Cranial Nerves and Skull Foramina Lecture

Flashcards covering the subdivisions of the nervous system, types of neurons, specific cranial nerves (I-XII), and skull openings (foramina).

Central Nervous System (CNS)

A division of the nervous system that includes the brain and the spinal cord.

Peripheral Nervous System (PNS)

A division of the nervous system that includes nerves and bundles of neuron cell axons.

Somatic Sensory Division

A functional division of the PNS that provides input to the CNS from the skin and joints.

Visceral Sensory Division

A functional division of the PNS that provides input to the CNS from the organs and blood vessels.

Motor Division

A functional division of the PNS that provides output from the CNS to the effectors.

Visceral Motor Division (Autonomic NS)

A division of the motor system that controls smooth muscle, cardiac muscle, and glands; includes sympathetic and parasympathetic subdivisions.

Sympathetic Division

A part of the Autonomic NS associated with action.

Parasympathetic Division

A part of the Autonomic NS associated with digestion.

Somatic Motor Division

A division of the motor system where the effectors are skeletal muscle tissue.

Sensory Neurons

Neurons that detect stimuli and send input to the brain or the spinal cord.

Interneurons

Neurons that process input and determine output.

Motor Neurons

Neurons that send signals from the CNS to effectors.

Action Potential

An electrical signal that travels in one direction along the neuron.

Soma

The cell body of a neuron usually containing a single, central nucleus.

Dendrites

Neuronal structures that receive input messages or stimuli.

Axons

The pathway for electrical messages in a neuron, containing the myelin sheath.

Terminal Ends

The final structure in the electrical pathway of a neuron.

Synapse

The site where chemical signals via neurotransmitters pass a message to the next cell.

CN I (Olfactory Nerve)

A sensory nerve for smell that exits through the cribriform plate of the ethmoid bone.

CN II (Optic Nerve)

A sensory nerve for vision.

CN III (Oculomotor Nerve)

A motor nerve that directs the gaze up, down, and medially.

CN IV (Trochlear Nerve)

A motor nerve for eye movement slightly downward and rotating the top of the eyeball.

CN V (Trigeminal Nerve)

A mixed nerve divided into Ophthalmic, Maxillary, and Mandibular branches used for facial sensation and mastication.

CN VI (Abducens Nerve)

A motor nerve for eye movement that controls the lateral rectus muscle of the eye.

CN VII (Facial Nerve)

A mixed nerve providing taste to the anterior $\frac{2}{3}$ of the tongue and motor control for facial expressions.

CN VIII (Vestibulocochlear Nerve)

A primarily sensory nerve for hearing and equilibrium, with a motor effect for tuning hearing.

CN IX (Glossopharyngeal Nerve)

A mixed nerve providing taste sensation for the posterior $\frac{1}{3}$ of the tongue and motor control for swallowing and gagging.

CN X (Vagus Nerve)

A mixed nerve for the regulation of viscera and organs; contains \text{90%} of parasympathetic fibers.

CN XI (Accessory Nerve)

A motor nerve for swallowing, neck, and shoulder movements.

CN XII (Hypoglossal Nerve)

A motor nerve for tongue movements, food manipulation, and swallowing.

Foramen magnum

The skull opening through which the Spinal Cord and CN XI pass.

Hypoglossal Canal

The skull opening through which CN XII passes.

Jugular Foramen

The skull opening through which the Jugular vein and CN IX, X, and XI pass.

Carotid Canal

The skull opening through which the Carotid artery passes.

Foramen Lacerum

A skull opening through which the Carotid artery passes.

Internal Auditory Canal

The skull opening through which CN VII and VIII pass.

Foramen Spinosum

The skull opening through which the artery for the meninges passes.

Foramen Ovale

The skull opening through which CN V passes.

Foramen Rotundum

The skull opening through which CN V passes.

Superior Orbital Fissure

The skull opening through which CN III, IV, and VI pass.

Optic Canal

The skull opening through which CN II passes.

Olfactory/Cribriform Foramina

The skull openings through which CN I passes.

Stylomastoid Foramen

The skull opening through which CN VII passes.