206 SSNS - Anatomy Flashcards
Borders of Pterygopalatine Fossa
Anterior - Posterior wall of the maxillary sinus
Posterior - Pterygoid process of the sphenoid bone
Inferior - Palatine bone and palatine canals
Superior - Inferior orbital fissure of the eye
Medial - Perpendicular plate of the palatine bone
Lateral - Pterygomaxillary fissure
Which part of the auricle is LEAST likely to be affected by an auricular hematoma?
Lobule
- The lobule is a non-cartilaginous structure, and therefore is unlikely to be affected by an auricular hematoma.
Which structure marks the end of the external auditory meatus?
Tympanic membrane
The tympanic membrane is connected to the surrounding bone by a fibrocartilaginous ring. Which bone is it connected to?
Temporal
- The tympanic membrane is connected to the surrounding temporal bone by a fibrocartilaginous ring
Which structure forms the roof of the middle ear?
Petrous part of temporal bone
- The roof is formed by a thin bone from the petrous part of the temporal bone. It separates the middle ear from the middle cranial fossa
Which nerve innervates the tensor tympani muscle?
Mandibular nerve
- The tensor tympani originates from the auditory tube and attaches to the handle of malleus, pulling it medially when contracting. It is innervated by the tensor tympani nerve, a branch of the mandibular nerve
Where are the mastoid air cells in relation to the epitympanic recess?
Posterior
In which part of the temporal bone is the inner ear located?
Petrous
- The inner ear is located within the petrous part of the temporal bone. It lies between the middle ear and the internal acoustic meatus, which lie laterally and medially respectively
What lies directly inferior to the cochlear duct?
Scala tympani
Which structure forms the lateral wall of the cochlear duct of the inner ear?
Spiral ligament
- The lateral wall is formed by thickened periosteum, known as the spiral ligament.
Which cranial nerve is most associated with the auditory pathway?
CN VIII
- CN VIII is the vestibulocochlear nerve, which carries auditory and balance information from the inner ear to the brainstem.
In the primary auditory pathway, the first order neurons receive information from which structure?
Organ of Corti
- The first order neurons receive information from hair cells in the Organ of Corti
What is the most internal layer of the scalp?
Periosteum
- The periosteum is the outer layer of the skull bones. It becomes continuous with the endosteum at the suture lines.
In a scalp laceration, the resting tone of which muscle inhibits closure of the bleeding vessel and surrounding skin?
Occipitofrontalis
Which nerve provides innervation to the area of scalp behind the pinna?
Lesser occipital
- The lesser occipital nerve is derived from the anterior rami (division) of C2 and supplies the skin behind the pinna. The auriculotemporal nerve innervates the skin anterosuperior to the pinna.
Which cranial nerve innervates the orbicularis oculi muscle?
Facial nerve
- The orbicularis oculi is a muscle of facial expression - and so it is innervated by branches of the facial nerve.
The corrugator supercilii is a muscle of facial expression. What is its main action?
Drawing the eyebrows together
- The corrugator supercilii acts to draw the eyebrows together, creating vertical wrinkles on the bridge of the nose.
Which embryological structure do the muscles of mastication develop from?
First pharyngeal arch
Which nerve provides motor innervation to the muscles of mastication?
Mandibular nerve
What is the main action of the masseter muscle?
Elevation of the mandible
- closing mouth
What is the innervation of the extraocular muscle which chiefly acts to adduct the eyeball?
Oculomotor nerve
- The main action of the medial rectus is the adduct the eyeball. It is innervated by the oculomotor nerve
Which nerve provides somatic motor innervation to the levator palpebrae superioris?
Oculomotor
Where is the lacrimal gland located within the bony orbit?
Superior and lateral
- The lacrimal gland is located anteriorly in the superolateral aspect of the orbit, within the lacrimal fossa – a depression in the orbital plate of the frontal bone.
Which nerve provides sensory innervation to the lacrimal gland?
Lacrimal nerve
- The sensory innervation to the lacrimal gland is via the lacrimal nerve. This is a branch of the ophthalmic nerve (in turn derived from the trigeminal nerve).
The tarsal plate of the eyelid lies immediately deep to which muscle?
Orbicularis oculi
Where in the eyelid do the Meibomian glands lie?
Tarsal plate
Which structure comprises the majority of the fibrous layer of the eyeball?
Sclera
Which structure forms the innermost layer of an eye?
Retina
- The inner layer of the eye consists of the retina, the light detecting part of the eye. The retina itself consists of a neural layer and pigmented layer
What is the name given to the fluid which fills the anterior and posterior chambers of the eye?
Aqueous humor
- the anterior and posterior chambers are filled with aqueous humor; a clear plasma-like fluid that nourishes and protects the eye.
What are the 4 functions of nose?
- Warms and humidifies the inspired air.
- Removes and traps pathogens and particulate matter from the inspired air.
- Responsible for sense of smell.
- Drains and clears the paranasal sinuses and lacrimal ducts.
What are the 3 divisions of nasal cavity?
- Vestibule
- Respiratory region
- Olfactory region
What are the 3 conchae & 4 meatuses?
Conchae: inferior, middle, superior
Meatuses
- Inferior meatus – between the inferior concha and floor of the nasal cavity.
- Middle meatus – between the inferior and middle concha.
- Superior meatus – between the middle and superior concha.
- Spheno-ethmoidal recess – superiorly and posteriorly to the superior concha.
Whats the function of conchae?
↑ S.A. of nasal cavity - ↑ amount of inspired air that come into contact with cavity walls
Disrupt fast, laminar flow of air, making it slow & turbulent → air spends longer time and can be humidified
What passes through cribriform plate?
Olfactory nerve
What passes through incisive canal?
Nasopalatine nerve & greater palatine artery
What are the internal & external carotid branches that supply the nose?
Internal carotid branches:
- Anterior ethmoidal artery
- Posterior ethmoidal artery
External carotid branches:
- Sphenopalatine artery
- Greater palatine artery
- Superior labial artery
- Lateral nasal arteries
What’s the Little’s area?
Found on the anterior nasal septum
Anastomoses of 5 arteries: anterior ethmoidal artery posterior ethmoidal artery sphenopalatine artery greater palatine artery septal branch of the superior labial artery
Which nerve innervates (special) the nose?
Olfactory
Which nerve innervates (general) septum & lateral walls of nose?
Nasopalatine nerve (branch of maxillary nerve) & Nasociliary nerve (branch of ophthalmic nerve)
Which nerve innervates (general) external skin of nose?
Trigeminal nerve
What is the epithelial lining of the respiratory region of the nasal cavity?
Pseudostratified
- The respiratory region is lined by a ciliated pseudostratified epithelium, interspersed with mucus-secreting goblet cells.
Which structure marks the opening of the frontal, maxillary and anterior ethmoidal sinuses in the nasal cavity?
Semilunar hiatus
- The semilunar hiatus is a crescent-shaped groove on the lateral wall of the middle meatus.
The cribriform plate forms the roof of the nasal cavity. Which cranial bone does it belong to?
Ethmoid