urinary final review

uremia

not producing enough urine

build up waste products damaged the kidney

dialysis

treat the signs and symptoms of uremia by filtering the blood for the patient

reabsorption

into the blood facilitated diffusion

secretion

from the bloodstream into the tubules

aquaporin

facilitate diffusion of water

diuresis (polyauria)

too much urine

anuria

not producing enough urine

micturition

urinating in urinary bladder

function of kidney

The function of kidneys is to create urine, filter blood and remove nitrogenous waste 

The structure and function of the nephron (including the glomerulus and tubules) 

• nephron is the machine that filters blood to make urine

• Glomerulus: capillaries that filter blood to make urine 

• (PCT): reabsorbs good stuff like glucose, salts, and water back into the blood

• (DCT) adjust water and pH level as needed 

The functions and layers of the filtration membrane of the glomerulus

• Fenestrations allow small solutes in

• Basal lamina: network of collagen fibers

• Visceral layer: composed of podocytes process filtration slits by wrapping around glomerular capillaries

What should and should not be found in filtrate and urine 

• SHOULD: water, glucose, amino acids & small protein ions, nitrogenous waste 

• SHOULD NOT: RBCs, WBCs, platelets, large plasma proteins (albumin) 

The molecules that are considered nitrogenous waste

Ammoniums ions, urea, uric acid, creatinine 

The forces at work that determine (NFP) and (GFR) and which direction those forces push

• Glomerular Hydrostatic Pressure: blood pressure pushing OUT of the blood vessel into the filtrate 

• Glomerular Colloid Osmotic Pressure: water pressure come back IN blood vessel bc of albumin 

• Capsular Hydrostatic Pressure: amt of force going IN the blood vessel 

• High NFP → high GFR speed 

• Low NFP → low GFR speed 

Results of urine output and waste build up in the blood when the NFP and/or GFR are too high or too low 

• NFP/GFR LOW: less plasma is filtered at the glomerulus, leading to decrease urine output and nitrogenous waste products remaining in the bloodstream

• NFP/GFR HIGH: urine output increase, less time for reabsorption of water & solutes, can result dehydration and loss of valuable substance such as electrolytes and glucose 

What is secreted and reabsorbed in the proximal tubules, nephron loop, and distal tubules 

•  PCT: reabsorbs water, sodium, glucose, amino acids, and bicarbonate & secreted nitrogenous waste and secretes hydrogen ions

• Nephron loop: reabsorbs water obligatory and chloride

• DCT: facultative water reabsorption and hydrogen

Know where obligatory and facultative enter reabsorption occur in the nephrons 

• Obligatory water reabsorption: reabsorbs water loss at proximal tube and the nephron loop 

• Facultative water reabsorption: water is reabsorbed on the body need of the distal tubule

The renin-angiotensin-aldosterone mechanism inside and out 

• Helps control blood pressure and GFR when its LOW 

• Baroreceptors detect the drops in blood pressure 

• Renin is released by the kidney and activates/bind to angiotensinogen 

• Angiotensinogen is an inactive form that converts into angiotensin I 

• Angiotensin I is also inactive and gets activated by angiotensinogen-converting enzyme to activate the angiotensin II 

• Angiotensin II is the active form which then raises blood pressure and stimulates thirst. 

Hormones associated with the urinary system and their functions 

• Aldosterone: increase sodium reabsorption and potassium secretion in the distal tubule and collecting duct. This causes water retention and increase blood pressure 

• Antidiuretic hormone: increase water reabsorption in the collecting ducts by inserting aquaporins. This reduces urine output and help conserve water 

• Atrial natriuretic peptide: sodium and water excretion to lower blood vol and pressure.