BIOL-2242: Nervous System Lab Practical 3

Flashcards covering sheep brain structures, human regional brain anatomy, cranial nerve modalities, detailed cranial nerve functions and clinical disorders, spinal nerve plexuses and muscular innervations, and neuroimaging landmarks for Lab Practical 3.

Somatic Motor

Functional nerve modality responsible for motor output to skeletal muscle.

Somatic Sensory

Functional nerve modality conveying sensation from cutaneous touch, pain, temperature, position, and pressure receptors.

Special Sensory

Functional nerve modality carrying somatic sensation from special sensory organs such as the eye and ear.

Visceral Motor

Functional nerve modality responsible for motor output to cardiac muscle, smooth muscle, and glands.

Visceral Sensory

Functional nerve modality carrying sensation from sensory receptors within visceral organs (e.g., stretch receptors in the bladder wall).

Olfactory Nerve (CN I)

Cranial Nerve
Type: Sensory-Only
General Function: pecial sensory function as the sensory nerve of smell.

Optic Nerve (CN II)

Sensory-only cranial nerve providing special sensory function as the sensory nerve of vision.

Oculomotor Nerve (CN III)

Motor-only cranial nerve providing somatic motor innervation to the levator palpebrae superioris and all extrinsic eye muscles except the superior oblique and lateral rectus, and visceral motor (parasympathetic) innervation to the ciliary body and iris (pupillary sphincter muscles).

Trochlear Nerve (CN IV)

Motor-only cranial nerve providing somatic motor innervation to the superior oblique extrinsic muscle of the eye for eye movement.

Ophthalmic Branch ($\text{CN } V_1$)

Division of the trigeminal nerve that provides somatic sensory innervation from the cornea, scalp, and forehead.

Maxillary Branch ($\text{CN } V_2$)

Division of the trigeminal nerve that provides somatic sensory innervation from the face, cheeks, and maxillary (upper) teeth.

Mandibular Branch ($\text{CN } V_3$)

Division of the trigeminal nerve providing somatic sensory sensation from the chin, mandibular (lower) teeth, and tongue, as well as somatic motor innervation to the muscles of mastication.

Abducens Nerve (CN VI)

Motor-only cranial nerve providing somatic motor innervation to the lateral rectus extrinsic muscle of the eye for lateral eye movement.

Facial Nerve (CN VII)

Mixed cranial nerve providing special sensory taste from the anterior two-thirds of the tongue, somatic motor innervation to the muscles of facial expression, and visceral motor (parasympathetic) innervation to the lacrimal glands and the submandibular and sublingual salivary glands.

Vestibulocochlear Nerve (CN VIII)

Sensory-only cranial nerve providing special sensory function as the nerve of hearing and balance.

Glossopharyngeal Nerve (CN IX)

Mixed cranial nerve providing special sensory taste and general somatic sensation to the posterior one-third of the tongue, cutaneous ear sensation, visceral sensation from the carotid body, carotid sinus, and pharynx, somatic motor output to the stylopharyngeus muscle, and parasympathetic visceral motor control to the parotid salivary gland.

Vagus Nerve (CN X)

Mixed cranial nerve providing taste from the palate and epiglottis, somatic sensation from the ear and posterior dura mater, visceral sensation from thoracic/abdominal viscera, somatic motor output to muscles of the pharynx, larynx, and palate, and visceral motor (parasympathetic) output to cardiac muscle and most thoracic and abdominal smooth muscles and glands.

Accessory Nerve (CN XI)

Motor-only cranial nerve providing somatic motor innervation to the trapezius and sternocleidomastoid muscles for shoulder shrugging and head rotation.

Hypoglossal Nerve (CN XII)

Motor-only cranial nerve providing somatic motor output to the intrinsic and extrinsic muscles of the tongue for tongue movement, speech, and swallowing.

Anosmia

The inability to smell, often caused by a fracture of the cribriform plate of the ethmoid damaging the olfactory nerves.

Anopsia

Visual field defects caused by an intracranial tumor or stroke damaging the optic nerve or optic tract, preventing visual information from reaching the brain.

Mydriasis

Pupil dilation; often the first sign of CN III damage or increased intracranial pressure compressing parasympathetic fibers on the nerve surface.

Ptosis

Drooping of the upper eyelid, which can occur as a result of muscle paralysis caused by oculomotor nerve (CN III) damage.

Trigeminal Neuralgia (Tic Douloureux)

A condition characterized by sudden, intense pain along the course of one of the divisions of CN V, caused by pressure from an adjacent artery stimulating sensory fibers and often triggered by touching structures inside the mouth.

Bell Palsy

Paralysis of the muscles of facial expression on the side of the face affected by facial nerve (CN VII) inflammation, most commonly resulting from a viral infection.

Ageusia

Loss of taste sensation, which can result from damage to CN VII (anterior two-thirds of the tongue) or CN IX (posterior one-third of the tongue).

Hypoptyalism

Decreased salivation resulting from damage interrupting parasympathetic innervation via the facial nerve (CN VII) or glossopharyngeal nerve (CN IX).

Acoustic Neuroma

A tumor originating in neurolemmocytes within the internal acoustic meatus that compresses the vestibulocochlear nerve (CN VIII), resulting in loss of balance, nausea, vomiting, dizziness, or deafness.

Dysphagia

Difficulty in swallowing; can result from interrupting the sensory component (CN IX) or the motor component (CN X) of the swallowing reflex.

Dysphonia

Hoarseness resulting from paralysis of the muscles of the larynx due to vagus nerve (CN X) damage.

Cervical Plexus

Nerve plexus formed by the ventral rami of spinal nerves $C_1\text{--}C_4$.

Phrenic Nerve

Nerve originating from spinal levels $C_3\text{--}C_5$ that innervates the diaphragm for breathing.

Ansa Cervicalis

A nerve arising from the cervical plexus that innervates the infrahyoid muscles.

Brachial Plexus

Nerve plexus formed by the ventral rami of spinal nerves $C_5\text{--}T_1$.

Musculocutaneous Nerve

Branch of the brachial plexus that provides motor innervation to the anterior arm muscles.

Median Nerve

Branch of the brachial plexus that provides motor innervation to the anterior forearm muscles.

Ulnar Nerve

Branch of the brachial plexus that provides motor innervation to anterior arm muscles and hand muscles.

Radial Nerve

Branch of the brachial plexus that provides motor innervation to the posterior arm and forearm muscles.

Axillary Nerve

Branch of the brachial plexus that provides motor innervation to the deltoid and teres minor muscles.

Intercostal Nerves (T1–T11)

Thoracic spinal nerves that innervate the chest and abdominal wall muscles.

Lumbosacral Plexus

Nerve plexus formed by spinal nerves $L_1\text{--}S_4$.

Femoral Nerve

Major nerve branching from the lumbosacral plexus that innervates the quadriceps and sartorius muscles.

Obturator Nerve

Nerve branching from the lumbosacral plexus that innervates the adductor muscles.

Iliohypogastric Nerve

Nerve of the lumbosacral plexus that innervates the internal obliques and transversus abdominus.

Tibial Nerve

Division of the sciatic nerve providing motor innervation to the hamstrings, adductor magnus, triceps surae, popliteus, and flexor muscles of the foot and toes.

Common Fibular Nerve

Division of the sciatic nerve providing motor innervation to the tibialis anterior and extensor muscles of the toes.

Superior Gluteal Nerve

Nerve of the lumbosacral plexus that innervates the gluteus medius and gluteus minimus muscles.

Inferior Gluteal Nerve

Nerve of the lumbosacral plexus that innervates the gluteus maximus muscle.

Cranial Nerves (Ventral Brainstem View)

The inferior anatomical view of the brain showing the attachment locations of cranial nerves I through XII along the forebrain and brainstem.

Spinal Nerves and Plexuses (Posterior View)

Anatomical arrangement showing the 31 pairs of spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal), their associated plexuses, and the cauda equina.

Midsagittal Brain MRI

Magnetic resonance imaging slice in the sagittal plane used to identify midline structures such as the corpus callosum, thalamus, ventricles, brainstem, and cerebellum.