Epidermal and dermal regions; cutaneous sense organs and glands.

Protects deeper organs

Excretes salts and urea

Body temperature

Produces vitamin D

Skeletal

Bones, cartilages, tendons, ligaments and joints.

Body support and protection of organs.

Provides levers for muscular action

Cavities provide a site for blood cell formation

Muscular

Muscles attached to the skeleton

Contract or shorten

Allows motion of muscles

Generates heat

Brain, spinal cord, nerves and sensory receptors

Allows body to detect change in environment and respond

Helps maintain homeostasis of body via rapid transmission of electrical signals

Pituitary, thymus, thyroid, parathyroid, adrenal and pineal glands; ovaries, testes and pancreas

Helps maintain homeostasis, promotes growth and development.

Produces hormones that travel in the blood to exert their effects on various "target organs" of the body.

Heart, blood vessels, blood

Transport system that carries blood to and from tissue cells where exchanges are made.

Antibodies and other protein molecules in the blood act to protect the blood.

Lymphatic vessels, lymph nodes, spleen, thymus, tonsils, and scattered collections of lymphoid tissue

Cleanses blood of pathogens and other debris

Houses lymphocytes that act via the immune response to protect body from foreign substances

Nasal passages, pharynx, larynx, trachea, bronchi and lungs

Keeps the blood continously supplied with oxygen while removing CO2

Contributes to the acid-base balance of the blood via its carbonic acid-bicarbonate buffer system

Oral cavity, esophagus, stomach, intestines, teeth, salivary glands, liver, and pancreas

Breaks down ingested foods to minute particles, which can be absorbed into the blood for delivery to the body cells

Undigested residue removed from the body as feces

Kidneys, ureters, bladder, and urethra

Rids the body of nitrogen-containing wastes, which result from the breakdown of proteins and nucleic acids by body cells

Maintains water, electrolyte, and acid-base balance of blood

Testes, prostate gland, scrotum, penis, and duct system, ovaries, uterine tubes, uterus, mammary glands, and vagina

Provides germ cells (sperm) for perpetuation of the species

Provides germ cells (eggs); uterus house developing fetus; mammary glands provide nutrition for the infant