A 26 -year-old male falls from the ladder and had suffered an intense head injury with moderate bleeding . suffers from head injury after falling from a ladder and bleeding in his head. During surgery , neurosurgeon noticed loss of sensation in the dura of middle cranial fossa. Which of the following nerves is injured ?

**Core Concept**
The middle cranial fossa contains various cranial nerves and structures that are susceptible to injury during head trauma. The dura mater, a protective membrane surrounding the brain, also plays a crucial role in this region. **The question requires identification of the nerve responsible for the loss of sensation in the dura of the middle cranial fossa.**

**Why the Correct Answer is Right**
The correct answer is **A. Olfactory nerve (I)**. The olfactory nerve is responsible for transmitting sensory information from the nasal cavity to the brain. However, it also provides sensory innervation to the dura mater covering the cribriform plate, which is located in the anterior part of the middle cranial fossa. The injury to the dura in this region suggests damage to the olfactory nerve. **The olfactory nerve is a branch of the trigeminal nerve (V) and is responsible for the transmission of sensory information from the nasal mucosa, including pain, temperature, and chemical sensations.**

**Why Each Wrong Option is Incorrect**
**Option B:** The **Optic nerve (II)** is responsible for transmitting visual information from the retina to the brain and does not provide sensory innervation to the dura mater of the middle cranial fossa.
**Option C:** The **Oculomotor nerve (III)** is responsible for controlling eye movements and does not have any sensory functions in the middle cranial fossa.
**Option D:** The **Trochlear nerve (IV)** also controls eye movements and does not have any sensory functions in the middle cranial fossa.

**Clinical Pearl / High-Yield Fact**
The **trigeminal nerve (V)** has three main branches: the ophthalmic (V1), maxillary (V2), and mandibular (V3) nerves. These branches provide sensory innervation to the face, including pain, temperature, and chemical sensations. The **olivary nucleus**, located in the medulla oblongata, receives input from the trigeminal nerve and is involved in the processing of pain and other sensory information.

**Correct Answer:** A. Olfactory nerve (I)

✓ Correct Answer: D. Trigeminal nerve