25/11/2025
Cranial Nerves 🧠
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▪️Overview :
- The cranial nerves are a set of 12 paired nerves that originate from the brain and brainstem.
- They transmit electrical signals between the brain, face, neck, and torso, allowing communication between the central nervous system and the rest of the body.
- Cranial nerves are responsible for essential sensory and motor functions , including taste, smell, hearing, vision, facial expression, eye movement, swallowing, and even heart rate control.
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⚙️ Function :
▪️ The cranial nerves are classified as sensory, motor, or mixed (both sensory and motor):
1) Sensory nerves help you:
- Feel touch and temperature.
- Hear.
- See.
- Smell.
- Taste.
2) Motor nerves control movement of:
- Facial muscles.
- Tongue and jaw.
- Neck and shoulder muscles.
- Certain glands (e.g., salivary and tear glands).
▪️ Some cranial nerves perform both sensory and motor functions.
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▪️The 12 Cranial Nerves and Their Main Functions :
1- Olfactory nerve (I) → Responsible for the sense of smell.
2- Optic nerve (II) → Allows you to see.
3- Oculomotor nerve (III) → Controls eye movement and blinking.
4- Trochlear nerve (IV) → Moves the eyes up and down or side to side.
5- Trigeminal nerve (V) → Provides facial sensation, helps with chewing, and contributes to taste.
6- Abducens nerve (VI) → Controls lateral eye movement.
7- Facial nerve (VII) → Enables facial expressions and contributes to taste sensation.
8- Vestibulocochlear (Auditory) nerve (VIII) → Responsible for hearing and balance.
9- Glossopharyngeal nerve (IX) → Helps in swallowing and taste.
10- Vagus nerve (X) → Controls digestion, heart rate, and internal organ functions.
11- Accessory nerve (XI) → Controls neck and shoulder movement.
12- Hypoglossal nerve (XII) → Controls tongue movement.
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