Unit 1: General Principles of Anatomy, Integumentary, Skeletal, Articular, and Muscular Systems

Vocabulary practice flashcards generated from introductory anatomy notes covering general principles, the integumentary system, skeletal system, articular system, and muscular system.

Anatomy

The branch of knowledge concerned with structure or morphology, derived from the Greek 'ana' (apart) and 'tomy' (cut).

Dissect

To cut apart, derived from the Latin 'dis' (apart) and 'sectare' (cut).

Systemic Method of Study

The method of studying the human body according to its $12$ body systems.

Regional Method of Study

The method of studying the human body according to its natural body subdivisions, such as head, neck, thorax, abdomen, pelvis, back, trunk, and extremities.

Anatomical Position

The reference position of the body defined by five criteria: body longitudinal, upper limbs by side, eyes directed forward, palms directed forward, and toes directed forward.

Median (midsagittal) plane

The vertical plane that passes through the body and divides it into equal right and left halves.

Sagittal plane

Any vertical plane that parallels the median plane and divides the body into unequal right and left parts.

Frontal (coronal) plane

Any vertical plane perpendicular to the median plane that divides the body into front and back parts.

Transverse (horizontal) plane

Any plane perpendicular to both the median and frontal planes that divides the body into upper and lower parts.

Medial vs. Lateral

Medial means nearer the median plane, whereas lateral means farther from the median plane.

Anterior (ventral) vs. Posterior (dorsal)

Anterior (ventral) means nearer the front, whereas posterior (dorsal) means nearer the back.

Superior (cephalic) vs. Inferior (caudal)

Superior (cephalic) means nearer the upper (head) end, whereas inferior (caudal) means nearer the lower (tail) end.

Proximal vs. Distal

Proximal means nearer the attached end of a limb or origin of a structure, whereas distal means farther from the attached end.

Superficial vs. Deep

Superficial means nearer the surface of the body, whereas deep means farther from the surface of the body.

Supine position vs. Prone position

Supine position is lying on the back with belly upward, whereas prone position is lying on the front with back upward.

Cell

The smallest unit of living matter and the characteristic building block of all plant and animal tissues.

Cytology

The study of cells, derived from Greek 'kytos' (cell) and 'logos' (knowledge of).

Tissue

A collection of cells of similar structure and function.

Histology

The study of tissue, derived from Greek 'histo' (tissue) and 'logos' (knowledge of).

Organ

A structure consisting of one or more tissues blended to perform one function or related functions.

Microanatomy vs. Gross anatomy

Microanatomy refers to structures seen with the aid of a microscope, while gross anatomy refers to structures seen with the unaided eye.

Integumentary System

The system of the body composed of the skin and underlying subcutaneous tissue, with the skin being the largest organ comprising $15\%$ of total body weight.

Epidermis

The outermost layer of skin, composed of avascular stratified squamous keratinized epithelium; it contains melanocytes and takes about $30\,\text{days}$ for a cell to go from birth to slough.

Melanocytes

Cells located in deeper layers of the epidermis that produce melanin, a dark pigment that determines skin color and protects against ultraviolet light.

Dermis

The layer deep to the epidermis that comprises $80\%$ of skin thickness and is composed of dense irregular connective tissue containing blood vessels, nerves, sweat glands, and hair follicles.

Subcutaneous Tissue

The layer deep to the dermis made of loose connective tissue with an abundance of adipose cells that provides insulation, conserves body heat, and acts as a shock absorber.

Sebaceous glands

Oil-producing glands derived from the epidermis whose secretion, sebum, is passed via a duct into the neck of a hair follicle.

Arrector pilorum muscles

Smooth muscles attached to the hair follicle and epidermal-dermal junction that contract in cold weather to pull hairs erect and trap an insulating layer of air.

Hemopoiesis

The manufacture of certain blood cells in the bone marrow.

Long bone

A bone in which length exceeds width, characterized by a medullary (marrow) canal, such as the humerus.

Short bone

A bone in which length equals width, such as a carpal bone.

Flat bone

A bone expanded into one plane, such as the scapula.

Irregular bone

A bone that does not fit into the long, short, or flat bone categories, such as a vertebra.

Axial Skeleton

The portion of the skeleton occupying the central axis of the body, comprising $80$ total bones including the skull, hyoid, vertebral column, ribs, sternum, and middle ear bones.

Appendicular Skeleton

The portion of the skeleton comprising the appendages, containing $126$ total bones across the upper and lower limbs.

Sesamoid bone

A bone located within tendons, such as the patella.

Ectopic bone

A pathological bone formation.

Epiphysis

The two wider ends of a long bone that take part in the formation of a joint.

Diaphysis

The shaft of a long bone.

Compact bone

Solid-appearing bone laid down in concentric layers, forming the outer surface of all bones and the diaphysis.

Spongy bone

Bone tissue consisting of thin plates meeting at various angles, found in the epiphysis and metaphysis.

Periosteum

A two-layered connective tissue sheath covering bone; its outer fibrous layer serves as a site of insertion for tendons, and its inner cellular layer produces growth in bone diameter.

Endosteum

A thin cellular layer lining the medullary cavity and spongy bone cavities whose primary function is to destroy bone to allow marrow cavity growth in diameter.

Articular Cartilage

A thin layer of hyaline cartilage covering the articular surface of each epiphysis to cushion the joint during movement.

Epiphyseal disc

A cartilaginous plate located at the junction of the epiphysis and diaphysis in a growing child that allows growth in bone length.

Metaphysis

Spongy bone tissue located at the junction of the diaphysis and epiphyseal disc.

Hyaline Cartilage

A type of cartilage with a glassy, translucent appearance found in embryonic skeletons, epiphyseal discs, articular cartilages, costal cartilages, larynx, trachea, bronchi, and nasal cartilages.

Fibrocartilage

A type of cartilage found in the interpubic disc (pubic symphysis) and intervertebral discs.

Elastic Cartilage

A flexible type of cartilage found in the auricle, auditory tube, and epiglottis.

Arthrology

The study of joints.

Suture

An immovable fibrous joint formed by bones with serrated articulating surfaces held together by fibrous tissue, found exclusively in the skull.

Syndesmosis

A slightly movable fibrous joint with a greater amount of intervening connective tissue than a suture, such as the radio-ulnar syndesmosis.

Synovial Joint

A freely movable joint characterized by a joint cavity lined with a vascular synovial membrane and filled with synovial fluid.

Flexion vs. Extension

Flexion is bending a joint so that the angle becomes more acute; extension is straightening a flexed joint.

Abduction vs. Adduction

Abduction is movement in a frontal plane away from the median plane, while adduction is movement in a frontal plane toward the median plane.

Circumduction

A joint movement combining flexion, extension, abduction, and adduction.

Pronation vs. Supination

Pronation is medial rotation of the forearm, whereas supination is lateral rotation of the forearm.

Dorsiflexion vs. Plantar flexion

Dorsiflexion is moving the dorsum of the foot toward the anterior leg; plantar flexion is moving the dorsum of the foot away from the anterior leg.

Plane Joint

A synovial joint with almost flat articular surfaces permitting sliding or gliding movements, such as between carpal and tarsal bones.

Hinge Joint

A uniaxial synovial joint allowing flexion and extension in one plane, such as the elbow or knee joints.

Pivot Joint

A uniaxial synovial joint permitting medial and lateral rotation around a longitudinal axis, such as between the radius and ulna.

Condyloid Joint

A biaxial synovial joint permitting flexion, extension, abduction, adduction, and circumduction, such as the wrist joint.

Saddle Joint

A biaxial synovial joint with reciprocally concave-convex surfaces allowing flexion, extension, abduction, adduction, circumduction, and rotation, such as the carpometacarpal joint of the thumb.

Ball and Socket Joint

A multiaxial synovial joint allowing movement in an infinite number of planes, such as the shoulder and hip joints.

Rule of Joint Stability

The principle stating that as the degree of freedom of movement in a joint increases, the stability of the joint decreases.

Bursa

A small closed connective tissue sac lined with a synovial membrane and filled with viscid fluid that minimizes friction between moving structures.

Synovial sheath

An elongated bursa that encloses a tendon.

Contractility

The property of muscle tissue enabling it to shorten or contract.

Extensibility

The property of muscle tissue enabling it to be extended or stretched within limits.

Elasticity

The property of muscle tissue enabling it to return to its original state after being stretched.

Irritability

The susceptibility of muscle tissue to react to external stimuli.

Tonus

The state in which a muscle is partially contracted, allowing it to react instantly when stimulated.

Smooth Muscle

Involuntary, non-striated muscle composed of long spindle-shaped cells with one nucleus per cell, located in walls of internal organs and blood vessels.

Cardiac Muscle

Involuntary, striated muscle located in the heart containing single-nucleated cells and intercalated discs.

Skeletal Muscle

Voluntary, striated, multinucleated muscle tissue attached to bones, with cells reaching up to $4\,\text{cm}$ in length.

Fascia

The connective tissue layer surrounding muscles and located between adjacent muscles that permits gliding, provides pathways for vessels and nerves, and has a rich blood and nerve supply.

Origin vs. Insertion

Origin is the nonmovable point of attachment of a muscle, whereas insertion is the movable point of attachment.

Aponeurosis

A flattened tendon that serves as a muscle attachment.