UNIT 3 – PART 1
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Transcript of UNIT 3 – PART 1
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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
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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
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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
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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
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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)
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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
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TYPES OF BLOOD VESSELS
• Arteries• Large and thick-walled• Carry blood from the heart to the rest of the body
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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
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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
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BLOOD FLOW THROUGH THE HEART
• Oxygen poor-1.) Superior and inferior vena cava2.) Right Atrium
3.) Right Ventricle
4.) Lungs
• Oxygen rich-5.) Left Atrium
6.) Left Ventricle
7.) Aorta
8.) Body
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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
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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
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 blood2. 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
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 filtrate1. Water2. Salts3. Glucose4. Amino acids5. 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
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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)