Changes

===Oculomotor nerve (III)===

===Oculomotor nerve (III)===

The oculomotor nerve is part of the group of cranial nerves responsible for innervating the muscles of the head. The nerves originate from the ventral [[Midbrain_-_Anatomy_%26_Physiology|midbrain]] and is a motor nerve. It is composed of '''general somatic efferent fibres''' and '''general visceral efferent fibres'''. The general somatic efferent fibres of the oculomotor nerve are responsible for the motor function of four of the six external muscles of the eyeball; the 'dorsal rectus', 'medial rectus', 'ventral rectus', 'ventral oblique' and 'levator of the upper eyelid'. The general visceral efferent fibres of the oculomotor nerve are responsible for the control of pupil diameter and therefore control the 'spincter pupillae' muscle and the 'ciliaris' muscle.

The oculomotor nerve is part of the group of cranial nerves responsible for innervating the [[Skull_and_Facial_Muscles_-_Anatomy_%26_Physiology#Facial_Muscles|muscles of the head]]. The nerves originate from the ventral [[Midbrain_-_Anatomy_%26_Physiology|midbrain]] and is a motor nerve. It is composed of '''general somatic efferent fibres''' and '''general visceral efferent fibres'''. The general somatic efferent fibres of the oculomotor nerve are responsible for the motor function of four of the six [[Eye_-_Anatomy_%26_Physiology#Around_the_Eye|external muscles of the eyeball]]; the 'dorsal rectus', 'medial rectus', 'ventral rectus', 'ventral oblique' and 'levator of the upper eyelid'. The general visceral efferent fibres of the oculomotor nerve are responsible for the control of pupil diameter and therefore control the 'spincter pupillae' muscle and the 'ciliaris' muscle.

<br />

<br />

<br />

<br />

The oculomotor nerve has a pre-ganglionic nucleus in the midbrain and the nerve passes through the '''orbital fissure''', along with the trochlear, abducens and opthalmic branch (V1) of the trigeminal nerve. It synapses in the ciliary ganglion of the eye. During a clinical examination, horizontal eye movements (strabismus) or an abscent pupillary light reflex (PLR) may indicate a problem.  

The oculomotor nerve has a pre-ganglionic nucleus in the midbrain and the nerve passes through the [[Skull_and_Facial_Muscles_-_Anatomy_%26_Physiology#Major_Foramen_and_Canals|'''orbital fissure''']], along with the trochlear, abducens and opthalmic branch (V1) of the trigeminal nerve. It synapses in the ciliary ganglion of the eye. During a clinical examination, horizontal eye movements (strabismus) or an abscent [[Neurological_Eye_Examination_-_Horse#The_pupillary_light_reflex_.28PLR.29|pupillary light reflex (PLR)]] may indicate a problem.

 

===Trochlear nerve (IV)===

===Trochlear nerve (IV)===

The trochlear nerve is part of the cranial nerve group responsible for innervation of the muscles of the head. The trochlear nerve originates from the dorsal mid-brain and is a motor nerve. It is composed of '''general somatic efferent fibres''' and is the smallest of the cranial nerves. The nerve is specifically responsible for the 'dorsal oblique muscle' muscle of the eye and also passes through the '''orbital fissure'''.

The trochlear nerve is part of the cranial nerve group responsible for innervation of the muscles of the head. The trochlear nerve originates from the dorsal mid-brain and is a motor nerve. It is composed of '''general somatic efferent fibres''' and is the smallest of the cranial nerves. The nerve is specifically responsible for the 'dorsal oblique muscle' muscle of the eye and also passes through the '''orbital fissure'''.