Upper respiratory tract and skull anatomy Flashcards
Bones of skull
frontal bone- forms forehead
parietal- large lateral and posterior bone
occipital- lateral and posterior bone beneath the parietal
temporal- lateral bones on either side
sphenoid- lateral bones more anterior to temporal
What does the face comprise of?
orbit, nose, upper jaw and lower jaw
orbit definition
bony protective socket for the eye
what forms the orbit?
frontal, sphenoid, maxilla and zygomatic bones
what bone forms the nose?
nasal bones form upper part of bridge of nose
What joins the maxilla and temporal bone? + what does it form?
zygomatic bone forming the zygomatic arch of the cheek
Jaw bones + articulation
upper jaw- maxilla
lower jaw- mandible
temporomandibular joint
Nose functions
warms air that passes into the lungs
olfaction- chemoreception, through the sensory olfactory system, that forms the perception of smell
Structure of nose
2 nasal bones- superior bridge of nose
2 lateral nasal cartilages
greater alar cartilages, form nostrils
soft tissue
adjacent to margin of maxilla
septum- formed by bony vomer, septal plate of the ethmoid and septal nasal cartilage
superior, middle and inferior meati
superior, middle and inferior conchae
what are the meati?
three nasal passages of the nasal cavity, located beneath the conchae
what are the conchae? + structure
long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose in humans
act to increase the surface area of the nasal passage
middle and upper conchae are part of the ethmoid bone
inferior conchae formed of different bone
what lines the nasal passage + function ?
mucus secreting cells and a rich blood supply that act to warm and add moisture to the air
upper part of nasal cavity lies a specialised sensory epithelium that enables the sensing of odours
What blood supply enters the nasal passage?
maxillary artery, facial artery and branches of the ophthalmic artery
originate from both the internal and external carotid supply
paranasal air sinuses location + definition
air-filled spaces that are lined with a mucus membrane and have openings into the nasal passage behind the conchae
within the bones surrounding the nasal passage
innervation of nose
sensory- trigeminal, 5th cranial nerve
parasympathetic innervation of mucosal glands- pterygopalatine ganglion which is supplied with pre ganglionic fibres from facial 7th cranial nerve
olfactory nerve innervates olfactory epithelium
which part of the jaw is moveable?
mandible
what muscles move the jaw?
muscles of mastication
muscles of mastication + function
temporalis and masseter- jaw closing muscles
medial and lateral pterygoid muscles- protrusion of the lower jaw and sideways movement
are all the muscles innervated by the same nerve + nerves
Yes
mandibular part of trigeminal nerve
two types of muscles in tongue
intrinsic and extrinsic
what are the muscles innervated by?
all innervated by hypoglossal nerve apart from palotoglossus
sensory
anterior 2/3rds from both trigeminal (general sensation) and facial (taste buds)
posterior third- glosssopharyngeal conveys both general and taste sensation
what are the muscles innervated by?
all innervated by hypoglossal nerve apart from palotoglossus (innervated by vagus)
sensory
anterior 2/3rds from both trigeminal (general sensation) and facial (taste buds)
posterior third- glosssopharyngeal conveys both general and taste sensation
what controls the parotid gland
otic ganglion, which receives parasympathetic pre-ganglionic innervation from the glossopharyngeal nerve
other two salivary glands + location and innervation
sub-mandibular and sublingual
lie adjacent to tongue
innervated by post-ganglion nerves from the sub-mandibular ganglion
ganglion innervated from facial nerve
explain the mouth
lips- densely innervated structures that act as a sensory surface and a muscular seal to the oral cavity
Different parts of the pharynx superior to inferior and markers where they change
nasopharynx
oropharynx
pharyngeal
What blocks the pharynx during swallowing?
nasopharynx is blocked off from oropharynx by the elevation of the soft palate
Important bone in pharynx + attachments
hyoid
lies in the upper part of neck, above the thyroid cartilage suspended by muscles and the stylohyoid ligament.
hyoid function
allows a wider range of tongue pharyngeal and laryngeal movements by bracing these structures alongside each other
muscles of pharynx and attachments
muscular tube formed by three constrictor muscles
superior, middle and inferior constrictors
attach to the medial pterygoid plate, hyoid bone, thyroid cartilage and the cricoid cartilage
fused posteriorly as the raphe
what innervates the constrictor muscles of the pharynx?
pharyngeal plexus
how do the muscles move?
undergo peristaltic contractions in response to stimulation of receptors in the upper part of the oropharynx
what is found between the pharynx and oesophagus?
sphincter called the cricopharyngeus
structures + function of the larynx
formed of a series of cartilages and membranes which protect the airway and vocal apparatus
epiglottis- leaf like cartilage which covers the opening of the larynx upon swallowing
thyroid cartilage- major anterior cartilage of the larynx- larger in males, Adam’s apple. within this there are two arytenoid cartilages which are the attachment points for the vocal cords and their points of attachment
cricoid cartilage- like a signet ring, lies on top of the trachea
vocal cord definition
pair of vibrating membranes responsible for vocalisation
How do the vocal cords work?
vocal cords are attached to the arytenoid cartilages- can be separated or brought together by the action of vocal muscles
thyroid cartilage also pivots relative to the cricoid cartilage
muscles pulling the the thyroid closer to the cricoid cartilage act to increase the tension in the vocal cords and hence pitch
muscles running parallel to the vocal cords between the thyroid cartilage and arytenoids slacken the vocal cords, decreasing the pitch
Why are men’s voices deeper?
thyroid cartilage is larger
What happens during swallowing?
- teeth breakdown food
- tongue mixes food with salivary secretions to form a paste like bolus
- tip of the tongue is elevated against the hard palate and the posterior part of the tongue is depressed, so the bolus moves to the oropharynx
- sensory receptors on the posterior part of the tongue- glossopharyngeal- initiates a swallowing reflex
- soft palate is tensed and elevated, sealing the nasal part of the pharynx
- hyoid bone is elevated as as the bolus passes into the pharynx, where the phayngeal constrictors force the bolus down toward the oesophagus
- elevation of the hyoid causes the epiglottis to cover the opening of the larynx, protecting the airway
- the bolus passes over the epiglottis, down into the pharynx and once past the cricophargyngeaus muscle, the hyoid descends and the epigottis flips back to reopen the airway
