Anatomy (bones, muscles, larynx and pharynx) Flashcards
how many cranial bones are there
8
what are the cranial bones
temporal, frontal, occipital, sphenoid, ethmoid, parietal
how many facial bones are there
14
what are the facial bones
maxilla x2 [2x + upper teeth]
zygomatic x2
nasal x2
palatine x2
inf nasal conchae x2
lacrimal x2
vomer
mandible
what bone looks like one bone but is two
maxilla
what bone is associated with the olfactory nerves and how?
the ethmoid bone protrudes up the base of the skull, and sits posterior to the NC forms the orbital side wall, which flattens forming a plate. Tiny holes are associated with the olfactory nerves
what muscles are involved in mastication
masseter
buccinator
obicularis oris
ptervgoid
temporalis
what does the masseter do?
covers the lateral aspect of the mandible, closes jaw, elevates the mandible
what does the temporalis do?
fan shaped which covers part of the temporal, parietal and frontal bones of the cranium. Closes jaw by retracting and elevating the mandible, maintains the mandible possible at rest
what does the obicularis oris do?
circular muscles which surround the lips, closing and pursing the lip. Work with the buccinator to keep food within the teeth
what does the ptervgoid do?
lateral and medial muscles which are concealed by the mandible, helps move the food side to side
what are the groups of salivary glands
submandibular
sublingual
parotid [largest group]
what nerve sits close to the parotid gland
facial nerve, can cause facial palsy
how is the pharynx laid out
nasopharynx -> oropharynx -> laryngopharynx -> oesophagus
how does the nasal cavity become the trachea
nasal cavity -> oral cavity -> epiglottis -> larynx -> trachea
the role of the anterior nares
forms an opening into the NC
the role of the posterior nares
creates a barrier between the nasopharynx and the cavity
what are the meatus
they are structures which create air turbulence, removing debris and pathogens
what is the role of the NC
air filtration, blood capillaries are close to the surface, so allows for humidification, moistening the air
the larynx extent
C3-C6
how many cartilages does the larynx have
nine
what type of cartilage covers the larynx, what structures doesnt have this cartilage
hyaline
epiglottis [elastic cartilage]
larynx relations
sup: hyoid bone, roof of tongue
inf: trachea
post: hypopharynx, C vertebrae
ant: muscles associated with the hyoid and neck
describe the thyroid cartilage
- 9 irregular cartilages joined by ligaments
- largest type (shield shape)
- stimulates hormones during puberty
- formed by two flat hyaline cartilages: thyroid lamina fused anteriorly at the laryngeal prominence
- at superior midline the laryngeal prominence separates forming thyroid notch [below the epiglottis attachment]
what is the cricoid cartilage
- below the thyroid cartilage
- narrow aspect is ant
- broad aspect is post which provides articulation for the arytenoid superiorly and the inferior cornu to the TC inferiorly
- lower border marks end of upper respiratory tract
epiglottis
- elastic cartilage
- attached to the TC, below the inferior end of the thyroid, which rises obliquely upwards behind the tongue and hyoid
- superior end free
- covered by taste bud mucosa
- covers and closes off larynx during swallowing, protects the lungs from inhaled pathogens
- initiates coughing if foreign material enters
what are the arytenoid cartillages
paired, pyramid cartilages at the top of the cricoid which provides attachment for the vocal chords, influence the position and tension of the true vocal chords
what is the corniculate cartilage
paired which open and close the glottis, and sound production
cuniform cartilages
pair wedged shaped found at the epiglottis fold
where does the larynx become continuous with the trachea
C6
vocal chords
- true and false which are folds of the mucous membrane
- true are formed from vocal ligaments [attached to the arytenoid cartilages to the thyroid cartilages, free edges extend from the thyroid prominence to the aryetenoid]
- anterior and posterior commissures are joinings of the vocal chord
- true appear white due to the poor blood supply
- false are vestibular folds found superior to the true with NO role in sound production
- false protect the true
- glottis is the opening between the TC through which air passes
what are the two laryngeal muscle groups
- extrinsic: attaches the cartilages to surrounding structures, position and stabilise the larynx
- intrinsic: attaches cartilages together, regulate tension of VC and open and closes the glottis
above the VC what is the lining
stratified squamous [sup TC + epiglottis]
below the VC what is the lining
ciliated columnar [inferior TC + cricoid + arynetoid]
what is the function of the larynx
- speech: during expiration when the glottis opens and closes, sound by the VC is manipulated by the tongue, cheeks and lips
- sound productivity
- pitch: tightness and cord length, longer chords = deep voice
- volume: greater force of vibration = louder sound
- resonance: tone of voice dependent on shape and position of mouth, tongue, lips, facial muscles and paranasal sinuses
- warming, filtering and humidifying air
- air passageway: between the pharynx and trachea
- protection: protects the lower respiratory tract during swallowing, the larynx occupies the pharynx opening and epiglottis moved to cover the larynx. makes sure the food bolus enters the oesophagus and not the trachea + lungs
what is the blood supply in larynx
arterial: sup + inf laryngeal arteries [branches off the sup and inf thyroid arteries]
venous: thyroid veins into internal jugular
what is the lymphatic supply in the larynx
anterior deep cervical -> superior deep cervical
what is the nerve supply in the larynx
superior and recurrent laryngeal nerves
branches off the vagus nerve, motor function to muscle, sensory function to lining
location of the pharynx
sits behind the NC, OC, larynx
opens to allow for communication between these sites
pharynx extent
base of skull - C6
is the pharynx mobile
mobility is restricted, but as you travel down to the oropharynx it becomes more mobile
how many regions does the pharynx have
3
attachments from the pharynx
anchored by the base of skull, attached laterally to the hyoid bone, mandible and base of tongue
what is the layers of tissue in the pharynx
mucous membrane
fibrous tissue
muscle
what parts of the pharynx have a digestive function
oropharynx
laryngopharynx
what part of the pharynx has a respiratory only function
nasopharynx
what is the nasopharynx composed of?
ciliated columnar
moves debris down to the oropharynx
what is the oropharynx and laryngopharynx composed of?
stratified squamous, provides protection due to the increased friction and chemical nature of the food
what is the thickness of fibrous tissue at the nasopharynx
thick (less muscle, rigid)
what is the thickness of the fibrous tissue at the oro and hypopharynx
thin (more muscle)
what does the muscle in the pharynx help with
swallowing, involuntary muscles: sup, inf and middle constrictor
describe the oropharynx
- opens into the OC
- extends from the soft palate, to the sup edge of the epiglottis [C3]
- largest portion
- uvula = extension of the soft palate, sparks vomit reflex
- palatine tonsils are collections of lymphoid tissue
- lingual, palatine, adenoids and pharyngeal form the waldeyers ring
describe the nasopharynx
- behind the NC
- at the soft palate level
- doesnt move
- adenoids have a immune response role
- auditory/ Eustachian tube equalizes pressure between the inner and outer ear
describe the hypopharynx
- associated with the larynx
- C3-C6
- becomes continuous with the oesophagus
- post = connects to oesophagus
- ant = connects to the larynx
what is the nerve supply of the pharynx
- via pharyngeal plexus
- parasympathetic = vagus + glossopharyngeal
- sympathetic = superior cervical plexus - constantly active to help with homeostasis
- autonomic = parasympathetic + sympathetic
what is the blood supply of the pharynx
arterial = via facial artery branches which is a branch off external carotid artery
venous = facial vein -> internal jugular vein
what is the lymphatic drainage of the pharynx
naso = internal jugular chain
oro = dependent on the subsite
soft palate = submandibular, superior internal jugular nodes
palatine = DCC/IJC
base of tongue = upper DCC
laryngo = DCC [post into retropharyngeal node, inferior into paratracheal nodes]
what are the lymph levels
IA = submental
IB = submandibular
IIA= jugulodigastric
IIB = internal jugular [sup]
III = middle internal jugular
IV = lower internal jugular, cricoid
VA = upper and middle spinal accessory
VB = lower spinal accessory
functions of the pharynx
- passageway for air and food
- warming and humidifying air
- hearing: maintains pressure balance both side of the tempanic membrane
- protection: waldeyers ring, collection of lymphoid tissue allows for antibody production
- speech: pharynx acts as an resonating chamber
- taste: nerve endings are related with the taste buds in the oropharynx
