104 terms

Anatomy Exam 5 (Renal Filtration)

Renal Capsule
A fibrous tissue that covers the kidneys.
Renal Hilus
A cleft or indentation on the medial surface of the kidneys, which serves as the landmark for the location of the ureters, blood vessels, and nerves that serve the kidney.
Cortex, Medulla, Pelvis
What are the three regions that the kidney's are broken up in?
Outermost region of the kidney's, appear granular.
Darker colored, middle region of the kidney's containing numerous funnel-shaped structural units called renal pyramids, each with a papilla at its tapered end.
Renal Column
Separates the pyramids; are projections of cortical tissue.
Central Region of the kidneys that have a pouch that narrows and extends directly into the ureter.
Structure branched off of the renal pelvis.
Minor Calyx
Surrounds each papillus of a renal pyramid to receive urine from it.
Major Calyx
Several minor calyces joined together.
Tract that branches off of the pelvis (where urine is collected) and leads urine to the bladder.
Renal Artery
Blood enters the kidney via _____ _____.
Interlobular Artery
Smaller vessels branched off of the renal artery in the renal cortex.
Afferent Arteriole
Branches off the interlobular artery and delivers blood to the glomerulus.
A special coiled ball of capillaries.
Glomerular Capsule
A cup-like structure the completely surrounds the glomerulus.
Renal Corpuscle
The glomerulus and glomerular capsule form a structure called the ______ _______.
The glomerulus is highly permeable primarily because of pores in its walls called _______.
Modified simple squamous epithelial cells that wrap around the glomerular capillaries.
Filtration only occurs in the _________.
The solution inside the glomerular capsule.
Through _______, the nephron returns nutrients such as sodium ions and water to the bloodstream.
In ______, unwanted substances in excess amounts, such as hydrogen ions, potassium ions, and antibiotics, are transported out of the blood and into the renal tubular system.
Glomerular Hydrostatic Pressure (GHP)
Force of blood pressure against the walls of the glomerulus.
Capsular Hydrostatic Pressure (CHP)
The force of the filtrate fluid against the wall of the glomerular capsule, it averages about 15 mm Hg and works against filtration.
Blood Colloidal Osmotic Pressure
Osmotic pressure being a force working against filtration, and averages 25 mm Hg.
Juxtaglomerular Apparatus
Vital to the GFR and consists of: Juxtaglomerular Cells and Macula densa.
Juxtaglomerular (JG) Cells
A group of modified smooth muscle cells around the afferent arteriole, which secrete the enzyme renin.
Macula Densa
A group of modified epithelial cells within the wall of the distal convoluted tubule adjacent to the afferent arteriole. These act as chemoreceptors that sense changes in solute concentration of the filtrate.
Glomerular Filtration Rate (GFR)
The volume of filtrate produced every minute by all nephrons in both kidneys and is equal to about 125 ml filtrate/min.
Autoregulation, Neural Regulation, Hormonal Regulation
What are the three major mechanisms used to control Glomerular Filtration Rate (GFR)?
The dominant control mechanism at rest, which is divided into two mechanisms: smooth muscle mechanism and tubular mechanism.
Smooth Muscle Mechanism
Stretching of the wall of the afferent arteriole as a stimulus to induce vasoconstriction of itself. This leads to a decrease in blood flow to the glomerulus and decreases GFR back to normal levels.
Tubular Mechanism
Involves the Macula Densa, and responds by constricting the afferent arteriole which reduces blood flow to the glomerulus and decreases the GFR back to normal levels.
Neural Regulation
Controls GFR during periods of physical activity and stressful situations.
Hormonal Regulation
Involves the hormone angiotensin II and is triggered by a decrease in blood volume or BP. Juxtaglomerular cells release the enzyme renin into the bloodstream, which leads to production of angiotensin II, a powerful vasoconstrictor. This causes peripheral blood vessels to constrict, which increases BP, which increases GFR.
The transport of nutrients such as sodium ions or water from the renal tubule into the blood of the peritubular capillaries.
Proximal Convoluted Tubule
Most of the reabsorption of filtrate occurs where?
Proximal Convoluted Tubule
What nephron region reabsorbs Na+, Cl-, K+, H2O, glucose, amino acids, HCO3-, Ca+2, and Mg+2?
Nephron Loop
What nephron region reabsorbs Na+, Cl-, H2O, HCO3-, Ca+2, and Mg+2?
Distal Convoluted Tubule
What nephron region reabsorbs Na+, Cl-, H2O, and Ca+2?
Collecting Tubule (CT)
What nephron region reabsorbs Na+, H2O, and HCO3-?
_______ is the transport of substances such as hydrogen ions from the blood of the peritubular capillaries into the renal tubules. The purpose is to remove these substances from the body in the urine.
Proximal Convoluted Tubule
What nephron region secretes H+, NH4+, Urea, and Creatinine?
Nephron Loop
What nephron region secretes urea?
Distal Convoluted Tubule
What nephron region doesn't secrete anything?
Collecting Tubule
What nephron region secretes H+ and K+?
What hormone does the kidney produce, that serves as the active form of vitamin D and helps regulate calcium homeostasis?
What hormone does the kidney produce, that stimulates the production of RBC's?
The renal cortex and renal pyramids of the renal medulla constitute the _________; the functional portion of the kidney.
Cortical Nephrons
What type of nephrons consists of 80-85% of nephrons, their renal corpuscle lies on the outer portion of the renal cortex, have short loops of henle that lie mainly in the cortex and penetrate only into the outer region of the medulla, and receive their blood supply from peritubular capillaries that arise from efferent arterioles?
Juxtamedullary nephrons
What type of nephrons consists of 15-20% of nephrons, their renal corpuscles lie deep in the cortex, close to the medulla, and they have a long loop of henle that extends into the deepest region of the medulla, and receives its blood supply from the peritubular capillaries and vasa recta that arise from the efferent arterioles?
Capsular (Bowman's) Space
Fluid filtered from the glomerular capillaries, enters the _______ _______ between the two layers of the glomerular capsule.
Principal Cells
What type of cell, located in the DCT, have receptors for both antidiuretic hormone and aldosterone.
Intercalated Cells
What type of cell, located in the DCT, play a role in the homeostasis of blood pH?
Glomerular Filtration
What is the first step of urine production, where water and most solutes in blood plasma move across the wall of glomerular capillaries into the glomerular capsule and then into the renal tubule.
Tubular Reabsorption
What term refers to the return of substances to the blood stream?
Tubular Secretion
What term refers to removing substances such as wastes, drugs, and excess ions from the blood?
What permits all solutes in blood plasma to exit glomerular capillaries but prevents filtration of of blood cells and platelets.
Mesangial Cells
What cells are located among the glomerular capillaries and in the cleft between afferent and efferent arterioles, and are contractile cells that help regulate glomerular filtration?
Basal Lamina
What prevents filtration of larger plasma proteins?
Slit Membrane
What prevents filtration of medium-sized proteins?
____ promotes filtration, while ___ and ____ oppose filtration.
Renal Autoregulation
What is the capability of the kidneys themselves help maintain a constant renal blood flow and GFR despite normal, everyday changes in blood pressure.
Myogenic Mechanism
What occurs when stretching triggers contraction of smooth muscle cells in the walls of afferent arterioles, and normalizes blood flow and GFR within seconds after a change in blood pressure?
Angiotensin 2
What hormone reduces GFR, by reducing blood flow of afferent & efferent arterioles?
What hormone increase GFR?
Proximal Convoluted Tubule (PCT)
The largest amount of solute and water reabsorption from filtered fluid occurs in what portion of the tubule?
Angiotensin 2
What hormone increases reabsorption of Na+, other solutes, and water, which increases blood volume?
What hormone increases secretion of K+ and reabsorption of Na+, Cl-; increases reabsorption of water, which increases blood volume?
What hormone increases facultative reabsorption of water, which decreases osmolarity of body fluids?
What hormone increases excretion of Na+ in urine (natriuresis; increases urine output (diuresis) and thus decreases blood volume?
Parathyroid Hormone
What hormone increases reabsorption of Ca2+?
Countercurrent Multiplication
What is the process by which a progressively increasing osmotic gradient is formed in the interstitial fluid of the renal medulla as a result of countercurrent flow?
Countercurrent Exchange
What is the process by which solutes and water are passively exchanged between the blood of the vasa recta and interstitial fluid of the renal medulla as a result of countercurrent flow?
Na+, Cl-, and urea are the three major solutes that contribute to high ________.
What is as analysis of the volume and physical, chemical, and microscopic properties of urine, and reveals much about the state of the body?
Blood Urea Nitrogen (BUN)
What is a test that measures the blood nitrogen that is part of the urea resulting from catabolism and deamination of amino acids?
Plasma Creatinine
What test is used to evaluate kidney function, which results from catabolism of creatine phosphate in skeletal muscle?
Renal Plasma Clearance
What is the volume of blood that is "cleaned" or cleared of a substance per unit of time, usually expressed in milliliters per minute?
Renal Plasma Flow
The clearance of para-aminohippuric acid (PAH) is used to measure ____ _____ ____, the amount of plasma that passes through the kidneys in one minute.
What is discharge of urine from the urinary bladder?
A small tube leading from the internal urethral orifice in the floor of the urinary bladder to the exterior of the body.
Only occurs in the glomerulus; force behind it is pressure of blood within the glomerulus.
Reclaiming the things the body needs.
Actively putting out things the body does not need to maintain homeostasis of pH and electrolytes, regulated by hormones.
Substances that are _______: Ions: Sodium, Potassium, Chloride; Nitrogenous Wastes: Urea Uric Acid, Creatinine; Organic Molecules: Glucose, Amino Acids
Myogenic Mechanism
Juxtaglomerular cells that act as mechanoreceptors in afferent arterioles.
Tubuloglomerular Feedback
Macula densa cells of distal tubule that act as chemoreceptors.
Neural Regulation
Sympathetic nervous system releasing NOREPI causing vasoconstriction of afferent arterioles, decreasing urine production and shunting blood to other areas, is the process of what?
What pathway of reabsorption occurs through tight junctions between cells of renal tubules and is a passive process- diffusion & osmosis?
What pathway of reabsorption, has substances that move all through the cell so most cross cells membrane twice and is one way movement because of combination of passive and active transport?
Proximal Convoluted Tubule (PCT)
What actively reabsorbs nutrients, plasma proteins, and ions from filtrate and releases them into peritubular fluid?
Distal Convoluted Tubule (DCT)
What actively secretes ions, toxins, and drugs, and reabsorbs sodium ions from tubular fluid?
Countercurrent Multiplication
What occurs between ascending and descending limbs of loop, creates osmotic gradient in medulla, facilitates reabsorption of water and solutes before the DCT, and permits passive reabsorption of water from tubular fluid?
Angiotensin 2
What hormone raises BP by causing vasoconstriction of afferent arteriole, stimulates Na+/H+ antiporters, and stimulates release of aldosterone?
What hormone raises blood pressure by stimulating the collecting duct to reabsorb more Na+ and Cl- and secrete more K+?
What hormone raises blood pressure by acting on collecting duct to reabsorb more water?
What hormone lowers blood pressure by decreasing Na+ and water reabsorption in PCT and collecting duct; suppressing ADH and Aldosterone?
Urine is concentrated in presence of _____ levels of ADH.
Urine is dilute when ADH levels are ___.
Osmotic Gradient, Countercurrent Mechanism
Urine concentration is dependent on what 2 things?
pH of 4.8-8.0, Urea, Sodium, Chloride, Bicarbonate, and Potassium ions, Uric Acid, and Creatinine, are all (Normal/Abnormal) in Urine?
Blood, Protein, Glucose, Ketone Bodies, Urobilinogen, Casts, and Microbes, are all (Normal/Abnormal) in Urine?