excretory system/urinary system

how is urea created

deamination in liver occurs, removing amino acid groups, ammonia is the byproduct

-ammonia combines with co2 to create urea

how is uric acid created

nucleic acids break down into uric acid

parts of urinary system

1. kidney- produces urine

2. ureters- transports urine

3. urinary bladder- contains urine/stores urine

4. urethra- excretes urine

what is the general flow of waste

1. renal arteries deliver blood to kidneys

2. blood is filtered through nephrons

3. useful materials is absorbed the rest go to ureters→bladder→urethra

what are the four processes of urine formation

1. glomerular filtration

2. tubular reabsorption

3. tubular secretion

4. water reabsorption

describe glomerular filtration

blood enters at high pressure and gets filtered through glomerulus(water,ions,glucose), bowmans capsule carries filtrate to tubule

describe tubular reabsorption

filtrate enters proximal tubule, reabsorbing glucose and amino acids, sodium and potassium is actively absorbed, negative ions are passively absorbed. filtrate enters loop of henle:

descending- water absorbed

ascending- sodium absorbed

filtrate enters distal tubule:

-sodium ions actively reabsorbed

-negative ions passively reabsorbed

describe tubular excretion

secretion occurs in distal tubule, movement of hydrogen, urea, and wastes move from blood to nephrons

describe water reabsorption

collecting duct reabsorbed remaining water, the liquid is now called urine

antidiuretic hormone(ADH)

osmoreceptors detect high concentration in blood

-ADH is released from hypothalamus, goes to nephrons/ collecting duct making it more permeable to water→absorbs more water

aldosterone

receptors detect decrease in blood pressure, sends signals to adrenal gland, releases aldosterone

-sodium and water is absorbed, blood pressure increases

diabetes inspidus

inability to produce ADH, less water is reabsorbed

diabetes mellitus

sweet urine due to blood sugar levels inscreasing, excess sugar remains in nephrons

nephritis

inflammation is glomerulus, affecting filtration