Intro to Animals: Structure and Function Necessary Life Functions - - Metabolism: all the chemical reactions that occur in the body Excretion: removal of wastes from the body Reproduction: cellular and organism levels o Cellular: an original cell divides ad produces 2 identical daughter cells o Organism: sperm and egg unite to make a whole new person Growth: increase in size of a body part or od the organism Levels of Structural Organization of Multicellular Organisms Atoms molecules organelles cells tissues organ organ system organism Organ Systems - Integumentary System o Forms the external body covering o Composed of skin, sweat glands, oil glands, hair, and nails o Protects deep tissues from injury and synthesizes vitamin D - Skeletal System o Composed of bone, cartilage, and ligaments o Protects and support body organs o Provides framework for muscles o Site of blood cell formation o Stores minerals - Muscular System o Composed of muscles and tendons o Allows manipulation of the environment, locomotion, and facial expression o Maintain posture o Produces heat - Nervous System o Is the fast-acting control system of the body o Responds to stimuli by activating muscles and glands - Cardiovascular System o Composed of heart and blood vessels o Heart pumps blood o Blood vessels transport blood throughout the body - Lymphatic System o Picks up fluid leaked from blood vessels o Contains white blood cells involved w/ immunity - Respiratory System o Keeps blood supplied w/ oxygen and removes carbon dioxide - Digestive System o Breaks down food into absorbable units that enter the blood o Eliminates indigestible food as feces - Urinary System o Eliminates toxins and nitrogen-containing wastes from the body o Regulates water, electrolyte, and pH balance of the blood - Endocrine System o System of glands, each of which secretes a type of hormone to regulate the internal conditions of the body o Is an information signal system o Works w/ the nervous system - Reproductive System o Main function is the production of offspring o Ovaries produce eggs and testicles produce sperm - Organ System Interrelationships o Integumentary system protects body from external environment o Digestive and respiratory systems, in contact with the external environment, take in nutrients and oxygen o Nutrients and oxygen are distributed by the blood o Metabolic wastes are eliminated by the urinary and respiratory systems