Nervous System Part 5: Cranial Nerves, Spinal Nerves, and Spinal Cord notes

A complete set of vocabulary flashcards covering the divisions of the peripheral nervous system, the 12 cranial nerves, and the organization and anatomy of the spinal cord.

Peripheral Nervous System (PNS)

Any neuron or nerve cell process located outside the bony confines of the skull and vertebral column, including all nervous tissue outside of the CNS.

Cranial Nerves

Bundles of axons attached to the brainstem carrying a combination of motor, sensory, and autonomic information to and from the CNS regarding the head and neck.

Spinal Nerves

31 pairs of mixed (sensory and motor) nerves extending from the spinal cord that innervate the body, including muscles, glands, mucous membranes, and joints.

Somatic Nervous System

A division of the peripheral nervous system that provides motor and sensory innervation to the joints, skin, and skeletal muscles.

Autonomic Nervous System

An involuntary division of the nervous system that innervates smooth muscles, glands, cardiovascular function, and internal organs to regulate arousal and body functions.

Sympathetic Nervous System

A division of the autonomic nervous system that uses energy to prepare the body for "fight or flight" situations during stressful scenarios.

Parasympathetic Nervous System

A division of the autonomic nervous system that conserves body energy and works to maintain internal balance (homeostasis).

Olfactory Nerve (CN I)

Sensory cranial nerve responsible for the sense of smell.

Optic Nerve (CN II)

Sensory cranial nerve responsible for vision.

Oculomotor Nerve (CN III)

Motor cranial nerve responsible for upward, downward, and medial eye movement, pupil constriction, and eyelid elevation.

Trochlear Nerve (CN IV)

Motor cranial nerve responsible for downward and outward eye movement.

Trigeminal Nerve (CN V)

Motor and sensory cranial nerve primarily responsible for jaw movement (chewing) and facial sensation, and partially responsible for soft palate movement and eustachian tube function.

Abducens Nerve (CN VI)

Motor cranial nerve involved in lateral eye movement.

Facial Nerve (CN VII)

Motor and sensory cranial nerve responsible for facial muscle movement, taste sensation on the anterior 2/3 of the tongue, and salivary gland function.

Vestibulocochlear Nerve (CN VIII)

Sensory cranial nerve responsible for hearing and balance.

Glossopharyngeal Nerve (CN IX)

Motor and sensory cranial nerve involved in pharyngeal sensation, taste on the posterior 1/3 of the tongue, innervating pharyngeal and lingual muscles, and stimulating salivary glands.

Vagus Nerve (CN X)

Motor and sensory cranial nerve involved in taste, swallowing, soft palate elevation, phonation, cardiac, respiratory, and digestive functions, as well as pharyngeal, palatal, and laryngeal movement.

Spinal Accessory Nerve (CN XI)

Motor cranial nerve responsible for neck and shoulder movement, which also assists in innervating muscles of the velum and pharynx.

Hypoglossal Nerve (CN XII)

Motor cranial nerve responsible for movement of the tongue.

Ventral Aspect of the Brain

Anatomy illustrating the ventral emergence locations of cranial nerves I through XII from the cerebrum and brainstem.

Spinal Cord

Neural tissue residing in the vertebral column, extending in adults from the first cervical vertebra to the first lumbar vertebra.

Cervical Segment

The upper segment of the spinal cord associated with 8 pairs of spinal nerves (C1–C8).

Thoracic Segment

The segment of the spinal cord associated with 12 pairs of spinal nerves (T1–T12).

Lumbar Segment

The segment of the spinal cord associated with 5 pairs of spinal nerves (L1–L5).

Sacral Segment

The lower segment of the spinal cord associated with 5 pairs of spinal nerves (S1–S5).

Coccygeal Segment

The terminal segment of the spinal cord associated with 1 pair of spinal nerves (CO1).

Spinal Cord Segmentation and Nerves

Structural organization showing the 5 spinal segments, conus medullaris, cauda equina, and associated 31 pairs of spinal nerves.

Transverse Section of Spinal Cord

Cross-sectional anatomy of the spinal cord showing an H-shaped interior mass of gray matter surrounded by white matter fasciculi, central canal, and roots forming a spinal nerve.