Lymphatic System Overview

A slightly movable joint made of fibrocartilaginous intervertebral discs that act as shock absorbers between vertebrae.

Connects bones with dense connective tissues AND a fluid-filled joint cavity, allowing for free movement (diarthroses).

Covers opposing bone surfaces in synovial joints, providing a smooth, low-friction surface for joint movement.

A fluid-filled space within a synovial joint, containing synovial fluid that lubricates and nourishes the joint.

A fibrous capsule that encloses the joint cavity of a synovial joint, providing stability and protection.

A viscous fluid found in the joint cavity of synovial joints, acting as a lubricant for smooth movement and providing nutrients.

Strong fibrous bands that reinforce synovial joints, providing stability and limiting excessive movement.

A type of synovial joint where one flat bone surface glides or slips over another (back and forth or side to side).

The most abundant type of sweat gland, found on most of the body surface and responsible for temperature regulation.

Larger sweat glands located deeper in the dermis, activated during puberty, and associated with body odor.

Modified apocrine glands located in the ear canal, producing earwax.

Modified apocrine glands located in the breasts, responsible for milk production.

Glands that secrete sebum, an oily substance that lubricates and softens skin and hair.

A physical barrier formed by the multiple layers of skin cells and their continuity, preventing entry of pathogens.

A chemical barrier formed by skin secretions like defensins and a low pH, inhibiting bacterial growth.

A pigment shield that protects against UV damage, produced by melanocytes in the skin.

Immune cells that patrol beneath the surface of the epidermis, capturing invaders and initiating an immune response.

Immune cells that act as a second line of defense in the dermis, engulfing invaders that penetrate the epidermis.

The framework of the body, providing support and structure for all other tissues and organs.

Rigid, specialized connective tissue that makes up the skeletal system.

A type of dense connective tissue that covers the ends of bones, providing a smooth surface for joint movement.

Tough, fibrous cords that connect muscles to bones, allowing for movement.

The point where two or more bones meet, allowing for movement.

The process of blood cell formation, which occurs in the red bone marrow of certain bones.

The process of bone formation, where new bone tissue is constantly being created and remodeled.

The process of bone tissue formation, important for skeletal development in embryos, growth throughout childhood and adulthood, and bone remodeling and repair throughout life.

Bone development from a fibrous membrane, resulting in membranous bone. Examples include the clavicle and skull bones.

Bone development by replacing cartilage, resulting in endochondral bone. This applies to all bones except the clavicle and skull bones.

Cells residing in the lacunae of bone, responsible for maintaining bone structure, monitoring bone health, and commanding the activity of bone-building and bone-resorbing cells.

Cells responsible for building bone tissue by calcifying bone matrix during bone formation.

Cells responsible for resorbing bone tissue by breaking down bone matrix, releasing calcium and phosphate into the bloodstream.

Cube-shaped bones that are as wide as they are long, providing stability and limited movement. Examples include wrist bones (carpals) and ankle bones (tarsals).

A special type of short bone shaped like a sesame seed, embedded within tendons. The knee cap (patella) is an example.

Thin, flat bones with a large surface area for muscle attachment. Examples include the breastbone (sternum), shoulder blades (scapula), ribs, and most cranial bones.

Bones with highly specialized shapes and structures, lacking a clear category. Examples include hip bones and vertebrae.

The tough, dense outer layer of bone, providing strength and support. It's made of osteons, tiny weight-bearing pillars.

The porous, inner layer of bone, providing flexibility and housing bone marrow. It's made of trabeculae, tiny bone struts.

The basic structural unit of compact bone, composed of hollow tubes called lamellae, filled with salts and collagen fibers. Each osteon contains a Haversian canal for blood vessels and nerves.

Tiny bone struts found in spongy bone, providing strength and housing bone marrow. They are important for resisting stress.

The outermost layer of skin; composed of stratified squamous epithelium; protects underlying tissues from abrasion, water loss, and UV radiation.

A tough, fibrous protein that makes up hair, nails, and the outer layer of skin; it helps protect and strengthen these structures.

Specialized cells in the epidermis that produce melanin, a pigment that protects the skin from UV radiation damage.

Cells in the epidermis that ingest foreign invaders, like bacteria and viruses, and activate the immune system to fight off infection.

Specialized touch receptor cells found in the epidermis that combine with nerve endings to detect touch and pressure.

The outermost layer of the epidermis, made of dead cells, containing keratin to protect against water loss and abrasion.

A layer of the epidermis present only in thick skin; it's a thin layer of flat, dead keratinocytes just below the stratum corneum.

A layer of the epidermis containing cells that are starting to accumulate keratin; it's responsible for the strength and resilience of the skin.

The deepest layer of the epidermis; it's the birthplace of new skin cells and contains stem cells that continuously regenerate the skin.

The second layer of skin, located beneath the epidermis; it's responsible for strength, elasticity, and providing support.

The upper layer of the dermis, containing areolar connective tissue, blood vessels, and nerve endings to provide sensation and nourishment.

The lower layer of the dermis, composed of dense irregular connective tissue, containing collagen and elastic fibers for strength and resilience.

The subcutaneous layer beneath the dermis, made mostly of adipose tissue (fat); provides insulation, energy storage, and cushions the body.

Long filaments of dead keratinocytes that grow out of hair follicles; they provide insulation, protection, and sensory function.

The visible part of the hair, extending above the skin surface.

The part of the hair below the skin surface, embedded within the hair follicle.

A small sac in the dermis from where hair grows; it contains the hair root and its surrounding structures.