1. UNIT 3 – PART 1 CIRCULATORY & EXCRETORY SYSTEMS

2. The Circulatory System

3. Functions • To transport O2 to the cells of the body so that cells may do cellular respiration • To Transport nutrients to the cells of the body • To transport CO2 and cellular wastes away from the cells

4. Parts • Heart • Blood Vessels • Blood

5. Components of Blood • Red blood cells • White blood cells • Platelets • Plasma

6. 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

7. 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

8. 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

9. 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)

10. 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

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

12. 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

13. 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 CO2 and waste products into the blood from cells

14. the Heart

15. 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

16. 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

17. 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

19. The Excretory System

20. 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

21. Parts of the Excretory System • Kidneys : • remove waste products from the blood • maintain blood pH • 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

22. Parts of the Excretory System

23. Kidney Structure • 2 regions of kidney • Renal cortex-outer region • Renal medulla-inner region • Nephrons • Functional units • (~1 million each kidney)

24. Step 1: Filtration Materials filtered from the blood by the nephron are called filtrate • Water • Salts • Glucose • Amino acids • Urea (the waste product of amino acid breakdown)

25. 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

26. 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)

27. Homeostasis by machine • Dialysis - blood is passed through a filtration system other than the kidneys and returned to the body Hemodialysis - machine Peritoneal dialysis