Organ systems

Integumentary system

forms the external body covering and protects deeper tissues from injury. synthesizes vitamin D and houses cutaneous receptors (pain, pressure, etc.) and sweat and oil glands

skin, hair, nails

Skeletal system

protects and supports body organs and provides a framework the muscles use to cause movement. blood cells are formed within bones. bones store minerals (think bones were once living before being fossilized)

think- bones and joints

Muscular system

allows manipulation of the environment, locomotion, and facial expression. maintains posture and produces heat

think- skeletal muscles

Lymphatic System/Immunity

picks up fluid leaked from blood vessels and returns it to the blood. disposes of debris in the lymphatic stream. houses white blood cells (lymphocytes) involved in immunity

think- lymph nodes, spleen, thoracic duct

respiratory system

keep blood constantly supplied with oxygen and removes carbon dioxide. The gaseous exchanges occur through the walls of the air sacs of the lungs

think- nasal cavity, pharynx, larynx, trachea, lung, bronchus

digestive system

breaks down food into absorbable units that enter the blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces

think- stomach, liver, anus, oral cavity, esophagus, rectum, small and large intestines

Male reproductive system

overall function is production of offspring. testes produce sperm and male sex hormone, and male ducts and glands aid in delivery of sperm to the female reproductive tracts.

Female reproduction system

Main function is reproduction. Ovaries produce eggs and female sex hormones. the remaining female structure serve as sites for fertilization and development of the fetus. mammary glands of female breasts produce milk to nourish the newborn

Urinary System

eliminates nitrogenous waste from the body. regulates water, electrolyte, and acid-base balance of the blood

think- kidney, ureter, urinary bladder, urethra

Cardiovascular system

Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood

think- blood vessels, heart

Endocrine system

glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells

think- pineal gland, pituitary gland, thyroid gland, thymus, arendal gland, testis

nervous system

as the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands

think- brain, spinal cord, nerves