Anatomy and Physiology Unit 1 Review: Muscular and Skeletal Systems

Comprehensive vocabulary flashcards covering skeletal cells, muscular system anatomy, sliding filament mechanism, structural hierarchy, joints, directional terminology, and ranges of motion.

Osteoblast

Bone cell that builds new bone (Memory: BLAST = BUILD).

Osteoclast

Bone cell that breaks down and removes bone tissue (Memory: CLAST = break down).

Muscular System Functions

Movement (contracting and pulling on bones), posture (keeping the body upright), heat production (producing heat via contractions), and joint stabilization.

Frontalis

Muscle located on the forehead.

Temporalis

Muscle located on the side of the skull.

Orbicularis oculi

Muscle encircling the eye.

Orbicularis oris

Muscle encircling the mouth.

Masseter

Muscle of the jaw.

Sternocleidomastoid

Major muscle located in the neck.

Trapezius

Muscle covering the upper back and neck.

Deltoid

Muscle covering the shoulder.

Pectoralis major

Large muscle of the chest.

Biceps brachii

Muscle located on the front of the upper arm.

Triceps brachii

Muscle located on the back of the upper arm.

Latissimus dorsi

Large muscle of the back.

Rectus abdominis

Abdominal muscle group, commonly referred to as the "abs."

External oblique

Muscle located on the sides of the abdomen.

Gluteus maximus

Largest muscle of the buttocks.

Sartorius

Long diagonal muscle running across the thigh.

Quadriceps

Muscle group on the front of the thigh; includes the rectus femoris and three vasti.

Hamstrings

Muscle group on the back of the thigh; includes the biceps femoris, semitendinosus, and semimembranosus.

Tibialis anterior

Muscle situated on the front of the lower leg.

Gastrocnemius

Large, superficial calf muscle.

Soleus

Deep calf muscle located beneath the gastrocnemius.

Actin

The thin protein myofilament within a sarcomere.

Myosin

The thick protein myofilament within a sarcomere.

Sliding Filament Theory

Mechanism of contraction where myosin pulls actin inward, causing the sarcomere to shorten while the filaments themselves do not change length.

Cross-bridge

The structural connection formed when myosin attaches to actin during muscle contraction.

Power Stroke

Step in muscle contraction where myosin pulls actin toward the center of the sarcomere.

Whole Muscle

The entire muscular organ as a complete unit.

Fascicle

A bundle of individual skeletal muscle fibers.

Muscle Fiber

A single muscle cell.

Myofibril

Contractile, cylindrical structures found inside a muscle fiber.

Sarcomere

The functional unit of skeletal muscle contraction.

Myofilaments

Filamentous protein structures consisting of actin and myosin.

Muscle Structural Hierarchy

The descending structural order: Muscle → Fascicle → Fiber → Myofibril → Sarcomere → Filaments.

Origin

Muscle attachment that generally remains more stationary during contraction (Origin = stays).

Insertion

Muscle attachment that generally moves when the muscle contracts (Insertion = moves).

Fibrous Joint

Joint where bones are connected by strong connective tissue allowing little or no movement; example: skull sutures.

Cartilaginous Joint

Joint where bones are connected by cartilage allowing limited movement; example: between some vertebrae.

Synovial Joint

A freely movable joint; examples include the shoulder, hip, knee, and elbow.

Ball-and-Socket Joint

Synovial joint allowing movement in many directions; found at the shoulder and hip.

Hinge Joint

Synovial joint permitting mostly bending and straightening movements; found at the elbow and knee.

Pivot Joint

Synovial joint permitting rotation around an axis; found in the neck.

Gliding/Plane Joint

Synovial joint where bones slide across one another; examples include some wrist joints.

Saddle Joint

Synovial joint permitting movement in several directions; found at the thumb.

Condyloid Joint

Synovial joint permitting movement in several directions with limited rotation; found at the wrist.

Flexion

Movement that decreases the angle of a joint; example: bending the elbow.

Extension

Movement that increases the angle of a joint; example: straightening the elbow.

Hyperextension

Extension of a joint beyond the normal anatomical position.

Abduction

Movement away from the body's midline (Memory: ABduction = Away).

Adduction

Movement toward the body's midline (Memory: ADDuction = Add it back).

Rotation

Movement around a longitudinal axis.

Circumduction

Circular movement tracing a cone-shaped pattern.

Supination

Forearm movement rotating the forearm so the palm faces up or anteriorly (Memory: holding soup).

Pronation

Forearm movement rotating the forearm so the palm faces down or posteriorly.

Dorsiflexion

Movement in which the toes and foot move upward toward the shin.

Plantar Flexion

Movement where the foot points downward, such as standing on tiptoes.

Inversion

Movement of the foot turning the sole inward.

Eversion

Movement of the foot turning the sole outward.

Sagittal Plane

Anatomical plane that divides the body into left and right sections.

Frontal Plane

Anatomical plane that divides the body into front and back sections.

Transverse Plane

Anatomical plane that divides the body into top and bottom sections.

Levels of Structural Organization

The biological hierarchy: Chemical → Cellular → Tissue → Organ → Organ System.

Axial Skeleton

The central division of the skeleton.

Appendicular Skeleton

The division of the skeleton comprising the limbs.