Question

How many oblique and rectus muscles are found to move the eyeball in various directions inside the eye orbit?
A) Two
B) Four
C) Six
D) Eight

Answer 1

Hint:Let us first understand what are oblique and rectus muscles in eyes. The superior oblique muscle is also known as obliquus oculi superior. It is a fusiform muscle that originates in the medial, upper side of the orbit. The medial rectus or rectus muscle of an eye is an adductor. It functions in conjunction with lateral rectus and abducts the eye.

Complete answer:
For each eye, six extraocular muscles work together to control the eye position and facilitate the eye movement in their bony orbit. These muscles help the eye to move up and down, side to side and in rotation of the eye. They are:
Lateral rectus: it is an extraocular muscle that is attached to the side of the eye near to the temple and helps to move the eye outward.
Superior rectus: it is an extraocular muscle that is attached to the top of the eye and helps to move the eye upward.
Inferior rectus: it is an extraocular muscle that is attached to the bottom of the eye and helps to move the eye downward.
Medial rectus: it is an extraocular muscle that is attached to the side of the eye near to the nose and helps to move the eye inward towards the nose.
Inferior oblique: it is an extraocular muscle that arises near the nose in front of the orbit. Before attaching to the bottom part of the eyeball, it goes through outward and backward in the orbit of the eye. It helps to move the eye front and back, that is it helps to rotate outward along the axis of the eye.
Superior oblique: it is an extraocular muscle that arises from the backside of the orbit. It goes through the trochlea in the orbit near the nose and is ten attached to the top of the eye. It helps to rotate the eye inward along the axis of the eye.

Therefore the correct answers option (C) six.

Note: Along with these muscles, the motor nerve or the oculomotor nerve also facilitates the movement of the eye. Cranial nerve III (oculomotor), cranial nerve IV (trochlear) and cranial nerve VI (abducens) helps to control the position of the eyeball. Cranial nerve III also helps to control the position of eyelids and dilation of pupils.