Module 7A Flashcards
the scalp
layers of subcutaneous tissue and skin that cover the bones of the skull
- consists of 5 layers - from superficial to deep = SCALP
S - SCALP
Skin
- contains all the epidermal appendages including hair follicles and sebaceous glands
C- SCALP
Dense Connective Tissue
- highly vascularized and innervates layer
- contains hair follicles
scalp lacerations to the dense connective tissue of the scalp
may bleed profusely due to the rich blood supply found here
A - SCALP
Aponeurosis
Aponeurosis
a thin, broad, tendon-like sheath that covers the dome of the skull and serves as an intermediate tendon between the occipitals muscle posteriorly and frontalis muscle anteriorly
action of occipitalis muscle and frontalis muscle
- move the scalp
- wrinkle the forehead
- raise the eyebrows
L - SCALP
Loose Connective Tissue
Loose Connective Tissue
“danger area of the scalp” as infections can easily spread within it and enter the cranial cavity
- provides an easy plane of separation between upper 3 layers and pericranium
P - SCALP
Pericranium
- thin layer of connective tissue that covers the bones of the skull
- protects the skull and provide nutrients to bone
Complications with Hair Transplants
- Nerve Damage
- Prolonged Pain
nerve damage from hair transplant
- numbness/lack of sensation from nerve damage
- bleeding from vascular damage of skin and connective tissue (dense) layers of the scalp
prolonged pain from hair transplants
pain post-surgery is a normal recovery process as the follicles are healing
- pain that doesn’t subside after 4-5 weeks is abnormal and may indicate infection of the new follicles
Ducts of the Salivary Gland
transport saliva from the glands to the oral cavity
2 ducts of the salivary glands
- Parotid gland
- Submandibular gland
parotid gland
secretions from the parotid gland exit the gland through stensens ducts
Stensens duct (parotid duct)
passes superficial to the massester muscle, and then pierces the buccinator to open the oral cavity opposite to the second upper molar tooth
submandibular gland
second largest salivary gland
- can be palpated in the neck medial to the lower border of the mandible
- mixed secretions exit through the 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
- can affect parotid and submandibular glands
***parotid = larger and less common
symptoms of Salivary Gland Stones
- swelling of gland and the cheek
- pain in lower jaw near the duct - especially after eating
- difficulty opening the mouth from a blockage of flow of saliva in the duct
Risk factors for the development of Salivary Gland Stones
- reduced saliva production
- thickened salvia
***both reduce flow of secretions through the ducts
factors leading to reduced/thickened salivary production
- dehydration
- poor eating
- certain meds
- trauma to salivary glands
- genetics - males higher risk
Muscles of facial expression
specialized group of voluntary muscles that protect the orifices of the face by acting as sphincters and dilators
- contraction causes changes in expressions of the face
Buccinator
contraction of the buccinator pulls the cheeks tightly against the teeth, preventing food collecting between the teeth and gums during mastication
- works on concert with the tongue to keep food between the molars
the facial nerve
CN VII
- supplied both sensory and motor innervation
5 branches of the facial nerve
- temporal
- zygomatic
- marginal mandibular
- cervical
- buccal
The Zombie Bit My Cat
what branch of the facial nerve innervates the buccinator?
the buccal branch
Buccinator Muscle Strain - Cause
may occur from strenuous activity of the jaw…
- chewing gum for a while
- ill-fitting mouthpieces (dentures)
- contact sport injury to the face
symptoms of a Buccinator Muscle Strain
- deep pain in cheek that resembles a painful cavity or abscessed tooth
- pain during movements like chewing, moving food around in the mouth, smiling and swallowing
Trigeminal nerve
CN V
- carries sensory and motor innervation to the face
- 3 branches
3 branches of the trigeminal nerve
- Ophthalmic (V1)
- Maxillary (V2)
- Mandibular (V3)
Ophthalmic branch (V1) of the trigeminal nerve
carries sensory information from skin of…
- the forehead
- upper eyelid
- midline of nose
Maxillary branch (V2) of the trigeminal nerve
innervated skin of lateral sides of…
- nose
- lower eyelid
- cheek
- temporal region
- upper lip
Mandibular branch (V3) of the trigeminal nerve
supplies skin of…
- lower lip
- lower face
- temporal region
- upper part of external ear
what is the only division of the trigeminal nerve that carries motor information to muscles of mastication?
the Mandibular division (V3)
Trigeminal Neuraligia
chronic pain condition resulting fro trigeminal nerve impairment
- can affect any branch of the trigeminal nerve
Causes of Trigeminal Neuralgia
- compression of trigeminal nerve by neighbouring structures
- multiple sclerosis
- natural aging process
- surgeries (parotid gland, reconstructive, plastic, maxillofacial)
Symptoms of Trigeminal Neuralgia
- brief periods of stabbing or shooting pain following path of trigeminal nerve, in teeth, jaw and gum region
- forehead region (V1) can also be affected
- pain triggered by brushing teeth, shaving, brushing hair - pain can last seconds to minutes with multiple attacks a day
Treatment for small salivary gland stones
- stimulate saliva flow by sucking on a lemon or sour candies
- physician may massage the cheeks to push stone out of duct
Treatment for large salivary gland stones
surgery needed
- small incision made in oral cavity to remove stone
***if they are recurrent of irreversible damage , surgical removal of entire gland may be necessary
- antibiotics if the stone have caused infection
extraocular muscles of the eye
7 muscles that control movement of the eyeball and eyelid
- movements occur around 2 axes
Extraocular muscles of the eye around the horizontal axis
- Superior rectus and inferior oblique
- Inferior rectus and superior oblique
Movement of the superior rectus and inferior oblique
elevation of the eyeball with the pupil in the midline
Movement of the inferior rectus and superior oblique
depression of the eyeball
Movement of the lateral rectus
abduction (moving pupil laterally) of the eyeball
Movement of the medial rectus
Adduction (moving pupil medially) of the eyeball
Arterial supply of the eye
the opthalamic artery
Opthalamic artery
branch of the internal carotid artery
- enters the orbit with the optic nerve through the optic canal
- branches of the opthalmic artery supply contents of the orbit and eyelids
branch of the opthalmic artery
central retinal artery
- nourishes the retina of the eyeball
Venous drainage of the eye
superior ophthalmic vein
superior ophthalmic vein
formed by the smaller veins that drain the orbit
- passes through superior orbital fissure to drain into the cavernous sinus
- inferior ophthalmic vein usually joins the superior ophthalmic vein before draining into the cavernous sinus
Pyomyositis
an scute bacterial infection caused by Staphylococcus aureus
Staphylococcus aureus
bacterium frequently found in the upper respiratory tract and on the skin
- affects skeletal muscles and if found in the orbit of the eye can develop into pyomyositis of the extraocular muscles
Symptoms of pyomyositis of the extraocular muscles
- pain
- swelling (bulging)
- redness in the eye as a result of immune response to the infection
- restricted movement of the eye due to swelling of muscles and pain
- infected and swollen extraocular muscles can compress the optic nerve leading to vision impairments
central retinal artery occlusion
may occur, depending on the location of pyomyositis
- will compromise the blood supply to the eye
the ear
contains the organs of hearing and balance, and is divided into 3 parts
3 parts of the ear
- external
- middle
- inner
the middle ear
an air-containing space within temporal bone of the skull, which functions to transmit vibrations from the tympanic membrane (ear drum) to the internal ear
eustachian tube
channel between the middle ear and nasopharynx
- helps equalize pressure on either side of tympanic membrane allowing the tympanic membrane to vibrate properly for transmission of sound to the inner ear
nasopharynx
upper part of the pharynx that connects to the nasal cavity
6 borders of the middle ear
- lateral
- medial
- posterior
- anterior
- roof
- floor
lateral border of the middle ear
lateral (membranous) wall is formed by the tympanic membrane
medial border of the middle ear
the medial (labyrinthine) wall separates the middle ear from the inner ear
the posterior border of the middle ear
the posterior wall is a thin bone separating the tympanic cavity from the mastoid air cells in the temporal bone
anterior border of the middle ear
- lower anterior (carotid) wall is a thin bone that separates the tympanic cavity from internal carotid artery
- upper anterior wall is incomplete - has an opening for eustachian tube
roof of the middle ear
tegmental wall
- formed by a thin plate of bone, the tegmen tympani, which separates the middle ear from the middle cranial fossa
floor of the middle ear
jugular wall
- thin bone which separates the middle ear from the internal jugular vein below
Eustachian Tube Dysfunction
temporary problem caused by the inability to equalize pressure in the middle ear
Symptoms of Eustachian Tube Dysfunction
- dulled hearing
- feeling of pressure or fullness in the affected ear
- if ear gets infected, may cause problems with balance
3 functions of the eustachian tube
- equalizing pressure across the tympanic membrane
- protect middle ear from nasopharynx fluid
- clears out middle ear secretions
muscles surrounding the eustachian tube
- levator veli palatini
- tensor veli palatini
- salpingopharyngeus
- tensor tympani
causes of Eustachian Tube Dysfunction
tube may not open because…
- a cold
- allergies
- tumors
- scarring
3 common dysfunctions of eustachian tube
- problems equalizing pressure, causing the tube to not open
- tube stays open rather than operating as a valve
- cilia unable to clear middle ear mucus secretions
treatment of Eustachian Tube Dysfunction
- relieve underlying issue - commonly an upper respiratory infection
- tympanostomy tubes to allow pressure to equalize
The nasal septum
forms the common medial wall that separates the right and left nasal cavities
- important supporting structure of the nasal cavity and is formed by cartilage and bone
anastomosis of arteries in the nasal septum
irritation caused by allergens, bacteria or foreign objets may cause swelling of these arteries which may restrict breathing
arterial supply of the nasal septum
- carotid arteries
- ophthalmic and maxillary artery
- kiesselbachs plexus
carotid arteries - nasal septum
internal and external carotid arteries ascend towards nasal septum
ophthalmic artery - nasal septum
branches off the internal carotid artery
maxillary artery - nasal septum
branches off the external carotid artery
kiesselbach’s plexus
branches off the ophthalmic and maxillary arteries, anastomose to form these
- a richly vascularized area in anterior portion of nasal septum
- common site of nosebleeds -rich blood supply
sensory information fo the nasal septum
carried by branches of the trigeminal nerve (CN V)
special sensory information (sense of smell)
carried by the olfactory nerve (CN I)
what innervates the anterosuperior part of the nasal septum
the ophthalmic branch (V1) of trigeminal nerve
what is the majority of the nasal septum innervated by (excluding the anterosuperior)
the maxillary branch (V2) of the trigeminal nerve
irritation of the nerves of the nasal septum
cause by allergens, bacteria or foreign objects
- cause an itchy sensation upon repeated stimulation
Nasal Polyps
soft, painless, noncancerous growths that hand down like teardrops or grapes from the lining of the nasal cavity
- common in adults
Causes of Nasal Polyps
chronic inflammation of the vascular supply in the walls of the nasal cavity which may be associated with asthma, recurring infection, allergies, drug sensitivity or certain immune disorders
Symptoms of Nasal Polyps
block nasal passages (congestion) if big, leading to a loss of smell, breathing problems, and a post-nasal drip
the oral cavity
bounded by a roof, composed of the palate, and a floor formed by a mucous membrane covering the mylohyoid muscle
what is on the floor of the oral cavity
the tongue
what is on the roof of the oral cavity
- hard palate
- soft palate
sensory innervation of the tongue
carried by three nerves
- divided into an anterior 2/3 section and a posterior 1/3 section
- receives general sensory and special sensory (taste) innervation
nerves that supply the tongue
- glossopharyngeal nerve (CN IX)
- Trigeminal nerve (CN V)
- Facial nerve (CN VII)
the glossopharyngeal nerve
has lingual branches that supply both general and special sensory innervation to posterior o1/3 of the tongue
the trigeminal nerve - the tongue
mandibular branch gives ride to the lingual nerve
- supplies general sensory innervation to the anterior 2/3 of the tongue
the lingual nerve
passes inferior to the lower third molar and is susceptible to injury during extraction of a lower wisdom tooth causing numbness or tingling sensations of the tongue
the facial nerve (CN VII) - the tongue
special sensory (taste) from the anterior 2/3 of the tongue is carried by lingual nerve to the chorda tympani, a branch of the facial nerve
the lingual artery
branch of the external carotid artery
- supplies the tongue, sublingual gland and the floor of the mouth
Dysgeusia
distortion of sense of taste
- tied to both the facial (chorda tympani) and glossopharyngeal nerves
symptoms with Dysgeusia
- loss of taste
- issues with swallowing
- impaired gag reflex
treatment for nasal polyps
- medications to reduce blood flow of ophthalmic and maxillary artery to reduce swelling
- surgery
- long-term management
the muscles of mastication
4 paired muscles that attach to the mandible
- responsible for movements of the jaw
pterygoid muscles
- internal and external
- located on inner surface of the mandible
- deep to temporalis and masseter muscles
lateral/external pterygoid muscle
fibres run horizontally to insert into the neck of mandible and capsule and articular disc of TMJ
medial/internal pterygoid muscle
fibres run obliquely downward and backwards to insert on medial surface of mandible near its angle
main action of muscles of mastication
chewing
- opening and closing of the mandible with side to side movements
elevation - muscles of mastication
- temporalis
- masseter
- medial pterygoid
depression - muscles of mastication
primarily gravity and relaxation of the muscles of mastication
lateral (side to side) - muscles of mastication
medial and lateral pterygoid muscles
protraction (protrusion)- muscles of mastication
lateral pterygoid muscle
retraction - muscles of mastication
temporalis muscle
what innervates the muscles of mastication?
the mandibular branch (V3) of the trigeminal nerve (CN V)
Lateral Pterygoid Strain Causes
- overuse
- clenching the jaw (maybe stress)
Lateral Pterygoid Strain
- chewing becomes very painful if the tongue, or food is pressed against the location of the muscle
- can result in TMJ dysfunction, due to insertion on capsule of TMJ
Symptoms of Lateral Pterygoid Strain
- pain radiating to maxilla (jaw)
- pain at TMJ
- TMJ dysfunction
Why does pain radiate to the maxilla with a Lateral Pterygoid Strain?
pain will follow the pathway of the mandibular nerve (V3), innervating the lateral pterygoid
TMJ dysfunction due to a Lateral Pterygoid Strain
if lateral pterygoid is strained it could cause displacement of the articular disc of TMJ, resulting in an impairment of masticatory function
- clicking may be heard due to resulting misalignment at the joint
the temporomandibular joint
a synovial, modified hinge joint between the head (condyle) of mandible, mandibular fossa, and the articular tubercle of the temporal bone
movements of the TMJ - normal chewing
TMJ acts like a hinge between the head of mandible and articular disc
movements of the TMJ - wide opening of the mouth
- mandible is depressed and pulled forward (protracted) by lateral pterygoid muscles
- head of mandible and articular disc slide anteriorly on articular tubercles
*** also prevents angle of mandible moving too far posteriorly
movements of the TMJ - elevation and retraction
elevation: temporalis and masseter
retraction: temporalis
TMJ Syndrome Causes
- problems with muscles of the jaw
- joint itself becoming compromised
- typically due to excess teeth grinding and jaw clenching resulting in misalignment of articular disc and damage to cartilage
Symptoms of TMJ Syndrome
- jaw clicking (most common symptom)
- pain and tenderness in jaw
- pain on one or both TMJs
- difficulty chewing
- locking of joint
articular cartilage in TMJ
serves as a cushion between the two bone surfaces
- attaches to lateral pterygoid anteriorly
- insensitive to pain due to lack of blood vessels and nerves
TMJ Syndrome
when the disc is dislocated anteriorly
- so the normal tissue is pulled between two bones because the cartilage is anterior
- causes pain and clicking as the condlye must slide anteriorly out of the socket to articulate with the disc - causes clicking
what vasculature supplies the muscles of mastication?
the maxillary artery
- terminal branch of the external carotid artery
middle meningeal artery
branch of the maxillary artery that enters the cranial cavity to supply much of the dura mater
Epidural Hematoma
occurs when a fracture in the skull tears the middle meningeal artery causing intracranial bleeding
-life-threatening
Causes of an Epidural Hematoma
blunt injury - head injury from collision, physical assaults, accidental falls
Symptoms of an Epidural Hematoma
- initial loss of consciousness following trauma
- rapid neurological deterioration
- severe headaches due to increase in intracranial pressure
- may damage nearby structures
- compression of oculomotor nerve resulting in permanent dilation of pupil on side of injury
Treatment for TMJ Syndrome
- physiotherapy to ease muscle pain
- meds to reduce pain and inflammation
- night guard to prevent grinding
- braces to correct misaligned bite
- surgery to repair or replace TMJ
Abducens nerve
provides motor innervation to the lateral rectus muscle
- responsible for maintaining a forward gaze plus the medial rectus
- dysfunction causes the eye to drift to midline (adduct)
Trigeminal nerve
carries general sensory information from the upper and lower jaw
- mandibular = lower jaw
Facial Nerve
provides motor innervation to muscles of facial expression
- if damages, cannot smile
Hypoglossal Nerve
controls the muscles of the tongue
- if damaged, moving the tongue in and out of mouth and using it to speak or swallow would be impaired
- left innervates left half, right innervates right half
Vestibulocochlear Nerve
transmits information regarding sound and equilibrium
- if damages, balance and hearing would be impaired
4 parasympathetic ganglia located within the head (top to bottom)
- the ciliary ganglia
- pterygopalatine ganglia
- submandibular ganglia
- otic ganglia
what innervates the parasympathetic ganglia?
1preganglionic fibres from the oculomotor (CN III), facial (CN VII), and glossopharyngeal nerves (IX)
The Otic Ganglion
small parasympathetic ganglion
- functionally associated with the glossopharyngeal nerve
- innervates the parotid gland
preganglionic parasympathetic fibres of the otic ganglia
the preganglionic parasympathetic fibres leave the medulla of the brainstem as the glossopharyngeal nerve (CN IX)
postganglionic parasympathetic fibres of the otic ganglia
the postganglionic parasympathetic fibres join the auriculotemporal nerve, a branch of mandibular branch of CN V, to innervate the parotid gland
Frey’s Sydrome
occurs when the auricolotemporal nerve is damaged, causing the parasympathetic nerve fibres of the parotid gland to switch to a sympathetic response, resulting in “gustatory sweating” instead of normal salivary response
- typically side effects of surgeries or near parotid gland
gustatory sweating
sweating in the anticipation of eating
how is Frey’s Syndrome diagnosed?
having individual eat an acidic lemon wedge
- usually lemon increases saliva, but is an individual has Frey’s, it will result in excessive sweating
3 arteries that supply the viscera of the face
- ophthalmic a. (branch of internal carotid a.)
- superficial temporal a.
- facial a.
(both branches of external carotid a.)
the opthhalmic artery
branch of the internal carotid a.
- its branches supply the eyes and forehead
terminal branches of the ophthalmic artery
form an anastomoses with branches of the facial, maxillary and superficial temporal arteries
- all arise from the external carotid a.
the superficial temporal artery (STA)
arises from the external carotid artery in parotid gland
- ascends the side of the face and crosses over the zygomatic arch to supply skin and muscles of temple and scalp, and parotid gland
pulse of the STA
can be felt where it crosses the zygomatic arch, anterior to the ear
the facial artery
enters the face by passing over the lower border of the mandible, running in a tortuous course towards the medial angle of the eye
- accommodates movements of the face - eyes, mandible, lips
what does the facial artery supply?
superficial structures of the skin and face
- such as muscles of facial expression and mastication
pulse of the facial artery
runs superficially, so can be felt where it crosses the mandible
Aneurysm
bulging or weakening of an artery wall
- 95% are brought on by traumatic injury - blunt force to the head
what is the main vein that drains the face?
the facial vein
the facial vein
runs alongside the facial artery and empties into the internal jugular vein
where does the facial vein drain into?
the cavernous sinus
the cavernous sinus
one of the dural venous sinuses, which function to drain blood from the brain
infections from the facial vein
the veins of the face do not contain valves, allowing blood to flow in either direction
- facial vein is a conduit for infection to spread from face to cavernous sinuses
what nerves would be affected by an infection of the cavernous sinus?
- trochlear nerve (CN IV)
- abducens nerve (CN VI)
- trigeminal nerve - ophthalmic branch (CN V3)
***nerves in the danger triangle
3 groups of lymph nodes that are responsible for lymphatic drainage of the head and neck
- Superficial ring of nodes (“collar nodes”)
- Superficial cervical nodes
- Deep cervical nodes
the collar nodes location
located at the collar - junction of the head and neck
the superficial cervical nodes location
found on the surface of the sternocleidomastoid (SCM)
- associated with the external jugular vein
the deep cervical nodes location
found deep to SCM
- closely related to the internal jugular vein
where do all lymphatic drainage of the head and neck empty?
in the deep cervical lymph nodes
- these continue to drain into the right lymphatic duct and thoracic duct, draining the right and left sides of the head, respectively
