ORGAN SYSTEMS WORKING TOGETHER Section 3.5

Million 100 Million 1 Billion 1 trillion 60 trillion cells (60, 000, 000, 000, 000) in the body Million 100 Million 1 Billion 1 trillion

ORGAN SYSTEMS There are two main classifications of organ systems; those that:  supply nutrients and remove wastes  regulate the body

SYSTEMS FOR NUTRIENT SUPPLY AND WASTE REMOVAL Respiratory System Parts: trachea, lungs, alveoli, blood vessels in the lungs Absorbs oxygen from the air and gets rid of carbon dioxide Exchange of gases occurs in the blood vessels in the lungs, so it is connected to the circulatory system

SYSTEMS FOR NUTRIENT SUPPLY AND WASTE REMOVAL Circulatory System Parts: heart, arteries, veins, capillaries  Distributes oxygen around the body and returns carbon dioxide to the lungs Also distributes nutrients from the digestive system to the cells and collects waste products and brings them to the kidneys (excretory system)

SYSTEMS FOR NUTRIENT SUPPLY AND WASTE REMOVAL Digestive System Parts: mouth, esophagus, stomach, intestines, liver Breaks down food, providing nutrients for cells (nutrients delivered to cells by the circulatory system)

SYSTEMS FOR NUTRIENT SUPPLY AND WASTE REMOVAL Excretory System Parts: kidneys, ureters, bladder, urethra Collects waste from the blood system and excretes it as urine Also regulates amount of water in body

Organ Systems

SYSTEMS FOR REGULATING THE BODY Endocrine System Produces hormones (chemical messengers) that travel to other organs and tell them how to adjust to our environment Example. adrenaline (made by adrenal gland) causes the body to react quickly to danger

SYSTEMS FOR REGULATING THE BODY Nervous System Detects what is going on outside/inside the body and sends electrical messages throughout the body to your brain, your muscles, or your endocrine glands The endocrine and nervous systems often work together to allow an organism to react to the environment