Nephrons Functions

Tubular reabsorption

99% filtrate flowing through renal tubules movement of H2O some salt, amino acid, glucose back into blood of the peritubular capillary reabsorbed into blood peritubular capillary is tubular reabsorption mechanism and stabilizes GFR

Regulation of Urinary

Blood volume and peruse adjusting EPO and renin release and water loss Control quantities of Na K Cl and other ion pH control Loss of H, HCO3 conservation of nutrient preventing excretion of urine assist liver on detoxifying poison during starvation deaminating amino acid

Functions of Urinary System

Excretion Elimination REgulation

Nephron Functions

Filtration Reabsorption Secretion

Renin Angiotensin

GFR falls

Counter current multiplier system loop of henle

Na H2O Positive feedback

Aldosterone accelerate

Na reabsorption in DCT

Renal tubule

PCT, loop of henle, DCT

Hormonal Regulation

Renin Angiotensin system Angiotensin II

GFR falls

Renin released by juxtaglomerular complex acts on Angiotensinogen-angiotensin I-Angiotensin II

DCT

active secretion of ion, etc, mineral primary secretion selective reabsorption of Na Ca from tubular fluid selective reabsorption of H2O

sympathetic nervous system

acute fall of BP triggers powerful vasoconstriction of afferent arterioles decreasing GFR slowing production of filtrate overrides local regulatory

Na counter current multiplier

ascending by active transport Cl accompanies it to keep flow of electrically neutral elevates osmotic pressure

Angiotensin I

converting enzyme (lung)

Loop of Henle

descending limb and ascending limb thick and thin portion

Renal Autoregulation

dilation of afferent arterioles constriction of efferent arterioles intrinsic control occurs in the kidney help kidney to regulate and maintain GFR

Elimination

discharge

Effects and Function of loop of henle

filtrate becomes more concentrated as it moves down the loop more dilute as it moves up the loop allow passive reabsorption of H2O reabsorption regulated by ADH controls H2O channels called aquaporin's tubular cells along DCT contain ion pump that reabsorb tubular Na in exchange of K ion pump control of aldosterone prolonged aldosterone production may cause hypokalemia

Renal Corpuscle

filtration occurs blood forced across a filtration membrane

Constriction

increases the glomerular blood pressure

extrinsic control

neural and hormonal mechanism maintain systematic blood pressure during stress neural control overcome renal autoregulatory control

Nephron Filtation

occurs in the glomerulus blood forces H2O and solutes across filtration membrane solute particles to pass through filtration membrane cortical by surrounding H2O allow H2O and soluble to extra bond tubular fluid

Dilation of afferent arterioles

occurs when blood pressure is up

H2O counter current multiplier

out of descending by osmosis raising solute concentration accelerates transport of NaCl into peritubular fluid positive feedback mechanism

Angiotensin II

peripheral vasoconstriction

Angiotensinogen

plasma protein

Descending limb

reabsorption of H2O

PCT

reabsorption of H2O and solutes from filtrate and returning to blood primary reabsorption of PCT

Ascending limb

reabsorption of ion

Excretion

remove organic waste

Nephron Reabsorption

removes H2O from filtrate into peritubular fluid reenters blood materials are nutrients H2O passively (osmosis) occurs in PCT

Tubular Secretion

removes products from blood of the peritubular capillary and return them to the filtrate (waste, NH3, Urea) helps pH

Components of the renal

renal corpuscle renal tubule proximal convoluted tubule loop of henle descending loop of henle ascending loop of henle distal convoluted tubule collecting duct

adrenal gland

stimulated to secrete aldosterone

Autonomic Regulation

sympathetic nervous system tubular reabsorption tubular secretion

Nephrons Secretion

transport of solute from peritubular fluid into tubular fluid necessary because does not dissolved materials from plasma back up for filtration lower plasma concentration of undesired materials primary method of excretion for some compound like drugs helps regulate pH

Angiotensin II causes

vasoconstriction of arterioles and precapillary sphincter BP up nephron causes constriction of efferent arterioles glomerular pressure and filtration rate up stimulates kidney to reabsorb Na and H2O follows passively Adrenal gland stimulates to secrete aldosterone Aldosterone accelerate Na reabsorption in DCT triggers thirst center triggers release ADH reabsorption of H2O in DCT and collecting system peripheral vasoconstriction