1 CIRCULATORY & EXCRETORY SYSTEMS UNIT 3 – PART 1

2 THE CIRCULATORY SYSTEM

FUNCTIONS To transport O 2 to the cells of the body so that cells may do cellular respiration To Transport nutrients to the cells of the body To transport CO 2 and cellular wastes away from the cells 3

PARTS Heart Blood Vessels Blood 4

COMPONENTS OF BLOOD Red blood cells White blood cells Platelets Plasma 5

WHAT ARE RED BLOOD CELLS? Also called erythrocytes Transport oxygen Shaped like disks Produced in the red bone marrow Contain Hemoglobin An iron containing protein that binds to oxygen Gives blood a red color 6

WHAT ARE WHITE BLOOD CELLS? Also called leukocytes Produced in the red bone marrow Can live for days, months or even years Guard against infection, fight parasites, and attack bacteria Can leave the circulatory system and go into the immune system fighting infection 7

WHAT ARE TWO KINDS OF WHITE BLOOD CELLS? Phagocytes (eating cells) Engulf and digest disease causing bacteria Lymphocytes Produce antibodies that are proteins to help destroy pathogens 8

WHAT ARE PLATELETS? Cell fragments needed for clotting Made in bone marrow Clotting process Platelet comes in contact with edges of broken blood vessel and becomes sticky A cluster of platelets gathers around the wound forming a clot (scab) 9

WHAT IS PLASMA? Fluid part of blood (mostly made of water) Straw colored Transport fatty acids, hormones and vitamins Regulate osmotic pressure and blood volume Fight viral and bacterial infections Aid in blood clotting 10

TYPES OF BLOOD VESSELS Arteries Large and thick-walled Carry blood from the heart to the rest of the body 11

TYPES OF BLOOD VESSELS Veins Smaller than arteries and not as thick- walled Carry blood from the rest of the body back to the heart 12

TYPES OF BLOOD VESSELS Capillaries Tiny blood vessels with walls that are only one cell thick Oxygen and nutrient absorption take place in the capillaries Also move CO 2 and waste products into the blood from cells 13

THE HEART 14

BLOOD FLOW THROUGH THE HEART Oxygen poor- 1.) Superior and inferior vena cava 2.) Right Atrium 3.) Right Ventricle 4.) Lungs Oxygen rich- 5.) Left Atrium 6.) Left Ventricle 7.) Aorta 8.) Body 15

BLOOD FLOW THROUGH THE BODY Pulmonary circulation Right side of the heart pumps blood from the heart to the lungs Systemic circulation Left side of the heart receives blood from the lungs and pumps it to the rest of the body 16

CLOSED VS. OPEN CIRCULATION Closed circulation – blood is contained in a system of vessels and forced through them by a heart or heart-like organ Open circulation – blood is partially contained in a system of vessels; a heart or heart-like pump pushes the blood though spongy tissues 17

18

THE EXCRETORY SYSTEM

FUNCTION OF THE EXCRETORY SYSTEM Maintains homeostasis in the body by removing waste products from the cells and expelling them from the body Single-celled organisms can use active transport or diffusion Multicellular organisms must have a complete system

PARTS OF THE EXCRETORY SYSTEM Kidneys : 1.remove waste products from the blood 2.maintain blood pH 3.regulates total blood volume by controlling water content in blood Ureters Urinary Bladder Urethra Skin – releases excess salts and water through pores Lungs – remove excess carbon dioxide from the blood

PARTS OF THE EXCRETORY SYSTEM

KIDNEY STRUCTURE 2 regions of kidney Renal cortex-outer region Renal medulla-inner region Nephrons Functional units (~1 million each kidney)

STEP 1: FILTRATION Materials filtered from the blood by the nephron are called filtrate 1.Water 2.Salts 3.Glucose 4.Amino acids 5.Urea (the waste product of amino acid breakdown)

STEP 2: RE-ABSORPTION Amino acids, fat, glucose and most water - returned to the blood. Urine - urea, excess salts and water; stays in the nephron

STEP 3: EXCRETION Flow of Urine: Nephron Ureters Urinary bladder Urethra Average bladder capacity is 500 ml (16 oz) ~48 gallons of filtrate are processed each day; 1% is excreted as urine (~.5 gallon) 26

HOMEOSTASIS BY MACHINE Dialysis - blood is passed through a filtration system other than the kidneys and returned to the body Hemodialysis - machinePeritoneal dialysis