2,4,4
Solitary nucleus is Sensory (visceral)

which nerves ?

aMbiguus is Motor. which nerves?

you know about the 2, 2, 4, 4, rule right?

why is this rule not perfect?
5, 7, 8 aren't so clean

5) although all divisions of CN5 enter the pons, the sensory nucleus of CN5 extends from the midbrain to spinal cord

7) 7 is both in pons and medulla

8) 8 is in pons and medulla
CN11 is a social climber and really not a cranial nerve....it's a spinal nerve which creeps through the foramne magnum, touches the ______ and comes back down again via the jugular foramen
which CN exits anterior/ventral to the inf olive?
12 (motor to tongue)
All the nuclei except that of the _____ nerve supply nerves of the IPSILATERAL side of the body.

(only one that decussates)
For ______ fibers, the cell bodies are in the nuclei themselves, and synapse on a LMN
--No ganglia, just cell bodies in nucleus

For _______ fibers, the cell bodies are in a ganglion, a peripheral structure
Ex: VIII. The ganglia are Scarpa’s and spiral g.
BUT, the nuclei are vestibular and cochlear n.

So, do have associated CN nuclei, but cell bodies are sitting in periphery, in ganglia

Questions to classify CN types

Is it motor (E, efferent) or sensory (A, afferent)?

Innervate structures from somites (somatic) or brachial arch derivatives (visceral)?

Is it simple (G, general) or complex (S, special)?

What are the possibilities?
- SSA (vision and hearing)
- SVA (taste and smell)
- SVE (branchial cleft muscles)

- no such thing as SSE…
draw coordination pathway between CN III and VI
INO think MLF think MS!

Lesion in medial longitudinal fasiculus (MLF)
Produces a medial rectus palsy with lateral gaze.
Lesion is in which side?

Nystagmus is in which eye?
The one that abducts, LEFT
How’s convergence?
Intact (b/c nothing wrong w/ CNIII or MR)
Lesion is in which side?
Nystagmus is in which eye?
The one that abducts, LEFT
How’s convergence?
Intact (b/c nothing wrong w/ CNIII or MR)
name all the nuclei of V:
SVE: motor to muscles of mastication & tensor tympani (motor trigeminal nucleus)

--light touch & proprioception for face (main sensory nucleus of trigeminal)
--Pain & temperature (spinal trigeminal nucleus)
--Jaw proprioception (mesencephalic nucleus, actually contains cell bodies…so more like a ganglion than a nuclei)
what's the nucleus?
spinal trigeminal--pain, temp of face

one of the 4 nuclei of trigeminal along with:
motor trigeminal nucleus
main sensory of the trigeminal
TRIGEMINAL's relationship with DC-ML and STT:

Light touch & prorioception:

CNV to ______ nucleus decussates (mostly) and travels up to the ________of the thalamus via the medial lemniscus
-we can toss mesencephalic nucleus in here as well since it deals with proprioception as well

-Pain & temperature:
CNV to ______ nucleus (& tract), decussates and travels up to the VPM of the thalamus via the anterolateral system

VPM & VPL are in the thalamus.
VPM is for the HEAD
VPL is for the BODY
main sensory

spinal trigeminal
ID this lesion....

LMN (lose ipsilateral face, both upper and lower)

w/ UMN lesion, you lose contralateral lower face
nuclei of CN VIII?
VIII – Vestibulocochlear
SSA: sound from cochlea (cochlear, cell body in spiral ganglion)
SSA: balance information from semicircular canals, utricle and saccule (vestibular, cell body in scarpa’s ganglion)

Don’t memorize the ganglion…I just wanted to remind you that the sensory cell bodies are in ganglions, NOT the nucleus
what's the deal with CN 8?
Actually 2 Nuclei with 3 divisions
----Dorsal: vertical sound localization. Fibers to inferior colliculus

----Anteroventral: horizontal sound localization. Bilateral projection to superior olivary complex
----Posteroventral: hair cell sensitivity. Bilateral projection to superior olivary complex

Actually 4 Nuclei
Lateral: deals with posture and balance
Medial: deals with head movements
Superior: helps orient eye movements (via abducens nucleus)
XI - Spinal accessory

GSE: motor to _______ and ______

Actually has 2 components
Spinal, which make up most of the fibers. Originates in the cervical spinal cord (spinal accessory nucleus)
The spinal part actually is the only nerve to enter the skull from outside and then leave again!

Convoluted Path: Start in cervical cord--> enter skull via foramen magnum -->travel in vicinity of medullary CNs --> leave via jugular foramen

Cranial, with very few fibers (nucleus ambiguus)
sternocleidomastoid, trapezius
what nerves go through the nucleus of the solitary tract?
solitary= 1=>carry 1 sense which is TASTE!!
VII: anterior 2/3 of tongue (chorda tympani) via geniculate ganglion
IX: posterior 1/3 of tongue via petrosal ganglion
X: epiglottis via nodose ganglion

** tract is inside the nucleus
what nerves go through the nucleus of the solitary tract?
solitary= 1=>carry 1 sense which is TASTE!!
VII: anterior 2/3 of tongue (chorda tympani) via geniculate ganglion
IX: posterior 1/3 of tongue via petrosal ganglion
X: epiglottis via nodose ganglion

** tract is inside the nucleus
what nerves go through the nucleus of the solitary tract?
solitary= 1=>carry 1 sense which is TASTE!!
VII: anterior 2/3 of tongue (chorda tympani) via geniculate ganglion
IX: posterior 1/3 of tongue via petrosal ganglion
X: epiglottis via nodose ganglion

** tract is inside the nucleus
nucleus ambiguus has motor to what muscles?
Motor to pharynx, larynx and esophageal mm

(nerves 9, 10)
name all the parasympathetic nuclei?
4 of them
Superior colliculus: important in orienting head & eyes
Ganglion cells --> brachium of superior colliculus -->_______ -->thalamus --> cortex (visual)

Inferior colliculus: important in _______
Cochlear nuclei/superior olive -->inferior colliculus --> brachium of inferior colliculus --> ____ (of thalamus)
superior colliculus

sound localization

Gag reflex
Touching back of oropharynx, causes gagging or reflex elevation of pharynx
Usually stated that IX is afferent limb of reflex and X is efferent limb, but . . .
Lesion of IX does not eliminate it; X must also innervate back of oropharynx.
you can see all the peduncles in the caudal pons
6 layers

how many layers?
Comes in 2 main types:

Archicortex (3 layers): hippocampus and dentate gyrus

Paleocortex: amygdala and olfactory cortex
less than 6
what's the main output layer?
(biggest for the primary motor cortex)

input layer?
5-main output

I: nothing much here
II: output
III: output
IV: input (thin in primary motor cortex, THICK in primary sensory cortex)
V: main output (THICK in primary motor cortex, THIN in primary sensory cortex)
VI: output
tentorium cerebelli is?
extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.
faux cerebri goes bw the?
descends vertically in the longitudinal fissure between the cerebral hemispheres.
The pituitary gland lies between the two paired ___________
cavernous sinuses.
An abnormally growing pituitary adenoma, sitting on the bony sella turcica, will expand in the direction of least resistance and eventually compress the ________
cavernous sinus
where's the sensory loss of axillary nerve damage?
regiment's patch

- loss of sensation on lateral shoulder
- superior lateral cutaneous n. of arm
Meninges is from _____except for those of the prosencephalon which come from ________
neural crest
In cross-section, the peripheral region of the cord contains neuronal white matter ______containing sensory and motor neurons. Internal to this peripheral region is the gray, butterfly shaped central region made up of ________

. This central region surrounds the central canal, which is an anatomic extension of the spaces in the brain known as the ______ and, like the ventricles, contains ______.

nerve cell bodies.


cerebrospinal fluid.
the brain consists of what 3 components
cerebrum (cerebral hemispheres + the diencephalon)

brainstem (midbrain, pons, medulla)

brain classified into what 6 postembryonic divisions
medulla oblongata
telencephalon consists of the
CEREBRAL HEMISPHERES (which comprises both cerebral cortex and white matter...the cerebral hemispheres contain the lateral ventricles)

the cerebral hemispheres are interconnected by the
the cerebral hemispheres contain 6 lobes. name them
name the gyri of the frontal lobe
precentral gyrus
superior frontal gyrus
middle frontal gyrus
inferior frontal gyrus
gyrus rectus and orbital gyri
anterior paracentral lobule
name the gyri of the parietal lobe
postcentral gyurs

superior parietal lobule

interior parital lobule (= supramarginal gyrus + angular gyrus)


posterior paracentral lobule
name the gyri of the temporal lobe
transverse temporal tyri of Heschl

superior temporal gyrus

middle temporal gyrus

inferior temporal gyrus

lateral occipitotemporal gyrus
gyri of occipital lobe
lingual gyrus
the insular lobe lies buried wi the ___________
lateral sulcus
basal ganglia are the ___________ of the telencephalon
subcortical nuclei
basal ganglia includes the
caudate nucleus


globus pallidus

amygdaloid nuclear complex (amygdala)
telencephalon consists of:
cerebral hemispheres
basal ganglia
lateral ventricles
cerebral cortex
white matter
corticospinal tract damage commonly caused by_____

what can happen?
interruption of the blood supply to the internal capsule

arm muscle weakness and impaired fine motor skills
the reticular formation forms the central core of the_____ has neurons with widespread connections
brain stem
on the dorsal brain stem surface, there are


dorsal columns
dorsal column tubercles
4th ventricle
the _____ are 4 bumps in the dorsal midbrain
name 4 landmarks on ventral surface of brainstem

all 4 of these landmarks of are compenents of the _________ system
base of the bons
basis pedunculi

bc of the ________decussation, one side of the brain controls muscles of the opp side of the body
recieving input from all the sensory modalities, neurons of the reticular formation can affect
neuronal excitability
the inferior olivary nucleus contains neurons whose axons project to the _______, where they form one of the strongest excitatory synapes in the entire central nervous system
the central canal of the spinal cord expands to form the _____ in the ______
4th ventricle

rostral medulla
the (4th) ventricular floor is formed by the __________

the roof consists of a thin tissue formed by the apposition of 2 glial layers during development: ______ and _____
dorsal medulla

pia & ependyma
The superior sagittal sinus sits in the_____________ (superiorly) and the inferior sagittal sinus runs through the inferior part of the falx cerebri.
falx cerebri
what's the other name of the central fissure?
Rolandic fissure.
the central sulcus separates the_____ and______ lobes

and primary ________ cortex from primary _____cortex
frontal and parietal

somatosensory, motor
what's in the longitudinal/saggital fissure?
The falx cerebri, the superior sagittal sinus, and the inferior sagittal sinus
The frontal lobe lies _______ to the Sylvian Fissure.
cuneatus: upper limbs

_______: lower limbs
where's the superior colliculus?

and what does it do?
A portion of the optic tract projects directly to superior colliculus. It also receives somatic sensory and auditory input. These convergent inputs from different sensory systems are important for orienting eye and head movements to stimuli in the environment.
_________are involved in the limbic system (part of Papez circuit).

-It is involved in memory, along with other structures.

-Of note, from a pathological perspective, it can be severely damaged in those with alcohol abuse (secondary to thiamine deficiency), called Wernicke-Korsakoff syndrome.
mamillary bodies

The mammillary bodies are a pair of small round bodies, located on the ventral surface of the brain at the posterior end of the hypothalamus, that form part of the limbic system (part of the Papez circuit). They are located at the ends of the anterior arches of the fornix.
why is the uncus important?

where is it?
the uncus is a very important structure because of its location spatially within the brain. When pressure builds up in the brain (secondary to mass effect from a rapidly growing lesion, acute hydrocephalus, an acute bleed, generalized brain edema, etc.), this structure can herniate (be pushed down).

temporal lobe
CNXI originates in the __________ and is purely a motor nerve fiber. It controls muscles in the neck and shoulders (sternocleidomastoid and trapezius, respectively) and some of the muscles in the throat involved in swallowing.
medulla and cervical spinal cord
____ is a portion of the diencephalon located lateral and ventral to the pineal gland. It is a part of a circuit with the midbrain medial dopaminergic and the serotonergic systems.
The ophthalmic and maxillary nerves are purely ______. The mandibular nerve has both sensory and motor functions.
where and what is the tuber cinereum?
tuber cinereum is a hollow eminence of gray matter situated between the mammilary bodies and the optic chiasm and is a part of the hypothalamus.
the tuber cinereum is continuous with a thin lamina, the ________
lamina terminalis
The______projects from the tuber cinereum.
infundibulum aka pituitary stalk

A small outgrowth of the ventral wall of the embryonic brain from which the pars nervosa (the posterior lobe) of the pituitary gland develops is also called the infundibulum.

infundibulum is composed of infundibular stem (curved arrow), median eminence of hypothalamus, from which it arises, and pars tuberalis (straight arrow).
On head CT what often appears as a hyperdensity (due to the calcium)?

should not be confused with real pathology.
pineal gland
Axons of______ ganglion cells exit the eye as CN II.
The _______cerebellar peduncle is the major output (efferent) pathway of the cerebellum.

Most of the efferent fibers originate within the dentate nucleus of the cerebellum and project to various midbrain structures (including the red nucleus), the ventral lateral/ventral anterior nucleus of the thalamus, and the medulla.
The middle cerebellar peduncle is composed entirely of_______(input to cerebellum) fibers originating within the pontine nuclei and is part of a pathway that begins in sensory and motor cortex, goes through pons and enters the cerebellum via the middle cerebellar peduncles. These fibers make the middle cerebellar peduncle the largest of the three cerebellar peduncles.
The ________cerebellar peduncle carries both input and output fibers involved in integrating proprioceptive sensory input with motor and vestibular functions such as maintanance of posture and balance. Proprioceptive information is relayed to the cerebellum through the inferior peduncle from the dorsal spinocerebellar tracts.
the pneumonic LR6 SO4 (I think of the anion SO4 -- sulfate).

refers to what?
Lateral rectus is innervated by VI, superior oblique by IV. The rest of the extraocular muscles are under the motor control of III.
______is an elevated area located on the dorsal pons that is formed by motor fibers of the facial nerve as they loop over the abducens nucleus. The facial nerve (CN VII) controls the muscles of facial expression.
facial colliculus
_______is where the fourth ventricle narrows to become the central canal of the spinal cord (in the caudal medulla). The decussation of dorsal column fibers occurs at the level of the obex.
The ________ colliculus is a part of the auditory pathway and is important in sound localization.

1) Ascending fibers from the ipsilateral and contralateral nuclei of the lateral lemniscus synapse in the inferior colliculus as well as

2) contralateral inputs from the dorsal cochlear nucleus and

3) ipsilateral and contralateral inputs from the superior olivary nuclei.

All these convergent inputs are important for sound localization.

The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain. Three distinct, primarily inhibitory, cellular groups are located interspersed within these fibers, and are thus named the nuclei of the lateral lemniscus.
The ______ relays information between the cerebellum and cortex, aids in relaying sensory and motor information, and regulates respiration.
brachium of the ______connects the ______ with the ______ geniculate nucleus. This pathway is part of the auditory system
inferior colliculus
inferior colliculus
The _______is a small lobe of the cerebellum. It is associated with the nodulus of the vermis, and together, these two structures compose the vestibular part of the cerebellum.

The flocculus receives input from the ________ system and regulates balance.

Also, many floccular projections descend to the spinal cord and connect to the motor nuclei involved in control of _______


eye movement
Dorsal cell types are ______ - need notochord to induce ventral cell types
nerve fibers are_________
1 “muscle” generally = how many nuclei?
the components of the intermediate gray matter
-Lateral horn
-sacral parasym nucleus (S2-S4)
-The remainder
- variety of sensory interneurons and projection neurons
Long ascending fibers project to (3)
thalamus, cerebellum and brain stem
Long descending fibers project from (2)
cerebral cortex and brainstem
Medial Lemniscus (in Medulla)
is where fibers of secondary neurons in medulla ______ and then project to ____

- project to thalamus
bw dura and arachnoid, there is always
potential space
how are subdural hematomas caused?
blow to front or back of skull shears off cerebral veins as they enter superior sagittal sinus
identify each color
Tentorium cerebelli: divides the brain into the (rostral) ________spaces and the (caudal) ______ space, or posterior fossa

Falx cerebri: divides the ___________space itself into the left and right sides

the arachnoid and pia together are referred to as
name the 3 primary brain vesicles?

now name the secondary brain vesicles from each?

now name the walls of each?

the cavities of each?

name the imp subarachnoid cisterna?
name all the paired structures you see in the dorsal brainstem
colliculi (2 sets, paired), cerebellar peduncles (3 sets, paired)
where's the straight gyrus?

(=gyrus recti)
name components of basal ganglion
caudate nucleus
globus pallidus +putamen (= lenticulate nucleus)
claustrum, amygdala
pons lies against the _______, part of the cranium..."slides" down into the foramen magnum

sometimes the brainstem can herniate into the foramen magnum by sliding over this structure
where is the largest subarachnoid cistern?
lumbar cistern (bw verebrae L2 and S2)
the _______ is the narrow zone of a funnel of motor and sensory fibers that converge upon the brain stem from the cerebral cortex
internal capsule
in general, cerebral lesions tend to cause contralateral malfunctioning, whereas ________lesions cause ipsilateral malfunctioning
cerebellar? check
3 main connections bw the cerebellum and the brain stem?
superior, middle, and inferior cerebellar peduncles
the spinocerebellar pathway enter the cerebellum via the ____ and _____ peduncles
superior and inferiour cerebellar peduncles
most lateral to medial.
start at Sylvian Fissure; note the basic organization: alternating between gray matter and white matter.

insula (gray matter, cortex) extreme capsule (white matter) claustrum (gray matter)
external capsule (white matter) putamen -> GPe -> GPi (gray, together are lenticular n.) internal capsule (white matter) thalamus (gray matter) thalamic adhesion (crosses midline)
red: putamen
green: nucleus accumbens
blue: caudate nucleus
yellow: internal capsule
where is the substantia nigra located?

what's just ventral to it?

cerebral peduncle is just ventral to the substantia nigra, however, they are NOT part of the basal ganglia.
The triangular structure (forever remember these three structures together) is the lenticular nucleus. Some anatomist thought a triangle looked like a lentil. This nucleus is made of the putamen and the two parts of the globus pallidus (internal and external components). The yellow dot is in the middle structure, which is the GPexternus. More medial to it (or more 'internal' to the brain) is the GPinternus. The putamen makes up the big lateral edge of the triangle, and is not specifically labeled in this picture. While the caudate and thalamus are ALSO part of the functions of the basal ganglia, they are more medial to the internal capsule and not part of the 'triangle.' The insular cortex, or insula, is the most lateral structure of gray matter on the cortical surface between the frontal/parietal and temporal lobe. Note the structures dotted with red, and see how they form a triangular shaped region of gray matter
what is this? what does it do?

modulates the output of the thalamus according to alertness levels
receives input from the brainstem reticular formation

regulates the output of thalamic relay nuclei

sends exclusively inhibitory outputs to thalamic relay nuclei

It regulates the output of thalamic relay nuclei by inhibiting neurons within thalamic relay nuclei like the LGN or VL.

The TRN receives input from the brainstem reticular formation, which is involved in controlling states of awareness. The TRN therefore shuts down relay nuclei (puts them into "burst mode") when the brainstem reticular formation signals "sleep," and puts the relay nuclei in "tonic mode" where it can relay information faithfully when the brainstem reticular formation is signalling "awake."

The thalamic relay nuclei derive from the middle portion of the embroyonic diencephalon. The TRN derives from a different portion of the embroyonic diencephalon, the VENTRAL portion (not dorsal portion) of the embroyonic diencephalon.

Ventrolateral nucleus (VL) relays cerebellar inputs to cortex.

The fornix connects hippocampus to mamillary body.
The LGN is the bent structure at the caudal pole of the thalamus and relays visual information to the cortex.
tell me about anterior nucleus, lateral genticulate, ventral posterior lateral (VPL) and VPM.
1) ANTERIOR NUCLEUS is a relay nucleus that receives input from the mamillary bodies via the mamillo-thalamic tract.

2) The LATERAL GENTICULATE nucleus is the primary relay nucleus for the visual system.

3) The Ventral Posterior Lateral nucleus (VPL) is the primary relay nucleus of the somatosensory system, receiving input from the body portions of the medial leminscus and anterolateral system.

4) VPM receives somatosensory information from the head.

The subthalamic nucleus is in the diencephalon, but not in the thalamus. It is associated with the basal ganglia. The amygdala is not in the diencephalon and is a structure associated with the limbic system. The mamillary bodies hang off the posterior part of the hypothalamus, are not part of the thalamus, and are connected to the hippocampus through the fornix. The pineal gland is part of the epithalamus (not the thalamus). It secretes melatonin.
what's the Papez circuit?
cingulate gyrus-->hippocampal formation-->(fornix)-->mamillary bodies-->(mamillothalamic tract)-->thalamus (anterior thalamic nuclei)-->cingulate gyrus
what's the disorder?

Characterized by visual agnosia, oral or tactile exploratory behavior, hypersexuality, bulimia, memory loss. Caused by bilateral temporal damage (trauma, infection, Alzheimer’s disease, cerebrovascular disease).
KlüverBucy Syndrome
You have the basic Papez circuit down. What are the additions? (include the amygdala, association cortex, prefontal cortex, hypothalamus)
(bold= Papez addition)
The_______________ is devoted mainly to motivation, emotion and memory; it is located on the medial and inferior surfaces of the cerebral hemispheres in portions of the parietal temporal and frontal lobes.
limbic association cortex
what are the 4 areas of the limbic association cortex?
- located on the medial surface of the cerebral cortex (temporal, parietal and frontal lobes).

consists of four areas
-medial orbital
-temporal pole
the limbic association cortex gets input from

output to?
input from the higher order sensory areas of the cortex and the two other association cortices

output to hippocampal formation and amygdala.
the hippocampal formation gets input from _________

consists of 3 components:
entorhinal cortex (part of the parahippocampal gyrus)

3 components:
dentate gyrus
hippocampus proper

The entorhinal cortex (EC) is an important memory center in the brain. The EC forms the main input to the hippocampus and is responsible for the pre-processing (familiarity) of the input signals.
nuclei of the amygdala?

Central nucleus
Input: brainstem
Output: hypothalamus, autonomic nuclei (in brainstem)

Basolateral nucleus
CONCEPT: reciprocal cortico-cortical
Back and forth between
medial-dorsal nuc of thalamus
cortex (a lot in frontal lobe)

Corticomedial nucleus
Back and forth between olfactory
Back and forth with hypothalamus via stria terminalis

**note that basolateral has nothing to do with hypothalamus, olfaction
what nucleus of the amygdala is described?

Attach emotional significance to a stimulus.
Learning the emotional significance of complex stimuli.
Behavioral responses to emotional stimuli (via the central nucleus).
Basolateral nucleus
what nucleus of the amygdala is described?

Behavioral responses to emotional stimuli.
- Direct and indirect (via hypothalamus) regulation of the autonomic nervous system.
central nucleus
what nucleus of the amygdala is described?

Regulates behaviors triggered by olfactory stimuli (via hypothalamus).
corticomedial nucleus
zones of the hypothalamus?
Periventricular: Release of endocrine hormones from the anterior Pituitary

Middle: Release of endocrine hormones from the posterior Pituitary

Lateral: Integrates information from the limbic system
nuclei of the hypothalamus...
name the tract (1 of 7 of the limbic system:

Cortical axons in the cingulate and parahippocampal gyri that terminate in the entorhinal cortex.
fornix tract: axons from pyramidal neurons in _________ and ________
that terminate in _________
hippocampus & subiculum

mamillary body
label #3

It's one of the main output pathways of the amygdala, consists of axons from corticomedial nucleus of the amygdala that terminate in the _______
3) Stria terminalis:

label 4

it's one of the tracts of the limbic system

Ventral amygdalofugal pathway: one main output pathway of the amygdala, consists of axons from basolateral and central nuclei of the amygdala that terminate in the ______, ______, and _________
ventral amygdalofugal pathway

thalamus, association cortex and dorsal motor nucleus of the vagus.
what's the tract?

from ______ to the ________ nucleus of the ______
mamillothalamic tract

mamillary body to anterior nucleus of the thalamus
name the tracts
6. Dorsal longitudinal fasciculus
7. Medial forebrain bundle:

Both include hypothalamic axons that terminate in the brainstem.
The ________ (of the cerebellum) receives input from the vestibular system and regulates balance. Also, many floccular projections descend to the spinal cord and connect to the motor nuclei involved in control of eye movement.
THALAMIC RETICULAR NUCLEUS (TRN) regulates the output of thalamic relay nuclei through inhibitory outputs that can suppress the activity of neurons within thalamic relay nuclei.

The TRN receives input from the _________, which is involved in controlling states of awareness.
brainstem reticular formation
the _________ of the dorsal thalamus receives input from the mamillary bodies through the mamillo-thalamic tract.
Anterior nucleus
The mamillary bodies hang off the _______ part of the hypothalamus
in Papez's view, what leads to behavioral respone to the emotional state?
what's the current view?
hypothalamus->behavioral response

limbic cortex-->amygdala-->hypothalamus->behavioral response
match the component of the limbic system to the function; conscious feeling, memory, autonomic/endocrine/skeletomotor behavioral response

match the component of the amygdala to the function; conscious feeling, memory, autonomic/endocrine/skeletomotor behavioral response

autonomic/endocrine/skeletomotor behavioral response
(along with hypothalamus)
match the component of the limbic system to the function; conscious feeling, memory, autonomic/endocrine/skeletomotor behavioral response:

the hippocampus is involved in _____ memory

while the neocortex, striatum, amygdala, Cerebellum and reflex pathways are involved in _______

what's the mossy fiber pathway and the schaffer collateral pathway?
after conditioning and testing...

1) would a person (with damage to hippocampus) remember colors shown?

how about damaged amygdala?

damage to both structures?

2) would person with damaged hippocampus show autonomic conditioned response?

damaged amygdala?

damaged both hippocampus + amgydala?
Cerebellar Peduncles
3 pairs
Superior: _______ (out of cerebellum) only
Middle: _______(into cerebellum) only
Inferior: Both

Caudal Medulla
1 Nucleus gracilis
2 Fasiculus cuneatus (remaining fibers)
3 Nucleus cuneatus
4 Spinal trigeminal tract
5 Spinal trigeminal nucleus
6 Spinothalamic tract (pain and temperature)
7 Corticospinal tract in the pyramids (volitional movement)
8 Medial lemniscus (light tough and proprioception)
9 Internal arcuate fibers (decussation of the DC-ML tract)
Rostral Medulla

Dorsal motor nucleus of vagus
Fourth ventricle
Hypoglossal nucleus
Vestibular nuclei
Inferior cerebellar peduncle (afferent from spinocerebellar tract, afferent from and efferent to inferior olive and vestibular nuclei…dealing with coordination/balance)
Spinothalamic tract
Corticospinal tract (pyramids)
Medial Lemniscus (DC-ML)
Inferior olive
Spinal trigeminal nucleus
Nucleus of the Solitary tract and the solitary tract
(pointing to the dotted line) Sulcus limitans

2. Inferior cerebellar peduncles
3. Facial nerve
4. Facial nucleus
6. Corticospinal tract (and some other stuff)
8. Medial lemniscus
9. Spinocerebellar tract
11. Abducens nucleus
12. Fourth ventricle

Cerebral aqueduct
Periaqueductal gray
Superior colliculus
Brachium of the inferior colliculus
Anteriolateral system (spinothalamic)
Medial lemniscus
Cerebral peduncle (corticospinal)
Substantia nigra
Medial longitudinal fasciculus (MLF)
Superior cerebellar peduncle

pia is HIGHLY vascular
arachnoid is AVASCULAR
2 of the 5 intracranial hematomas:

often tumors/lesions bleed into brain tissue, esp. basal ganglia and internal capsule. Commonly caused by __________

blood into the ventricles, often in premature neonates
the 5 types of intracranial hematomas
name them
what's in these layers?
I: nothing much here
II: output
III: output
IV: input (thin in primary motor cortex, THICK in primary sensory cortex)
V: main output (THICK in primary motor cortex, THIN in primary sensory cortex)
VI: output

What is the output anyway? 3 types: Coritococortical neurons, callosal neurons, descending projection neurons
in which lobes are the Wernick's and Broca's areas?
Broca: frontal
Wernick's: temporal
do you see the taco?

1 is the septum pellucidum
3 is the Internal Capsule
2 is caudate,
4 is putamen,
5 is globus pallidus,
-remember, it is 2 parts!!!
6 is nucleus accumbens
name some primary relay nuclei of the thalamus
where does the structure (encircled by the orange) get its input?
this is the anterior nucleus of the thalamus

PAPEZ!!! input from mamillary bodies, output to cingulate gyrus
what's the orange?

orange: VentroLateral
blue: DorsoMedial

VL = Cerebellum

Prefrontal Ctx
Limbic Ctx
-higher order
caudal thalamus!

(now we see the ventromedial nucleus...for the face)
Posterior thalamus
what can you see in the most posterior parts of the thalamus?
The ______ and __________ are highly connected (by the stria terminalis) and both can affect the endocrine system (e.g., via hypothalamus => pituitary) and autonomic system (e.g., via amygdala => dorsal motor nucleus of the vagus).
amygdala + hypothalamus
components of CSF circulation in the brain?
subarachnoid space (inc cisterns)
middle meningeal artery comes from
external carotid-->maxillary artery-->middle meningeal
basilar artery gives rise to what
so 2 vetebrals (coming from the subclavian artery??) join to form the BASILAR

internal carotid gives rise to what
the anterior cerebral artery (ACA) and middle cerebral artery (MCA)
the vetebral artery gives rise to
posterior inferior cerebeller....then both vetebral merge to form BASILAR
choose from:

Medial aspect of hemispheres
choose from:

inf. cerebellum
AICA (anterior inferior cerebellar)
choose from:

lateral hemispheres and BG structures, internal capsule
choose from:

cerebellar hemispheres
choose from:

midbrain, thalamus, occipital lobe
choose from:

cerebellum and medulla
Capillaries in the brain are ___________ endothelial cells and connected via gap junctions
what drains in dural venous sinuses?

all drain into?
blood and CSF

Walls of the dural venous sinuses composed of __________ lined with _____________

how does it differ from other blood vessels?
dura matter

lack the vessel wall layers (ie, no tunica media)
the straight sinus connects what?

is it anterior or posterior?
superior and inferior sagittal sinus

superior petrosal sinus --> _________sinus --> sphenoparietal sinus and ________vein
cavernous sinus

opthalmic vien
the great cerebral vein (of Galen)

Drains from: _______
Drains to: _________
Drains from: internal cerebral veins
Drains to: straight sinus
the __________houses the ICA after it enters the calvaria, as well as these cranial nerves
cavernous sinus
what's housed by the cavernous sinus?
ICA, cranial nerves
III (Oculomotor)
IV (Trochlear)
VI (Abducens)
the cavernous sinus is an entry of
transverse sinus gives rise to sigmoid + _____
superior petrosal sinus
which 2 sinuses drain directly into IJV
Inferior petrosal sinus
Sigmoid sinuses
CSF fills ______, __________ and ________
Fills subarachnoid space, ventricles and spinal canal

Circulates through ventricles and into subarachnoid space
CSF secreted by ________ in choroid plexus in ____________
epithelial cells

ventricles in brain
what happens to the CSF on a daily basis?
more is produced than exists...the rest gets dumped into venous system via arachnoid villi
The posterior cerebral arteries comes off the basilar artery. They course around the midbrain and supply the ______lobe and portions of the medial and inferior temporal lobe.
The dura is most adherent to the _______, which connect the various bones of the skull.
in an epidural hematoma, blood between _______ and dura
naked bone

dura has 2 layers:
1) periosteum of the bone
2) meningeal layer

clinically, both are considered dura
what kind of epidural can result?
Epidural Hematoma:

Trauma -> fracture & concussion
Tearing/stripping of both layers
from inner table
Laceration of outer periosteal
Laceration of meningeal vessels
Inner (meningeal dura) intact

Blood between naked bone and

Epidural hematomas form between the skull and the outer layer (dura mater) of tissue covering the brain (meninges)
how can you get a subdural hematoma?
Blow to front or back of head

shearing of cerebral veins
what are major branches of the ICA
inc ophthalmic artery, the anterior choroidal artery, the middle cerebral artery and the anterior cerebral artery.
Extradural (Epidural) hematoma
e.g., blow to ___ ruptures ________

middle meningeal artery
which subclavian artery would you inject with contrast to demonstrate both the carotid and vetebral circulations?

bc the right subclavian connects to the right common carotid (= brachiocephalic artery) so dye in the right subclavian will get to the right common carotid

the left subclavian, however, connects directly to the aorta
remember the ABC'S (aorta, brachiocephalic artery, carotid (left), subclavian (left)
occlusion of which area of willis will result in total unilateral blindness
opthalmic artery (first branch of the ICA)
From the paired lateral ventricles (LV), CSF passes through the paired interventricular foramina of Monro (yellow arrow) into the single midline third ventricle (TV). CSF then flows down the single midline aqueduct of Sylvius (a channel shaped like a toothpick; green arrow) into the single midline fourth ventricle (FV). CSF leaves the ventricular system through the two lateral foramina of Luschka and the midline foramen of Magendie. Here, CSF is shown exiting through the foramen of Magendie (blue arrow) and entering the cisterna magna (CM). Within the subarachnoid space (SAS), CSF flows over the convexities of the brain and the folia of the cerebellum, and around the brainstem (curved arrows). From the CM, CSF also courses inferiorly to surround the spinal cord (orange arrow).
CSF is produced by
specialized ependymal
cells of the choroid plexus

Choroid is found in all
components of the ventricular
system except
1. cerebral aqueduct
2. occipital and frontal horns of the lateral ventricles
whats the path of CSF flow

start from the lateral ventricle?
Lateral ventricles
via the foramina of Monro
into the third ventricle
via the cerebral aqueduct of Sylvius
into then the fourth ventricle

2 options (technically 4 different holes/spaces)
can pass into the central canal of the spinal cord OR
into the cisterns of the subarachnoid space via three small foramina:
the central foramen of Magendie (one, Medial)
and the two lateral foramina of Luschka (paired, Lateral).
CSF recycled at the level of the
arachnoid villi
Decreased absorption of CSFcan lead to
“normal” pressure hydrocephalus (NPH)
describe the pathway of CSF flow

(name the ventricles and the foramina)
The anterior cerebral artery courses within the _______fissure and around the rostral end of the _________

corpus callosum
The common carotid arteries divide in the ____---to form the external and internal carotid arteries.
The internal carotid artery arises from the bifurcation of the __________ In its passage through the carotid canal and along the side of the body of the _______ bone, it has a double curvature and resembles the letter .
common carotid


middle cerebral artery runs through the ______sulcus (also called the Sylvian fissure), along the surface of the_______ and supplies blood to parts of the frontal, temporal and parietal lobes.

insular cortex
The middle cerebral artery largely supplies the lateral aspect of the brain where ________, _______, and _______areas are located in both sensory and motor cortex as well as ____ and _______ speech areas
trunk, arm, face

Broca's and Wernicke's speech areas.
Occlusion of the middle cerebral artery may result in paralysis and sensory loss in the contralateral/ipsilateral (?)

_____, ______, and _______
as well as different types of aphasia (ex. Broca's, Wernicke's, or conduction).

trunck, face, upper limbs
Occlusion of the posterior cerebral artery can result in ________defects, Weber syndrome (oculomotor nerve palsy and contralateral hemiparesis due to midbrain infarction), and ipsilateral deficits of CN V, VIII IX, X and XI.
visual field
The anterior cerebral artery supplies the dorsal and medial portions of the ___ and ____ lobes which includes the leg and foot areas of motor and sensory cortices.

Occlusion of the anterior cerebral artery may result in paralysis and sensory loss of the contralateral _________
frontal and parietal

foot and leg
an occlusion to the anterior cerebral artery results in loss of strength and sensation in the_____ part of the body
whereas middle cerebral artery affects ____


"LAH" (leg is medial, then arm, then hand)

anterior cerebral does medial cerebrum, and middle cerebral does lateral cerebrum
occlusion of the basilar artery at the junction of the 2 post cerebral arteries will result in _______ because they supply the visual cortex
total blindness!
(not true for either of the 2 vetebrals though..bc the intact vetebral covers the territory of the other)
if either the post cerebral artery and the superior cerebellar artery have an aneurysm, which CN nerve can it affect
occulomotor (3)

Willis has hairy armpits!
each cerebral hemisphere contains 1 internal capsule....(just behind Willis's head)

the anterior choroidal artery and striate arteries (the tiny arteries that arise from COW) supply the _______
internal capsule
in injecting the right carotid artery in an angiogram, how might one simultaneously fill the circulation in the left anterior and middle cerebral aa?
simultaneously compress the left carotid-->pressure differential allows blood to go to left circulation via ant communicating
identify all the aa here
rabi zidni ilma
rabizidni ilma
Lateral ventricles
the anterior or frontal horn (F) extends into the ______ lobe

the posterior or occipital (P) horn into the _____ lobe

the inferior or temporal (I) horn into the _____ lobe


Subarachnoid _______ are expanded parts of the subarachnoid space

Ventral surface of diencephalon and brainstem
Pontine cistern
Interpeduncular cistern
Chiasmatic cistern

Dorsal surface of diencephalon and brainstem
Cisterna magna (= cerebellomedullary cistern)
Superior (= quadrigeminal) cistern
Ventral surface of diencephalon and brainstem:
Pontine cistern
Interpeduncular cistern
Chiasmatic cistern
where are the 3 cisterns in the Ventral surface of diencephalon and brainstem:

there's 3!
Pontine cistern
Interpeduncular cistern
Chiasmatic cistern
Subarachnoid Cisterns
in dorsal surface of diencephalon and brainstem
Cisterna magna (= cerebellomedullary cistern)
Superior (= quadrigeminal cistern)
how does ct of epidural hematoma look like?
what are these things?
circumventricular organs

chemical signaling (hormones) need to enter and leave the brain, so we have spots in the BBB that are breached, or ‘leaky’…

OVLT: outlet for LHRH, somatostatin
Median eminence: releases hormones into the hypophyseal portal system
Subfornical organ: receptor site for Angiotensin II
Subcommissural organ:
Pineal gland: melatonin and serotonin
Area postrema: in the fourth ventricle, sense emetics, make you vomit

Area Postrema!! Makes you vomit, in response to circulating emetics– CLINICAL, so we give anti-emetics!
skull fracture is to epidural hemorrhage as aneurysm is to
subarachnoid hemorrhage
Subarachnoid hematomas are caused by:
--Ruptured intracerebral aneurysm
of COW vessels:Ant. Communicating, branches of middle cerebral, distal basilar, posterior inferior cerebella

Subarachnoid hematoma
Sudden rupture (usually of aneurysm)
Thunderclap headache
Stiff neck
The two layers of dura mater run together throughout most of the skull. Where they separate, the gap between them is called a dural venous sinus. These sinuses drain blood and cerebrospinal fluid

The arachnoid mater is one of the three meninges, the membranes that cover the brain and spinal cord. It is interposed between the two other meninges, the more superficial dura mater and the deeper pia mater, and is separated from the pia mater by the subarachnoid space.... that extend into the venous sinuses. These villi act as one-way valves.
middle meningeal artery runs between ____ and ____layers of the dura
periosteal and meningeal
Anterior choroidal artery is a branch of the _____
MCA territory includes Broca’s and Wernicke’s speech areas--> aphasias.

Lateral striate-->strokes associated with hypertension; infarct of internal capsule causes pure motor hemiparesis.
Functions mainly in equilibrium, postural control and
coordination of voluntary movements (plus other stuff)
the cerebellum has a cortex with a somatotopic map of body
how is the cerebeller cortex different from cerebral cortex?
None of the activity directly contributes to consciousness

- Hemispheres have ipsilateral representation of body parts (in contrast to cerebral cortex)
Three is the magic number!

for the cerebellum
Divided sagitally into 3 regions

Divided horizontally into 3 lobes with 3 naming schemes

Connected to brainstem by 3 peduncles

Cerebellar cortex has 3 layers

Cerebellar efferents arise from 3 nuclei

Cerebellar blood supply come from 3 vessels

There are 3 important cerebellar syndromes
what are the nuclei of the cerebellum?
what is this?

what comes through this?

from where?
Inferior cerebellar peduncle
- mostly afferent fibers from
- spinal cord
- Clarke’s nuc.- legs
- lateral cuneate nuc. - arms
- brainstem
- inferior olivary nucleus
- trigeminal nuclei
- reticular formation
- vestibular nuclei
what is this?
what does it carry?

from where?
Middle cerebellar peduncle
- entirely afferent fibers
- largest peduncle
- input from basilar pons

Route of afferent information from
the cerebral cortex via internal capsule,
cerebral peduncles and pontine nuclei
what is this?

what does it carry?

to where?
Superior cerebellar peduncle
(= brachium conjunctivum)
- mostly efferent fibers
(except ant spinocerebellar tract)
- output to cerebral cortex
via thalamus and int. capsule
Purkinje cells
- giant dendritic tree
- large cell body
- project to _______
- inhibitory
- project to cerebellar nuclei
what are the cells projecting to the cortex of the cerebellum?
climbing fibers, mossy fibers
Climbing fibers
- originate only in _____
- each climbs dendrite of single Purkinje cell (molecular layer)

- tens of thousands of synapses
- excitatory synapses
- alter Purkinje cell activity while learning new motor tasks
inf. olivary nucleus
Mossy fibers
- originate in many places
- each projects to 100s of granule cells
(granular layer)
- __________ synapses
- communicate with _____cells via granule cells and parallel fibers

what's posterior lobe syndrome?
- lesion to posterior lobe
commonly caused by a variety of factors
(e.g., strokes, tumors, trauma & degenerative diseases)

- loss of coordination of voluntary movements (ataxia)

intention tremor - only during voluntary movements
dysmetria - overshoots or undershoots when reaching for target
dysdiadochokinesia - inability to perform rapid alternating movements
(e.g. repetitive pronation/supination of hand)

-decrease in muscle tone

what's anterior lobe syndrome?
- lesion to anterior lobe
most common cause is malnutrition
associated with chronic alcoholism
loss of lower limb coordination
- gait ataxia - (walk as if drunk, staggering)
- difficult performing heel-shin test
Flocculonodular Lobe Syndrome?
- lesion to flocculonodular lobe and posterior vermis
most commonly caused medulloblastomas in young children

loss of control of axial muscles
(truncal ataxia)
- difficulty walking (wide-based gait with swaying trunk)

- difficulty sitting or standing in severe cases
what does the cerebellum do?
The cerebellum is involved in a feedback loop for muscle movement. When the cortex sends a message for motor movement to the lower motor neurons in the brain stem and spinal cord it also sends a copy of this message to the cerebellum.This is conveyed from pyramidal fibers in the cortex on the corticopontinecerebeller tract to the cerebellum. In addition, information gets to the cerebellum from muscle spindles, joints and tendons. This information (proprioception and kinesthesia) lets the cerebellum know about the movements that have been executed, so that it can determine how well motor commands coming from the cortex are being carried out. This has been called its comparator function.

The cerebellum plays a major role in the coordination of muscle activity for the production of smooth movement through its connections with the pyramidal and extrapyramidal systems and the descending reticular formation .Due to its role in the coordination of fine motor movements the cerebellum makes important contributions to the control of rapid, alternating muscle movements necessary for speech.
the role of each of the peduncles?
The superior cerebellar peduncle (aka the superior brachium conjunctivum) connects the cerebellum to the midbrain and contains efferent fibers from the deep nuclei. These are the axons that send feedback to the motor cortex in the frontal lobe via the red nucleus in the midbrain and the thalamus.

The middle cerebellar peduncle or the middle brachium pontis is the largest of the peduncles and links the cerebellum with the pons. Via this connection, the cerebellum receives a copy of the information for muscle movement that the pyramidal tract is carrying down to lower motor neurons.

The inferior cerebellar peduncle (aka restiform bodies) connects the cerebellum with the medulla, but also to the vestibular nuclei located in the lower pons and medulla and with cells of the reticular formation.
what's the feedback loop for motor movement?
Precentral gyrus --> pontine nuclei -- > cerebellum -- > (after input from muscles innervated by lower motor neurons, and comparisons made by the cerebellum between output from the cortex and input from muscles) --> red nuclei --> thalamus --> precentral gyrus where adjustments are made.
name all the components of the basal ganglia in the telencephalon, diencephalon, and mesencephalon?
caudate nucleus
nucleus accumbens
globus pallidus

subthalamic nucleus

Mesencephalon (midbrain)
substantia nigra
pars reticulata
pars compacta
what's the function of the basal ganglia?
Play an important role in
- initiating and controlling voluntary movements
forming motor habits - “Chunking”
instrumental learning

Action selection
choosing one action from all the possible, mutually-exclusive options (cannot run and sit at the same time)

Group together repeated movements so that you can get to more and more complex behavior
Hard-wire a series of movements together, so it is easier to perform them together without having to think of each next step

Instrumental learning
operational = procedural = reinforcement
Individual makes action first, and then learns/associates the consequences
Like the idea of classical conditioning from psychology, but with an action, instead Pavlovian bell-ringing.
CLINICALLY, the basal ganglia is referred to as the ‘______system because they modulate the pyramidal (or corticospinal) system.
projections of each part of the substantia nigra?
Pars compacta
SNc -->striatum = nigrostriatal tract

Pars reticularis

Pedunculopontine nucleus (in reticular formation at ponto-mesencephalic jxn)
Superior colliculus (saccades)
Multiple Parallel Circuit Loops connect BG to ____

what are these pathways? (3)

SKELETOMOTOR loop: control facial, limb, trunk musculature (Putamen)

PREFRONTAL loop: influence motivation and strategic planning of behavior; to prefrontal area (Caudate Nucleus)

ANTERIOR CINGULATE/LIMBIC loop: emotionality, motivated-behavior; to anterior cingulate gyrus (Nucleus accumbens)
The striatal _______decides which action/thought/emotion to release from inhibitory clamp

Constitute 98% of the striatal neurons
medium spiny neuron
why does the internal capsule look striped?
You know how the internal capsule looks striped?
Links between caudate and putamen:
Striatal cell bridges

Developmentally, the striatum is one, and axons course to-from the cortex incompletely divide the striatum
although dopamine can be either excitatory/inhibitory depending on the receptor, overall effect of dopamine is to _____ inhibitory output of BG: so promotes movement
Output of the BG is like cerebellar cortex: It is INHIBITORY/EXCITATORY
what's the NT used by medium spiny neurons in the striatum?
what NT is used by corticostriatal neurons: input to BG
what NT is used by local neuronal circuits within the striatum

Facilitating the ___ loop

Inhibiting the ____ loop
direct loop (which reduces inhibition of what you WANT TO DO)
indirect loop (which increases inhibition of what you don't want to do !)

so overall, dopamine reduces inhibition...promotes movement
hyperkinetic disorder (of basal ganglia) results from an _____of output to the thalamus

hypotkinetic disorder; _____ of output to the thalamus

A.  Intention tremor, or a tremor that appears when a patient makes a voluntary movement, is caused by damage to the _______ that is ipsilateral/contralateral to the limb.
lateral cerebellar hemisphere

Parkinson's disease symptoms are caused by a loss of ___neurons in the substantia nigra pars ______that project to the striatum.

Huntington's disease involves degeneration of neurons in several areas of the brain, it is in the _____ that this degeneration is particularly severe.


caudate nucleus
The___ and ____are involved in coordinating posture and gait; damage to these areas will result in leg ataxia even when the patient is neither walking nor standing

The flocculonodular lobe is connected mainly with the _____ nuclei, and is involved in balance and equilibrium.  Damage to this area results in posture and gait impairment, but does not result in limb ataxia when a patient is lying down.
vermis and paravermis

A unilateral flailing arm and leg, known as hemiballismus, results from unilateral damage to a ______.  As this nucleus is functionally related to the ____motor cortex (which controls the contralateral side of the body), the deficit is seen in the _____ limb. Hemiballismus, which can result from damage to the subthalamic nucleus, is thought to be accompanied by insufficient inhibitory activity of the globus pallidus internus on the thalamus. 
subthalamic nucleus


Overshooting or undershooting targets that one is reaching for is called ____.  It is one of the manifestations of damage to the lateral cerebellar hemispheres (and would affect limbs ipsilateral to the damage)
Parkinsonian symptoms are thought to be accompanied by overly strong inhibition of the thalamus by the ______ (often due to a lack of dopaminergic stimulation earlier in the basal ganglia pathway). 
globus pallidus internus

Careful ablation of parts of the globus pallidus internus (as well as to the VA/VL thalamic nuclei) has been found to partially ameliorate symptoms of both of these disorders, perhaps by correcting the inappropriate levels of thalamic inhibition.
One of the pathways that
conveys information from
GP(internal) to motor thalamus is
the _____

In addition to the ansa
lenticularis (often called the
jug handle), information from
the more caudal part of globus
pallidus can also reach the VA/
VL via the ___

While en
route to the thalamus, the ansa
and lenticular fasciculus fibers
join other (e.g.,
cerebellothalamic) fibers that
are also headed for VA/VL. This combined bundle is obvious in fiber stained sections and is called
ansa lenticularis

lenticular fasciculus.

thalamic fasciculus.

AL + LF = TF
Thus, the basal ganglia affect
function mediated by the ipsilateral
motor cortex. Since motor cortex
controls the movements of the
contralateral body....
Basal ganglia
circuits affect
movements of the
There is a
population of cholinergic (ACh) neurons in the striatum whose axons do not leave the striatum
(called interneurons or local circuit neurons). These cholinergic interneurons synapse on the
GABAergic striatal neurons that project to GP(internal) AND on the striatal neurons that project to
GP(external). The cholinergic actions INHIBIT striatal cells of the Direct pathway and EXCITE
striatal cells of the Indirect pathway. Thus the effects of ACh are OPPOSITE the effects of
dopamine on the direct and indirect pathways so the ACh effects on motor activity are opposite those
of dopamine.
what's the most well known hypokinetic syndrome?
Parkinson’s disease,
One of the pathways that
conveys information from
GP(internal) to motor thalamus is
the _____

In addition to the ansa
lenticularis (often called the
jug handle), information from
the more caudal part of globus
pallidus can also reach the VA/
VL via the ___

While en
route to the thalamus, the ansa
and lenticular fasciculus fibers
join other (e.g.,
cerebellothalamic) fibers that
are also headed for VA/VL. This combined bundle is obvious in fiber stained sections and is called
ansa lenticularis

lenticular fasciculus.

thalamic fasciculus.

AL + LF = TF
Thus, the basal ganglia affect
function mediated by the ipsilateral
motor cortex. Since motor cortex
controls the movements of the
contralateral body....
Basal ganglia
circuits affect
movements of the
There is a
population of cholinergic (ACh) neurons in the striatum whose axons do not leave the striatum
(called interneurons or local circuit neurons). These cholinergic interneurons synapse on the
GABAergic striatal neurons that project to GP(internal) AND on the striatal neurons that project to
GP(external). The cholinergic actions INHIBIT striatal cells of the Direct pathway and EXCITE
striatal cells of the Indirect pathway. Thus the effects of ACh are OPPOSITE the effects of
dopamine on the direct and indirect pathways so the ACh effects on motor activity are opposite those
of dopamine.
ACh ____ striatal cells in the direct loop
ACh _____ striatal cells in the indirect loop

DA _____ striatal cells in the direct loop via D1 receptors
DA ______ striatal cells in the indirect loop via D2 receptors

what's the most well known hypokinetic syndrome?
Parkinson’s disease,
In Parkinson’s disease, rigidity is present in all muscle groups, both flexor and extensor, so
that the resistance to passive movement is intense and consistent through the entire range of motion,
so-called lead-pipe______
dopaminergic neurons
in substantia nigra pars compacta are lost in
Parkinson’s disease. The degenerating nigral
dopaminergic cells accumulate deposits of
protein called _________
Lewy Bodies.
Huntington’s disease
Chorea (quick uncontrolled movements), athetosis (slow writhing), poorly coordinated eye movements, cognitive changes (memory loss, personality changes, psychosis)
Degeneration of GABA neurons, mainly in _____ → loss of thalamic inhibition → increased thalamic output, unwanted movements
caudate nucleus
what are the 3 main parallel loops?
with which part of the striatum & cortical areas are they associated with?
function of each?

each passes through a specific part of the striatum and is connected to a specific cortical area
all of the inputs to cerebellar cortex are mossy fibers, except for the inputs from the ______ in the _____; those are the climbing fibers
inferior olivary complex

inferior peduncle
Each cerebellar hemisphere gets info from the______cerebral hemisphere, thalamus, and pontine nuclei, and is thus dealing with the ______ side of the body

inferior peduncle gets input from:

spinal cord
trigeminal nucleus
inferior olivary nucleus
reticular formation
Granule cells are the _____between mossy fibers and Purkinje cells; they send out long synapses called parallel fibers that synapse on many Purkinjes
(granule cells are also the only excitatory interneuron in cerebellar cortex)
Upper motor neuron
Think, “a loss of inhibition from above”
So, increased tone, spasticity, and reflexes, and positive Babinksi
But also: pyramidal pattern weakness: results in flexed arms (weaker extensors), stretched legs (weaker flexors)

Lower motor neuron
Think, “no input to the muscle”
So, decreased tone and reflexes, no Babinksi sign, atrophy, and weakness that can be proximal, distal, or everywhere
But also: fasciculations
twisting of body parts, often into relatively fixed positions (lack of coordination of opposing flexors and extensors)
lack of coordination
slow, writhing movements

writhe: to twist so as to distort

Chorea – jerky, dance-like movements
which CN nuclei are associated with the corticobulbar tract?

Bilateral innervation (slightly stronger from contralateral side) Except lower facial nucleus only gets contra
how does blood travel to spinal cord?
2 small posterior spinal arteries, one BIG anterior spinal artery
name spinal nerve responsible for:
-abduction of arm
-flexion of elbow
-flexion of digits
-abduction /adduction of digits:
-abduction of arm: C5 (axillary nerve innervated deltoid)
-flexion of elbow: C(5)6
-flexion of digits: C8
-abduction /adduction of digits: T1
what's the bicipital reflex?
Tests musculocutaneous n. and C5,C6 spinal nerves

bicipital: having two heads or points of origin as a biceps

A reflex test that examines the function of the C5 reflex arc and to a lesser degree the C6 reflex arc. The test is performed by using of a tendon hammer to quickly depress the biceps brachii tendon as it passes through the cubital fossa. Specifically, the test activates the stretch receptors inside the biceps brachii muscle which communicates mainly with the C5 spinal nerve and partially with the C6 spinal nerve to induce a reflex contraction of the biceps muscle and jerk of the forearm.
List the nerves responsible for the myotomes:

- Flexion of Hip =
- Extension of Knee =
- Flexion of Knee =
- Plantarflexion of Ankle =
- Flexion of Hip = L1, L2
- Extension of Knee = L3, L4
- Flexion of Knee = L5 - S2
- Plantarflexion of Ankle = S1, S2
what's the nn controlloing the following reflexes?

- Patellar tendon =
(knee extends)
- Calcaneal tendon =
(ankle plantarflexes)
- Patellar tendon = (L2), L3, L4
(knee extends)
- Calcaneal tendon = S1, S2
(ankle plantarflexes)
Cells of the neural plate give rise to most of the spinal cord except _________ which comes from ________
dorsal root neurons
(neural crest)
Alar plate -
Basal plate -
Floor and roof plates -
posterior (dorsal) horn
anterior (ventral) horn
ependymal cells
The spinal cord is stabilized within the dura mater by the connecting _______which extend from the enveloping _____mater laterally between the dorsal and ventral roots.
denticulate ligaments

pia mater
the dural sac of the spinal cord ends at
6–8 motor nerve rootlets branch out of right and left _______sulci in a very orderly manner. Nerve rootlets combine to form nerve _____
ventro lateral

sensory nerve rootlets form off right and left _____ sulci and form sensory nerve roots.

The ventral (motor) and dorsal (sensory) roots combine to form spinal nerves(mixed; motor and sensory), one on each side of the spinal cord.
dorsal lateral
________is the terminal end of the spinal cord. It occurs near lumbar nerves 1 (L1) and 2 (L2).
conus medullaris
1. Conus medullaris
2. Filum terminale
3. Cauda equina
name the spinal cord levels and how many nerves are in each
C8, T12, L5, S5, C1 (coccygeal)
conus medullaris is in the L1-L2 interspace and the ________ is at S2
dural sac
Also, because the spinal cord stops growing in infancy while the bones of the spine continue growing, the spinal cord in infants ends at about the level of the vertebra
cervical-sacral = preganglionic parasympathetics

thoraco-lumbar (T1 - L2/3)= preganglionic _______
he gray matter 'butterfly' is organized into laminar sheets of neurons, called _____________ laminae
there are 10 Rexed's laminae, and first 6 belong to the dorsal horn,
the 7th is in the 'intermediate zone' and the lower 3 belong to the ventral horn.

I-VI: Posterior/dorsal horn
Lamina I: posteromarginal nucleus (called the 'Marginal zone' because it delineates the gray matter from the white matter of Lissauer's tract)

Laminae II/III: together, called 'substantia gelatinosa'

Laminae III/IV/V: nucleus proprius

Lamina VI: nucleus dorsalis

VII-IX: Anterior/ventral horn

Lamina VII: intermediolateral nucleus

Lamina VIII: motor interneurons

Lamina IX: motor nuclei are here

Lamina X: neurons surrounding the central canal
Unlike in the skull where the dura is attached to the bone, in the spinal column, there is space between the dura mater and vertebrae: ___________
epidural space
Motor nuclei have both ____and ____ motor neurons
- ____ motor neurons control skeletal muscles
- ______ motor neurons “tune” muscle spindle receptors

Motor nuclei are regionally clustered
- Nuclei for proximal muscles located ______
- Nuclei for distal muscles located ________

components of the posterior horn?
lissauer's tract
substantia gelatinosa
Clarke's nucleus
Lissauer’s tract
- lightly myelinated and unmyelinated fibers
- project to _____
substantia gelatinosa
lateral horn is from___ to ___

and contains ____
T1 to L3

presynaptic sympathetic motor neurons
Sympathetic second neuron cell bodies are in ganglia not associated with target organ.

Skin and thoracic viscera: cell bodies in paravertebral ganglia of the sympathetic trunk.
Abdominopelvic viscera: cell bodies in prevertebral ganglia.

They are the site of relay of the postganglionic sympathetic fibres that supply abdominal and pelvic viscera.


These include the celiac ganglia (which can include the aorticorenal ganglion), superior mesenteric ganglia, and inferior mesenteric ganglia.

Only the cervical ganglia have specific names. They are arranged thus:
* cervical ganglia - 3 ganglia
* thoracic ganglia - 12 ganglia
* lumbar ganglia - 5 ganglia
* sacral ganglia - 4 ganglia
Outside head, parasympathetic second neuron cell bodies are in ganglia not associated with target organs.
- interconnect neurons at different spinal cord levels
- important in coordinating reflexes
Propriospinal fibers
components of arterial circulation in the brain?
circle of willis and branches


meningeal aa (from maxillary, which is from ext carotid)
axillary nerve damage can cause what to do the deltoid?
what sensory loss can you get from axillary damage?
- loss of sensation on lateral shoulder (Regiment's patch!!)
- superior lateral cutaneous n. of arm
list the 4 common causes of axillary nerve damage?
Common causes of damage
- Fracture of surgical neck of humerus
- Dislocation of glenohumeral joint
Improper use of crutches
- Intramuscular injections
what can happen to deltoid muscle with axillary nerve damage?
paralysis or atrophy