Module 7a: The head Flashcards
Layers of the scalp
S- skin
C- dense connective tissue
A- aponeurosis
L- loose connective tissue
P- pericranium
Skin of scalp
Contains all epidermal appendages including hair follicles and sebaceous glands
Dense connective tissue of scalp
Highly vascularized and innervated layer, also contains hair follicles
Aponeurosis of scalp
Thin, broad, tendon like sheet that covers the dome of the skull
Loose connective tissue of scalp
Danger area, infections easily spread within it and enter cranial cavity
Pericranium of scalp
Thin layer of CT that covers bones of skull; protects skull and provides nutrients to bones
Complications of hair transplant
Nerve damage causing numbness, bleeding from vascular damage, prolonged pain
Three salivary glands
- Parotid gland
- Sublingual gland
- Submandibular gland
Ducts of parotid gland
Secretions exit through Stensen’s duct
Stensen’s duct
Passes superficial to masseter muscle and pierces buccinator to open up into oral cavity opp second upper molar tooth
Ducts of submandibular gland
Mixed secretions exit through Wharton’s duct into the sublingual papillae behind the lower incisors on side of lingual frenulum
Salivary gland stones
Calcified stones that form when chemicals in the saliva accumulate in the duct or gland
What glands do salivary gland stones affect?
Parotid and submandibular
Symptoms of salivary gland stones
Swelling, pain in lower jaw, difficulty opening mouth
Risk factor of salivary gland stones
Reduced saliva production or thickened saliva
Factors leading to reduced/thickened saliva
Dehydration
Poor eating
Meds
Trauma ro glands
Genetics
Buccinator
Contraction pulls cheeks tightly against teeth, preventing food from collecting btwn teeth and gums during mastication
Branches of facial nerve
- Temporal
- Zygomatic
- Cervical
- Buccal
- Marginal mandibular
Buccinator muscle strain
Deep pain in cheek that can resemble a painful cavity or an abscessed tooth; occurs from strenuous activity of jaw
Symptoms of buccal muscle strain
Pain during chewing, moving food in mouth, smiling, swallowing `
Trigeminal nerve innervation
Sensory and motor info
3 branches of trigeminal nerve
- Mandibular nerve (V3)
- Maxillary (V2)
- Opthalmic (V1)
Mandibular branch of trigeminal nerve
Supplies skin of lower lip, lower face, temporal region and upper part of external ear
Mandibular nerve motor supply
Only this division carries motor info to muscles of mastication
Maxillary branch of trigeminal nerve
Innervates skin of lateral sides of nose, lower eyelid, cheek, temporal region and upper lip
Opthalmic branch of trigeminal nerve
Carries sensory info from skin of forehead, upper eyelid, midline of nose
Trigeminal neuralgia
Chronic pain condition resulting from damage to trigeminal nerve
Causes of trigeminal neuralgia
Compression of nerve
Multiple sclerosis
Natural aging process
Symptoms of trigeminal neuralgia
Stabbing/shooting pain
Forehead region affected
Pain triggered by brushing teeth, shaving, brushing front of hair and putting on cream
Pain comes in attacks
Elevation of eyeball
Superior rectus and inferior oblique muscles
Depression of eyeball
Inferior rectus and superior oblique muscles
Abduction of eyeball
Lateral rectus
Adduction of eyeball
Medial rectus
Arterial supply of eyeball
Opthalmic artery
Opthalmic artery
Branch of internal carotid artery, enters orbit w optic nerve through optic canal
What does the opthalmic artery supply?
Contents of orbit and eyelids
What artery supplies retina of eyeball?
Central retinal artery
Venous drainage of eyeball
Superior opthalmic vein
Superior opthalmic vein
Passes through superior orbital fissure to drain in to cavernous sinus
Pyomyositis of extraocular muscles
Acute bacterial infection caused by staphylococcus aureus
Symptoms of pyomyositis of extraocular muscles
Pain, swelling, redness, restricted movement, vision impairment, reduced blood supply to eye
Three parts of the ear
- External
- Middle
- Inner
Middle ear
Air-containing space within temporal bone that functions to transmit vibrations from tympanic membrane to internal ear
Lateral border of middle ear
Tympanic membrane
Medial border of middle ear
Separates middle ear from inner ear
Posterior border of middle ear
Thin bone separating tympanic cavity from mastoid air cells in temporal bone
Roof (tegmental wall) of middle ear
Tegmen tympani
Separates middle ear from cranial fossa
Floor (jugular wall) of middle ear
Separates middle ear from internal jugular vein
Lower anterior border of middle ear
Separates tympanic cavity from internal carotid artery
Upper anterior border of middle ear
Incomplete bc it has opening for eustachian tube
Eustachian tube
Btwn middle ear and nasopharynx
Equalizes air pressure on either side of tympanic membrane allowing it to vibrate freely
Parts of the nasal septum
Perpendicular plate of ethmoid bone superiorly
Vomer bone inferiorly
Septal cartilage anteriorly
Arterial supply of nasal septum
Internal and external carotid arteries
Ophthalmic and maxillary arteries
Kiesselbach’s plexus (anastomoses of opthalmic and maxillary arteries)
Sensory innervation of anterosuperior part nasal septum
Ophthalmic branch of trigeminal nerve
Sensory innervation of rest of nasal septum
Maxillary branch of trigeminal nerve
Nasal polyps
Soft, painless, noncancerous growths that hand down like teardrops or grapes from lining of nasal cavit
Causes of nasal polyps
Chronic inflammation of vascular supply in walls of nasal cavity which may be associated with asthma, infection, allergies
Symptoms of nasal polyps
Larger ones can block nasal passages leading to loss of smell, breathing problems and post nasal drip
Sensory innervation of tongue
- Glossopharyngeal nerve
- Trigeminal nerve
- Facial nerve
Glossopharyngeal nerve supply of tongue
Lingual branches supply general and sensory innervation to posterior 1/3
Trigeminal nerve supply of tongue
Mandibular branch gives rise to lingual nerve that supplies anterior 2/3
Lingual nerve and wisdom tooth extraction
Susceptible to damage during wisdom tooth surgery
Facial nerve supply of tongue
Taste from anterior 2/3 of tongue is carried by lingual nerve to chorda tympani
The lingual artery
Branch of external carotid
Supplies tongue, sublingual gland, floor of mouth
Dysgeusia
Distortion of sense of taste, issues with swallowing and impaired gag reflex
Muscles of mastication
Medial and lateral pterygoid
Masseter
Buccinator
Temporalis
Lateral pterygoid muscle insertion
Neck of mandible and capsule of articular disc of TMJ
Fibres run horizontal
Medial pterygoid insertion
Medial surface of mandible near its angle
Fibres run downward and backward
What muscles of mastication perform elevation?
Temporalis, masseter, medial pterygoid
What causes depression of muscles of mastication?
Gravity and relaxation of muscles
What muscles of mastication perform lateral movement?
Medial and lateral pterygoids
What muscles of mastication perform protraction?
Lateral pterygoid
What muscles of mastication perform retraction?
Temporalis
Innervation of muscles of mastication
Trigeminal nerve via mandibular nerve
Lateral pterygoid strain symptoms
Pain radiating to maxilla
Pain at TMJ
TMJ dysfuction
Temporomandibular joint (TMJ)
Synovial modified hinge joint btwn head of mandible, mandibular fossa and articular tubercle of temporal bone
TMJ syndrome
Caused by excessive teeth grinding and jaw clenching that results in the misalignment of articular disc or damage to articular cartilage
Symptoms of TMJ syndrome
Jaw clicking
Pain and tenderness in jaw
Difficulty chewing
Locking of jaw
What artery supplies muscles of mastication?
Maxillary
Branch of external carotid
What artery supplies dura mater?
Middle meningeal artery
Branch of maxillary
Epidural hematoma
Injury to skull resulting in the tearing of arterial branches and intracranial bleeding
Causes of epidural hematoma
Head injury
Physical assaults
Accidental falls
Break in temporal bone
Symptoms of epidural hematoma
Rapid neurological degeneration
Severe headaches
Nerve damage
Abducens nerve (CN VI)
Provides motor innervation to the lateral rectus muscle; abduction
Facial nerve (CN VII)
Motor innervation to muscles of facial expression, sensory innervation to tongue
Vesibulocochlear nerve (CNVIII)
Transmits info regarding sound and equilibrium
Hypoglossal nerve (CN XII)
Controls muscles of tongue
The autonomic nervous system
Parasympathetic and sympathetic systems
Where do parasympathetic ganglia receive innervation from?
Receive preganglionic fibres from oculomotor, facial and glossopharyngeal nerves
4 Parasympathetic ganglia
- Ciliary
- Pterygopalatine
- Submandibular
- Otic
Otic ganglion
Glossopharyngeal nerve
Innervates parotid gland
Preganglionic fibres of otic ganglion
Leave medulla oblongata of brainstem as glossopharyngeal nerve
Postganglionic fibres of otic ganglion
Join auriculotemporal nerve to innervate parotid gland
What is the auriculotemporal nerve a branch of?
Mandibular division of trigeminal nerve
Frey’s syndrome
Damage to auriculotemporal nerve causing parasympathetic nerve fibres to switch course to sympathetic response resulting in gustatory sweating in anticipation of eating instead of normal salivary response
How is Frey’s syndrome diagnosed?
Eat a lemon wedge, if they sweat excessively they can be diagnosed with it
Arterial supply of face
- Ophthalmic artery
- Superficial temporal artery
- Facial artery
Ophthalmic artery
Branch of internal carotid artery, supplies eyes and forehead
Superficial temporal artery
Arises from external carotid artery in parotid gland
Supplies temple, scalp and parotid gland
Facial artery
Supplies superficial structures of skin and face and some muscles of facial expression and mastication
Branch of external carotid
Superficial temporal artery anuerysm
Bulging or weakening of STA caused by injury to head
Symptoms of superficial temporal artery anuerysm
Lump and headaches
What vein drains the face?
Facial vein
Where does the facial vein empty in to?
Internal jugular vein
Where does facial vein drain into?
Cavernous sinus
The danger triangle
Cavernous sinus region
Called this due to risk of spread of infection via facial vein
What nerves would be affected by an infection in danger triangle?
Trochlear (CNIV), Abducens and ophthalmic nerve
Lymph nodes of face
- Deep cervical nodes
- Superficial cervical nodes
- Collar nodes
Deep cervical nodes
Deep to SCM
Closely related to internal jugular vein
Superficial cervical nodes
Found on SCM and associated with external jugular vein
Collar nodes
Collar location at junction of head and neck
Where does all lymphatic drainage of head empty into?
Deep cervical nodes which drain into either right lymphatic duct or thoracic duct
