neuro 2 midterm Flashcards
CN 1
terminates in
olfactory bulb
CN 1
fibers
SSA
CN 2
terminates in
hypothalamus
CN 2
fibers
SSA
CN 3
innervates
sup/med/inf rectus and inf oblique
CN 3
fibers
GVE & GSE
CN 4
innervates
superior oblique
CN 4
special
right controls left muscle and vice versa
CN 4
fibers
GSE
Mesencephalic nerves
CN 3 & 4
Metencephalic nerves
CN 5, 6, 7, 8
Mylencephalic nerves
CN 9, 10, 11, 12
CN 5
sensory ganglion
semilunar
CN 5
fibers
GSA & SVE
CN 6
innervates
lateral rectus
CN 6
fibers
GSE
CN 7
from & sensory ganglion
facial nucleus (pons) geniculate ganglion
CN 7
fibers
GVE & SVA & SVE
CN 8
2 nerves
vestibular & cochlear
CN 8
cell bodies
bipolar
CN 8
fibers
SSA
CN 8 # of vestibular ganglia
2
CN 8 # of cochlear ganglia
1
CN 9
from & innervates
inferior salivatory nucleus
parotid gland
CN 9
fibers
GVE & SVA
CN 10
from
dorsal motor nucleus of 10 to guts
nucleus ambiguus to heart
CN 10
temporarily joined by
cranial portion of CN 11
CN 10 fibers
GVE + SVA + GVA
CN 11
divisions and destinations
cranial—-pharynx, larynx, upper esophagus
spinal—– trapezius, SCM
CN 11
cranial part AKA after union with ten
recurrent laryngeal
CN 11
origin of divisions
cranial—-nucleus ambiguus
spinal—-laminae 9 of C1-4
CN 12
from and destination
hypoglossal nucleus
tongue
CN 12
fibers
GSE
CN 9, 10, 11
exit from
jugular foreamen
Does CN 1 have any ganglion cells?
no
HOw many axons per side does CN 1 contain?
5 million
How many axons does CN 2 have per side?
900k-1.2 million
How many axons does CN 8 have per side?
70k
Semilunar ganglion AKA
gasser/ trigeminal
Sup vestibular + inf vestibular AKA
ganglion of Scarpa
CN 9 superior ganglion AKA
jugular
CN 9 inferior ganglion AKA
petrosal
CN 10 superior ganglion
jugular
CN 10 inferior ganglion AKA
nodose
CN 8 cochlear ganglion AKA
spiral
decussation
crossing over of axons up and down
commissure
crossing over of axons left to right
Corticospinal tract
AKA
pyramidal
Corticospinal tract
axons per side
1 million
Corticospinal tract
axons are from
pyramidal cells
Corticospinal tract
axons clump together to form
medullary pyramid
Corticospinal tract
criss-cross before spinal cord
pyramidal decussation
DCs name and meaning of DC
name-fasiculus gracilis and cuneatus
meaning- dorsal columns
fasiculus is a group of axons between a _________ and a _______ (in terms of compactness)
bundle and tract
DCNs name and meaning of DCN
name- nuclei gracilis and cuneatus
meaning- Dorsal Column Nuclei
DCNs
what terminates and synapses
the DCs
nucleus of tractus solitarius
divisions (general)
superior
middle
inferior
Inferior olive
cell bodies
(gray matter)
Inferior olive
afferents
1 ML
2 Spinal olivary tract
3 Trigeminal-Olivary tract
Inferior olive
efferents
- olivocerebeller tract
Inferior olive
surrounded by
amiculum oliva
Inferior olive
ML sensation sensed
discrimination touch
pressure
proprioception
FROM BODY
Inferior olive
Spinal-olivary tract
brings in what sensation
pain
temperature
light touch
FROM BODY
Inferior olive
trigeminal-olivary tract
all types of reception
FROM FACE
Inferior olive
olivocerebellar tract
travels via
inferior cerebellar pedunkle
Inferior olive
is a _______ ______ _______ to the cerebellum
somatic sensory relay
What are the cell bodies of the DCs?
the DRG of C1-T6
Where do the DCs occupy?
dorsal funiculus
Fasiculus gracilis
shape
slender, and medial
Fasiculus cuneatus
shape
wedge, more lateral w/ more axons
What do the DCs become superiorly?
DCNs
What do the DCNs become superiorly?
Medial Lemniscus
Where are the DCNs found?
inferior medulla
Where does the ML descussation happen?
midline inferior to inferior olive
nucleus of tractus solitarius
gustatory nucleus location and afferents
superior
1 geniculate
2 petrosal
3 nodose
nucleus of tractus solitarius
gustatory nucleus fibers
SVA
nucleus of tractus solitarius
middle part contents (nuclei)
dorsal respiratory nucleus
baroreceptor nucleus
nucleus of tractus solitarius
what fibers enter the middle part and continue to the dorsal respiratory nucleus?
GVA parasympathetic fibers from the carotid bodies (CN 9) petrosal ganglion
GVA parasympathetic fibers from the Aortic Bodies (CN 10) nodose ganglion
2 major centers of respiratory control not in tractus solitarius
- Nucleus parabrachialis (pons)
2. Pre-Boetzinger complex (medulla)
Nucleus parabrachialis is the
pneumotaxic center
sets interval between inhalation and exhalation
Pre-Boetzinger complex is the
respiratory pattern generator
neurons of phrenic nucleus (lamina 9 of C3-C5) causes contraction of diaphragm
nucleus of tractus solitarius
baroreceptors
Carotid sinus
aortic sinus
nucleus of tractus solitarius
Carotid sinus and aortic sinus fibers
GVA parasympathetic
nucleus of tractus solitarius
Carotid sinus axon destination
petrosal ganglion——->baroreceptor nucleus
nucleus of tractus solitarius
aortic sinus destination
nodose ganglion—–>baroreceptor nucleus
How does BP increase along this pathway?
GVE fibers from solitaryspinal tract to reach T1-L2 lateral horns—–>3 cervical sympathetic ganglia——>to heart
nucleus of tractus solitarius
visceral nucleus
location
inferior
nucleus of tractus solitarius
visceral nucleus
fibers from where?
GVA from guts/ organs
touch, pressure, distension, chemicals
nucleus of tractus solitarius
visceral nucleus
what detects the distension signal from the guts?
CN 10
GVE fibers from dorsal motor nucleus of 10 to induce motility and secretions
the core of the brainstem =
reticular formation
what is the RAS?
the areas of the reticular formation that are provoked to keep you awake
dorsal motor nucleus of 10
sends ___ fibers to all viscera up to the _____ _______ ______ except the heart
GVE
left colic flexure
dorsal motor nucleus of 10
uses what kind of ganglion?
intramural
Nucleus Ambiguus
rostral portion
fibers and destinations
SVE-CN 9——->stylopharyngeus
GVE-CN 10——->heart
Nucleus Ambiguus
caudal portion
fibers and destination
SVE-CN 11 cranial division——->larynx/pharynx/upper esophagus
Nucleus Ambiguus
central region
origin of fibers
oropharynx
CN 5, 9, 10
Hypoglossal nucleus
fibers/destination
GSE—–>muscles of the tongue
How many vestibular nuclei?
4
What fibers do the vestibular nuclei recieve?
SSA from vestibular apparatus
What is the vestibular apparatus?
utricle +saccule +semicircular canals (3)= bony labrynth
What happens in the vestibular apparatus?
fluid moves around and moves hair cells, this is detected as “head position in space”
How many vestibular ganglia?
2
superior & inferior (Scarpa)
bipolar cells
How many cochlear nuclei?
3
What fibers do the cochlear nuclei recieve?
SSA from spiral ganglion (bipolar cells)
How many times do each of the 70k axons terminate in the cochlear nuclei?
3 (1 time in each nucleus)
Does the ventral cochlear nuclei have two parts?
yes, anterior and posterior parts
The facial nerve sends what fibers to the muscles of facial expression?
SVE
What do the axons from the facial nucleus loop around? What does this form?
- abducens nucleus
2. genu of 7
CN 6 sends what fibers where?
GSE to lateral rectus
What is the largest CN?
5 trigeminal
What are the nuclei of CN 5?
- Mesencephalic
- principal (main) sensory nucleus of 5
- motor nucleus of 5
- spinal nucleus of 5
What is special about the mesencephalic nucleus of 5?
only nucleus in the brain with psudounipolar cells
What does the mesencephalic nucleus of 5 recieve (sensation)?
muscle stretch from jaw
What does the main nucleus of 5 detect?
touch (all kinds) + pressure from the face
What does the motor nucleus of 5 detect?
proprioception from V3 (muscle stretch from the jaw)
Where are the psuedounipolar cells for the motor nucleus of 5?
the mesencephalic nucleus of 5 (psuedounipolar cells)
Where do the fibers from the motor nucleus go?
masseter (SVE) myotatic reflex
The spinal tract of of 5 runs next to what?
spinal nucleus of 5
What does the spinal nucleus of 5 receive?
sensory (GSA)
pain, temp, crude touch from face
What brings in the signals to spinal nucleus of 5?
spinal tract of 5 (trigeminal tract)
What are the three parts of the spinal nucleus?
- pars oralis
- pars interpolaris
- pars caudalus
What parts of the spinal nucleus are part of the cornea blink relex?
- interpolaris
2. caudalis
T or F
does the trigeminal tract run the distance of the medulla?
T
Where does the trigeminal tract end inferiorly?
lamina 2 (S. gelatinosa)
What does the spinal tract carries what sensations?
pain, temperature, crude touch
What nucleus of 5 does not send axons to higher stations in the brain?
spinal nucleus
What are the four types of reflexes?
- somatosomatic - muscle stretch
- somatovisceral- cornea- blink reflex
- viscerovisceral- stomach distension/ contraction
- viscerosomatic- stomachache/ rectus abdominus contraction
What is the cornea blink reflex?
touch the cornea—>pars interpolaris & pars caudalis—–>blinking of both eyes
Where is the peduculopontine nucleus found?
Upper pons
What is the PPN part of?
the ascending chemical pathways of the brainstem
The PPN sends axons where?
neocortex/ limbic system
The PPN regulates what?
cortical activity and REM sleep
The PPN releases what neurotransmitter?
ACh
The locus ceruleus releases what neurotransmitter?
NE
The dorsal raphe releases what neurotransmitter?
serotonin
Where are the locus ceruleus and dorsal raphe both visible in cross section?
pontomesencephalic junction
What is the core of the reticular formation known as?
central gray (when in pons or medulla)
What is the narrow waistline at the pontomesencephalic junction known as?
isthmus
What is the nucleus in the most ventral part of the midbrain at the midline?
interpeduncular nucleus
The locus ceruleus and dorsal raphe are involved in? And are involved in these processes
- ascending chemical pathway of the brainstem
2. wakefulness & mood
How many raphe are there?
7
What neurotransmitter do all the raphe secrete?
serotonin
The inferior raphe are named what?
- pallidus
- magnus
- obscurus
(collectively raphespinal tracts)
What do the raphespinal tracts do?
pain-gating
The raphespinal tract terminates in
lamina 2 (S. gelatinosa)
The superior raphe are named
- dorasal raphe
2. pontis
In the same location as the PPN (upper pons) the _______ at the midbrain IC level and the _______ in the midbrain at SC?
- trochlear nucleus
2. oculomotor complex
The red nucleus contains high what?
iron
The red nucleus is directly ventral to what structure?
cerebral aquaduct
The red nucleus has what two parts?
- pars parvicellularis
2. pars magnocellularis
The pars magnocellularis sends axons to spinal cord via?
rubrospinal tract
Substantis nigra has what two parts?
- compacta
2. reticularis
What is the extension of pars compacta known as?
ventral tegmental area
The VTA and pars compacta are part of what pathway?
ascending chemical pathway of the brainstem
What type of neurotransmitter do the pars compacta and VTA secrete?
dopamine (dopenergic)
The mesocortical pathway goes from where to where?
VTA—->neocortex
The mesolimbic pathway goes from where to where?
VTA—->limbic system (especially nuclesu acumbins)
Dopamine is involved in
reward/pleasure
Stimulation of the VTA will flood what nucleus with dopamine?
acumbens
Pars compacta sends axons to ______ _______ in the telencephalon
corpus striatum
The pathway from the pars compacta to the corpus striatum is called
nigrastriatum pathway
the nigrastiatum pathway is involved in
motor function
How many degrees does the vision field overlap?
120
Why do humans have 50% crossing of the optic tract axons?
The axons from the temporal retina do not cross at the chiasm
What are the five places the optic tract terminate?
- Accessory optic nuclei
- Superior colliculus
- Suprachiasmatic nucleus
- Lateral Geniculate nucleus
- pre-tectal nucleus
All the signals going to the primary visual cortex must stop where?
LG (thalamus)
Optic tract axons terminating in the SC go to
striatum cinerum
The superficial layers of the SC send axons to
the LG—–>area 17
The deeper layers send axons to
the pulvinar nucleus (thalamus)—–>secondary visual cortex (areas 18,19)
The superchiasmatic nucleus is in the
hypothalamus
Signals from the optic tract that reach the SC nucleus eventually go to after first hitting these two stops?
terminate—-pineal gland
pass through—–lat horn T1-T2 & superior cervical ganglion
SC nucleus AKA
entrainer of internal clock
The pre-tectal nucleus is found where?
small area between the midbrain and diencephalon
The pre-tectal nucleus sends
parasympathetic signals to EW nucleus—–>ciliary ganglion—–>constrictor pupilla
The pre-tectal nucleus is involved in what reflex?
pupillary light reflex
The left and right pre-tectal nuclei are connected where?
posterior commissure
The pupillary light reflex is what kind of reflex?
somatovisceral
The pupillary light reflex has what 2 parts?
- direct reflex—–pupil + light = constrict
2. consensual reflex—-opposite pupil constricts due to commissure connection
The three most superficial layers of the Superior Colliculus are
striatum zonale
striatum cinerum
striatum opticum
The striatum cinerum is made of what and sends signals where?
cell bodies (gray matter) sends signals to deep layers
the striatum opticum is made of what and recieves axons from where?
- axons
2. axons from optic tract pass through here and synapse in cinerum
What are the middle and deep layers of the superior colliculus called collectively? These layers are highly ________
- strata lemnisci
2. integrative
What layers make up the strata lemnisci? what color is each one?
- Straiatum giseum medium (gray)
- Striatum album medium (white)
- Straiatum giseum profundum (gray)
- Striatum album profunda (white)
What are the superificial afferents to the SC?
- Optic tract
- Area 17 (corticotecal tract)
- Area 8 (voluntary eye movement)
What is the corticotecal tract?
The tract from area 17 to the superior colliculus
tecal=
SC
cortical=
neocortex
What are the afferents to the deeper layers of the SC?
- Striatum cinerum
- IC
- ML
- spinotecal tract
- trigeminal tract
- cerebellum & substanti nigra
the cerebellum and substantia nigra are involved in
motor function
the spinaltecal tract carries what
pain + temp from the body
Where is the pulvinar located?
thalamus
What creates the dorsal tegmental decussation?
tectospinal tract
What are the superficial efferents from the SC?
2 tectothalamic tracts
- Superficial layers—>LG—>area 17
- Superficial layers—->pulvinar—–>araes 18,19
What are the efferents from the deep /lower layers of the SC?
- tectomesencephalic tract
2. tectospinal tract
Does the tectalspinal tract descend past the cervical region?
no
Where does the tectospinal tract end?
Lamina 9 of cervicals
Where does the tectomesencephalic tract go?
to nuclei of CN 3,4,6 to move extrinsic eye muscles
IS the tectomesocephalic tract considered voluntary?
no
the hypothalamus is roughly ______
motor
The hypothalamus is seperated from thalamus by
hypothalamic sulcus (from limitans)
The hypothalamus contains nuclei that perform _________ __________
vegetative function (eating, drinking, sexuality, aggression)
What are vegetative actions AKA
sham behavior
Is the lateral hypothalamus divided into parts?
no
What are the two nuclei in the lateral hypothalmus?
- lateral hypothalamic nucleus
2. tuberomamillary nucleus
The medial hypothalamus is divided into how many parts? What are their names?
3 parts
- anterior hypothalamus
- tuberal hypothalamus
- posterior hypothalamus
The anterior hypothalamus has how many nuclei? what are their names?
4 nuclei
1. pre-optic nucleus (Pr)
2. supraoptic nucleus (SO)
3. suprachiasmatic nucleus (SC)
do not confuse with superior colliculus
4. paraventricular nucleus (PVN)Is the Pr nucleus divided? where is it located?
yes (lateral, medial), in front of the optic tract
Where is the SO nucleus located?
directly over the optic tract
Where is the SC nucleus located?
dorsal to the optic chiasm
The afferents going to the SC nucleus are from where?
optic tract
Where is the PVN nucleus located?
next to the third ventricle
The tuberal region of the hypothalamus is directly over the _________ _________. It contains a bulge at the base of the pituitary stalk called the _______ _________.
- tuberum cinerum
2. median eminence
How many and what are the nuclei of the tuberal hypothalamus?
4 nuclei
- dorsomedial nuclei (DM of hypo)
- ventromedial nuclei (VM)
- arcuate nucleus of the hypothalamus
- tuberomamillary nucleus = (straddles part two and three)
The posterior hypothalamus is over what structure?
mammillary bodies
How many and what are the names of the posterior nuclei of the hypothalamus?
3 nuclei
- posterior nucleus of the hypothalamus
- mammillary bodies (medial and lateral)
- pre-mammillary nuclei
What are the pre-mammillary nuclei?
2 more swellings in front of the MBs
The PVN and So release what substance?
hormones
The PVN has what kinds of cells?
large and small
The axons from the PVN and SO nuclei make up what tract to the posterior pituitary gland?
hypothalamohypophyseal tract
The PVN large cells and So nuclei release what hormones?
vasopressin (ADH)
oxytocin
The cell bodies of the hypothalamohypophyseal tract are found in what?
PVN large cells and SO nuclei
Some axons from the hypothalamohypophyseal tract terminate where in the spinal cord?
lateral horn (T1-L2)
How do hormones regulate the sympathetic nervous system?
because of the hypothalamohypophyseal tract
What are the three sources of the hypothalamohypophyseal tract?
- PVN large cells
- SO nuclei
- lateral hypothalamus
What hormones do the PVN small cells release?
- thyroid releasing hormone (TRH)
2. corticotropin releasing hormone (CRH)
WHat does the Pre-Optic nucleus deal with?
sexual behavior
What is special about the Pre-Optic nucleus?
it contains three subnuclei that are sexually dimorphic
What does INAH stand for?
interstitial nuclei of the anterior hypothalamus
The pre-optic nucleus has the highest density of ____ receptors in the brain?
testosterone
When do pre-optic neurons fire the most?
during sexual arousal
When do pre-optic neurons fire least?
after ejaculation
How many more neurons do males have than females in the pre-optic nucleus?
2 times as many
How many more neurons do males have in the pre-optic nucleus than homosexual males?
2 times as many
The neurons in the bed of stria terminalis is equal in males/________ but _____ have half as many.
- homosexuals
2. females/transgender
What is the bed of stria terminalis?
- the connection between the anterior corpus collosum and the amygdala
- literally the closing of the anterior neurospore on day 24
The bed of stria terminalis plays a major role in _______ ________.
sexual behavior
The ventromedial nucleus (VM) has what 2 main function?
- sexual arousal/ activity in females
2. Acts as a feeding stop center—>satiety center
What is the feeding start center?
lateral hypothalamus
What are the three major hunger theories?
- glucostatic
- lipostatic
- thermostatci
What stimulates hunger in the lateral hypothalamus?
orexin
What other functions does the lateral hypothalamus have?
- reward circuitry
2. aggressive/violent behavior
The arcuate nucleus of the hypothalamus is from ________. Where does it send axons? What does it release?
- tuberal hypothalamus
- lateral hypothalamus & PVN
- neuropeptide Y (NPY)
What is leptin?
a hormone produced by fat cells to turn off the arcuate nucleus
CRH is produced by the ________.
Leptin causes _________ CRH release and thus ________cortisol production.
- small cells of the PVN
- CRH
- cortisol
Why does antihistamine cause drowsiness?
because histamine will be inhibited from being released
histamine does what
wakefulness
alertness
what releases histamine in the ascending chemical pathways of the brainstem?
tuberomammillary nucleus
