W7 flashcards
overview of the skull
- Houses the brain & special sensory organs (eyes, inner ear, tongue)
- Houses the face
- Has ONE mobile joint = TMJ
- important for communication, eating, seeing, smelling & tasting
two parts of the skull
neurocranium
viscerocranium
Neurocranium purpose
- Protects the brain
- Provides attachment for head & neck muscles
- Houses the special sense organ for hearing
Viscerocranium purpose
- Houses special sense organs for vision, smell & taste
- Contains openings for the respiratory & digestive tracts
- Anchors muscles of facial expression
- Includes the (TMJ)
Neurocranium components
frontal bone
parietal bone
occipital bone
temporal bone
sphenoid bone
ethmoid bone
Viscerocranium components
zygomatic bone
maxilla
mandible
vomer
palatine bone
nasal bone
lacrimal bone
inferior nasal concha
sphenoid bone
- Butterfly-shaped‘
- Divided into three parts (body, lesser wings, greater wing)
- Helps form the base & lateral sides of the skull
ethmoid bone
- In-between eyes and where the nose sits
- contributes to the medial wall of the orbit
- Directs inhaled air from the nostrils to the nasal cavity to the lungs
Infant skull
- Larger neurocranium
- smaller facial skeleton
- Thin & soft bones
fontanelles
~ soft spot of the skulls where the bones haven’t fully fused yet
~ this is so baby’s head can fit through the birth canal during childbirth
Child skull
- Larger facial skeleton – however proportion is more even
- Bones are fully fused
- Infant teeth with adult teeth developing
Adult skull
- Facial skeleton is larger
- Adult teeth only (possibly tooth gaps or decay)
- Paranasal sinuses fully developed
Elderly skull
- Smaller mandible & general smaller facial skeleton
- Thinner bones
- Loss of teeth
Anatomical spaces of the skull
Cranial cavity = contains the brain
Orbits = Contain the eyes & associated structures
Nasal cavity = contains nasal passages
Oral cavity = contains teeth, tongue etc
Paranasal sinuses
Air-filled extensions of the nasal cavity - into the surrounding skull bones
- Warm and humidifying the inspired air (air we breathe in)
Temporomandibular joint (TMJ)
connects your jaw to your skull
TMJ - Articular surfaces
- Mandibular fossa & articular tubercle of temporal bone
TMJ - movement
- Elevation (closing) & depression (opening)
- Protrusion & retrusion
- Lateral excursion / deviation (Side-to-side gliding in chewing)
GLIDIDNG MOVEMENTS = Mandible being moved from one position to another
face - function
- Brings together the organs for seeing, speaking, smelling, eating (including suckling) and tasting
Sensory innervation of the face
trigeminal nerve (CN V)
Trigeminal nerve components
Ophthalmic nerve (V1)
Maxillary nerve (V2)
Mandibular nerve (V3
V1 - ophthalmic
forehead, upper eye lids, nose ridge
V2 - maxillary
Lower eyelids, sides of nose, upper lip
V3 - mandibular
Lower lip, chin, sides of face
Blood supply of the face
Arteries supplying blood to the face are mainly branches of the external carotid artery (branch of common carotid artery)
Branches of exterior carotid artery
- superior thyroid artery
- Lingual artery
- Facial artery
- Superficial temporal artery
- Maxillary artery
Venous drainage of the face
veins draining the face accompany the arteries & ultimately drain into the jugular veins
vein components
- Superior thyroid vein
- Lingual vein
- Facial vein
- Superficial temporal vein
- Maxillary vein
Lymphatic drainage – process
- Lymph drains into the venous system
- Blood is delivered to your tissues, entering the venous system and returning to your heart
- End up with excess fluid in your tissues, that doesn’t get collected by the venous sytem & need to return its way into circulation
- Lymphatic vessels collect excess fluid and take it back into the venous system
Muscles of mastication
= all innervated by the TMJ
- Temporalis
- Masseter
- Medial pterygoid
- Lateral pterygoid
temporalis
Origin – temporal fossa
Insertion – coronoid process & tucks inside the ramus on the inside of the mandible
Actions – elevates & retracts mandible (superiorly)
Masseter
Origin – zygomatic arch
Insertion – angle & lateral surface (outside) of ramus and mandible
Actions – pull on the mandible upwards (elevates)
Medial pterygoid
Origin – has 2 parts
- Superficial head
- Deep head:
Insertion – medial surface of ramus of mandible – inside of madible
Actions
- Bilaterally: elevates & protrudes mandible (both sides)
- Unilaterally: laterally deviates mandible to contralateral side (one side)
Lateral pterygoid
Origin
- upper head: greater wing of sphenoid bone
- Lower head: lateral surface of lateral pterygoid plate of sphenoid bone
Insertion – physically attaches to the neck of condylar process of mandible, TMJ capsule and articular disc
Actions
- Bilaterally: protrudes mandible forward for opening your mouth wide
- Unilaterally: laterally deviates mandible to contralateral side (one side)
Mouth opening movement – process
- Head of the mandible sits on the mandibular fossa of the temporal bone when your open your mouths
- As you open your mouth further, the lateral pterygoid muscle pulls your jaw forward (protrude mandible)
mandible - fully opened
- condyle of the mandible slides forward
- is super imposed on the articular cubicle of the temporal bone
- (gliding action)
Oral region
- Oral cavity
- Teeth
- Gums (gingivae)
- Tongue
- Palate
- Oropharyngeal isthmus (fauces)
oral cavity divisions
Oral cavity proper: internal to the teeth & gingivae
Oral vestibule: between teeth & gingivae and the lips & cheeks
oral cavity - functions
= Passage for ingested material
- Hold ingested material prior to swallowing
- Begin digestion
- Articulation & resonance for speech
oral cavity - boundaries
Roof = palate
Floor = muscles (tongue sits on the floor)
~ Anterior = lips
~ Lateral = cheeks
~ Posterior = oropharyngeal isthmus
Hard palate
- Palate separated into 2 parts = hard palate & soft palate (closes nasopharynx during swallowing)
- Has a midline ridge called the palatine raphe
- has irregular folds of connective tissue called palatine rugae
Palatine rugae
~ extend from anterior palate to area of first premolars
~ highly sensitive
~ assist with speech & swallowing
Alveolar process (or ridge)
~ Bony ridge area closest to the teeth
~ thickened part of the maxillae – containing tooth sockets
~ Important for articulation of alveolar consonants (d, l, n, s, t, z)
Mucous membrane (mucosa)
= oral cavity is lined by a mucous membrane (mucosa)
- gingivae (gums) when it surrounds the teeth
- Gingivae and mucosa allow for greater withstanding of abrasion from ingested material
Cleft palate
= a birth defect that occurs when the maxillae don’t fuse in utero
- implication for speech & swallowing
- Often associated with cleft lip & palate (the incomplete formation of upper lip)
Tongue
Can be divided into two parts, separated by a V-shaped groove called the sulcus terminalis
~ Oral part: anterior 2/3
~ Pharyngeal part: posterior 1/3
cheeks (buccae)
Form the lateral walls of the oral cavity
~ moveable
~ continuous with the lips
- Linked by mucosa
- Contain fat pads, muscles, nerves & allow the duct of the parotid gland
Oropharyngeal isthmus
- form the posterior wall/boundary of the oral cavity
- Narrow passage (isthmus = narrow) between soft palate and tongue
- Boundary between oral cavity and oropharynx
- Bound by the pillars of fauces/faucial pillars
major salivary gland - 3 divisions
- Parotid gland
- Submandibular gland
- Sublingual gland
functions of saliva
- Cleans and moistens the oral cavity
- Maintains oral hygiene (antibacterial properties, neutralises acid)
Parotid gland
- largest salivary gland
- Located superficially on the face
- Produces mostly serous secretions
Submandibular gland
- Produce most of the total saliva
- Located deep & inferior to the body of the mandible
- Produces a mixture of serous & mucous secretions
Sublingual gland
- smallest of major salivary glands
- Located on the floor of the oral cavity
- Produces mostly mucous secretions
nerve supply
Parasympathetic NS – rest & digest
= increases salivation
Sympathetic NS – fight or flight
= innervation decreases salivation (via vasoconstriction)
Facial nerve (CN VII)
= submandibular & sublingual glands
Glossopharyngeal nerve (CN IX)
= parotid gland
CN V
= fibers are carried to the glands they innervate via the V3 division of the trigeminal nerve
facial nerve CNVII
Taste to anterior 2/3 of the tongue
glossopharyngeal nerve (CN IX)
Taste & general sensation to posterior 1/3 of tongue and pillars of fauces
vagus nerve (CN X)
Taste & general sensations to epiglottis and small area of the tongue
