Nolte – Chapter 3 (Gross Anatomy and General Organization of the Central Nervous System and Peripheral Nervous System) and all Class-Notes and Lab-Notes tagged with Chapter 3
Navigate this page:
Peripheral Nervous System
Nolte – Chapter 3 (Gross Anatomy and General Organization of the Central Nervous System and Peripheral Nervous System) and all Class-Notes and Lab-Notes tagged with Chapter 3.
all throughout CNS
The cephalic flexure would spate the axes, but we keep the terminology as if it was the same.
Cephalic flexure visible at the junction between the brainstem and the diencephalon.
Splenium at posterior
Genu at anterior
Goes a bit ventral to the rostrum.
A particularly deep sulci is a fissure
Lobe and section markers
Anterior limit: None
Ventral Limit: Separated from the temporal lobe by the lateral sulcus (sylvian fissure)
Most ventral region is the orbital part.
Ventral Limit(Medial): On the medial surface extends to the cingulate sulcus (but doesn’t include)
Posterior Limit (Medial): imaginary continuation of the central sulcus to the cingulate.
Anterior Limit: Central Sulcus
Posterior Limit: Imaginary line connecting the top of the parieto occipital sulcus and the preoccipital notch.
Ventral Limit: as if the calcarine and sylvian connected.
Vental Limit(Medial): subparietal and calcarine sulci
Posterior limit (medial) parietooccipital sulcus.
Dorsal Limit: Sylvian Fissure extension to calcarine
Posterior Limit: line connecting
of the parietooccipital notch and the preoccipital notch.
Posterior Limit(Medial): imaginary line from preoccipital notch to the splenium.
Dorsal Limit (Medial): Collateral Sulcus.
Anterior Limit: parietal and temporal lobes on both medial and lateral and surface.
Encircles the telencephalon-diencephalon junction.
Interposed between corpus collosum and rest of cortical lobes.
operculum covers the insula
Made up of frontal, parietal and temporal.
Circular sulcus outlines the insula and marks it borders with the opercula.
Precentral and forward is motor.
Post central and back is sensory.
IFG is split into 3
Oribital(anterior), triangular(middle), opercular(posterior up to the precentral gyrus).
Brocas is in Orbital and triangular.
The medulla part of the frontal lob just medial to olfactory bulb
On the other side of the olfactory bulb(siting in its sulcus) st the orbital gyrus extension.
Superior parietal Lobule
Intraparietal sulcus runs from the postcentral gyrus to the parietooccipital sulcus to separate it from the inferior parietal lobule.
Inferior parietal lobule
Made up of supramarginal gyrus(anterior up to the postcentral gyrus) and angular gyrus(rest)
Supramarginal caps the lateral fissure.
Angular caps the superior temporal gyrus.
Back to the parietoccipital sulcus is the precuneus and bounded ventrally by the calcarine.
All that is left after precuneus is the posterior paracentral lobule.
These two are separated by the cingulate sulcus.
Superior Temporal gyrus
Primary auditory cortex
Wernicke’s area is the posterior most portion of this.
Wraps around in the anterior portion a bit to the medial
Fusiform is most dorsal
Separated by the occipitotemporal sulcus from the inferior temporal sulcus
ParietoOccippital and calcarine corner off the cuneus.
Just inferior to that calcarine sulcus is the lingual gyrus.
Most inferior is the fusiform gyrus
Lateral Side is all “lateral occipital gyri”
V1 is contained in the
walls of the calcarine sulcus
Rest of the lobe is “visual association”
Cingulate and parahippocampal
Cingulate is on top of diencephalon
After it hooks around the genu we see the subcollasal area cap off the cingulate gyrus.
Parahippocampal is below.
Anterior end that hooks back is the uncus.
Amygdala lies beneath the uncus and the hippocampus follows posteriorly.
Superior to it we see the hippocampal sulcus
Thalamus has the third ventricle as a roof(their meeting point is the stria medullaris)
The medial surfaces are fused by the massa intermedia
Hypothalamic sulcus seperates the thalamus from the more inferior hypothalamus.
Hypothalamus connectes with the pituitary by the infundibular stalk.
More inferior are the mammillary bodies.
SCN takes 10% of retinal input
Right on top of optic chiasm
On the dorsal side, right above the superior colliculi, we find the pineal gland.
The tectum goes over the cerebral aqueduct and is made up of the collulculi and the brachium of the inferior.
The cerebral peduncles
Rubrospinal tract starter
motor nuclei for cerebellum
Pontine tegmentum forms floor of the fourth ventricle.
Rostral open, caudal closed.
Medullary pyramids are just below the basal pons.
Decussate at region of medulla to the spinal cord.
Vermis – midline
Lateral hemisphere encapsulating it
Separated by the primary fissure.
Afferent inputs from spinal cord
Nodulus(vermal portion), flocculus(vestibulocochlear nerve)
Afferents from vestibular
Gets relay from pontine nuclei.
Coordination of voluntary movements.
Efferent fiber bundle: fornix
Folded into the termporal lobe forming part of the wall of the alteral ventricle.
Becomes smaller as the temporal lobe curves into the parietal lobe.
Ends near the splenium of the CC
Fornix ends in the mammillary bodies.
Putamen and globus pallidus
Head in frontal lobe
Body and tail that follow the lateral ventricle around into the temporal lobe
Sepearted from the lenticular by the internal capsule which interconnects cerebrum with basal ganglia
processes and thalamus
Relevant Cranial Nerves
II goes into the chiasm and becomes the tract
Only one that projects directly into the diencephalon(remember retina is actually part of diencephalon)
III emerges from the interpeduncular fossa between the cerebral peduncles.
This is just below the mammilarry bodies
The infundibulum is superior to mammillary bodies.
IV the only to emerge from the dorsal side
Just caudal to the inferior colliculi
V emerges from the lateral portion of the basal pons.
Thalamocortical fibers are uncrossed
Cerebellum is ipsilateral
Spinothalamic is pain-temperature
Cerebellar outputs return to the motor cortex and affect corticospinal activite (but go through thalamus)
Must cross midline before thalamus.
Basal ganglia also affect motor output this way.
They don’t receive sensory input as directly, though.
Layer IV receives sensory input
this layer is tiny
, then its probably not a sensory based cortex
Layer V is output (pyramidals)
Go down through the peduncles and medulla(decussate) and go down the spinal cord to contact primary motor neurons
This is the coricospinal tracts
Layer VI receives input from thalamus
Peripheral Nervous System
Peripheral nerves do not cross the midline
Go towards the CNS
Primary afferents in the dorsal root ganglia hug the spinal cord
These are psudounipolar
Fibers that go away
reside inside the gray matter
Sensory axons enter the dorsal root
But not limbo-sacral pain fibers
Motor axons exit via the ventral root
Organized web of fibers like a tree branch that get more and more focal as you get closer to innervations.
E.g: brachial plexus will cover everything in the arms.
Peripheral Nerves and Conduction
Ia are primary muscle spindle afferents
Ib are golgi tendon organ afferents
II are spindle secondaries
Meissner, merkel, etc.
III are free nerve endings for temperature and sharp pain
IV(c) are free nerve endings as well
Reception depends on intensity and duration
pacininian can absorb initial
energy and adapt quickly
, so vibration would be something that would get it to fire.
Receptor type depends on location and quality
Extrinsic mechanism can affect reception as well
bright light can be received but can also trigger a contraction of the pupil.
intrafusal and extrafusal efferents can made more and less sensitive.
Wrap around the axon in an engulfing fashion
also provide metabolic support
especially in dorsal root ganglia
they can make a type of matrix and rovide scaffolding for axonal growth after injury.
receptor organs that lie in parallel to our muscle fibers
tell us about the length of our muscle and the rate of change of this muscle
nuclear chain fibers and their flower outbranches respond primarily to length and will fire when the muscle is lengthened.
nuclear bag fibers with their annulospiral endings will to the rate of change
Gamma motor neurons will regulate the sensitivity to stretch when muscle is relaxed.
allows the nucleur bag to stay tense
Golgi tendon organs are between the muscle and tendon and will be activated by isometric contractions.
slow adapting, so they can keep up the maintenance.
Autonomic Nervous System
nerves that go to our viscera
all the efferents go through a ganglia
flight or fight
efferents comes out of ventral horn
B type fibers will synapse near the sympathetic ganglion with acetylcholine and then innervate with norepinephrine.
except for sweat glands which are cholinergic.
preganglionic can also innervate the adrenal medulla that then secretes norep.
the sympathetic ganglion are near the spinal cord
and primarily in thoracic and upper lumbar
can be interconnected to form a sympathetic chain.
travel from spinal cord to the sympathetic chain ganglion via the white communicating rami
Ganglion are closer to the vicera of interest
use acetylcholine on parasympathetic ganglia and the actual viscera.
mainly in sacral spinal
nerves and cranial nerves
none in the limbs
more focal in its control than the sympathetic.
There is always a stop at autonomic ganglia(post ganglionic)
the preganglionic has its cell body in the CNS and are thinly myelinated in route to the ganglia.
the actual postgalionic innervations are unmyelinated.
this is different from the somatic motor system where we just have the cell body in CNS whose axons go directly to skeletal muscle.
damage to a nerve causes willerian degeneration, where neurons distal to the cut will start to die and the axon will regress to the closest node of ranvier.
the schwann cells will remain, though, as scaffolding.
Collateral sprouting can occur from preserved tips f axons
they can follow the NGF given off by schwann cells and simultaneously grow through the schwann scaffolding.
dull aching (due to damage of neural tissue)
Free nerve endings release potassium and other chemical mediators
slow conduction(no myelinated)
A-delta Fibers III
incoming pain stimuli can be regulated because the incoming stimuli compete with sensory inputs and cortical modulations.
we rub periphery so that the signal can compete
touch will be faster than the slow transmitting c fibers, so we keep touching and rubbing to overpower the slow pain.
the area to which pain is referred correspond to the dermatome innervated by the spinal segment to which the visceral afferent project.
visceral afferent fibers accompany sympathetic efferents
subserve visceral reflexes and don’t really reach consciousness but can if it is enough or if the organ is inflamed.
2014 -> 13th June 2008 Athens Greece abstracts session I present Status of Dentistry as a Health Profession
2014 -> Patient information 25331 ih-10 West, Suite 207 San Antonio, tx 78257
2014 -> Letters to the Editors
2014 -> Community health centers
2014 -> Everyday Encounters with Oral Pathology: Review, Refresh, Discover
2014 -> Discussion on the contemporary management of tooth wear
2014 -> Dental release form
Share with your friends:
The database is protected by copyright ©dentisty.org 2019
Human head and neck