Peripheral Nervous System and Cranial Nerves

Flashcards covering the key vocabulary and concepts related to the peripheral nervous system, cranial nerves, spinal nerves, and related anatomy as discussed in the lecture.

Central Nervous System

Brain and spinal cord

Peripheral Nervous System

Anything beyond the spinal cord, including spinal and cranial nerves.

Sensory or Afferent Division

Division of the peripheral nervous system carrying information to the central nervous system.

Efferent or Motor Division

Division of the peripheral nervous system carrying information from the central nervous system.

Somatic Nervous System

Part of the efferent division controlling voluntary muscle movement.

Autonomic Nervous System (ANS)

Part of the efferent division controlling automatic functions like heart rate and digestion.

Sympathetic Division

Division of the autonomic nervous system associated with fight or flight responses.

Parasympathetic Division

Division of the autonomic nervous system associated with rest and digest functions.

Homeostasis

The maintenance of a stable internal environment.

Preganglionic Neuron (Sympathetic)

Neuron with its soma usually in the spine in the sympathetic nervous system.

Postganglionic Neuron (Sympathetic)

Neuron with its soma in the sympathetic ganglion, releasing norepinephrine.

Preganglionic Neuron (Parasympathetic)

Neuron usually in the brainstem or sacral region in the parasympathetic nervous system.

Postganglionic Neuron (Parasympathetic)

Neuron with its soma in a ganglion near the target organ, releasing acetylcholine or nitric oxide.

Thoracolumbar Region

Region from which the preganglionic neurons of the sympathetic nervous system originate (T1-L2).

Conus Medullaris

The area where the spinal cord terminates.

Cauda Equina

Nerve fibers beyond the conus medullaris.

Craniosacral Region

Brainstem and sacral region, which is the origin of preganglionic neurons for the parasympathetic nervous system.

Plexuses

Areas in the peripheral nervous system where several nerve roots come together.

Epineurium

Outer layer of connective tissue surrounding a peripheral nerve.

Perineurium

Layer of connective tissue surrounding a nerve fascicle.

Endoneurium

Innermost layer of connective tissue surrounding individual nerve fibers.

Spinal Nerves

Pairs of nerves originating from the spinal cord.

Neural Foramen

Opening through which nerve roots exit the spinal column.

Dorsal Root

Root carrying afferent or sensory information into the central nervous system.

Dorsal Root Ganglion

Collection of cell bodies from afferent neurons located on the dorsal root.

Ventral Root

Root carrying efferent or motor information from the central nervous system.

Brachial Plexus

Plexus formed by nerve roots from C5 to T1, giving rise to the median nerve.

Ulnar Nerve

Nerve associated with the brachial plexus, originating from C8 and T1.

Cervical Plexus

Plexus from which the phrenic nerve, important for breathing, originates.

Lumbar Plexus

Plexus associated with the femoral nerve.

Sacral Plexus

Plexus associated with the sciatic nerve.

Sciatic Nerve

The largest nerve in the body, running down the posterior part of the leg.

Dermatomes

Specific areas of skin innervated by specific spinal nerve roots.

Cranial Nerves

Pairs of nerves originating from the brainstem.

Olfactory Nerve (CN I)

Cranial nerve responsible for the sense of smell.

Optic Nerve (CN II)

Cranial nerve responsible for sensory information related to sight.

Oculomotor Nerve (CN III)

Cranial nerve that supplies four of the six eye muscles

Trochlear Nerve (CN IV)

Cranial nerve involved in the movement of the eyeball

Trigeminal Nerve (CN V)

Largest cranial nerve with three branches: ophthalmic, maxillary, and mandibular.

Mastication

The act of chewing.

Abducens Nerve (CN VI)

Cranial nerve involved in the movement of the eyeball.

Facial Nerve (CN VII)

Cranial nerve responsible for facial expressions.

Vestibulocochlear Nerve (CN VIII)

Cranial nerve responsible for hearing and equilibrium.

Glossopharyngeal Nerve (CN IX)

Cranial nerve responsible for swallowing and taste sensation in the posterior tongue.

Vagus Nerve (CN X)

Cranial nerve that wanders to the heart, lungs, liver, gallbladder, spleen, stomach, kidney, intestine, colon.

Accessory Nerve (CN XI)

Cranial nerve that supplies the trapezius, and sternocleidomastoid muscle.

Hypoglossal Nerve (CN XII)

Cranial nerve responsible for motor function of the tongue