functions of the excretory system. your body must eliminate wastes to remain healthy. these systems...
Post on 05-Jan-2016
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Functions of the Excretory System
• Your body must eliminate wastes to remain healthy.
• These systems function together as parts of your excretory system.
• The urinary system rids the blood of wastes produced by the cells.
• The urinary system also controls blood volume by removing excess water produced by body cells during respiration.
• Gets rid of excess salts
The Urinary / Excretory System The Urinary / Excretory System
Organs of the Urinary System
• The main organs of the urinary system are two bean-shaped kidneys.
• The kidneys filter blood that contains wastes collected from cells.
• It is made up of about 1 million tiny filtering units called nephrons (NEF rahnz).
Narrow part of pyramid
Renal pelvis w/ pyramid
Inner layer
Outer layer
Triangle shape in medulla
Drains urine from calyx
Expansion of upper end of ureter
Clean deO2
Dirty & O2
Microscopic Structure
Each kidney > 1 million Nephrons Basic unit of S&F of kidney
3 Steps in Urine Formation in Nephrons
Filtration in Renal Copuscle
Reabsorption between tubules and peritubular capillaries (both 1 cell thick)
99% H2O by osmosis, glucose AT, Na+ based on intake
Secretion opposite of reabsorption, substances move from peritubular capillaries into tubules (Ex. NH3 diffusion)
Urine voided from bladder urethra in micturition
Regulating Fluid Levels
• The hypothalamus constantly monitors the amount of water in the blood.
• When the brain detects too much water in the blood, the hypothalamus releases a lesser amount of ADH (anti diuretic hormone)
• This signals the kidneys to return less water to the blood and increase the amount of wastewater, called urine, that is excreted.
• Alcohol & caffeine ADH levels
What does this do to urine volume, why?
• Nicotine ’s ADH levels
• What does this do to urine volume, why?
Urinary Diseases and Disorders• Waste products that are not removed build
up and act as poisons in body cells.
• Water that normally is removed from body tissues accumulates and causes swelling of the ankles and feet.
• Without excretion, an imbalance of salts occurs. If the balance isn’t restored, the kidneys and other organs can be damaged.
• If not treated Death :(
Dialysis
• A person who has only one kidney still can live normally.
• The remaining kidney increases in size and works harder to make up for the loss of the other kidney.
• If both kidneys fail, the person will need to have his or her flood filtered by an artificial kidney machine in a process called dialysis or have a kidney transplant.
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