Urinary System Powerpoint Lecture 7314z

Excretion: the removal of organic waste from the body fluids.  Elimination: the discharge of these products into the environment.  Homeostatic regulation: Maintaining volume and solute concentration of blood plasma. 

 Regulates blood volume by adjusting content of urine.  Regulates blood pressure by controlling red blood cell

production.  Regulates plasma concentrations of electrolytes: sodium, potassium, and chloride.  Regulates and stabilizes blood pH.

Adrenal Gland

Kidney

Posterior Vena Cava

Abdominal Aorta

Rectum Ureter Bladder Urethra

Placed against the dorsal body wall, in front of the last false rib.  The right kidney is slightly lower than the left to accommodate the liver. 

Renal Medulla Calyx Renal Vein Renal Artery

Renal Pyramid Renal Pelvis Renal Capsule

Ureter Renal Cortex

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Located on the top of the kidney.  Responsible for

releasing adrenaline into the blood stream  Causes fight or flight response

Blood to be filtered enters through the renal artery and exits through the renal vein.  The functional unit of the kidney is the nephron. 

 Each kidney has over

1.25 million with a total length of about 85 miles of tubing.

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As blood enters the nephron, water and any dissolved substances smaller than proteins enter the glomerulus, a network of capillaries.  Large proteins and red blood cells

exit through the afferent arteriole.

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This filtration is ive.

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Substances needed by the body are reabsorbed in the renal tubule.    

Water Glucose Amino acids Electrolytes

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Other waste products are not reabsorbed and will be eliminated.  Urea – Waste product of protein digestion.  Uric acid – Waste product of nucleic acid digestion  Creatine – Waste product of creatine phosphate

digestion in muscles. 

Any remaining fluid will collect in the renal pelvis and exit the kidneys through the ureter.

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The kidneys have 64 sq. ft. of filtration surface, producing about 48 gallons of filtrate per day. 99% is reabsorbed back into the body.

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About 1-2 liters of urine are produced every day. Urine is…  Sterile, or free from microorganisms  Slightly acidic (pH = 6)  Contains unneeded electrolytes, waste products,

and ammonia.  Yellow due to a pigment produced when old red blood cells are broken down.

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The presence of other substances in urine could indicate a disease or disorder.  Glucose – Excess intake of sugary foods; Diabetes  Proteins – Intense physical exertion, pregnancy.  Pus – Urinary tract infection.  Erythrocytes – Damage to the urinary tract.  Bile – Liver disease.

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Ureter  Drains urine into the urinary bladder

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Urinary Bladder  Stores urine.

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Urethra  Tube that exits the body from bladder.

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Urinary Reflex  The process of urination is a the result

of two actions occurring simultaneously: ▪ The muscles surrounding the urinary bladder contract, squeezing its contents out. ▪ The external urinary sphincter relaxes, allowing urine to leave the body.

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Kidney stones are crystalized minerals in the urine. Dietary factors that increase the risk of stone formation:  Low fluid intake  High intake of animal

protein, sodium, sugars.

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Males have a much longer and narrower urethra.  Higher risk of kidney stones, lower risk of

urinary tract infection. 

Females have a shorter and wider urethra.  Higher risk of urinary tract infection, lower risk

of kidney stones.