EXAM #3 Flashcards
Which nerves contain inflow/outflow of brain
Cranial nerves
Which nerves contain inflow/outflow of spinal cord?
Spinal nerves
What are functional components?
Neurons carrying similar modalities
What are functional columns?
Collectively functional components will form functional columns
Cranial nerve nuclei are:
Either sensory or motor but never both
T/F: There is a one-to-one correlation between cranial nerves and functional columns
False
T/F: A particular cranial nerve cannot carry several distinct functional modalities
False:
A particular cranial nerve can carry several distinct functional modalities
Somatic (S) =
types of neurons innnervating structures derived from somites (skin, skeletal m., carriage ect.)
Visceral (V) =
types of neurons innervating gut, structures derived from or associated with gut and branchial arches; also vascular system, smooth muscle, internal organs and glands
Efferent (E):
Motor neurons to skeletal and smooth muscle; Also secretomotor neurons to glands
Afferent (A):
Sensory neurons
What is General Somatic Afferent (GSA):
Carry pain, temperature and mehcanical information from receptors in the skin, muscles and joints
What is Visceral Afferent (GVA):
Carry info from receptors in visceral structures (pain/reflex)
What is General visceral efferent (GVE):
Preganglionic autonomic fibers
What is General somatic efferent (GSE):
Innervated skeeltal muscle (alpha and gamma motor neurons)
Which kind of nerves can carry special nerve fibers ie (SSA, SVA, SVE)?
Cranial nerves;
Spain nerves are only GSA, GVA, GVE, and GSE
What is Special Somatic Afferent (SSA):
Special sensors of vision, auditory sensation and vestibular apparatus
What is Special Visceral Afferent (SVA):
Chemical senses of taste and smell
What is Special Visceral Efferent (SVE):
Motor to voluntary muscles derived from branchial arches
- Facial expression
- Phonation
- Mastication
- Deglutition
Which CN are located in the Prosencephalon?
Telencephalon:
- CN I Olfactory
- Derived from embryonic nasal placode
Diencephalon:
- CN II Optic
- Neural tract of diencephalon: Considered an outgrowth of the CNS; Covered in all 3 meningeal layers
What CN are located in the Midbrain of the Brainsstem?
- CN III Oculomotor
- CN IV trochlear
What is the only CN that exits dorsally?
CN IV Trochlear
What CN are located in the Pons of the brain stem:
- CN V Trigeminal
- CN VI Abducens
- CN VII Facial
What CN are located in the medulla of the brain stem?
- CN VIII Vestibulocochlear
- CN IX Glossopharyngeal
- CN X Vagus
- CN XII hypoglossal
These will exit laterally of medulla
Have large trunks/roots
Located at pyramids of medulla
What CN is located on the spinal cord?
- CN XI Spinal Accessory
What makes the spinal accessory Nerve (XI) unique?
It has two parts:
- Cranial part: Arise from cells in nucleus ambiguous: Fibers emerge as 4-5 rootlets from side of medulla oblongata and will innervate pharyngeal muscles
- Spinal part: Arises from VH in sc C1-C5: Will innervate SCM and Trapezius
Which Motor nuclei are associated with the extra ocular m.?
(GSE: Somatic Motor)
- CN III: Located at Midbrain
- CN IV: Located at Midbrain
- CN VI: Located at Pons
Which Motor nuclei are associated with the trapezius and SCM?
(GSE: Somatic Motor)
- CN sXI: Located at cervical cord
*Note cranial part of accessory is higher up in medulla
What motor nuclei is associated with the tongue?
(GSE: Somatic Motor)
- CN XII: Located at Medulla
Which Motor nuclei will run with CN III:
(GVE: parasympathetic)
Edinger Westphal
Which motor nuclei will run with CN VII and IX:
(GVE: parasympathetic)
Salivatory Nuclei
Which motor nuclei will run with CN X?
(GVE: Parasympathetic)
Dorsal n. of X
Which motor nuclei are associated with the muscles of mastication?
(SVE: Branchiomotor)
- Motor n. of CN V
Which motor nuclei are associated the muscles of facial expression and platysma, post belly digastric and stylohyoid?
(SVE: Branchiomotor)
- Motor n. CN VII
Which motor nuclei are associated with the stylopharyngeus?
(SVE: Branchiomotor)
- CN IX
Which motor nuclei are associated with the nucleus ambiguous?
(SVE: Branchiomotor)
CN IX, X, cXI
Note: cXI leaves jugular foramen with CN X to pharynx so sometimes it is considered as part of PP (Motor)
Which sensory nuclei are associated with SSA (vision)?
- CN II: located up in diencephalon
Which sensory nuclei are associated with SSA (hearing and balance)?
- CN VIII vestibular
- CN VIII cochlear
Located at pons/medulla
What CN V is associated with GSA (Somatosensory). Where is it located and what are the functions of the associated nerves?
located from midbrain to all the way down in spinal cord
> Mesencephalic n. : proprioception for oral cavity
Main sensory n. : proprioception and discriminative touch
Spinal n. : Pain and touch
Other than CN V what other nerves are associated with GSA?
- CN VII: Uses spinal tract and n. of V: Info from external ear and tympanic membrane
- CN IX: uses spinal tract and n. of V: Info from post ear and post 1/3 tongue
- CN X: uses spinal tract and n. of V: Info from ext. ear
What nerves are associated with SVA?
- CN I: Olfaction
- CN VII, IX, X: Taste
- nucleus solitarius (rostral) is a series of nuclei that stretch through the medulla. It is located inside the tract of solitarius
What nerves are associated with GVA? (Pain or reflex)
- CN VII, IX, X
- Nucleus solitarius
CN VII: Palate and nasal cavity
CN IX: Chemoreceptors/carotid bodies, nasopharynx, oropharynx, middle ear
CN X: Chemoreceptors/carotid bodies, palate, pharynx, larynx
- Nucleus solitarius
T/F: Both GVA and SVA components use the same cranial n. (Except for CN I) and the same nucleus
True
What nerve(s) exits at the Cribiform plate?
CN I (Olfactory)
What nerve(s) exit at the optic canal?
CN II (Optic)
What nerve(s) exit at the Superior orbital Fissure?
CN III, IV, V1, VI
What nerve(s) exit at the Foramen rotundum?
V2
What nerve(s) exit at the Foramen Ovale?
V3
What nerve(s) exit at the Foramen lacerum?
No Cranial nerves
- greater petrosal nerve, which represents the pre-ganglionic parasympathetic fibers, and the deep petrosal nerve
What nerve(s) exit at the Foramen spinosum?
No Cranial nerves
-middle meningeal artery, middle meningeal vein, and the meningeal branch of the mandibular nerve
What nerve(s) exit at the Internal auditory meatus?
VII, VIII
What nerve(s) exit at the Jugular foramen?
IX, X, XI
What nerve(s) exit at the hypoglossal canal?
XII
What is the path of the Facial Nerve?
It arises from brainstem (pons), Runs through the facial canal (temporal bone) and will exit the stylomastoid foramen. After exiting it splits into terminal branches at the posterior edge of parotid gland.
What is the motor function of the facial nerve?
Muscles of facial expression + others
What is the parasympathetic function of the facial nerve?
Glands of oral cavity, nasal cavity, and lacrimal gland
What is the sympathetic function of the facial nerve?
Ant 2/3 of tongue, nasal cavity, palate and ear
SVE components of Facial nerve:
- M. of facial expression
- Post belly digastric
- Stylohyoid
- Stapedius
GVE (PS) of Facial nerve:
- Lacrimal gland
- Submandibular gland
- Sublingual gland
- Mucous membranes in nasopharynx and palate
GVA of Facial:
- Nasal cavity
- Soft Palate
SVA (taste) of Facial:
- Ant 2/3 tongue
- Hard and soft palate
GSA of Facial:
Skin (Behind ear and auditory tube)
What are the components of facial SVE?
Craniomotor:
CN VII, TZBMC
Components of facial GVE?
Greater petrosal
Chorda tympani
Components of facial SVA?
Chorda tympani
Components of facial GSA?
Posterior auricular (motor and sensory)
Components of facial GVA?
Greater petrosal (minor)
Where is the nuclei located for GSA of facial?
With the Spinal n. of V in the Geniculate ganglion.
IT provides somatic sensory, from outer ear.
Where is the nuclei located for SVA, GVA of facial?
With the solitary n. in the geniculate ganglion.
It provides visceral sensory, from taste buds on anterior two thirds of tongue, Visceral sensory from nasal cavity and palate.
The Superior salivatory n. is associated with:
SVE of the facial nerve which provides branchial motor to muscles of facial expression and stapedius.
- MULTIPOLAR NEURON
The motor nerve of VII is associated with:
GVE of the facial nerve which provides visceral motor to salivary, nasal, palatine, and lacrimal glands (Via submandibular and pterygopalatine ganglia)
- MULTIPOLAR NERUON
What is the Branchiomotor of the Facial n.?
SVE
- Voluntary movement of:
- M of facial expression
- Buccinator, platysma, occipitalis (post auricular)- Motor
- Post. Belly digastric
- Stylohyoid
- Stapedius
Where is the origin of the Motor n of CN VII?
Located in the Caudal pons
SVE fibers of the Facial N. will loop over:
Abducence motor nucleus
After SVE fibers of facial N. Loop over the abducence it bulges into:
Floor of 4th ventricle.
The SVE of facial nerve will exit along with:
Nervus intermedius (Intermediate nerve: Cranial nerve #7 without SVE fibers)
The SVE of facial nerve will eventually go to the:
Internal acoustic meatus
Nervous intermdius contains:
Sensory and parasympathetic fibers
^^^^^^^**(NO SVE)*****^^^^^^^^
The Nervous Intermedius is located:
between motor part of VII (SVE) and CN VIII
The rostra portion of the nucleus solitaries is associated with:
SVA of Nervous Intermeidus
The abducens nucleus is associated with:
CN VI- Somatic Motor
The spinal nucleus of the trigeminal nerve is associated with:
GSA (ear) of Nervous Intermedius
The Motor nucleus of CN VII is associated with:
SVE- Branchiomotor
The superior salivatory (lacrimal) nucleus is associated with:
GVE (Visceral motor/ parasympathetic) of the Nervous intermedius
What is the Intracranial course- SVE?
Emerges from pons and enters internal auditory meatus (along with CN VIII). It will pass thru the facial canal. The components separate at the geniculate ganglion. SVE fibers pass thru geniculate ganglion without synapsing. It will turn 90 degrees post-laterally and proceed inferiorly medial to middle ear. It will exit skull thru sylomastoid foramen. Note: Nerve to stapedius and chords tympani is given off before exiting.
The nerve to stylohyoid and post belly digastric are given off after exiting:
From stylomastoid foramen. Remainder enter parotid (TZBMC)
What is the function of the Visceral Motor- GVE (PS)
Stimulate secretions:
- Submandibular gland
- Sublingual gland
- Lacrimal gland
- Mucous membranes of nasopharynx and palate
Where are the cell bodies of the facial Visceral motor- GVE?
In superior salivatory Nucleus
Where do the cell bodies of facial GVE exit?
Exits pons as part of nervous intermedius. Does not loop around abducens
What is the Intracranial course (GVE) (PS):
Enter int auditory meatus along with CN VIII. Fibers will pass thru facial canal then divide at geniculate g. The Lacrimal nasal and palatine glands will split off the greater petrosal. The submandibular and sublingual glands will split off the chords tympani. Both of the above will carry GVE fibers to targets.
What are the ganglion for the Chords tympani?
Submandibular ganglion
What are the ganglion for the Greater petrosal?
Pterogopalatine ganglion
What is the special visceral afferent (SVA):
Afferent fibers
Function: Covey taste from ant 2/3 of tongue and soft palate.
Will pick up info in periphery and carry to brain.
What is the path of the Chords tympani?
Last branch given off in facial canal. Runs through ossicles of middle ear and exits thru peterotympanic fissure where it will join with the lingual nerve.
- Carries GVE to submandibular ganglion
- Carries SVA from ant tongue. (Pseudounipolar ganglion located in geniculate ganglion)
SVA 1* Neuron located:
Geniculate ganglion
What is the Peripheral course (SVA)?
Chemoreceptors of taste buds/palate activate receptor potential communicate with PP of SS neurons from CN VII>
- PP travel with lingual n. (V) and chords tympani (VII)
Cell bodies of afferent neuron #1 reside in geniculate
What is the Central course (SVA)?
Central processes of SS neurons (1* neuron) pass form geniculate ganglion thru facial canal and enter brainstem as part of CN VII. Fibers join tracts solitaries and ascend to synapse in solitary nucleus (2* neuron). 3* neurons from VPM project to posterior limv of internal capsule and then to area of cortex responsible for taste.
Where is the solitary nucleus located and what does it receive?
Solitary nucleus is located in the medulla and receives SVA fibers from VII, IX, and X
What are the General somatic afferent (GSA)?
Afferent fibers
Function: Convey sensory Information from ear:
- External ear (including acoustic meatus)
- Small area behind ear
GSA via posterior auricular n. (sensory) originates from?
Originates from facial n. just as it exits from stylomastoid foramen?
What is the pathway of the GSA of Facial??
Cell body #1 in geniculate ganglion. Peripheral process will pass from sensory area and enter stylomastoid foramen with branchial motor fibers of CN VII and then pass thru temporal bone to ganglion. Central process will travel thru facial canal and exit internal acoustic meatus which will enter the brainstem as part of nervous intermedius. It will descend in the spinal tract of CN V and synapse on neuron #2 of spinal n. of CN V. and then ascends to contralateral VPM via trigeminal system. 3* neuron in VPM projects to sensory cortex via post limb of internal capsule
Pseudounipolar neurons of GVA (facial) reside in:
The geniculate ganglion
PP of the GVA (facial) run:
In the greater petrosal and terminate in nasal cavity and soft palate
CP of GVA (Facial) run:
the nervous intermediate, join the ipsilateral solitary tract and terminate in the solitary nucleus
What does GVE innervate?
Cardiac tissue, smooth muscle and glands (visceromotor)
GVE will run with:
PS only in CN (III, VII, and X)
Sympathetics of the head originate in:
IML (T1-4) and synapse in the superior cervical ganglion.
Sympathetics that run with CN are:
Postganglionic
What is the nuclei for CN III:
Edinger-Westphal
parasympathetic
What is the nuclei for CN IX:
Inferior salivatory nucleus
parasympathetic
What is the nuclei for CN X:
Dorsal motor n. of X
parasympathetic
Ciliary is associated with:
Orbit and CN III
parasympathetic
Ptergopalatine and submandibular ganglia is associated with:
Nasal cavity and glands in oral cavity
- CN VII
parasympathetic
Optic ganglia is associated with:
Parotid gland and CN IX
parasympathetic
Intramural ganglia is associated with:
CN X and is located w/ in cell wall of viscera
parasympathetic
The 2 neuron system of the (parasympathetics?) has:
- CB #1 in CNS
- Preganglionic fibers are myelinated
- Cell body #2 is para or prevertebral ganglion
- Post ganglionic fibers are unmyelinated
- largest visceral organ
Where is the Sympathetic: Thoracolumbar region located?
The IML T1-L2/3
Sacral refers to:
IML S2-4 Splanchnics
What is the pathway of the IML fibers?
Fibers will enter the sympathetic chain via the white ramps and will make their way up to the superior cervical ganglion where synapse occurs
What happens after the fibers synapse at the superior cervical ganglion?
Post ganglionic fibers are going to form large plexiglass that are located on the external carotid and internal carotid
What forms off of the Internal carotid plexus?
Deep petrosal nerve. It will join the greater petrosal in the pterygoid canal.
Do postganglionic sympathetic fibers synapse in the pterygopal. ganglion?
No because they are postganglionic (have already synapsed) but they do run through it. However, Fibers (of the greater petrosal n?) that are being carried on the greater petrosal will synapse
The deep petrosal nerve will target:
Blood vessels, Mucous glands
Sympathetics distribute with:
Sup/Inf division of CN III and nasociliary (CN V1) to get to eye (orbit)
What are the short ciliary:
PS (CN III) synapse in ciliary g. Sympathetic from IC plexus sensory from V1
What are the Long ciliary:
Sympathetics from IC plexus and sensory from V1
What are the symptoms and causes of Horner’s Syndrome?
Symptoms:
- Pupillary constriction
- Ptosis (eye doesn’t open all the way)
- Anhydrosis (lack of sweating)
- Flushing
Causes:
- Neck trauma
- Surgery
- Stroke
- Injury to ICA
Overview of the Hypothalamus:
- Part of the Diencephalon
- Lies ventral to the thalamus
- Highly vascularized
Functions: (Maintain homeostasis)
- Maintains organ function
- Eating
- Drinking
- Reproduction
- Achieved thru control of ANS and hormone production
What is the Epicenter for converging and diverging neural pathways?
Hypothalamus
What is the Periventricular zone?
Borders 3rd ventricle (most medial)
What is the middle zone?
- Contains nuclei that regulate the release of vasopressin and oxytocin
- contains neurons important for regulating ANS
- Circadian rhythms are driven by neurons in this zone
what is the lateral zone?
Lymbic system
- Important in emotions
- Integrates info from telencephalon structures engaged in emotions and transmits to other parts of brain
What is the Anterior region:
Directly above topic chiasm
what is the puberal region?
Includes tuber cinereum (ventral hypothalamus, median eminence and pituitary gland)
What is the posterior region?
Are directly above maxillary bodies
What is the blood supply of the hypothalamus?
Perforating branches from the Circle of Willis
- Infundibular stalk of pituitary lies in middle of circle of willis
- Arterial circle surrounds the entire surface of the hypothalamus
What connects the pituitary gland to the hypothalamus?
Infundibular stalk (blood vessels and nerve fibers
What regulates hormone release by epithelial cells of the ant. pituitary into circulation?
Small dial hypothalamic neurons
Axons of Ig diameter hypothalamic neurons project to the:
Posterior lobe. Peptides released from terminals directly on capillaries of systemic circulation.
Hypothalamic neurosecretory neurons terminate on capillaries of the:
Pituitary portal circulation
Hypothalamic neurons release:
Peptides that promote (releasing hormones) or inhibit (release-inhibiting hormones)
Release or release-inhibiting hormones are carried to:
The ant lobe in portal veins where they act directly on epithelial secretory cells
What does Vasopression do?
(ADH) elevates BP via action on vascular smooth muscle, promotes water resorption from kidney to reduce urine volume— Posterior pituitary hormone
What does Oxytocin do?
Stimulates uterine contractions, milk letdown, social bonding, empathy, generosity— Posterior pituitary hormone
Where do the axons of the hypothalamic neurons terminate?
On capillaries in the post lobe of pituitary: Neurohormones pass into capillaries
Hypothalamic neurons make direct and indirect connections with:
sympathetic and parasympathetic preganglionic neurons
Hypothalamic neurons receives input from:
visceral and pain receptors and the external environment (among others)
- Project to CN uncle and IML
- Can control sweating, digestion, HR, vasoconstriction, ect.
Afferents from brainstem and spinal cord relay:
Visceral and somatic sensory info
Afferents from the limbic system convey info necessary for the:
Hypothalamus to mediate the autonomic and somatic aspects of homeostasis
What are the parts of the limbic system that provide neural connections:
Hippocampus, Amygdala, Insula, Orbitofrontal cortex, Retina
What is the limbic system?
The limbic system is made up of cortical and subcortical structures necessary for normal behavior:
- Memories
- Thoughts
- Personality
- Emotions
What two gyrus make up the limbic cortex?
Cingulate gyrus
Parahippocampal gyrus
What two gyrus make up the hippocampal formation?
Dentate gyrus (deep) Hippocampus
Besides the Limbic cortex and the Hippocampal formation what is the last structure that makes up the limbic system:
Amygdala
What is the function of the limbic system?
Works with hypothalamus, ANS and endocrine system to influence emotional behavior.
- Fear, anger and emotions associated with sexual behavior can trigger and autonomic and or endocrine response via the limbic system
- Memory
- Addiction
- Social cognition
- Olfaction
- Appetite
- Sleep patterns
What is the function of the Parahippocampal gyrus?
Role in memory encoding and retrieval
Damage of the Cingulate gyrus would cause issues with:
- Coordinating smells and sights with pleasant memories
- Induces emotional run to pain
- Regulating aggressive behavior
What is the function of the Hippocampus?
Consolidating explicit memory (recollection of facts) and forming spatial memories
What is the function of the Amygdala?
- Involved in emotions and their behavioral expressions
- Learns emotional content of an experience
- Implicated in depression, anxiety and substance abuse (along with hypothalamus)
Epilepsy:
Temporal lobe epilepsy is most common form in adults
Often caused by damage to hippocampus
Dementia:
Plaques and tangles (alzheimer’s) are often seen in hippocampus and amygdala
Schizophrenia:
disoriented thinking, blunted affect, paranoia, hallucinations
What is the reticular formation?
RF is group of neurons that form the core of the brainstem
What is divergence?
A mechanism for spreading stimulation to multiple neurons or neuronal pools in the CNS
What is convergence?
A mechanism for providing input to a single neuron from multiple sources
The reticular formation can influence:
Skeletal muscle, somatic and visceral sensory input as well as the autonomic and endocrine systems
The reticular formation extends from:
The medulla to midbrain
where is the Raphe nuclei?
Located in sagittal plane of brainstem
Where is the medial (RF)?
- Along side midline raphe nuclei
- source of many of the projections from RF
Where is the Lateral (RF)?
Located lateral to medial zone
Primarily concerns with CN reflexes and visceral fn.
The midbrain and upper pons midline (raphe) ascending projections for:
Arousal and attention
Along with the medial located in the lower pons and medulla
Lower pons and medulla has intrinsic connections for:
control of eye movements, swallowing, and brainstem reflexes
The Lateral portion located around lower pons and medulla has descending projections for:
control of muscle one, respiration, and arterial pressure
What is the function of the the Reticular formation?
Gives rise to reticulospinal tract:
- Postural adjustments
- Correction of movement erros
- Along with spinal cord and cerebellum facilitates motor control
Pain modulation
Autonomic reflex circuitry
Maintaining normal state of consciousness
