Human Biology: Tissues, Organ Systems, and Homeostasis

Comprehensive vocabulary flashcards covering tissues, organ systems, anatomical terminology, the integumentary system, and homeostatic mechanisms from Chapter 4.

Tissue

A collection of cells of the same type that perform a common function.

Connective tissue

A major tissue type that binds and supports body parts; it consists of specialized cells, ground substance, and protein fibers.

Muscular tissue

A major tissue type specialized to contract, which moves the body and its parts.

Nervous tissue

A major tissue type that conducts nerve impulses and consists of neurons and neuroglia.

Epithelial tissue

A major tissue type that covers body surfaces and lines body cavities; also referred to as epithelium.

Ground substance

The noncellular material between cells in connective tissue that varies in consistency from solid to fluid.

Collagen fibers

Unbranched protein fibers in connective tissue that are strong but flexible.

Reticular fibers

Thin, highly branched collagen fibers that form a network.

Elastic fibers

Connective tissue fibers containing elastin, a protein that allows them to stretch and recoil.

Fibroblasts

Cells in fibrous connective tissue that divide to produce other types of cells and fibers.

Adipose tissue

A type of loose fibrous connective tissue containing adipocytes that store fat for energy storage, insulation, and cushioning.

Tendons

Dense fibrous connective tissue structures that connect muscles to bones.

Ligaments

Dense fibrous connective tissue structures that connect bones to other bones at joints.

Cartilage

A supportive connective tissue with a solid yet flexible matrix; it lacks a direct blood supply and contains cells called chondrocytes and chondroblasts located in lacunae.

Lacunae

Small chambers in the matrix of cartilage or bone where cells like chondrocytes or bone cells are located.

Hyaline cartilage

Cartilage containing fine collagen fibers found in the tip of the nose, ends of long bones, and the fetal skeleton.

Elastic cartilage

Cartilage with a high concentration of elastic fibers, found in the outer ear.

Fibrocartilage

Cartilage with strong collagen fibers found in the disks between vertebrae.

Compact bone

The bone tissue making up the shafts of long bones, consisting of cylindrical structural units called osteons.

Plasma

The fluid matrix of blood.

Erythrocytes

Red blood cells that carry oxygen.

Leukocytes

White blood cells that fight infection.

Thrombocytes

Platelets, which are pieces of cells that function in clotting blood.

Lymph

A fluid connective tissue derived from fluid surrounding tissues, containing white blood cells and returned to the cardiovascular system by lymphatic vessels.

Skeletal muscle

Voluntarily controlled, striated muscle tissue with long, multinucleated fibers attached to the skeleton by tendons.

Smooth muscle

Involuntarily controlled, spindle-shaped muscle tissue with one nucleus and no striations, found in the walls of viscera.

Cardiac muscle

Involuntary, striated muscle tissue found only in the heart walls; cells have a single nucleus and are connected by intercalated disks.

Neuron

The functional cell of nervous tissue, consisting of dendrites (carry info toward cell body), a cell body (contains nucleus), and an axon (conducts impulses away).

Neuroglia

Nervous tissue cells that support and nourish neurons, outnumbering them by a ratio of $9 \text{ to } 1$.

Myelin

A fatty substance that covers some axons.

Basement membrane

A layer that anchors epithelial tissue on one side.

Stratified squamous epithelia

Epithelial tissue with multiple layers of flattened cells, forming the outer skin layer and lining the mouth and esophagus.

Exocrine glands

Glands that secrete their products into ducts.

Endocrine glands

Ductless glands that secrete hormones directly into the bloodstream.

Organ

A group of tissues performing a common function.

Anterior

Also known as ventral; refers to the front of the body.

Posterior

Also known as dorsal; means toward the back of the body.

Distal

An anatomical term meaning away from the trunk of the body.

Diaphragm

A muscle that separates the thoracic cavity from the abdominal cavity.

Meninges

Connective tissue membranes in the dorsal cavity that surround the brain and spinal cord.

Synovial membranes

Membranes composed of loose connective tissue that line freely moveable joints and secrete lubricating fluid.

Epidermis

The thin, outermost layer of the skin made of stratified squamous epithelium.

Dermis

The thick, inner layer of skin made of dense fibrous connective tissue containing collagen, elastic fibers, blood vessels, and sensory receptors.

Melanocytes

Cells in the epidermis that produce melanin, which provides skin color and protection from UV light.

Sebaceous glands

Oil glands that produce sebum to soften hair and skin and retard bacterial growth.

Sudoriferous glands

Sweat glands located in the dermis that help regulate body temperature.

Homeostasis

A relatively constant internal environment within the body.

Negative feedback

The primary mechanism for maintaining homeostasis where the output of the system turns down or off the process (e.g., body temperature regulation).

Positive feedback

A mechanism that brings about change in the same direction as the original stimulus (e.g., oxytocin release during childbirth).