Anatomy Flashcards
Which structure gives rise to the cupid’s bow?
Philtrum
From which part of the nasal cavity to we get sense of smell?
Olfactory epithelium
Nasal septum - anterior component
Hyaline cartilage
Nasal septum - posterior compartment
Bony
- perpendicular place of ethmoid bone (superiorly)
- vomer (inferiorly)
What divides the nasal cavity from the anterior cranial fossa?
Cribiform plate of ethmoid bone
Where is the crista galli of the ethmoid located?
medially and superiorly.
Superior to the nasal septum
Which conchae are part of the ethmoid bone?
Superior and middle
Where are the conchae located?
In the lateral wall of the nasal cavity
Function of conchae?
They create turbulence of the nasal cavity which ultimately creates better gas exchange
Where are the meatuses in relation to the conchae?
The space under each concha where the paranasal sinuses drain into
What are paranasal sinuses?
Extensions of the nasal cavities which aim to make the skull lighter
Name the 4 paranasal sinuses
Frontal sinus (2)
Maxillary sinus - antra (2)
Ethmoidal air cells (2)
Sphenoid sinus (2)
Where do frontal sinuses drain to?
Middle meatus
Where do maxillary sinuses drain to?
Middle meatus
Where do ethmoidal air cells drain to?
Anterior and middle drain into middle meatus
Posterior drains into superior meatus
Where do sphenoid sinuses drain to?
Sphenoethmoidal recess
What drains into the inferior meatus?
Nasolacrimal duct
3 types of mucosa in the nasal cavities
Keratinised stratified squamous epithelium
Respiratory epithelium
Olfactory mucosa
Keratinised stratified squamous epithelium in the nasal cavities
Located at the entrance of the nostril
The verbose hairs here start to filter foreign objects out of the air that you are breathing in
Respiratory epithelium in nasal cavities
This makes up the majority of the nasal cavity mucosa Columnar, glandular Warms the air Humidifies the air Secretes mucous Traps foreign bodies
Special sensory nerve supply to the nasal cavities (e.g. for smell)?
CN I (olfactory)
Where does CN 1 leave the brain?
Cribriform plate of ethmoid bone
Somatic nerve supply to the nasal cavities (e.g. for ho, cold, touch, pain)?
CNV1 (ophthalmic division) supplies anterosuperiorly
CNV2 (maxillary division) supplies posteroinferiorly
Which arteries does blood supply to the nasal cavities originate from?
External and internal carotid arteries
Branching of internal carotid artery which supplies the nasal cavities
Internal carotid artery ->
Ophthalmic artery ->
Anterior and Posterior ethmoidal artery -> supplies the medial and lateral walls of the nasal cavity
Branching of external carotid artery which supplies the nasal cavities
External carotid artery -> facial artery and maxillary artery
Facial artery -> lateral and septal branch
Maxillary artery -> sphenopalatine artery (lateral and medial walls), greater palatine (medial wall only)
What is Kiesselbach’s area
The anastamotic site of the nasal arteries in the nasal septum.
It is the most common site of epistaxis (nosebleed)
NG tube is passed through the SUPERIOR/INFERIOR aspect of the nasal cavity
Inferior
How do you ensure an NG tube has been correctly inserted into a patient?
X-ray
- NG tube should remain in the midline down to the level of the diaphragm and the tip should be seen in the diaphragm
Temporal bone 2 parts
Squamous (flat)
Petrous (stony/rocky)
What is the pterion
H shaped structure connecting 4 bones of the skull
It is the thinnest part of the skull
Which 4 bones does the pterion connect?
Temporal
Frontal
Parietal
Sphenoid
Which CN exit at the anterior cranial fossa ?
CN I
Which CN exit at the middle cranial fossa ?
CN II, CN III, CN IV, CNV1,V2,V3, CN VI
Which CN exit at the posterior cranial fossa ?
CN VII, CN VIII, CN IX, CN X, CN XI, CN XII
External ear
Collects sound and processes sound waves to the tympanic membrane
What are the 2 sections of the external ear
Auricle
External acoustic meatus
External ear: Auricle - function
Captures and transmits sound to the external acoustic meatus
External ear: Auricle - structure
Helix - outer curvature of ear
Tragus
Lobe - ear piercing site
External ear: Auricle - innervation
Mainly C2, C3 spinal nerve
CN VII - just posterior to tragus
External ear: EAM - function
Tube which extends to the tympanic membrane
External ear: EAM - innervation
CN V3 - superior part of EAM
CN X - inferior part of EAM
External ear: EAM - shape (adult vs children)
Adult: Curved
Child: short and straight
Middle ear - function
Amplifies and conducts sound waves (by transmitting vibrations) to the inner ear
Middle ear - which type of mucosa is present
Change from squamous epithelium -> columnar glandular mucosa
Middle ear: tympanic membrane
The connection between the external and middle ear
Middle ear: tympanic membrane - innervation
External surface:
CN V3 - most of tympanic membrane
CN X - inferior part of tympanic membrane
Internal surface
CN IX
Middle ear: tympanic membrane - umbo
ost inwardly depressed part of tympanic membrane
Created from handle of malleus
Middle ear: tympanic membrane - what is the thick part called?
Pars tensa
Middle ear: tympanic membrane - what is the thin part called?
Pars flaccida
Middle ear: tympanic cavity
Medial to tympanic membrane
Contains most of the bones of the middle ear
Middle ear: epitympanic recess
Superior to tympanic membrane
Near mastoid air cells
Middle ear: What are the bones of the middle ear called?
Auditory ossicles
Middle ear: name the 3 bones which link the tympanic membrane to the oval window
Malleus
Incus
Stapes (looks like a horses stirrup)
What is the smallest bone in the human body
Stapes
Middle ear: how do the auditory ossicles articulate with each other?
Synovial joints
Middle ear: aditus
The doorway from the epitympanic recess -> mastoid antrum
Where are mastoid air cells located
Posterior to epitympanic recess
Internal ear: location
From the oval window to the internal acoustic meatus (IAM)
Internal ear: function
Maintain balance
Convert mechanical signals from middle ear into electrical signals which transfer info to the auditory pathway of the brain
Internal ear: innervation
CN VIII (vestibulocochlear nerve)
2 parts
- vestibular nerve (balance)
- cochlear nerve (hearing)
Internal ear: bony labyrinth
A series of bony cavities Composed of: - cochela - vestibule - 3 semicircular canals All of these structures contain perilymph fluid
Internal ear: bony labyrinth - vestibule
In the middle of the bony labyrinth. Communicates with cochlea (anteriorly) and semicircular canals (posteriorly)
Internal ear: bony labyrinth - cochlea
Looks like a snails shell
Contains cochlea duct (responsible for hearing)
If it is unrolled you can visualise the basilar membrane
Internal ear: semicircular canals
Anterior, lateral, posterior
Contains semicircular ducts (responsible for balance)
Internal ear: Membranous labyrinth
Continuous system of sacs and ducts which is suspended within the bony labyrinth.
Filled with endolymph
Surrounded by perilymph of bony labyrinth