1) Excretion, The removal of organic waste from the body fluids
2) Elimination, the discharge of these waste products into the environment
3) Homeostatic regulation of the volume and solute concentration of blood plasma.
The urinary has several essential homeostatic functions that are often overlooked. They are:
1) Regulating blood volume and blood pressure
2) Regulating plasma concentrations of sodium, potassium, chloride, and other ions.
3) Helping to stabilize blood pH
4) Conserving valuable nutrients
5) Assisting the liver in detoxifying poisons
Organ that produces urine
organ that transports urine toward the urinary bladder
Organ that temporarily stores urine prior to elimination
Conducts urine to exterior; in males, transports semen as well.
what is the renal corpuscle's primary function?
Filtration of plasma
Primary Function:Reabsorption of ions, organic molecules, vitamins, water; secretion of drugs, toxins, acids
what is the descending limb of the nephron loop's primary function?
The reabsorption of water from tubular fluid.
What is the ascending limb of the nephron loop's primary function?
Reabsorption of ions; assists in creation of concentration gradient in medulla
What is the primary function of the distal convoluted tubule (DCT)?
Reabsorption of sodium ions and calcium ions; secretion of acids, ammonia, drugs, toxins.
In the collecting system, the primary function of the collecting duct is:
Reabsorption of water, sodium ions; secretion or reabsorption of bicarbonate ions or hydrogen ions
In the collection system, the papillary duct has what primary functions?
Conduction of tubular fluid to minor calyx; contributes to concentration gradient of the medulla
______ Nephrons perform most of the reabsorptive and secretory functions of the kidneys because they are more numerous than _____ Neprons.
The ______ Nephrons enable the kidneys to produce concentrated urine.
Different segments of the nephron form urine in what 3 ways?
The goal of urine production is to maintain homeostasis by regulating the _______ and _______ of blood.
Volume & Composition
Our bodies form form three important organic waste products:
3) Uric Acid
This organic waste is the moste abundant; you generate approximately 21g of it each day, most of it through the breakdown of amino acids.
Skeletal muscle tissues generate this organic waste through the breakdown of a high energy compound that plays an important role in muscle contraction; our bodies generate roughly 1.8 g of it each day; virtually all of it is excreted in urine.
A waste product formed during the recycling of the nitrogenous bases from RNA Molecules. our bodies produce approximately 480 mg of this each day.
In this process, blood pressure forces water and solutes across the wall of the glomerular capillaries and into the capsular space. Solute molecules small enough to pass through the ____ membrane are carried by the surrounding water molecules.
Filtration X 2
This process Involves the removal of water and solutes from the filtrate, and their movement across the tubular epithelium and into the peritubular fluid.
The transport of solutes form the peritubular fluid, across the tubular epithelium, and into the tubular fluid.
Hydrostatic forces water through membrane pores, and solute molecules small enough to pass though those pores are carried along; ____ takes place as larger solutes and suspended materials are left behind.
The processes of reabsorption and secretion at the kidneys involve a combination of what transport mechanisms?
3) Channel-mediated diffusion
4) Carrier mediated transport
Type of Carrier-mediated transport where a carrier protein transports a molecule across the plasma membrane without expending energy.
Type of carrier-mediated transport that is driven by the hydrolysis of ATP to ADP on the inner membrane surface. Exchange pumps and other carrier proteins are active along the kidney tubules; can operate despite concentration gradients.
Type of Carrier-Mediated Transport where protein activity is mot directly linked to the hydrolysis of ATP. Instead, two substrates (ions, molecules, or both) cross the membrane while bound to a carrier protein.
Resembles cotransport except that the two transported ions move in opposite directions; operates in the PCT, DCT, and collecting system.
Characteristics of Carrier-Mediated Transport that are essential for kidney function:
1) A specific substrate binds to a carrier protein that facilitates movement across the membrane.
2) A given carrier protein typically works in one direction only.
3) The distribution of carrier proteins can vary among portions of the cells surface.
4) The membrane of a single tubular cell contains many types of carrier proteins.
5) Carrier proteins, like enzymes, can be saturated.
General functions are the filtration of plasma; generates approximately 180L/day of filtrate similar in composition to blood plasma without plasma proteins
The general functions of the Proximal Convoluted tubule (PCT): Reabsorption of ______ of the water (108-116L/Day), and _____ of the organic substrates, and _________ of the sodium and chloride ions in the original filtrate.
60-70% of water
99-100% of organic Substrates
60-70% of Na & Cl ions
General Functions of the nephron loop include: Reabsorption of ______ of the water (45 L/Day)and ______ of the sodium and chloride ions present in the original filtrate; creation of the concentration gradient in the medulla.
20-25% of Na & Cl ions
General functions of the Distal convoluted tubule (DCT) include: Reabsorption of a variable amount of water (usually ____, or 9 L/Day), under ADH stimulation, and a variable amount of sodium ions, under aldosterone stimulation
5% of water
The General Functions of the collecting system include: Reabsorption of a variable amount of water (Usually ______, or 16.8L/Day) under ADH stimulation, and a variable amount of sodium ions, under aldosterone stimulation
9.3 % of water
The general functions of the ________ _____ are the redistribution of water and solutes reabsorbed in the cortex.
General functions of the ____ _____ are Redistribution of water and solutes reabsorbed in the medulla and stabilization of the concentration gradient of the medulla