POSTERIOR MUSCULAR SYSTEM Flashcards
What consists in muscular system?
Superior levator palpebrae
Suerpior and inferior tarsal muscle of muller
Where does the superior palpebral leavtor muscle found?
From lesser wing of sphenoid
Function of palberal leavtor m.?
Main retractor of the upper eyelid
What is whitnall’s ligament?
Serves as a fulcrum and changes the course of the muscle from anterior to posterior to superior inferior, which allows it to perform its function
What is the course of the palpebral leavtor muscle?
M. goes into the eyelid and become a fan shaped tendon know nas levator aponeurosis
Attach itself anterior surface of the tarsal plate
Forms the superior and inferior palpebral furrows
What is Whitnall’s ligament?
This is the anterior part of the levator, its the transition between the fleshlh part of the leavator muscle to the fibrous aponuresis
What is the function of Whitnall’s ligament?
Serve as a fulcrum and changes the course of the muscle from anterior to posterior direction to superior - inferior directions
What is levator aponeurosis?
Whitnall’s ligmanet extends itself into the eyelid and becomes a a fan shaped tendon
This tendon forms superior and inferior palpebral furrows
What is Muscle of Muller?
This is a smooth muscle that have Alpha 2 receptors
Innverated by sympathetic nervous system
What are the characteristics of Muller muscle?
Originates on the levator and extends into the tarsal plate
Widens the palpebral fissure by providing 2-3mm
This is minor retractor of the upper eyelid life
Ptosis and retraction of the eyelid can occur
Muller ptosis –> occurs in horner’s syndrome, results in slight ptosis
Muller retraction –> Occurs in thyroid eye disease, results in “stare appearance”
Levator ptosis –> occurs in 3rd nerve palsy; results in significant ptosis
which nerve opens the eye?
oculomotor CN III
Which eye closes the eye?
Facial Nerve VII
What is the function of tarsal plate?
This is the main supporting structure of the eyelids
Provides rigidity to the eyelids
Collagen fibrils that run horizontally and vertically that surround meibomian glands
They enclose meibomian glands and sebaceous glands that are found posterior to the eyelashes
