3.4 Circulatory System

Circulatory System Transport substances around the body Carries nutrients from the i cells delivers oxygen from the lungs carries carbon dioxide to the lungs Blood carries waste from body

Circulatory System 3 necessary components: Blood (fluid) Heart (pump) Blood vessels (arteries and veins)

Blood Connective tissue about 5L Mostly Red Blood Cells Contain hemoglobin which carries the oxygen Produced in the bone marrow Lack a nucleus

Blood White blood cells Leukocytes Produced by bone marrow Fight infections by destroying invading bacteria/viruses <1% of the blood volume Have a nucleus

Blood Platelets Assist in blood clotting <1% of blood volume

Blood Plasma (mostly water) Protein-rich liquid Half of blood’s volume

Heart 4 chambers right side pumps to the lungs Left side pumps to the rest of the body

Heart - Anatomy

Blood Vessels Network of tubes throughout the body to transport blood Arteries Carry blood AWAY from the heart Largest – Aorta Smallest – arterioles Contain elastic connective tissue and muscle

Blood Vessels Veins Carry blood BACK TO the heart Receive blood from capillaries Largest – Superior/inferior vena cava Smallest – venules Contain muscle, connective tissue, and valves Valves prevent backflow

Blood Vessels Capillaries microscopic vessels, one cell thick the place where substance get into or out the circulatory system Bridge between arteries and veins

Homework P 87 # 3, 4, 9 Circulatory CROSSWORD