BI-205 Ch 24 LO

LO CH-24

• Regulation of composition of ions in the blood (Na+, Cl-, Ca2+, HPO42-,K+)
• Blood pH regulation via H+ and HCO3-
• Blood volume regulation by water excretion or reabsorption
• Blood pressure regulation via renin secretion
• Hormone production (Active form of Vitamin D= Calcitriol, Erythropoietin)
• Blood glucose regulation by gluconeogenesis (formation of glucose from amino acid glutamine)
• Waste and foreign material excretion (creatinine, urea, ammonia, bilirubin, uric acid, drugs, environmental toxins)

• Nephron
• Collecting duct
• Papillary duct
• Minor Calyx
• Major Calyx
• Renal Pelvis
• Ureter
• Urinary bladder

• Renal artery
• segmental arteries
• interlobar arteries
• arcuate arteries
• interlobular arteries
• afferent arterioles
• glomerular capillaries
• efferent arterioles
• Peritubular capillaries
• interlobular veins
• arcuate veins
• interlobar veins
• renal vein

• Glomerular (Bowman's) capsule
• Proximal convulated tubule
• Descending limb of Henle
• Ascending limb of the loop of Henle
• Distal convulated tubule( drains into collecting duct)

• Macula densa (Simple cuboidal epithelial cells of the ascending loop of Henle in contact with the afferent arteriole)
• Juxtaglomerular cells (modified smooth muscle fibers of the afferent arteriole)Together the juxtaglomerular apparatus regulates the blood pressure.

• Glomerular filtration: The movement of the water and solutes from the blood plasma across the glomerular capillary endothelium into the glomerular capsule and renal tubule (proximal)
• Tubular reabsorption: Return of most of the water and the solutes from the renal tubule into the blood in the peritubular capillaries and vasa recta.
• Tubular secretion: Movement of substances from the blood in the peritubular capillaries or from the tubular or duct cells into the renal tubule.

• 1. Large surface area of the glomerulus,
• 2. Large fenestrations in the endothelium,
• 3. Blood pressure in the glomerulus is higher than in the capillaries in the rest of the body

amount of filtrate formed in all renal corpuscles of both kidneys per minute

• Although blood pressure goes up and down, renal autoregulation keeps glomerular filtration rate constant. In other words, the same amount of fluid usually is filtered out of the blood no matter what the blood pressure. 2 processes work together to make this happen.
• Process 1: As blood pressure rises, the walls of afferent arterioles are stretched, which makes the afferent arterioles constrict, lowering the glomerular filtration rate. As blood pressure lowers, the walls of afferent arterioles relax, which makes the afferent arterioles dilate, raising the glomerular filtration rate.
• Process 2: As blood pressure rises, the macula densa stop the juxtaglomerular cells from releasing nitric oxide, the afferent arterioles constrict, lowering the glomerular filtration rate. As blood pressure lowers, the macula densa shut down, the juxtaglomerular cells release nitric oxide, which makes the afferent arterioles dilate, raising the glomerular filtration rate.

Xalcium oxalate, uric acid and calcium phosphate crystals present in urine get deposited and solidified in the kidneys forming renal calculi commonly called renal stones or kidney stones.

constitutes juxtaglomerular apparatus with macula densa

• When blood pressure is LOW: juxtaglomerular cells release renin to activate the renin-angiotensin-aldosterone system water levels in the blood increase, which raises blood pressure.
• When blood pressure is HIGH: Macula densa inhibits the juxtaglomerular cells from releasing renin Turning off the renin-angiotensin-aldosterone system which lowers blood pressure.

the ADH influences the permeability of the convoluted tubules, this will help the water and nutrients be reabsorbed into the cells and into the blood stream

lack of ADH, water is not reabsorbed and as a result, large volume of urine is excreted

• H2O reabsorbed in descending loop of Henle resulting in more concentrated tubular fluid. Ascending Loop of Henle reabsorbs more solutes but not water, resulting in progressively dilute tubular fluid this continues in distal convoluted tubule further diluting tubular fluid. Absence of ADH makes collecting ducts impermeable to water but allows absorption of solutes leaving increasingly diluted tubular fluid to drain into the renal pelvis.
• The osmotic gradient that attracts water out of the collecting ducts is created by the salt concentration in the kidney medulla. It is high there because of reabsorbed Na+ ions combined with Cl- to form NaCl. Water is pulled from the filtrate to dilute the high salt side.

symporters in thick ascending limb establish osmotic gradient; principal cells in collecting duct reabsorb more water when ADH is present; urea recycling causes buildup in renal medulla.

The convoluted tubules are impermeable to water when antidiuretic hormone is absent or low. So, low ADH results in diluted urine and high ADH results in concentrated urine.

Substances that causes diuresis or increased flow of urine by decreasing the renal absorption of water.

• caffeine - inhibits the absorption of Na+
• alcohol - inhibits ADH secretion

The procedure to cleanse blood artificially. It is the separation of large solutes from smaller ones by diffusion through a selectively permeable membrane.

Transitional epithelium lines the urinary bladder and ureters.It has the ability to stretch which enables the ureters and bladdar to change its size thus enabling them to accomodate varying volumes of urine.

Around the opening to the urethra the muscularis forms an internal urethral sphincter. Inferior to the urethral internal sphincter is the external urethral sphincter.

discharge of urine fron urinary bladder into urethra

• Increased pressure inside the bladder due to the increased volume stretch receptors send impulses to spinal cord (sacral region)
• parasympathetic impulses from the spinal cord to the detrusor muscle of the bladder, causing contraction of the smooth muscle and relaxation of the internal urethral sphincter spinal cord inhibits somatic motor neurons to the skeletal muscle of the external urethral sphincter, relaxing it.

• Define cystitis.---->Inflammation of the urinary bladder.
• Define pyelonephritis - inflammation of the kidney and upper urinary tract that usually results from noncontagious bacterial infection of the bladder (cystitis).

Inability over voluntary control of urination.

Inability to completely empty the bladder (despite the urge to urinate.)

a homeostatic challenge for the kidney to keep pH level of body fluids in the appropriate range (neither basic or acidic), so that the body can function normally. KISS: a homeostatic mechanisms to keep pH level of body fluids in the appropriate range (between 7.35 and 7.45).

• The Urinary system helps regulate acid-base balance by the removal of H⁺ from body fluids and subsequent elimination from the body via three major mechanisms:
• buffer systems.
• excretion of H⁺ in urine.
• exhalation of carbon ioxide.

the concentration of solutes in urine, usually measured by comparing the weight of urine to distilled water.

Precence of microbes, pus

• this test it reflects the acidity or alkalinity of the urine.
• high pH indicates high protein diet(acidic urine)
• low pH indicates a low protein diet like vegetarian diets(alkaline urine).

• Low specific gravity: dehydration or glucosuria.
• High specific gravity: diebetes insipidus, kidney infection, kindey failure

Glucose in the urine, due to a high blood concentration of glucose. Most common cause is diabetes mellitus.

Presence of RBC in the urine, could be due to a damage to the glomerular filtration membrane allowing large items such as RBC to pass through (pyelonephritis), in cystitis or urethritis-damage to the epithelium caused by a inflammation or infection

high amounts of albumin in urine, caused by high blood pressure, kidney trauma, disease or inflammation

Caused by metabolic condition called ketosis for lack of enough glucose to break down the fatty acid

regulation of blood ionic composition, blood pH, blood volume, blood pressure, production of hormones, blood glucose, excretion of waste/foreign substance.

it is the smooth-textured area extending from the renal capsule to the bases of the renal pyramids and into the spaces between them.

Drains urine to the minor calyx.

it receives urine from the papillary ducts of renal papilla and delivers it to the major calyx

Receives urine from papillary ducts.

acts as funnel for urine flowing to ureter

it is an indentation through which the ureter leaves the kidney, and blood vessels, lymphatic vessels, and nerves enter and exit.

Functional unit of the kidney.

a capillary network used to carry plasma to the renal corpuscle for filtration

filters plasma from glomerulus and transports it to the renal tubule

where the filter fluid from the renal corpuscle passes though and consist of the proximal convoluted tubule, loop of henle, and the distal convoluted tube

connects from the glomerular capsule

Reabsorption into blood of: H2O, Na+, K+, Cl-, HCO3-, Ca2+, Mg2+. Secretion into urine of Urea. At end of loop of Henle, tubular fluid is hypotonic.

Reabsorption into blood of: H2O, Na+, Cl-, Ca2+ and Urea. Secretion into urine of K+ and H+. Tubular fluid leaving the collecting duct is dilute when ADH level is low and concentrated when ADH level is high.

Carries blood in the glomerulus

carriess blood out of the glomerulus

receives blood from Efferent arteriole.

Receive blood from vasa recta.

Blood drains through from vasa recta

Blood runs between the renal pyramids.

it transport urine to the urinary bladder.

it stores and release urine

contracts to squeeze urine out and relaxes to fill the urinary bladder

triangle region of the bladder base, consisting of the two ureteric orifices and urethra

folds in the mucosa and allows of the urinary bladder to expand

small tube leading from the urinary bladder to the exterior of the body. In males, it allows for semen discharge