Biology 12 - Human Organization

Comprehensive vocabulary flashcards covering tissue types, epithelial, connective, muscular, and nervous tissues, skin layers, organ systems, and homeostasis from Biology 12.

Tissues

Cells of the same type joined together.

Organs

Different tissues joined together to perform specific functions.

Organ System

Various organs arranged together to carry out major body functions.

Epithelial Tissue

Tissue type that covers body surfaces and lines body cavities.

Connective Tissue

Tissue type that binds and supports body parts.

Muscular Tissue

Tissue type that causes body parts to move.

Nervous Tissue

Tissue type that responds to stimuli and transmits impulses from one body part to another.

Squamous Epithelium

Epithelial tissue made of flat cells that functions in protection, diffusion, and filtration; lines alveoli and walls of capillaries and blood vessels.

Cuboid Epithelium

Epithelial tissue made of cube-shaped cells that functions in secretion, absorption, and protection; lines kidney tubules and surface of ovaries.

Columnar Epithelium

Epithelial tissue composed of column-shaped cells, often featuring microvilli or cilia, that functions in protection, secretion, and absorption; lines the intestine, oviduct, and uterus.

Stratified Epithelium

Epithelial tissue arranged in layers stacked on top of each other, such as the lining of the mouth, nose, and vagina.

Pseudostratified Columnar Epithelium

Epithelial tissue that appears to be layered but is really just one layer of cells; functions in protection, secretion, and movement of mucus and sex cells, lining the respiratory tract.

Simple Squamous Epithelium

Single layer of flat epithelial cells responsible for filtration, diffusion, and osmosis, located in the oral cavity and lining of blood vessels.

Simple Cuboidal Epithelium

Single layer of cube-shaped epithelial cells responsible for secretion and absorption, located on the surface of ovaries and linings of kidney tubules.

Simple Columnar Epithelium

Single layer of column-shaped epithelial cells responsible for protection, secretion, and absorption, located in the lining of the uterus and tubes of the digestive tract.

Stratified Squamous Epithelium

Multiple layers of flat epithelial cells providing protection, located in the outer layers of skin, vagina, and anal canal.

Matrix

Non-cellular material found between cells in connective tissue, usually made up of either collagen or elastin.

Loose Connective Tissue

Connective tissue that joins tissues, holds organs in place, and stores fat.

Structure of Loose Connective Tissue

Diagram depicting loose connective tissue components including collagen fibers, elastin fibers, and cells within a non-cellular matrix.

Fibrous Connective Tissue

Very strong connective tissue consisting of bundles of collagen fibers, used in tendons and ligaments.

Tendons

Fibrous connective tissue structures that connect muscle to bone.

Ligaments

Fibrous connective tissue structures that connect bones to other joints.

Cartilage

Connective tissue with a flexible matrix rich in protein and fibers, found in the nose, ears, vertebrae, and ends of bones.

Bone

Rigid connective tissue characterized by a matrix of calcium salts.

Blood

Connective tissue characterized by a liquid matrix called plasma.

Actin and Myosin

Proteins in muscle tissue fibers whose interaction is responsible for muscle movement.

Skeletal Muscle

Striated, voluntary muscle attached to bones used for movement; can contract quickly and strongly but will fatigue in time.

Smooth Muscle

Non-striated, involuntary muscle found in the walls of internal organs, intestine, stomach, and blood vessels; contracts more slowly but over a longer period of time.

Cardiac Muscle

Striated, involuntary muscle found only in the heart that can contract quickly and beats continuously throughout life.

Neurons

Specialized cells in nervous tissue that conduct electrical and chemical messages.

Structure of a Neuron

Anatomy of a motor neuron, highlighting the cell body, dendrites, axon, and synaptic endings.

Dendrites

Nerve fibers that conduct messages to the cell body.

Axon

Nerve fiber that sends messages away from the cell body.

Nerves

Bundles of nerve fibers (axons and dendrites) that conduct messages to and from the spinal cord, brain, and sense organs.

Glial Cells

Cells that surround nerve cells to support, protect, and nourish them by providing nutrients and keeping tissue free of debris.

Gland

A single cell or a collection of cells that secrete something.

Exocrine Glands

Glands that secrete products into ducts, such as sweat glands or the gallbladder secreting bile.

Endocrine Glands

Glands that secrete chemicals, especially hormones, directly into the bloodstream, such as the pituitary gland or pancreas secreting insulin.

Skin

The body's largest organ, made of three tissue layers; covers body surfaces, protects from water loss and microorganisms, contains sense organs, and helps regulate body temperature.

Anatomy of Human Skin and Organ System

Diagram illustrating the three structural layers of skin alongside internal organ layout.

Epidermis

The outer layer of skin composed of stratified squamous epithelial cells, containing basal cells, melanocytes, and keratin protein.

Basal Cells

Cells located at the base of the epidermis that produce new cells.

Melanocytes

Pigment cells in the epidermis that produce melanin, which is responsible for skin color.

Keratin

A protein that hardens skin cells and tightly packs together to form hair and nails.

Dermis

Middle layer of skin composed of loose connective tissue with elastic fibers; contains sweat glands, nerve endings, blood vessels, and hair follicles.

Subcutaneous Layer

Bottom layer of skin composed of loose connective tissue containing adipose cells (fat).

Coelom

A body cavity that encloses many internal organ systems.

Homeostasis

The maintenance of a stable internal environment, including regulation of temperature, pH, glucose concentration, and blood pressure.

Digestive System

Organ system that functions to convert food to usable nutrients.

Circulatory System

Organ system that functions in the transport of necessary molecules to cells.

Immune System

Organ system responsible for defense against invading pathogens.

Respiratory System

Organ system responsible for gas exchange.

Excretory System

Organ system that functions to get rid of metabolic wastes.

Nervous & Sensory System

Organ system responsible for regulation and control, response to stimuli, and processing information.

Muscular & Skeletal System

Organ system responsible for body support and movement.

Hormonal System

Organ system responsible for the regulation of internal environment and development.

Reproductive System

Organ system responsible for producing offspring.