Anatomy and Physiology: Articulations, Muscular System, and Nervous System

Vocabulary practice flashcards based on lecture review material covering joints (arthrology), muscular anatomy and physiology (myology), and nervous system signaling.

Arthrology

The study of joint structure, function, and dysfunction.

Rotator Cuff

A musculotendinous structure whose tendons enclose the shoulder joint on all sides except inferiorly, explaining why most shoulder dislocations occur in an inferior direction.

Plantar Flexion

A movement of the ankle that points the foot or toes downward, such as when standing on tiptoes to reach something high.

Collateral Ligaments of the Elbow

The radial (lateral) and ulnar (medial) collateral ligaments that restrict side-to-side movements of the elbow joint.

Adduction of the Fingers

Movement of the fingers toward the midline of the hand, closing gaps between them when cupping hands to hold water.

Synostosis

An immovable, bony joint formed when the fibrous or cartilaginous connection between two bones ossifies; represents the least movable class of joints.

Symphysis

A cartilaginous joint where two bones are joined by fibrocartilage, such as the intervertebral joint between the L2 and L3 vertebrae.

Extension

The movement occurring at the hip and knee joints to straighten the lower limbs and lift body weight when walking up stairs.

Suture

An immovable fibrous joint found between bones of the skull, such as the sagittal suture between the left and right parietal bones; it is not a synovial joint.

Temporomandibular Joint (TMJ)

A synovial jaw joint formed by the articulation of the condyle of the mandible with the temporal bone.

Talocrural Joint

The ankle joint formed by the articulation and union of the tibia, fibula, and talus.

Synchondrosis

A cartilaginous joint united by hyaline cartilage, such as the epiphyseal plate binding the epiphysis and diaphysis in a child's long bone, or the joint between the first costal cartilage and the sternum.

Bursa

A fibrous sac filled with synovial fluid associated with a synovial joint that cushions muscles and prevents friction.

Labrum

A fibrocartilaginous ring found in specific ball-and-socket joints to deepen the joint socket; it is not a feature present in all synovial joints.

Humeroscapular Joint

The shoulder joint, which functions as a multiaxial ball-and-socket synovial joint.

Condylar Joint

A type of synovial joint with an oval convex surface fitting into a complementary depression, such as the metacarpophalangeal joints at the base of the fingers.

Inversion and Eversion

Special foot movements where inversion tips the soles medially so they face each other, and eversion tips the soles laterally so they face away from each other.

Circumduction

A movement in which one end of an appendage remains stationary while the other end describes a circle, such as the shoulder action required to paint a circle on a canvas with an outstretched arm.

Hyperextension of the Neck

Extension of the cervical spine beyond anatomical position, as required when looking up at the stars.

Medial Meniscus

The fibrocartilage pad located between the medial condyle of the femur and the medial condyle of the tibia.

Anterior Cruciate Ligament (ACL)

An intracapsular knee ligament that prevents hyperextension of the knee joint.

Myology

The scientific study of the muscular system.

Temporalis

A muscle of mastication responsible for elevation of the mandible.

Masseter

A chewing muscle that attaches superiorly to the zygomatic arch and inferiorly to the angle of the mandible.

Sartorius

The longest skeletal muscle in the human body, extending obliquely across the anterior thigh.

Fascicle

A bundle of skeletal muscle fibers surrounded by perimysium.

Biceps Femoris

A posterior thigh (hamstring) muscle that acts to flex the knee and extend the hip, commonly injured in sprinters.

Direct Attachment

A form of skeletal muscle attachment where muscular tissue emerges directly from bone with little or no visible collagenous tendon separating them.

Thigh Adductors

A group of medial thigh muscles whose function is impaired by fractures extending across the symphysis pubis and inferior pubic ramus.

Erector Spinae

A deep muscle complex of the back that extends the vertebral column to straighten the trunk after bending forward.

Flexor Retinaculum

A fibrous connective tissue band in the wrist surgically incised or excised to relieve pressure on the median nerve in carpal tunnel syndrome.

Intercostal Muscles

Muscles that occupy the spaces between the ribs, composing the meat found in rib cuts of beef.

Pronator Teres

A forearm muscle located near the cubital fossa that can be accidentally pierced by a needle during venipuncture.

Inguinal Ligament

A cordlike band formed by the rolled-over inferior margin of the external abdominal oblique aponeurosis.

Extensor Carpi Radialis Longus

A forearm extensor muscle whose origin attachment at the lateral epicondyle is commonly injured in tennis elbow.

Supraspinatus

The rotator cuff (SITS) muscle whose tendon is most frequently torn in throwing athletes such as baseball pitchers.

Tendinous Intersections

Transverse bands of collagen fibers that divide the rectus abdominis muscle into distinct segments.

Fascia

A fibrous sheet of connective tissue that separates neighboring whole muscles or muscle compartments.

Transverse Abdominal

The deepest layer of muscle in the anterior abdominal wall, with fibers oriented horizontally.

Orbicularis Oris

A sphincter muscle of the facial expression group encircling the mouth, responsible for closing and protruding the lips.

Modiolus

A point of convergence for several facial expression muscles situated at the angle of the mouth.

Sarcolemma

The plasma membrane of a muscle fiber along which action potentials are propagated.

Elastic Filament

A myofilament composed of the giant protein titin that runs through the core of each thick filament and anchors it to the Z disc.

Motor Nerve Varicosities

Beadlike swellings along autonomic nerve fibers that release neurotransmitters onto smooth muscle cells.

Threshold

The minimum electrical voltage or stimulus required to produce an action potential and cause muscle contraction.

Creatine Kinase

An enzyme that catalyzes the rapid transfer of a high-energy phosphate group from creatine phosphate (CP) to ADP, forming ATP.

Troponin

A calcium-receptor regulatory protein on the thin filament of skeletal muscle that triggers contraction upon binding calcium ions.

Type IIB Fast Glycolytic Fibers

White, fast-twitch muscle fibers adapted for rapid force production through anaerobic pathways, serving as the primary source of lactate production.

Tropomyosin

A filament-blocking regulatory protein that shifts to uncover myosin-binding sites on actin during muscle excitation-contraction coupling.

Absolute Refractory Period

The phase during and immediately following an action potential during which no stimulus of any strength can trigger a new action potential.

Schwann Cells

Glial cells of the peripheral nervous system (PNS) that wind spirally around axons to form the neurilemma and myelin sheath.

Multipolar Neuron

The most common structural category of neuron, possessing a single axon and two or more dendrites.

Local Potential

A graded, reversible change in membrane potential whose magnitude varies proportionally with the strength of the incoming stimulus.

Action Potential

A rapid, dramatic, all-or-none electrical voltage fluctuation that propagates nondecrementally down an excitable membrane.

Spatial Summation

The process by which postsynaptic potentials from multiple distinct presynaptic inputs arrive simultaneously and are integrated at the trigger zone.

Synaptic Facilitation

The accumulation of $\text{Ca}^{2+}$ in the presynaptic axon terminal after rapid stimulation, enhancing neurotransmitter release and contributing to short-term memory.

Interneuron

A neuron that lies entirely within the central nervous system (CNS) between incoming sensory pathways and outgoing motor pathways, comprising about 90% of all neurons.