Anatomy and physiology 2 - study questions (PNS)

What are the different parts of a nerve?

1. Axon: This is the long thread-like part of a nerve cell along which impulses are conducted from the cell body to other cells.

2. Dendrites: These are short branched extensions of the nerve cell, which carry impulses to the cell body.

3. Myelin Sheath: This is a protective covering that surrounds the axons and increases the speed at which impulses are transmitted.

4. Nodes of Ranvier: These are small gaps in the myelin sheath where the axon is exposed.

5. Synapse: This is the junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

Where are the different cranial nerves located, and what are their functions?

1. Olfactory Nerve: Located in the nose and is responsible for smell.

2. Optic Nerve: Located in the eyes and is responsible for vision.

3. Oculomotor Nerve: Controls most of the eye movements and pupil constriction.

4. Trochlear Nerve: Controls the superior oblique eye muscle.

5. Trigeminal Nerve: Responsible for facial sensation and controlling the muscles of mastication (chewing).

6. Abducens Nerve: Controls the lateral rectus muscle in the eye.

7. Facial Nerve: Controls facial expressions and the sense of taste in the anterior two-thirds of the tongue.

8. Vestibulocochlear Nerve: Responsible for hearing and balance.

9. Glossopharyngeal Nerve: Controls the sense of taste in the posterior one-third of the tongue and swallowing.

10. Vagus Nerve: Controls the heart rate and digestion.

11. Accessory Nerve: Controls the trapezius and sternocleidomastoid muscles in the neck.

12. Hypoglossal Nerve: Controls the movements of the tongue.

What are the different branches of the trigeminal and facial nerves?

The trigeminal nerve's major branches are the ophthalmic, maxillary, and mandibular nerves. They carry sensory information from various parts of the face and provide motor innervation to chewing muscles.

The facial nerve branches include the temporal, zygomatic, buccal, marginal mandibular, and cervical branches. They control muscles around the eyes, cheeks, mouth, chin, and neck.

Which holes in the skull do the different cranial nerves pass through?

1. Olfactory Nerve: Passes through the cribriform plate of the ethmoid bone.

2. Optic Nerve: Passes through the optic canal.

3. Oculomotor Nerve: Passes through the superior orbital fissure.

4. Trochlear Nerve: Passes through the superior orbital fissure.

5. Trigeminal Nerve: The ophthalmic division passes through the superior orbital fissure, the maxillary division passes through the foramen rotundum, and the mandibular division passes through the foramen ovale.

6. Abducens Nerve: Passes through the superior orbital fissure.

7. Facial Nerve: Passes through the internal acoustic meatus and exits through the stylomastoid foramen.

8. Vestibulocochlear Nerve: Passes through the internal acoustic meatus.

9. Glossopharyngeal Nerve: Passes through the jugular foramen.

10. Vagus Nerve: Passes through the jugular foramen.

11. Accessory Nerve: Passes through the jugular foramen.

12. Hypoglossal Nerve: Passes through the hypoglossal cana

What are the major nerves of the arm and leg?

The major nerves of the arm include the radial nerve, ulnar nerve, and median nerve. These are responsible for sensation and motor function in the arm and hand.

The major nerves of the leg include the sciatic nerve, which splits into the tibial nerve and the common peroneal nerve. These nerves control sensation and movement in the leg and foot.