A3- anatomy basics Flashcards
List bones that contribute to the 4 walls of the orbital cavity
Superior wall: frontal and sphenoid
Inferior wall: zygomatic, maxilla, palatine
Medial wall: sphenoid, lacrimal, ethmoid, maxilla
Lateral wall: zygomatic, sphenoid
Where does the lateral palpebral ligament attach?
From zygomatic bone to superior and inferior tarsus
Where does the medial palpebral ligament attach?
From maxilla to superior and inferior tarsus
What is the flow of fluid through the lacrimal system?
1: Lacrimal gland secretes fluid continually
2: Moved across surface of eyes as eyelids blink
3: Accumulates medially in lacrimla lake
4: Fluid passes into lacrimal punctum (opening)
5: Drained by superior and inferior lacrimal canaliculi
6: Forms the common lacrimal canaliculi
7: Drains into lacrimal sac
8: Drains into nasolacrimal duct
9: Empties into the inferior meatus of the nasal cavity
What is the attachment of the rectus muscles?
All originate at the common tendinous ring
All insert onto the sclera, posterior to the cornea-sclera junction (i.e. SR - to superior sclera, LR - lateral sclera etc.)
Where does the superior oblique attach?
O: body of sphenoid
I: Sclera deep to SR, but goes via the trochlear so changes direction
Where does the inferior oblique attach?
O: Anterior floor of orbit
I: Sclera deep to LR
Where does levator palpebral superioris attach?
O: Lesser wing of sphenoid
I: superior tarsus
What bones make up the external nose?
Frontal process of the maxilla
Frontal bones
Nasal bones
What makes up the nasal septum?
Anteriorly= septal nasal cartilage
Posteirorly= vomer and perpendicular plate of ethmoid
What bones contribute to the nasal cavity?
Nasal
Maxilla
Sphenoid
Vomer
Palatine
Lacrimal
Ethmoid
(“Nerdy Medical Students are often Very PaLE)
Describe the position of the meatus in the nasal cavity
Spheno-ethmoidal meatus
Superior concha
Superior nasal meatus
Middle concha
Middle nasal meatus
Inferior concha
Inferior nasal meatus
What opens up into each of the meatus?
Spheno-ethmoidal recess: sphenoid sinus
Superior meatus: posterior ethmoid sinus
Middle meatus: frontal sinus, maxillary sinus, anterior and middle ethmoid sinus
Inferior meatus: nasolacrimal duct
Where is the sphenoid sinus found?
Within the body of the sphenoid
Which sinus is the largest?
Maxillary
What bones form the orbital rim?
Superiorly: by frontal bone
Medially: by frontal process of maxilla
Inferiorly: by zygomatic process of maxilla and zygomatic bone
Laterally: by zygomatic bone and zygomatic process of frontal bone
What passes through the optic foramen/ canal?
Optic nerve
Ohpthlamic artery
What passes through the infra-orbital foramen?
Infra-orbital nerve (branch of maxillary)
What passes through the inferior orbital fissure?
Maxillary nerve and infraorbital vessels
What passes through the superior orbital fissure?
Oculomotor, trochlear, abducens, ophthlamic (V1)
Superior ophthalmic vein
What sinus can be used to access the pituitary gland?
Sphenoid
What is the hiatus semilunaris?
Crescent shaped groove in the middle meatus where the frontal, maxillary and ethmoid (anterior and middle) sinuses empty
What is the hiatus semilunaris?
Crescent shaped groove in the middle meatus where the frontal, maxillary and ethmoid (anterior and middle) sinuses empty
