Anatomy - Block 1 Flashcards
Cell Body of Optic Nerve?
Ganglionic layer of retina
What does the oculomotor nucleus innervate?
Superior, Inferior, Medial Rectus, Inferior Oblique, Levator Palpebrae
**What doe the Edinger-Westphal nucleus innervate?
Postganglionic short ciliary nerves to constrictor papillae and ciliary muscles of eyeball (originally from Oculomotor Nerve - CN III)
What foramen does CN III, CN IV , CN V1 and CN VI go through?
Superior Orbital Fissure
**What are the three nuclei of the trigeminal nerve?
- Trigeminal motor nucleus (motor)
- Trigeminal Ganglion (sensory)
- Mesencephalic Nucleus (sensory - proprioception)
What does the Trigeminal motor nucleus innervate?
Muscles of mastication, tensors tympani and veli palatine, mylohyoid, anterior digastric
-Goes through Foramen Ovale (Mandibular division)
What does the Trigeminal ganglion innervate?
Face, nose, mouth, supratentorial dura (sensory)
- Ophthalmic - superior orbital fissure
- Maxillary - foramen rotundum
- Mandibular - foramen ovale
What does the mesencephalic nucleus innervate?
Proprioception from head, TMJ and tooth sockets
-Runs with opthamlmic, maxillary and mandibular branches of CN V
What type of innervation does Abducens do?
Motor to the lateral rectus
What are the three nuclei of the facial nerve (CN VII)?
Facial Motor Nucleus, Superior Salivatory nucleus, Geniculate Ganglion
What does the facial motor nucleus innervate?
Motor to muscles of facial expression, stylohyoid, posterior digastric, stapedius
What does the superior salivary nucleus innervate?
Goes to pterygopalatine ganglion and chords tympani to submandibular ganglion
- Post ganglionic fibers follow maxillary nerve branches to glands
- Post ganglionic fibers to sublingual glands, glands of oral cavity
What does the geniculate ganglion innervate?
(Sensory) - Submandibular.
Innervates Taste buds on anterior 2/3 of tongue and palate, external auditory meatus and skin back of ear
What ganglion supply CN VIII?
Vestibular Ganglion
Spiral Ganglion
(Sensory)
What does the vestibular ganglion supply?
Cristae of semicircular canals, maculae of utricle and saccule
What does the spiral ganglion supply?
Organ of corti
What are the ganglion of CN IX (glossopharyngeal)?
Nucleus Ambiguus (motor) Inferior Salivatory Nucleus (motor) Inferior Ganglion (Sensory - Taste) Superior Ganglion (Sensory) [all go through jugular foramen]
What does the nucleus ambiguous ganglion supply (CN IX branch)?
Stylopharyngeus muscles (motor)
What does the inferior salivatory nucleus supply (CN IX) ?
Postganglionic fibers by auriculotemporal nerve to parotid gland
-Travels from jugular foramen, to tympanic plexus, to lesser petrosal to otic ganglion
What does the inferior ganglion supply (CN IX)?
Taste buds of circumvallate papillae
Pharyngeal wall and post. 1/3 of tongue, eustachian tube, carotid sinus and body
(sensory)
What does the superior ganglion supply (CN IX)?
Cutaneous back of ear, middle ear (sensory)
What ganglion supply the vagus nerve (CN X)?
Nucleus ambiguus, dorsal motor nucleus, inferior ganglion, superior ganglion
What does the nucleus ambiguous ganglion supply (CN X)?
Pharyngeal and largyngeal muscles (motor)
Preganglionic parasympathetic to the heart
What does the dorsal motor nucleus supply (CN X)?
Preganglionic fibers to viscera of thorax and abdomen (smooth muscle and glands)
What does the Inferior Ganglion supply (CN X)?
Pharynx, Larynx, Trachea, esophagus, thoracic and abdominal viscera, aortic bodies and sinuses
Taste buds in epiglottis (sensory)
What does the Superior Ganglion supply (CN X)?
Auricular branch to ear (Arnold’s nerve)
sensory
What does ganglion supplies CN XI?
Accessory nucleus in C 1-5
What does the accessory nucleus supply?
Sternocleidomastoid, trapezius muscles
What is primary craniosynostosis?
Premature closure of cranial sutures; possible due to genetics
What is scaphocephaly?
Premature closure of sagittal suture; anterior fontanelle is small or absent - long narrow head
What is plagiocephaly?
Premature closure of coronal or lambdoidal suture occurring on one side - twisted cranium - “flat head” facial asymmetry
What is oxycephaly?
Premature closure of coronal suture. Top of skull is pointed/conical.
What is Bell’s Palsy?
Paralysis of facial muscles
- Injury to facial nerve CN VII or its branches, produces paralysis of some/all facial muscles on affected side
- Inferior eyelid evert and lacrimal fluid doesn’t spread over cornea - cornea vulnerable to ulceration
- Affects speech, eating
- Tumor of parotid gland could cause same problems
What is Trigeminal Neuralgia?
- Sensory disorder of the sensory root of CN V
- Sudden attacks of excruciating, lightening-like jabs of facial pain (paroxysm), may wince, tic, may have psychological disturbances due to pain (depression, suicide)
- CN V2 (maxillary) most often involved
- Initiated by touching trigger zone
- Caused by demyelination of axons in sensory roots - often caused by pressure of small aberrant artery
How do you treat Trigeminal Neuralgia?
- Block infra-orbital foramen (V2) with alcohol
- Surgical cutting
- Placing piece of foam between V2 and aberrant artery (possibly superior cerebellar)
What is a TMJ dislocation?
- Excessive contraction of lateral pterygoid causes heads of mandible to dislocate anteriorly, mandible remains depressed with person unable to close mouth
- May also be accompanied by fractures
What happens with infection to the Parotid Gland?
Viral Parotiditis or Mumps
- Pain intensifies with chewing due to compression against mastoid process of temporal bone and tightening of facial covering of gland
- Mumps virus inflammation of parotid duct producing redness of parotid papilla
What are epidural hemorrhages?
involve rupture of a meningeal artery with blood forming a hematoma between the dura and the bone of the skull.
Involve blunt trauma to middle meningeal artery.
What are subdural hemorrhages?
Occurs between dura and arachnoid membrane
- Involves rupture of cerebral vein
- Usually occurs in older people and will develop over time
- History of headache? Can often occur days after a car accident
What are subarachnoid hemorrhages?
Between subarachnoid membrane and pia
- Involves rupture of cerebral artery
- Blood accumulates in subarachnoid space
- Most common cause of “just this” is a ruptured berry aneurysm
What does the premotor area do?
Motor programming or indirect motor movement control
What do the frontal eye fields do?
Voluntary eye movements
What does the supplementary motor area do (located on medial surface/midline of brain)?
- Motor movement organizing/planning motor movements
- Cortical micturition (urination) control center
What type of memory is stored in the prefrontal cortex?
“Working memory” or short-term memory (intermediate memory)
Where is broca’s area and what does it do?
- Left inferior frontal gyrus - Above the lateral sulcus
- Involved in formulation of speech
What does the right (non dominant) frontal gyrus help with (non-broca’s side)?
Language expression (prosody of speech)
What is the post central gyrus?
Primary somatosensory cortex
What areas are located behind the post central gyrus?
- Somatosensory assciation cortex (more medial/higher) - sup. parietal lobule
- Multimodal association cortex (integration of info) - inf. parietal lobule
Where are your analytical skills located?
Posterior parietal lobule (left)
Where is your visuospatial orientation located?
Posterior parietal lobule (right)
Where is the primary visual cortex?
Back tip of occipital lobe (calcarine cortex - area 17 - lingual gyrus and cuneus)
Where is the visual association cortex and what does it detect?
Lateral, medial and inferior occipital gyri
-Color, motion, depth
Where are the involuntary cortical eye fields located and what are they involved in?
A circle in the lateral occipital gyri
-Scanning eye movements
Where is the primary auditory cortex?
Transverse temporal gyri
-Under the upper end of the lateral sulcus
Where is the auditory association cortex and what is it associated with?
- Surrounding the primary auditory cortex
- Superior temporal gyrus/Wernicke’s Area!!
- Language comprehension
Where is the hippocampal formation and what is it associated with?
Between the temporal and occipital lobes.
It is associated with memory storage (long-term storage)
What is the temporal lobe associated with?
Long-term memory storage
Where does the long-term storage of memories take place?
Association cortex: [Frontal lobe, Parietal lobe, Occipital lobe, Temporal lobe]
What areas make up the limbic lobe?
Cingulate Gyrus Isthmus of the cingulate gyrus Parahippocampal Gyrus Septal or Subcallosal area Parahippocampal Gyrus Hippocampal formation
What is the anterior part of the limbic lobe involved in?
Emotional behavior and homeostasis
What is the posterior part of the limbic lobe involved in?
Cortical processes of learning and memory (consolidation of memories - declarative)
What is the insular cortex involved in?
Visceral functions (smell, taste, pain) -It serves to integrate visceral input (olfactory, gustatory, and pain and thermal information)
Where is the primary olfactory cortex located?
Rostral parahippocampal gyrus, uncus, tempral pole
look at brain from underneath and it’s on the temporal lobe very close to the cerebral peduncles and optic chiasm
Where is the insular cortex?
In lateral fissure, lateral to basal ganglia (lentiform nucleus)
Afferent?
Coming toward
Efferent?
Going away/out of
Where are the afferent and efferent fibers to the cortex located?
Internal Capsule
Where are:
- Pyramidal cells
- Purkinje cells
- Pyramidal = cortex
- Purkinje = cerebellum
UMN & LMN
UMN - cell bodies in CNS, end up in CNS
LMN - cells bodies in CNS, end up in PNS
Anterolateral (lenticulostriate) arteries off the middle cerebral artery supply. . .
The major portion of the internal capsule (anterior limb, genu, portion of posterior limb)
Agnosia
Inability to understand or recognize sensory stimuli (ex: somesthetic, visual, auditory)
Parietal association cortex
Involved in observing surface texture, shape, size and weight of an object
Prosopagnosia
Face blindness - underside of occipital lobes - agnosia
Apraxia
Inability to carry out a motor action in response to verbal request in absence of paralysis, sensory abnormality, comprehension deficit, disturbance of coordination (ataxia). Usually associated with the dominant cerebral hemisphere (left).
Aphasia
Defect in language processing that can occur due to brain lesions.
Expressive Aphasia
Broca’s aphasia
- Non-fluent aphasia
- Problem in speech formulation
Receptive Asphasia
- Wernicke’s aphasia
- Fluent aphasia
- A form of auditory agnosia in which the patient fails to recognize or comprehend the meaning of known words - “word deafness”
- Patient will speak in nonsense
What are the five branches of the facial nerve?
- Temporal
- Zygomatic
- Buccal
- Marginal Mandibular
- Cervical
What does the masseter muscle develop from?
First branchial arch
Where does masseter muscle attach?
Superiorly- zygomatic bone & zygomatic arch
Inferiorly - outer surface of the angle of the mandible
What is the facial artery a branch off of?
External carotid artery
How is pneumoparotid treated?
It’s usually left to resolve on its own unless its infected.
What is the masseter muscle derived from?
1st brachial arch!
What innervates the temporalis muscle?
V3 - Trigeminal
Inferior Alveolar nerve
Branch of V3, enters mandibular foramen, sensory to teeth of the mandible and exits at mental foramen to supply lower lip. Mylohyoid is a branch off of this.
Mylohyoid innervation:
Mylohyoid muscle & anterior belly of the digastric = from 1st pharyngeal arch
Lateral pterygoid insertion & origin:
Origin: inferior surface of greater wing of sphenoid & posterior maxilla
Inserts: capsule of TMJ and neck of condylar process
Where is the trigeminal motor nucleus?
In the pons! And runs in to join up with trigeminal ganglion.
What does the mandibular branch go through?
Foramen ovale
What does the maxillary branch go through?
Foramen rotundum
The facial motor nucleus supplying the facial muscles is located. . .
In the brainstem at junction of the pons and medulla.
What is the auriculotemporal nerve a branch of?
Trigeminal (V3)
What is the buccal nerve (long buccal) a branch of?
Trigeminal (V3)
How does the deep cerebral parts of the brain drain blood?
Venous tributaries –> internal cerebral veins –> Great Cerebral Vein (of Galen) –> Straight Sinus –> Confluence of the sinuses
What are branches of the internal carotid artery?
- Anterior communicating artery
- Anterior cerebral artery
- Middle cerebral artery
- Posterior cerebral artery (calcarine artery)
- Anterior choroidal artery
- Posterior communicating artery
- Hypophesial artery - pituitary gland
- Opthalmic artery
What is the cisterna magna?
Large CSF containing space between base of skull and cerebellum - right above foramen magnum
Where is the third ventricle?
It’s located midline between the diencephalons (thalamus, hypothalamus)
What does the cerebral aqueduct connect?
3rd and 4th ventricles (its in the midbrain)
What is an uncal herniation?
Transtentorial herniation off the inner most part of the temporal lobe, the uncus, can be squeezed into tentorium and put pressure on the midbrain
What are the terminal branches of the external carotid?
Maxillary artery & Superficial temporal artery
What does the maxillary artery become?
Sphenopalatine artery
What is the auricultemporal a branch of?
V3 - Mandibular
What is the middle meningeal a branch of (where does it pass?)?
Maxillary artery - through the foramen spinosum
Where are the pre and post ganglionic fibers of the otic ganglion?
Preganglionic fibers - in CN IX
Postganglionic fibers (cell bodies in otic) - postgang. parasympathetic (digest!) fibers are carried by auriculotemporal nerve to the parotid gland for salivary secretion
Otic ganglion - located medial to V3
What is the pathway of parasympathetic nerves to the parotid gland?
- Glossopharyngeal nucleus (inferior salivary nucleus in medulla)
- Lesser petrosal nerve
- Otic ganglion
- Auriculotemporal nerve
- Parotid gland
What types of receptors are found on postgang. parasympathetic neurons?
Nicotinic receptors
Where is the otic ganglion located?
Medial side of V3!
What is the lingual nerve sensory to?
Anterior 2/3 of the tongue
What is the buccal nerve sensory to?
The cheek
What innervates (motor) the lateral and medial pterygoid?
(Lateral & medial pterygoid nerve) Trigeminal - V3
What do the mylohyoid muscle and anterior belly of the digastric develop from?
First pharyngeal arch!
What does the medial pterygoid do?
Elevates the mandible
What does the chorda tympani carry?
Preganglionic parasympathetic fibers to the submandibular ganglion, and special sensory fibers to the anterior 2/3 of the tongue
What is the lingual nerve a branch of? What joins it? What does it supply?
Sensory branch of V3, general sensation to anterior 2/3 of tongue, joined by chorda tympani
What is the function of the lateral pterygoid muscle?
Protrusion and depression of the mandible
What is the inferior alveolar artery a branch of?
Maxillary artery
What innervates the buccinator muscle?
Facial nerve - buccal branch because you use this muscle to smile!
What nerve innervates the posterior belly of the digastric and is derived from the 2nd pharyngeal arch?
Facial Nerve!
What is the pathway from the superior salivatory nucleus to the submandibular, sublingual and tongue glands?
- Superior salivatory nucleu
- Geniculate ganglion
- Chorda tympani
- Lingual nerve
- Submandibular ganglion
- Submanibular gland, sublingual gland and tongue
Where is the geniculate ganglion located?
In cranial cavity, not brainstem past internal auditory meatus
Where do the taste fibers of the facial nerve have their cell bodies?
Geniculate ganglion
What nerves are parasympathetic?
Think rest and digest CN III CN VII CN IX CN X S2, S3, S4
What is the insula involved in?
Visceral association functions
What doe the septum pellucidum do?
Separates the two lateral ventricles
Significance of the fornix?
Part of the limbic system that connects the mamillary bodies to the hippocampal formation
What is the nucleus acumen?
Part of ventral striatum; located where the head of the caudate and the anterior portion of the putamen meet
Where is the hypothalamus?
Ventral/under the thalamus, boarders third ventricle and gives rise to infundibular stalk
When traveling from cortex to brainstem, where do corticobulbar fibers go?
Gene of internal capsule
Hemorrhage of middle cerebral artery damages. . .
Internal Capsule (lenticular nucleus)
