Renal Flashcards
Course Objectives for Renal
Function of renal corpuscle
Produce filtrate
Function of proximal convoluted tubule
Reabsorption of water, ions, and all organic nutrients
Function of loop of henle
further reabsorption of water (descending limb) and both sodium and chloride ions (ascending limb)
Function of distal convoluted tubule
secretion of ions, acids, drugs, toxins. Variable reabsorption of water, sodium, potassium, hydrogen, and bicarbonate ions
Function of collecting system (collecting tubules and collecting duct)
variable reabsorption of water and reabsorption or secretion of sodium, potassium, hydrogen, and bicarbonate ions
Function of peritubular capillaries
capillary network associated with cortical nephrons. 85% of nephrons
Function of vasa recta
capillary network associated with juxtamedullary nephrons. Responsible for creating osmotic gradient that reabsorbs water
Function of glomerulus
Filtration unit of kidney
Function of bowman’s capsule/glomerular capsule
“catches” the filtered material from the glomerulus
Function of juxtaglomerular apparatus
regulate blood pressure and the filtration rate of the glomerulus. Releases renin
What is vasculature of kidney
R-SIACA
Renal artery - segmental artery - interlobar artery - arcuate artery - cortical radiate artery - afferent artery - glomerulus - efferent arteriole - peritubular capillaries (or vasa recta) - cortical radiate vein - arcuate vein - interlobar vein - renal vein
What is fibrous/renal capsule?
Surrounds kidney; made of dense, irregular connective tissue
What is Hilum?
indentation of kidney. Ureter, renal artery/vein exit kidney here
What is cortex?
Outer layer of kidney
What is medulla?
Inner layer of kidney. Location of 6-18 triangular renal pyramids
What are renal pyramids?
triangular structure consisting of renal tubules; site of urine production
What is renal papilla?
Tip of renal pyramid; projects into renal sinus
What are renal columns?
Cortical tissue found between renal pyramids. (Kidney lobe consists of renal pyramid + overlying renal cortex + adjacent tissues of renal columns)
What are ureters?
Drain kidney and transport urine towards urinary bladder
What is urinary bladder?
Temporarily stores urine prior to urination
What is urethra?
Transports urine to exterior
What is the juxtaglomerular apparatus?
Composed of macula densa (chemoreceptors and baroreceptors that detect sodium levels and regulate GFR); juxtaglomerular cells (baroreceptors in afferent arteriole that secretes renin); extraglomerular mesangial cells (in triangular space between afferent and efferent arteriole. feedback control between macula densa and juxtaglomerular cells).
What is the hormonal control of GFR?
Stimulus: Decrease in renal blood flow.
Effector: Juxtaglomerular apparatus
Response: Renin released, angitensinogen becomes AG1, AG1 becomes AG2 due to ACE, vasoconstriction increases renal blood flow.
What is neural control of GFR?
AG2 causes production of aldosterone from adrenal glands. Aldosterone secretion increases pressure and GFR
What is GFR?
Amount of filtrate kidneys produce each minute. Normally 125 ml/min, or 180 L per day
What determines GFR?
Glomerular hydrostatic pressure - (capsular hydrostatic pressure + blood colloid osmotic pressure)
What is primary determinant of GFR?
blood pressure
How does PCT affect electrolyte balance?
Active transport of sodium, potassium, bicarbonate, magnesium, and phosphate for reabsorption. Passive transport of chlorine for reabsorption
How does nephron loop affect electrolyte balance?
Ascending limb pumps out sodium and chlorine for reabsorption
How does DCT affect electrolyte balance?
Active transport of sodium and chlorine for reabsorption. Aldosterone causes sodium to be reabsorbed and potassium secreted. This is also primary site of calcium reabsorption, regulated by parathyroid hormone and calcitriol.
How does kidney regulate acid-base balance?
Bicarbonate is reabsorbed in PCT, and collecting duct (in exchange for chlorine). Hydrogen ions secreted at DCT in countertransport with sodium.
What are two types of acidosis?
Metabolic acidosis (lactic acidosis, ketoacidosis) Respiratory acidosis (hypoventilation, CO2>50)
What are two types of alkalosis?
Metabolic alkalosis (alkaline tide w/excessive vomiting, prolonged aldosterone stimulation). Respiratory alkalosis (hyperventilation. CO2<35)
What is role of kidney in erythrocyte production?
JGA releases EPO in response to low O2 pressures. EPO stimulated bone marrow to increase RBC production.
What is diabetes insipidus?
Disorder of pituitary gland characterized by polyuria and polydipsia that results from inadequate production of ADH
How does diabetes mellitus relate to urine volume?
Excessive glucose levels secondary to diabetes mellitus cause glucose concentrations to exceed threshold maximum for reabsorption leading to glycosuria. Polyuria results due to water being drawn into the renal tubules because of high glucose levels
