Anatomy 1: Introduction, Shoulder, and Elbow

Comprehensive vocabulary flashcards covering the basics of anatomy, directional terms, body systems, skeletal histology, and the detailed anatomy of the shoulder and elbow regions.

Anatomy

The study of the structures of the body and the relationships among those structures.

Physiology

The study of how body structures function.

Chemical level

The level of structural organization consisting of atoms and molecules.

Tissue level

Groups of similar cells performing a common function.

Anatomical Position

The standard position where the person is standing upright, facing forward, arms at sides, palms facing forward, and feet flat pointing forward.

Superior (Cranial)

Toward the head or upper part; for example, the head is superior to the chest.

Inferior (Caudal)

Toward the feet or lower part; for example, the stomach is inferior to the lungs.

Anterior (Ventral)

Toward the front; for example, the sternum is anterior to the heart.

Posterior (Dorsal)

Toward the back; for example, the spine is posterior to the sternum.

Medial

Toward the body’s midline; for example, the heart is medial to the lungs.

Lateral

Away from the midline; for example, the arms are lateral to the chest.

Proximal

Nearer the trunk or point of attachment; for example, the elbow is proximal to the wrist.

Distal

Farther from the trunk or point of attachment; for example, the fingers are distal to the wrist.

Superficial

Near the body surface.

Deep

Farther from the body surface.

Ipsilateral

On the same side of the body.

Contralateral

On opposite sides of the body.

Sagittal Plane

An imaginary flat surface that divides the body into right and left portions.

Frontal (Coronal) Plane

Divides the body into anterior (front) and posterior (back) portions.

Transverse (Horizontal) Plane

Divides the body into superior (upper) and inferior (lower) portions.

Dorsal Body Cavity

Contains the cranial cavity (brain) and the vertebral cavity (spinal cord).

Ventral Body Cavity

Consists of the thoracic and abdominopelvic cavities, separated by the diaphragm.

Epidermis

The outermost, avascular layer of skin made of keratinized stratified squamous epithelium.

Stratum Basale (Germinativum)

The deepest layer of the epidermis that produces new skin cells through mitosis and contains melanocytes.

Stratum Lucidum

A clear epidermal layer found only in thick skin (palms and soles) for extra protection.

Dermis

Connective tissue beneath the epidermis containing blood vessels, nerves, and glands; consists of papillary and reticular layers.

Hypodermis (Subcutaneous Tissue)

Tissue mostly composed of adipose that cushions the body, provides insulation, and anchors skin to underlying tissues.

Axial Skeleton

The $80$ bones forming the central axis, including the skull, vertebral column, ribs, and sternum.

Appendicular Skeleton

The $126$ bones of the upper and lower limbs and the pectoral and pelvic girdles.

Hematopoiesis

The process of blood-cell formation occurring in red bone marrow.

Long bones

Bones that are longer than they are wide, such as the humerus, radius, and femur.

Sesamoid bones

Bones that develop inside tendons, such as the patella.

Epiphysis

The end of a long bone, mainly containing spongy bone and covered by articular cartilage.

Diaphysis

The shaft of a long bone, mainly composed of compact bone.

Periosteum

The outer covering of bone containing blood vessels and nerves; serves as an attachment for tendons and ligaments.

Endosteum

A thin membrane lining the medullary cavity containing bone-forming and bone-removing cells.

Osteoblasts

Bone cells that build new bone and produce bone matrix.

Osteocytes

Mature bone cells that maintain bone tissue.

Osteoclasts

Bone cells that break down bone and release calcium into the blood.

Osteon (Haversian System)

The structural unit of compact bone containing a central canal, lamellae, osteocytes, and lacunae.

Ossification

The process of bone formation from a fibrous membrane or hyaline cartilage model.

Wolff’s Law

States that bones become stronger with stress and weaker without use.

Open (Compound) Fracture

A break where the bone pierces the skin, creating an open wound and higher infection risk.

Greenstick Fracture

An incomplete fracture where one side of the bone breaks and the other bends; common in children.

Synovial Joints

Freely movable joints characterized by a fluid-filled joint cavity.

Diarthrosis

A functional classification for a freely movable joint.

Bursae

Small fluid-filled sacs that reduce friction between tissues at a joint.

Flexion

A movement that decreases the angle between bones.

Abduction

Movement away from the body’s midline.

Pronation

Rotation of the forearm so the palm faces posteriorly or downward.

Supination

Rotation of the forearm so the palm faces anteriorly or upward; mnemonic: holding a bowl of soup.

Agonist (Prime Mover)

The muscle primarily responsible for a specific movement.

Isometric Contraction

A contraction where the muscle produces tension without changing length or producing joint movement.

Glenoid Cavity

A shallow socket on the scapula that articulates with the head of the humerus.

Surgical Neck of Humerus

A common fracture site on the humerus closely related to the axillary nerve.

Sternoclavicular Joint

The only true bony connection between the upper limb and axial skeleton.

Scapulohumeral Rhythm

The ratio of $2^{\circ}$ of glenohumeral movement for every $1^{\circ}$ of scapular upward rotation during abduction.

Rotator-Cuff (SITS)

The group of four muscles (Supraspinatus, Infraspinatus, Teres minor, Subscapularis) that stabilize the glenohumeral joint.

Serratus Anterior

A muscle that protracts and upwardly rotates the scapula; weakness causes a winged scapula.

Brachialis

The primary and most consistent elbow flexor, often called the workhorse; inserts on the ulnar tuberosity.

Cubital Fossa

A triangular depression on the anterior elbow containing the radial nerve, biceps tendon, brachial artery, and median nerve (TAN).

Tennis Elbow (Lateral Epicondylitis)

Overuse injury of the wrist-extensor tendons attached to the lateral epicondyle.