PPt Kritika Hada Cranial nerve system-1.pdf

Anatomy of cranial nerve system

1. Anatomy of Cranial Nerve
3,4,6.
Presented by:-KRITIKA HADA
Submitted to:-KADYROVA
FARZONA
RAJABALIEVNA
MA'AM

2. 
Cranial nerve 3, also known as the oculomotor nerve, is responsible
for several crucial functions related to vision and eye movement.
Here are its key functions:
1.Controlling most eye movements: The oculomotor nerve
innervates four of the six extraocular muscles, allowing eyes to
move up, down, and inwards. This enables us to track objects,
change gaze, and maintain focus.
2.Lifting the upper eyelid: The oculomotor nerve innervates the
levatorpalpebraesuperiorismuscle, which raises
theuppereyelid.
3.Constricting the pupil and adjusting the lens: The oculomotor
nerve includes parasympathetic fibers that control the sphincter
pupillaemuscle, constricting the pupil to regulate light intake. It
also innervates the ciliary muscle, which changes the shape of the
lens to allow for near and far vision (accommodation).
1.Cranial nerve 3

3. 
Oculomotor nerve

4. 
Damage to the oculomotor nerve, known as oculomotor
nerve palsy, can cause various vision problems,
including:
a)Ptosis (drooping eyelid)
b)Diplopia (double vision)
c)Inability to move the eye in certain directions
d)Pupillary abnormalities
If you experience any concerning eye symptoms, it's crucial
to consult a healthcare professional for proper
diagnosisandtreatment.

5. 
Cranial nerve 4, also known as the trochlear nerve, is one
of the 12 cranial nerves that originate directly from the
brainstem. It is a purely motor nerve, meaning it only
carries signals awayfrom the brain to a muscle.
The trochlear nerve is responsible for innervating
(supplying) the superior oblique muscle, one of the six
extraocular muscles that control eye movement. The
superior oblique muscle helps to:
i.Depress (move downward) the eye
ii.Adduct (move inward) the eye
iii.Intort(rotateinward)theeye
2. Cranial nerve 4

6. 
Trochlear nerve

7. 
It is the smallest cranial nerve in terms of the number of
axons it contains.
It has the longest intracranial course of any cranial
nerve, meaning it travels the farthest distance within the
skull before exiting.
It is the only cranial nerve to have a dorsal exitfrom the
brainstem, meaning it exits the back of the brainstem
instead of the front.

8. Damage to the trochlear nerve can cause
** trochlear nerve palsy**, which can lead
to:
a.Double vision
b.Headache
c.Difficulty moving the eye downwards
d.Tilting of the head
If you are experiencing any of these symptoms, it is
important to see a doctor todeterminethe cause and
discuss treatmentoptions.

9. 
Cranial nerve 6, also known as the abducensnerve,
is one of the 12 cranial nerves that originate directly
from the brainstem. It is a purely motor nerve,
meaning it only carries signals away from the brain
to a muscle.
The abducensnerve is responsible for innervating
(supplying) the lateral rectus muscle, one of the six
extraocular muscles that control eye movement. The
lateral rectus muscle helps to abduct(move
outward)theeye.
3. Cranial nerve 6

10. 

11. Here's a summary of the abducensnerve:
a)Function:Controls the lateral rectusmusclefor outward
eye movement.
a)Origin:Pons of the brainstem.
b)Path:Travels through the base of the skull to reach the
eye.
a)Termination:Lateral rectus muscle.
Damage to the abducensnerve, known as abducensnerve palsy,
can cause the affected eye to be unable to move outward. This
results in double vision (diplopia) when looking at objects to the
side, as the brain receives conflicting information from the two
eyes about the object'slocation.

12. 
THANK YOU