Bio Final Urinary System

Front 1

What are the parts and functions of the urinary system?

Back 1

Kidneys (2) – bean-shaped, fist-sized organ where urine is formed
Ureters (2) – small, muscular tubes that carry urine from the kidneys to the bladder
Bladder (1) – expandable organ that stores urine until it is expelled from the body
Urethra (1) – tube (longer in men than women) that carries urine from the bladder to the outside of the body

Front 2

Functions of urinary system

Back 2

1.Excretion of metabolic wastes
2.Maintenance of water-salt balance
3.Maintenance of acid-base balance
4.Hormone secretion: renin and erythropoietin

Front 3

Excretion

Back 3

Mostly of nitrogenous wastes:
Urea made by the breakdown of amino acids in the liver
Uric acid made by the breakdown of nucleotides
Creatinine made by muscle cells from the breakdown of creatine phosphate

Front 4

Maintenance of water-salt and acid-base balance

Back 4

Both are homeostatic mechanisms
Water-salt balance helps to maintain blood pressure
The kidneys by excreting hydrogen ions and reabsorbing the bicarbonate ions this acid-base balance helps maintain a blood pH of ~7.4

Front 5

Kidney structure

Back 5

Renal cortex – an outer granulated layer
Renal medulla – cone-shaped tissue masses called renal pyramids
Renal pelvis – central cavity that is continuous with the ureter

Front 6

nephrons

Back 6

Microscopic functional unit of the kidney that produces urine
> 1 million per kidney

Front 7

Glomerulus

Back 7

a knot of capillaries inside the glomerular capsule where pores produce a blood filtrate

Front 8

Proximal convoluted tubule

Back 8

epithelial layer with a brush border of microvilli to allow reabsorption of filtrate components

Front 9

loop of nephron

Back 9

U-shaped structure that has a descending limb to allow water to leave and an ascending limb that pushes out salt

Front 10

distal convoluted tubule

Back 10

made of epithelial cells rich in mitochondria and thus is important for movement of

Front 11

Collecting ducts

Back 11

several nephrons share a collecting duct which serve to carry urine to the renal pelvis

Front 12

What are the 3 processes in the formation of urine?

Back 12

Glomerular filtration
Tubular reabsorption
Tubular secretion

Front 13

Glomerular filtration

Back 13

Water and small molecules move from the glomerulus to the glomerular capsule while large molecules and formed elements remain in the glomerular blood

Front 14

Tubular reabsorption and secretion

Back 14

Many molecules and ions are reabsorbed from the nephron into the blood
A second way to remove substances such as drugs, H+ and creatinine from the blood

Front 15

Reabsorption of salt

Back 15

increases blood volume

Front 16

Atrial natriuretic hormone (ANH)

Back 16

secreted by the heart when blood volume increases and inhibits the secretion of aldosterone which promotes the excretion of Na+

Front 17

Establishment of solute gradient

Back 17

a greater concentration is towards the inner medulla

Front 18

Reabsorption of water

Back 18

due to the solute gradient water leaves the descending limb of the loop of the nephron then antidiuretic hormone (ADH) from the pituitary plays a role in water reabsorption at the collecting duct

Front 19

What role does alcohol play in this process?

Back 19

Alcohol inhibits ADH secretion and thus increases the amount of urine and dehydration

Front 20

How is the acid-base balance maintained?

Back 20

Buffers are a chemical or a combination of chemicals that can take up excess H+ or excess OH-

Front 21

Kidney function disorders

Back 21

Diabetes, hypertension and inherited conditions are the most common cause of renal disease and failure such as:
Urethritis – localized infection of the urethra
Cystitis – infection in the bladder
Pyelonephritis – infection of the kidneys
Kidney stones – hard granules formed in the renal pelvis due to UTI’s, enlarged prostate, pH imbalances or intake of too much calcium
Uremia – high levels of urea and other waste substances in the blood that causes a serious condition when water and salts are retained due to extensive nephron damage

Front 22

how can Kidney failure be treated?

Back 22

Hemodialysis – uses an artificial kidney machine to subtract and add substances to the blood as needed
Continuous ambulatory peritoneal dialysis (CAPD) – used the peritoneal membrane to filter the blood and allows a person to go about their normal life without interruption
Kidney replacement – single kidney transplant with a high success rate
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Front 23

How do the kidneys maintain homeostasis?

Back 23

Excrete wastes
Urea, creatinine and uric acid
Water-salt balance of blood
Helps regulate blood volume and pressure
Acid-base balance of blood
Helps regulate pH
Assistance to other systems
Endocrine, cardiovascular, skeletal, muscular, nervous and digestive