Human Anatomy and Physiology: Muscular and Nervous Systems Review

Vocabulary flashcards covering muscular tissue, muscle contraction mechanisms, axial and appendicular muscles, spinal cord, cranial nerves, and special senses from lecture slides.

Muscle Tissue

Specialized tissue composed of myocytes that plays a crucial role in movement and is contractile, vascular, and innervated.

Skeletal Muscle Tissue

Voluntarily controlled muscle tissue characterized by long, multinucleated, striated fibers mostly attached to the skeleton.

Cardiac Muscle Tissue

Involuntary, striated muscle tissue located exclusively in the heart.

Smooth Muscle Tissue

Involuntary, non-striated (smooth) muscle tissue found in the walls of visceral organs such as the digestive tract and blood vessels.

Epimysium

Dense irregular connective tissue layer surrounding an entire skeletal muscle.

Perimysium

Connective tissue layer surrounding a bundle of muscle fibers called a fascicle.

Endomysium

Connective tissue layer surrounding individual muscle fibers within a fascicle.

Sarcolemma

The specialized plasma membrane of a skeletal muscle fiber containing voltage-gated $\text{Na}^+$ and $\text{K}^+$ channels.

Sarcoplasm

The specialized cytoplasm of a muscle fiber containing myoglobin for oxygen storage.

T-tubules

Transverse tubules extending from the sarcolemma into the muscle fiber that contain voltage-sensitive $\text{Ca}^{2+}$ channels.

Sarcoplasmic Reticulum (SR)

Specialized endoplasmic reticulum in muscle fibers that stores, releases, and pumps $\text{Ca}^{2+}$.

Sarcomere

The functional contractile unit of a skeletal muscle myofibril bounded by adjacent Z discs.

Sliding Filament Theory

The mechanism of muscle contraction where thin and thick filaments slide past each other toward the center of the sarcomere, causing the sarcomere to shorten.

Cross-Bridge Cycling

The multi-step process where myosin heads attach to actin, pivot in a power stroke, detach via ATP binding, and reset.

Creatine Phosphate

A high-energy molecule stored in muscle cells that combines with ADP to rapidly regenerate ATP via direct phosphorylation for about 15 seconds of movement.

Isometric Contraction

A muscle contraction where tension is created, but the length of the muscle fibers remains unchanged, resulting in no movement.

Isotonic Contraction

A muscle contraction in which muscle tension results in a change in muscle fiber length, categorized into concentric (shortening) and eccentric (lengthening).

Calmodulin

Calcium-binding protein in smooth muscle cells that activates myosin light-chain kinase (MLCK) to initiate contraction.

Origin

The proximal muscle attachment site to a less movable bone.

Insertion

The distal muscle attachment site to a more movable bone.

Flexion

A movement that decreases the angle between articulating bones or joints.

Extension

A movement that increases the angle between articulating bones or joints.

Abduction

Movement of a body part away from the midline of the body.

Adduction

Movement of a body part toward the midline of the body.

Supination

Rotation of the forearm so that the palm faces anteriorly with the radius and ulna parallel.

Pronation

Rotation of the forearm so that the palm faces posteriorly, causing the radius to cross over the ulna.

Dorsiflexion

Movement at the ankle joint that points the toes superiorly toward the shin.

Plantarflexion

Movement at the ankle joint that points the toes inferiorly.

Occipitofrontalis

Facial muscle composed of frontal and occipital bellies connected by the epicranial aponeurosis that raises eyebrows and wrinkles the forehead.

Sternocleidomastoid (SCM)

Neck muscle attaching from the sternum and clavicle to the mastoid process that laterally flexes and rotates the head and neck.

Diaphragm

Primary muscle of respiration attaching from the rib cage to a central tendon that increases thoracic dimensions during inspiration.

Erector Spinae Group

Deep vertebral muscle group consisting of the iliocostalis, longissimus, and spinalis that extends the trunk and maintains posture.

Rectus Abdominis

Vertical abdominal muscle extending from the pubic symphysis to the xiphoid process enclosed by the rectus sheath that flexes the trunk.

Conus Medullaris

The tapered, pointed inferior end of the spinal cord terminating at the L1 vertebra level.

Cauda Equina

The collection of spinal nerve roots extending inferiorly from the conus medullaris through the vertebral canal.

Filum Terminale

A thin strand of meningeal tissue anchoring the conus medullaris of the spinal cord to the coccyx.

Posterior Root Ganglion

A nodular swelling on the posterior root of a spinal nerve containing the cell bodies of sensory neurons.

Phrenic Nerve

Nerve originating from the cervical plexus (C1–C4) that provides motor innervation to the diaphragm.

Sciatic Nerve

Large nerve originating from the lumbosacral plexus that innervates the hamstring muscles before dividing into tibial and common fibular branches.

CN I (Olfactory Nerve)

Sensory cranial nerve responsible for carrying olfactory (smell) information from the nasal cavity to the temporal lobe.

CN II (Optic Nerve)

Sensory cranial nerve responsible for carrying visual information from the photoreceptors in the retina to the occipital lobe.

CN V (Trigeminal Nerve)

Mixed cranial nerve providing somatosensory input from the face and motor innervation to the muscles of mastication.

CN VII (Facial Nerve)

Mixed cranial nerve providing motor control to facial expression muscles, parasympathetic stimulation to lacrimal/salivary glands, and taste sensation from the anterior 2/3 of the tongue.

CN X (Vagus Nerve)

Mixed cranial nerve providing parasympathetic motor control to thoracic and abdominal organs and sensory feedback from throat and internal organs.

Meissner's Corpuscular Receptor

Sensory mechanoreceptor in the skin that senses light touch.

Pacinian Corpuscular Receptor

Sensory mechanoreceptor located deep in the skin that senses pressure.

Retina

The inner sensory tunic of the eye containing photoreceptor cells (rods and cones) that detect light.

Fovea Centralis

Depressed area in the retina with high photoreceptor density serving as the visual focus spot for sharpest vision.

Lacrimal Apparatus

System that produces, collects, and drains lacrimal fluid across the anterior eye surface into the nasal cavity.

Cochlea

Snail-shaped fluid-filled structure in the inner ear containing perilymph and the spiral organ with hair cell mechanoreceptors for hearing.

Semicircular Canals

Inner ear structures containing perilymph and hair cells that detect rotational movements of the head to maintain equilibrium.

Rotator Cuff

Group of four scapular muscles—Supraspinatus, Infraspinatus, Teres minor, and Subscapularis (S.I.T.S)—that strengthen and stabilize the glenohumeral joint.

Pectoralis Major

Chest muscle attaching from the clavicle and sternum to the humerus that adducts and flexes the arm.

Deltoid

Shoulder muscle attaching from the clavicle and scapula to the humerus that abducts and flexes the arm.

Latissimus Dorsi

Large back muscle attaching from the lumbar fascia to the humerus that extends, adducts, and medially rotates the arm.

Biceps Brachii

Two-headed anterior arm muscle attaching from the scapula to the proximal radius that flexes the forearm.

Triceps Brachii

Three-headed posterior arm muscle attaching from the scapula and humerus to the olecranon of the ulna that extends the forearm.

Quadriceps Femoris

Anterior thigh muscle group composed of rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius that extends the leg at the knee.

Hamstrings

Posterior thigh muscle group comprising biceps femoris, semitendinosus, and semimembranosus that extends the thigh and flexes the leg.

Gastrocnemius

Posterior leg muscle attaching from the femur to the calcaneal tendon that flexes the knee and plantarflexes the foot.