Untitled Quiz

Cranial Nerves

• 12 pairs of cranial nerves originate from the brain and exit the skull through foramina.
• Each nerve has a specific function and is crucial for various bodily activities.

Cranial Nerve Functions

• Olfactory Nerve (1st): Smell
• Optic Nerve (2nd): Vision
• Oculomotor Nerve (3rd): Controls most eye muscles
• Trochlear Nerve (4th): Controls one eye muscle
• Abducens Nerve (6th): Controls one eye muscle
• Trigeminal Nerve (5th): Mixed nerve (motor and sensory); controls chewing muscles, sensory facial sensation
• Facial Nerve (7th): Mixed nerve (motor, sensory, and parasympathetic); facial expressions, taste
• Auditory Nerve (8th): Hearing and equilibrium
• Glossopharyngeal Nerve (9th): Mixed nerve (motor, sensory, and parasympathetic); taste, swallowing
• Vagus Nerve (10th): Mixed nerve (motor, sensory, and parasympathetic); vital functions (respiration, digestion, heart rate), sensation from many areas
• Accessory Nerve (11th): Pure motor; head and neck muscles (trapezius, sternocleidomastoid)
• Hypoglossal Nerve (12th): Pure motor; tongue muscles

Function Types of Cranial Nerves

• Motor: Controls muscle movement
• Sensory: Detects sensations (taste, touch, temperature)
• Parasympathetic: Regulates involuntary functions (digestion, heart rate)

Origin and Exit Points of Cranial Nerves

• Cranial nerves originate from different locations within the brainstem.
• They exit the skull through specific foramina (openings).

Branches and Divisions - Trigeminal Nerve

• Trigeminal Nerve has three divisions
  • Ophthalmic nerve (sensory)
  • Maxillary nerve (sensory)
  • Mandibular nerve (mixed)

Branches of Cranial Nerves Facial Nerve

• Temporal, Zygomatic, Buccal, Mandibular Branches

Branches of Glossopharyngeal Nerve

• (Sensory & Parasympathetic)

Branches of Vagus Nerve

• (Sensory, Motor & Parasympathetic)

Branches of Accessory Nerve

• (Motor)

Branches of Hypoglossal Nerve

• (Motor)

Cranial Nerve Functions - Detailed

• Trigeminal Nerve (5th):
  • Motor: Muscles of mastication (chewing)
  • Sensory: General sensations (touch, pain, temperature) from the face, teeth, and mouth
• Facial Nerve (7th):
  • Motor: Facial expressions, muscles of facial expression
  • Sensory: Taste from the anterior two-thirds of tongue
  • Parasympathetic: Salivary glands, tear glands
• Glossopharyngeal Nerve (9th):
  • Motor: Muscles of pharynx and larynx (swallowing)
  • Sensory: Taste from the posterior one-third of tongue, general sensations from pharynx and carotid body
  • Parasympathetic: Salivary glands
• Vagus Nerve (10th):
  • Motor: Muscles of pharynx and larynx (swallowing), smooth muscle in internal organs
  • Sensory: General sensations from the thoracic and abdominal viscera
  • Parasympathetic: Regulation of many bodily functions
• Accessory Nerve (11th):
  • Motor: Trapezius and sternocleidomastoid muscles (shoulder movement and head turning)
• Hypoglossal Nerve (12th):
  • Motor: Intrinsic and extrinsic muscles of tongue (movement of tongue)

Effects of Injury to Cranial Nerves

• Hemiatrophy: Affected side of the tongue may shrink.
• Deviation during protrusion: Tongue deviates to the affected side.