AUBF LEC-Module 1

Erythropoietin

Major glycoprotein that kidneys produce for blood production

7.4

At what pH does the kidney maintain blood

bicarbonate; H+ ions

What does the kidneys absorb and secrete in order to maitain to maintain acid-base balance?

Renal artery

Serves as the source of kidney’s blood supply and is the blood’s portal of entry into the kidney

Renal vein

The blood’s portal of exit into the kidney

Kidneys

Bean shaped paired organs located in the posterior wall of the abdomen

25%

How much of blood does the human kidneys receive?

afferent arteriole

Blood enters the capillaries of the nephron through the _______

hydrostatic pressure

The varying sizes of these arterioles help create the _______ that is important for glomerular filtration and to maintain consistency of glomerular capillary pressure and renal blood flow within the glomerulus.

cortex and medulla

2 layers of the kidneys

peritubular capillaries, vasa recta

Before returning to the renal vein, blood from the efferent arteriole enters the _____ and ______

glomerulus, efferent arteriole

After entering the nephron through the afferent arteriole, it then flows to the _____ and into the ______

proximal and convoluted tubules

The peritubular capillaries surrounds what tubules?

proximal convulated tubule

Site for immediate reabsorption of essential substances from the fluid

ascending and descending loops of Henle

In this area, the major exchanges of water and salts take place between the blood and the ______________.

1.73m²; 1200mL/min, 600-700mL/min

Based on an average body size of ______ of surface, the total renal blood flow is approximately _________, and the total renal plasma flow ranges from _________.

Cortical Nephrons

Type of nephrons that are seen in the cortex alone and functions for tubular reabsorption and secretion

85%

Cortical nephrons make up how much of the kidney?

Juxtamedullary Nephrons

Located in the loops of Henle and extends into the renal medulla and functions for the concentration of urine

glomerular filtration barrier

The glomerulus consists of a coil of approximately eight capil- lary lobes, the walls of which are referred to as the _________

Bowman capsule

Forms the beginning of the renal tubule.

capillary wall membrane, basement membrane, and visceral epithelium of Bowman capsule

Plasma filtrate must pass through three glomerular filtration barrier cellular layers: _____, _____, and ______.

Fenestrated endothelium

The capillary wall endothelium differs from other capillaries by containing pores and are referred to as ________

filtration slits

Further restriction of large mole- cules occurs as the filtrate passes through the basement membrane and the thin membranes covers the ______

shield of negativity

In addition to the structure of the glomerular filtration barrier that prohibits the filtration of large molecules, the barrier contains a _____ that repels molecules with a negative charge even through tehy are small enough to pass through the three layers of the barrier

Glomerular Filtration Barrier

Prohibits the filtration of large molecules

albumin

What protein is prohibited by the shield of negativity and is seen in most renal diseases?

Renin-Angiotensin-Aldosterone-System

Regulates the flow of blood to and within the glomerulus and the system responds to changes in blood pressure and plasma sodium content

Renal blood flow, Glomerular filtration, Tubular Reabsorption, Tubular Secretion

4 Main processes associated with renal function

juxtaglomerular cells and macula densa

What consists the monitoring of blood pressure and plasma sodium content?

Renin; juxtaglomerular cells; angiotensinogen; angiotensin I

____ is an n enzyme produced by the ______, is secreted and reacts with the bloodborne substrate _____ to produce the inert hormone ______

alveoli of the lungs; angiotensin-converting enzyme (ACE); angiotensin II

As angiotensin I passes through the ______, ________ changes it to the active form _______.

1.010

Analysis of the fluid as it leaves the glomerulus shows the filtrate to have a specific gravity of _______ and confirms that it is chemically an ultrafiltrate of plasma.

active transport and passive transport

The cellular mechanisms involved in tubular reabsorption are termed ______ and _______

glucose, AA, salts, chloride, Na

Substances included for the active transport

glucose, amino acids, salts

In the PCT, what substances are reabsorbed?

chloride

What are rebasorbed in the ascending loop of Henle?

Sodium

What are reabsorbed in both proximal and distal convulated tubules?

water, urea, sodium

What are reabsorbed using passive transport?

PCT, DLH, CD

Where is water passively transported?

PCT, ALH

Where is urea passively reabsorbed?

ALH

Where is sodium passively reabsorbed?

Sodium

What substance can be actively and passively transported?

Active transport

The substance to be reabsorbed must combine with a carrier protein contained in the membranes of the renal tubular epithelial cells.

Passive Transport; gradients

movement of molecules across a membrane as a result of differences in their concentration or electrical potential on opposite sides of the membrane and these physical differences are called _________

ALH

Passive reabsorption of water takes place in all parts of the nephron except the _______ since they are impermeable to water

maximal reabsorptive capacity

When the plasma concentration of a substance that is normally com- pletely reabsorbed reaches a level that is abnormally high, the filtrate concentration exceeds the ________

renal threshold

The plasma concentration at which active transport stops is termed the ________

160-180mg/dL

For glucose, the plasma renal threshold is _________

DLH and ALH

Renal concentration begins in the ______ where the filtrate is exposed to the high osmotic gradient of the renal medulla.

descending loop of Henle

Water is removed by osmosis in the ________

countercurrent mechanism

Excessive reab- sorption of water as the filtrate passes through the highly con- centrated medulla is prevented by the water-impermeable walls of the ascending loop. This selective reabsorption process is called the __________ and serves to maintain the osmotic gradient of the medulla

late distal convoluted tuble and collecting duct

The final concentration of the filtrate through the reabsorption of water begins in the __________ and con- tinues in the _______

low hydration and high ADH

increases per- meability, resulting in increased reabsorption of water, and a low-volume concentrated urine.

high body hydration and low ADH

renders the walls impermeable to water, resulting in a large volume of dilute urine.

tubular secretion

involves the passage of substances from the blood in the peritubular capillaries to the tubular filtrate

PCT

The major site for removal of these nonfiltered substances

clearnace tests

The standard tests used to measure the filtering capacity of the glomeruli are termed ________

exogenous procedure

A test that requires an infused substance is termed an ________

Creatinine

waste product of muscle metabolism that is pro- duced enzymatically by creatine phosphokinase from creatine, which links with adenosine triphosphate (ATP) to produce adenosine diphosphate (ADP) and energy.

PCT

Reabsorbs ions, water, and nutrients; removes toxins and adjusts filtrate pH

Glomerulus

Filters small solutes from the blood

Ascending loop of Henle

Reabsorbs Na+ and Cl- from the filtrate into the interstitial fluid

Descending Loop of Henle

This is where aquaporins allow water to pass from the filtrate into the interstitial fluid

Distal convuluted tubules

Selectively secretes and absorbs different ions to maintain blood pH and electrolyte balance

Collecting Duct

Reabsorbs solutes and water from the filtrate

aldosterone and ADH

What hormones control the final concentration of urine?

aldosterone

Responsible for Na reabsooption and K excretion,

sodium; adrenal cortex; Na Reabsorption and K Secretion

Aldosterone responds to the body’s need for _____ and is produced by _____. Its action is for _______

hydration; hypothalamus; posterior pituitary gland; DCT and CD; water

ADH responds to the body’s state of _____ and is produced by the _____ but released by the ______. Its action is to make the walls of _____ and _____ permeable or semi-permeable to ______

Tubular secretion

Involves the passage of substances from the blood in the peritubular capillaries to the tubular filtrate

BUN, Creatine, Uric Acid

Substances that could evade glomerular filtration include ______ and undergoes tubular secretion

carrier proteins of endothelial cells of peritubular capillaries and vasa recta

Attaches with the waste products and transfer them to the ultrafiltrate during when they evade glomerular filtration or tubular secretion

mL/minute

Clearance test measures the rate in _____ in which the kidneys are able to remove (to clear) a filterable substance from the blood.

Cystatin C Clearance, B2 Microglobulin Clearance, and Radionucleotide Clearance

Gold standards in glomerular filtration tests

Cystatin C

Small protein (molecular weight 13,359) produced at a constant rate by all nucleated cells and is filtered readily by the glomerulus and reabsorbed and broken down by the renal tubular cells.

Cystatin C Clearance Test

Recommended for pediatric patients, people with diabetes, the elderly, and patients who are critically ill.

Beta2-Microglobulin Clearance Test

dissociates from human leukocyte antigens at a constant rate and is removed rapidly from the plasma by glomerular filtration.

Beta2-Microglobulin Clearance Test

used to identify end-stage renal disease and early rejection of a kidney transplant.

Radionucleotides clearance test

provides a method for determining glomerular filtration through the plasma disappearance of the radioactive material and enables visualization of the filtration in one or both kidneys.

Radionucleotide Clearance Test

procedure can be valuable to measure the viability of a transplanted kidney.

51 Cr-EDTA, 99-Tc-DTPA

Other exogenous markers used are radioiso- topes ____ and _____

concentration tests

Tests to determine the ability of the tubules to reabsorb the essential salts and water that have been nonselectively fil- tered by the glomerulus are called _______

para-aminohippuric acid test

The test most commonly associated with tubular secretion and renal blood flow is the _________

peritubular capillaries

PAH is removed from the blood primarily in ________

Titratable acidity and urinary ammonia

The ability of the kidney to produce an acid urine depends on the tubular secretion of hydrogen ions, as well as production and secretion of ammonia by the cells of the distal convoluted tubule are tested through _______ and _______

dye phenolsulfonphthalein

Was used to evaluate acidity and ammonia levels in urine

Edwin Smith Surgical Papyrus

References to the study of urine can be found in the drawings of cavemen and in Egyptian hieroglyphics, such as the ____________.

bladder-shaped flask of urine

Pictures of early physicians commonly showed them examining a ________

Hippocrates; uroscopy

Many well-known names in the history of medicine are associated with the study of urine, including Hippocrates, who, in the 5th century BCE, wrote a book on “_______.”

Frederick Dekker’s; 1694; albuminuria

Chemical testing progressed from “ant testing” and “taste testing” for glucose to _______ discovery in ______ of _________ by boiling urine

pisse prophets; Thomas Bryant; 1627

The credibility of urinalysis became compromised when charlatans without medical credentials began offering their pre- dictions to the public for a healthy fee. These charlatans, called “_______” became the subject of a book published by ________ in _____.

Thomas Addis

Who invented the methods for quantitating the microscopic sediment?

Richard Bright; 1827

Who introduced the concept of urinalysis and when?