The 12 Systems of human Body

Skeletal System

Components: Bones and joints of the body and their associated cartilages. Functions: Supports and protects body: provides surface area for muscle attachments; aides body movements; houses cells that produce blood cells; stores minerals and lipids (fats).

Nervous System

Components: Brain, spinal cord, nerves, and spinal sense organs, such as eyes and ears Functions: Generates action potentials (nerve impulses) to regulate body activities; detects changes in body's internal and external environments, interprets changes, and responds by causing muscular contractions or glandular secretion

Endocrine System

Components: Hormone-producing glands--pineal gland, hypothalamus, pituitary gland, thymus, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries and testes--and hormone-producing cells in several other organs. functions: Regulates body activities by releasing hormones (chemical messengers transported in blood from endocrine gland or tissue to target organ.

Urinary System

Components: Kidneys, ureters, urinary bladder and urethra Functions: Produces, stores and eliminates urine; eliminates wastes and regulates volume and chemical composition of blood; helps maintain the acid-base balance of body fluids; maintains body's mineral balance; helps regulate production of red blood cells.

Lymphatic System and Immunity

Components: Lymphatic fluid and vessel; spleen, thymus, lymph nodes and tonsils; cells that carry out immune responses (B cells, T cells and others). Functions: Returns proteins and fluid to blood carries lipids from gastrointestinal tact to blood; contains sites of maturation and proliferation of B cells and T cells that protect against disease-causing microbes.

Digestive System

Components: Organs of gastrointestinal tact, a ling tube that includes the mouth, pharynx (food tubes), stomach, small and large intestines, and anus; also includes accessory organs that assist in digestive processes, such as salivary glands, liver, gallbladder and pancreas. Functions: Achieves physical and chemical breakdown of food absorbs nutrients; eliminates solid wastes.

Muscular System

Components: Specifically, skeletal muscle tissue--muscle usually attached to bones (other muscle tissue include smooth and cardiac) and Tendons. Function: Participates in body movements, such as walking; maintains posture, produces heat

Male Reproduction System

Components: Testes and associated organs--epididymides, ductus, deferens, seminal vesicles, prostate and penis Functions: Gonads produces sperm that unite to form a new organism; gonads also release hormones that regulate reproduction and other body processes; associated organs transport and store sperm

Female Reproduction System

Components: ovaries and associated organs--uterine tubes, uterus, vagina and mammary glands. Functions: Gonads produce ocoytes that unite to form a new organism; gonads also release hormones that regulate reproduction and other body processes; associated organs transport and store gametes; mammary gland produces milk.

Cardiovascular System

Components: Blood, heart and blood vessels: veins and arteries Functions: Heart Pumps blood through blood vessels; blood carries oxygen and nutrients to cells and carbon dioxide and waste away from cells and helps regulate acid-base balance, temperature and water content of body fluids; blood components help defend against disease and repair damaged blood vessels.

Respiratory System

Components: Lungs and air passageways such as the pharynx (throat), larynx (voice box), trachea (windpipes), and bronchial tubes leading into and out of lungs. Functions: Transfers oxygen from inhaled air to blood and carbon dioxide from blood to exhaled air; helps regulate acid-base balance of body fluids; air flowing out of lungs through vocal cords produces sounds.

Integumentary System

Components: Skin and associate structures, such as hair, fingernails and toenails, sweat glands, and oil glands Functions: Protects body: helps regulate body temperature; eliminates some waters; helps make vitamin D; detects sensations such as touch, pain, warmth, and cold