BIOL 2113 Lab Exam 4 – Key Vocabulary

A comprehensive set of vocabulary flashcards covering muscles, nervous system structures, cranial nerves, and special senses for BIOL 2113 Lab Exam 4 preparation.

Skeletal muscle tissue

Striated, voluntary muscle attached to bones; contracts quickly and tires easily.

Cardiac muscle tissue

Striated, involuntary muscle found only in the heart; connected by intercalated discs and contracts rhythmically.

Smooth muscle tissue

Non-striated, involuntary muscle of hollow organs and blood vessels; slow, sustained contractions.

Rotator cuff

Group of four shoulder muscles that stabilize the glenohumeral joint and assist in rotation.

Supraspinatus

Rotator-cuff muscle that abducts the arm; located above the scapular spine.

Infraspinatus

Rotator-cuff muscle that laterally rotates the arm; sits below the scapular spine.

Teres minor

Small rotator-cuff muscle that laterally rotates and adducts the arm; inferior to infraspinatus.

Subscapularis

Rotator-cuff muscle on anterior scapula that medially rotates the arm.

Hamstrings

Posterior thigh muscle group that flexes the knee and extends the hip.

Biceps femoris

Hamstring muscle with two heads; lateral knee flexor and hip extensor.

Semitendinosus

Hamstring with long tendon; medial knee flexor and hip extensor.

Semimembranosus

Hamstring deep to semitendinosus; medial knee flexor and hip extensor.

Cerebrum

Largest brain region; responsible for conscious thought, memory, and voluntary movement.

Cerebellum

Brain region that coordinates balance, posture, and fine motor control.

Thalamus

Relay station that filters and directs sensory information to the cerebrum.

Hypothalamus

Autonomic and endocrine control center regulating hunger, temperature, and hormones.

Epithalamus

Contains the pineal gland; involved in circadian rhythms and CSF production.

Midbrain

Upper brainstem region controlling visual and auditory reflexes.

Pons

Middle brainstem region that links cerebellum with cerebrum and regulates breathing rhythm.

Medulla oblongata

Lower brainstem that houses vital centers for heart rate, blood pressure, and respiration.

Corpus callosum

Large fiber tract connecting the two cerebral hemispheres.

Meninges

Three protective connective-tissue membranes of brain and spinal cord: dura mater, arachnoid mater, pia mater.

Dura mater

Tough, outer meningeal layer that protects CNS and forms dural sinuses.

Arachnoid mater

Middle, web-like meningeal layer that houses cerebrospinal fluid in the subarachnoid space.

Pia mater

Delicate, vascular meningeal layer tightly adhering to brain and spinal cord surface.

Spinal cord

CNS structure running through vertebral canal; conducts impulses and mediates reflexes.

Central canal

CSF-filled channel running through the spinal cord’s gray matter.

Gray matter (spinal cord)

Butterfly-shaped internal region containing neuron cell bodies and synapses.

White matter (spinal cord)

Peripheral region of myelinated axon tracts carrying ascending and descending signals.

Brachial plexus

Network of C5–T1 spinal nerves that supplies motor and sensory innervation to the upper limb.

Nerve

Bundle of axons in the PNS surrounded by connective tissue sheaths.

Endoneurium

Delicate connective tissue surrounding individual axons within a nerve.

Perineurium

Connective tissue sheath that encloses a fascicle (bundle) of nerve fibers.

Epineurium

Outermost dense connective tissue covering an entire nerve.

Fascicle (nerve)

Bundle of axons within a nerve surrounded by perineurium.

Olfactory nerve (I)

Sensory cranial nerve for the sense of smell.

Optic nerve (II)

Sensory cranial nerve that transmits visual information from retina to brain.

Oculomotor nerve (III)

Motor cranial nerve controlling most eye movements, pupil constriction, and lens shape.

Trochlear nerve (IV)

Motor cranial nerve that moves the eyeball via the superior oblique muscle.

Trigeminal nerve (V)

Mixed cranial nerve providing facial sensation and muscles of mastication.

Abducens nerve (VI)

Motor cranial nerve that abducts the eye via the lateral rectus muscle.

Facial nerve (VII)

Mixed cranial nerve for facial expression, taste (anterior 2⁄3 tongue), and tear/saliva secretion.

Vestibulocochlear nerve (VIII)

Sensory cranial nerve for hearing and equilibrium.

Glossopharyngeal nerve (IX)

Mixed cranial nerve for taste (posterior tongue), swallowing, and monitoring blood pressure.

Vagus nerve (X)

Mixed cranial nerve that controls thoracic and abdominal viscera; main parasympathetic nerve.

Accessory nerve (XI)

Motor cranial nerve that innervates sternocleidomastoid and trapezius muscles.

Hypoglossal nerve (XII)

Motor cranial nerve controlling tongue movements.

Rods

Retinal photoreceptors for dim-light, black-and-white vision; highly sensitive, low acuity.

Cones

Retinal photoreceptors for bright-light, color vision; provide sharp visual acuity.

Cornea

Transparent anterior eye covering that refracts incoming light.

Sclera

Tough, white, fibrous outer layer of the eye that maintains shape.

Iris

Colored part of eye containing smooth muscle to control pupil size.

Pupil

Opening in the iris through which light enters the eye.

Lens

Biconvex transparent structure that focuses light onto the retina.

Retina

Innermost eye layer containing rods, cones, and neurons that initiate vision.

Macula lutea

Yellowish central retinal region with high cone density for detailed vision.

Fovea centralis

Small pit within macula possessing the greatest visual acuity.

Choroid

Vascular middle eye layer that nourishes retina and absorbs stray light.

Aqueous humor

Clear fluid in anterior eye chamber that maintains intraocular pressure and nourishes lens/cornea.

Vitreous humor

Gel-like substance in posterior eye chamber that maintains eyeball shape.

Auricle (Pinna)

External ear structure that collects and directs sound waves into canal.

External auditory canal

Passage leading sound to the tympanic membrane; contains ceruminous glands.

Tympanic membrane

Eardrum; vibrates in response to sound waves and transfers energy to ossicles.

Malleus

First auditory ossicle that transmits vibrations from eardrum to incus.

Incus

Middle auditory ossicle that passes vibrations from malleus to stapes.

Stapes

Smallest ossicle; presses on the oval window to send vibrations into inner ear.

Auditory (Eustachian) tube

Canal connecting middle ear to nasopharynx; equalizes air pressure.

Cochlea

Spiral inner-ear structure containing organ of Corti for hearing.

Vestibule

Central inner-ear chamber with utricle and saccule for static equilibrium.

Semicircular canals

Three fluid-filled inner-ear loops detecting rotational (dynamic) equilibrium.