ANATOMY

Head and Neck

Click on the -?- to reveal/hide the answer.

Somatic Portions

The scalp layer of loose connective tissue between the epicranial aponeurosis and the periosteum forms the subaponeurotic or "danger" space. Emissary veins connect with the dural sinuses with potential for -?-Hematogenous spread of infection through the calvaria.
Cranial fractures preferentially pass through cranial foramina injuring the contained -?-Nerves.
Principal Foramina of the Anteiror Cranial Fossa:
Foramen Contents Results of Injury
Olfactory -?-Olfactory nerves Anosmia
Foramen cecum -?-An emissary vein  
Principal Foramina of the Middle Cranial Fossa:
Foramen Contents Results of Injury
Optic canal -?-CN II Unilateral blindness
  -?-Ophthalmic artery Ischemic unilateral blindness
Superior orbital fissure -?-CN III Ophthalmoplegia
  -?-CN IV Inability to look down and out
  -?-CN V Unilateral loss of blink reflex
  -?-CN VI Inability to abduct eye
  -?-Superior ophthalmic vein Retinal engorgement
Foramen rotundum -?-CN V2 Loss of sneeze reflex
Foramen ovale -?-CN V3 Masticatory paralysis, loss of jawjerk reflex
Foramen spinosum -?-Middle meningeal artery  
Foramen lacerum -?-Nothing (except occasionally the greater superficial petrosal nerve)  
Hiatus of the facial canal -?-Gr. Superficial petrosal n. Dry eye, loss of submandibular and sublinguinal secretion
Principal foramina of the posterior cranial fossa:
Foramen Contents Results of Injury
Internal auditory meatus CN VII -?-Facial paralysis
  CN VIII -?-Auditory and vestibular deficits
Jugular foramen CN IX -?-Loss of gag and carotid reflexes
  CN X -?-Loss of cough reflex. Paralysis of laryngeal muscles and some palatine muscles
  CN XI -?-Inability to shrug shoulders
  Internal jugular vein  
Anterior condylar canal CN XII -?-Paralysis of tongue muscles. Lingual deviation toward side of injury upon protusion
CSF is produced by the choroids plexuses which project into the ventricles of the brain:
CSF Production Through Into
Lateral ventricles Foramina of Monro -?-Third ventricle
Third ventricle Iter (cerebral aqueduct) -?-Fourth ventricle
Fourth ventricle Foramina of Magendie & Luschka -?-Cisterna magna of subarachnoid space
From Through CSF Uptake
Subarachnoid space -?-Arachnoid villi Superior sagittal venous sinus
The cerebral aqueduct is prone to occlusion, leading to -?-Hydrocephalus.
Cranial and cerebral hematomas:
Hematoma Prognosis Location Cause
Epicranial -?-Resolves Subaponeurotic Space Superficial vessels
Epidural -?-Life-threatening Epidural space Torn middle meningeal artery
Subdural -?-Less serious Subdural Space Torn cerebral vein
Subarachnoid -?-Lethal Subaracnhnoid space Torn cerebral artery, cerebral aneurysm
Subpial -?-Usually resolves Cerebrum Cerebral contusion
Regions of the orbit that are prone to fracture include the ethmoid lamina papyracea and the -?-Maxilla about the infraorbital groove.
Contraction of the orbicularis oculi muscle, innervated by the facial nerve, produces the -?-Blink.
Orbital muscle function and innervation:
Muscle Primary function Secondary functions (normally balance) Innervation
Pupil -?-Constriction Dilation   CN III parasympathetic sympathetic chain
Ciliary body -?-Accommodation   CN III parasympathetic
Superior tarsal muscle -?-Augment levator palpebrac superioris   Sympathetic chain
Levator palpebrae superioris -?-Elevate eyelid   CN III (oculomotor)
Medial rectus -?-Adduction   CN III (oculomotor)
Superior rectus -?-Elevation Adduction, intorsion CN III (oculomotor)
Inferior oblique -?-Elevation Abduction, extorsion CN III (oculomotor)
Inferior rectus -?-Depression Abduction, extorsion CN III (oculomotor)
Superior oblique -?-Depression Abduction, intorsion CN IV (Trochlear)
Lateral rectus -?-Abduction   CN VI (Abducens)
Parasympathetic innervation to the -?-Pupil is by the oculomotor nerve. Temporal lobe herniation (from tumor, hematoma, or edema) -?-Compresses the oculomotor nerve within the tentorial notch, causing a dilated pupil that is unresponsive to light.
Special sensory tests and dysfunction:
Nerve Foramen Dysfunction Test
CN I (Olfactory) Cribriform plate Anosmia -?-Whiff of clove
CN II (Optic) Optic canal Blindness -?-Optic field tests
CN VIII
Cochlear
Vestibular
Internal auditory meatus
Internal auditory meatus
Deafness
Balance
-?-Hearing threshold
-?-Nystagmus
Paralysis of the stapedius muscle, as a result of facial nerve palsy, produces -?-Hyperacusis.

Visceral portions

The infrahyoid muscles, innervated by the ansa cervicalis (C1-C3), stabilize the hyoid bone and larynx during -?-Deglutition and phonation.
The pretracheal space, deep to the pretracheal fascia, surrounds the trachea and thyroid gland, but is anterior to the esophagus. Infection I this space may track into the -?-Superior mediastinum.
The retropharyngeal (retrovisceral) space lies posterior to the oroparynx and esophagus and is defined by septa from the pretracheal fascia. Infection within this space may track into the -?-Posterior mediastinum.
The mandibular neurovascular bundle enters the mandibular foramen adjacent to the lingual, the point of -?-Minimal movement. It may be anesthetized by directing a needle posteriorly through the buccal wall just -?-Lateral to the pterygomandibular raphe.
The deep cervical nodes receive lymph from the -?-Anteroinferior portion of the face, the nasal cavities, and the oral cavity.
The nasal vestibule (the most common site for nose bleeds) receives vascular branches from internal and external -?-Carotid arteries.
The -?-Palatine tonsil receives vascular branches from the maxillary, facial, and lingual arteries.
Abduction of the vocal cords is a function of the posterior cricoarytenoid muscle only, innervated by the recurrent -?-Laryngeal nerve.
Branchiomeric nerve functions and tests:
Nerve Course Sensory Motor Test
CN V (tigeminal)
VI Superior orbital fissure, supraorbital notch Forehead None -?-Blink relfex
V2 Foramen rotundum, maxillary foramen -?-Midface None Sneeze reflex
V3 Foramen ovale, mandibular foramen, mental foramen Anterior pinna, jaw Muscles of mastication, mylohyoid ant, belly of digastric, tensor palatine and tensor tympani -?-Jaw jerk
-?-CN VII (facial) Internal autitory meatus, facial canal, stylomastoid foramen Concha of ear, taste anterior 2/3 of tongue via chorda tympani Muscle of facial expression, stylohyoid, post belly of digastric, tensor tymani, parasympathetic to lacrimal nasal, palatine, lingual and submandibular glands via gr. Superficial petrosal nerve Blink reflex
CN IX (glossopharyngeal) Jugular foramen External auditory, meatus, oropharynx, carotid body and sinus, taste posterior 1/3 of tongue Stylopharyngeus muscle, parasympathetic to parotid gland via tympanic and lesser superficial petrosal nerves -?-Gag reflex, carotid reflex
CN X (vagus) Jugular foramen External auditory matus, larynx, taste from epiglottis, aortic body Palatine muscles, pharyngeal muscles, laryngeal muscles -?-Phonation
Nerve functions and tests:
Nerve Course Sensory Motor Test
CN XI (spinal accessory) Foramen magnum, jugular foramen None Sternomastoid Upper trapezius -?-Turn head to opposite side
CN XII (hypoglossal) -?-Hypoglossal canal None Intrinsic and extrinsic tongue muscles Protrudes straight
Close Window