Unit XiI (Book Notes) Flashcards
serves a crucial biochemical role in the physiological pH buffering system
Bicarbonate (HCO3)
It is called a base which the body needs to help keep a normal acid-base (pH) balance
Bicarbonate (HCO3)
pH ___ is neutral
7
pH of face and body
between 4.7 - 5.75
ACE means
angiotensin-converting enzyme
___ are medications needed to treat and manage hypertension (HPN)
ACE inhibitors
___ is a corticosteroid hormone that stimulates the absorption of sodium by the kidneys and regulates water and salt balance
Aldosterone -
The ___ system is the major excretory system of the body.
urinary
Urine consists of:
Excess water
Excess ions
Metabolic wastes
Toxic substances
As long as about ___ of one kidney remains functional, survival is possible.
⅓
The kidney functions include:
Excretion
Regulation of blood volume and pressure
Regulation of blood solute concentrations
Regulation of extracellular fluids
Regulation of blood cell synthesis
Regulation of vitamin D synthesis
The kidneys secrete the hormone ___ which regulates the synthesis of red blood cells in bone marrow.
erythropoietin
A layer of connective tissue called a ___ surrounds each kidney.
renal capsule
On the medial side of each kidney is the ___, where the renal artery and nerves enter and where the renal vein, ureter, and lymphatic vessels exit the kidney.
hilum
The hilum opens into a cavity called the ___ which contains blood vessels, part of the system for collecting urine, and adipose tissue.
renal sinus
The kidneys are organized into two major regions:
The outer cortex
Inner medulla
The ___ is the location for the blood-filtering structures of the kidney.
cortex
The ___ is composed of many cone-shaped structures called renal pyramids, whose bases project into the cortex.
medulla
The ___ are a collection of tubes and ducts that transport fluid throughout the kidney and modify it into urine.
renal pyramids
Once urine is formed, ducts in the renal pyramids transport it toward the ___.
renal sinus
The tips of the pyramids, the ___, point toward the renal sinus.
renal papillae
In the ___, another set of tubes collects urine for movement to the urinary bladder.
renal sinus
In the renal sinus, another set of tubes collects urine for movement to the ___.
urinary bladder
When urine leaves a renal papillae, it empties into a small, funnel-shaped chamber surrounding the tip of the papilla called a ___.
calcyx
Urine from several calyces is emptied into a single, enlarged, funnel-shaped chamber called the ___
renal pelvis.
At the hilum, the renal pelvis narrows significantly, forming the small diameter tube called the ___.
ureter
The ___ is the histological and functional unit of the kidney. It consists of specialized structures including small tubes that are called tubules.
nephron
The nephron is the histological and functional unit of the kidney. It consists of specialized structures including small tubes that are called ___.
tubules
There are approximately ___ nephrons distributed throughout the cortex and medulla of each kidney.
1.3 million
The four regions of a nephron are:
A renal corpuscle
A proximal convoluted tubule
A loop of Henle
A distal convoluted tubule
Generally speaking, the ___ filters the blood, the ___ returns filtered substances to the blood, the ___ helps conserve water and solutes, and the ___ rids the blood of additional wastes.
renal corpuscle
proximal convoluted tubule
loop of Henle
distal convoluted tubule
The fluid in the distal convoluted tubule then empties into a ___ which carries the newly formed urine from the cortex of the kidney toward the renal papillae deep in the medulla.
collecting duct
Near the tip of the renal papillae, several collecting ducts merge into a large-diameter tubule called a ___, which empties into a calyx.
papillary duct
There are two types of nephrons in the kidney:
Juxtamedullary nephron
Cortical nephron
___ have renal corpuscles that are found deep in the cortex near the medulla. They have long loops of Henle which extend deep into the medulla. Longer loops of Henle are well adapted for water conservation.
Juxtamedullary nephrons
Only about ___% of nephrons are juxtamedullary nephrons.
15%
___ have renal corpuscles that are distributed throughout the cortex. Their loops of Henle are shorter and are closer to the outer edge of the cortex.
Cortical nephrons
The filtration portion of the nephron is housed in the ___
renal corpuscle.
The renal corpuscle consists of:
The glomerulus
The bowman capsule
The ___ is a network of capillaries twisted around each other like a ball of yarn.
glomerulus
Fluid filtered from the glomerular capillaries is called the ___.
filtrate
The ___ is an indented, double-walled chamber surrounding the glomerulus. From here, the filtered fluid flows into the proximal convoluted tubule region of the renal tubule.
bowman capsule or glomerular capsule
A bowman capsule consists of two layers:
An outer layer
An inner layer
The outer layer of the Bowman capsule is constructed of _ cells.
simple squamous epithelial
The inner layer of the Bowman capsule is constructed of specialized cells called _ which wrap around the glomerular capillaries.
podocytes
The renal corpuscle has several unique characteristics that make it particularly efficient at filtration:
Porous capillaries
Porous inner layer of Bowman capsule
High pressure
An ___ arteriole supplies blood to the glomerulus for filtration.
afferent
An ___ arteriole transports the filtered blood away from the glomerulus.
efferent
The ___ capillaries have higher pressure than other capillaries due to the smaller diameter of the efferent arteriole compared to the afferent arteriole.
glomerular
The ___ performs the first major step in urine production
filtration membrane
Urine production begins when the filtration membrane filters the blood. The filtered fluid, called filtrate, then enters the ___
lumen or space inside the bowman’s capsule.
An important regulatory structure called the ___ is located next to the glomerulus. It consists of a unique set of afferent arteriole cells and specialized cells in the distal convoluted tubule that are in close contact with each other.
juxtaglomerular apparatus
___ can be found at the point where the afferent arteriole enters the renal corpuscle. It is a cuff of specialized smooth cells around it.
Juxtaglomerular cells
___ can be found at the part where the distal convoluted tubule of the nephron lies between the afferent and efferent arterioles next to the renal corpuscle.
Macula densa
Secretion of the enzyme ___ by the juxtaglomerular apparatus plays an important role in the regulation of filtrate formation and blood pressure.
renin
Once the blood is filtered, the resulting fluid is modified to form urine as it passes through each section of the renal tubule. The first section is the ___
proximal convoluted tubule.
The wall of the proximal convoluted tubule is composed of ___ cells
simple cuboidal epithelium.
Every loop of Henle has two limbs:
The descending limb
The ascending limb
The distal convoluted tubule is shorter/longer than the proximal convoluted tubule? Its epithelium is ___
shorter
simple cuboidal.
A system of blood vessels allows the exchange of materials that occurs in the kidneys. The renal arteries branch off the ___ and enter the kidneys.
abdominal aorta
The ___ arteries pass between the renal pyramids.
interlobar
The ___ arteries branch from the interlobar arteries. They arch between the cortex and medulla.
arcuate
___ arteries branch off the arcuate arteries and project into the cortex.
Interlobular
The ___ arterioles arise from the branches of the interlobular arteries.
afferent
The ___ arterioles carry blood to the glomerular capillaries.
afferent
___ arterioles carry blood from the glomerular capillaries.
Efferent
The ___ capillaries branch from the efferent arterioles. They surround the proximal convoluted tubules, the distal convoluted tubules, and the loops of Henle.
peritubular
The ___ are specialized portions of the peritubular capillaries that extend deep into the medulla of the kidney and surround the loops of Henle and collecting ducts.
vasa recta
The primary function of the kidney is the ___
regulation of body fluid composition.
The ___ is the organ that sorts the substances from the blood for either removal in the urine or return to the blood.
kidney
The structural components that perform the sorting of body fluid composition are the ___. They are the functional units of the kidney.
nephrons
Scientists usually categorize urine formation into three major processes:
Filtration
Tubular Respiration
Tubular secretion
With ___, blood pressure in the glomerular capillaries forces fluid and small molecules out of the blood to create filtrate. It is nonselective and separates based only on the size or charge of molecules.
filtration
An average of ___% of the blood pumped by the heart each minute flows through the kidney.
21%
With ___ , cells in the renal tubules contain many transport proteins. They move water and some filtered molecules from the filtrate back into the blood in the peritubular capillaries.
tubular respiration
With ___, certain tubule cells transport additional solutes from the blood into the filtrate. Some of the solutes may not have been filtered by the filtration membrane.
tubular secretion
For the filtration membrane, three forces or pressures determine the amount of filtrate formed:
Glomerular capillary pressure
Capsular pressure
Colloid osmotic pressure
The ___ is essentially the blood pressure inside the glomerular capillaries. It is an outward pressure from blood pressing on the fenestrated capillary walls.
glomerular capillary pressure
The ___ is the inward pressure that opposes filtration. It is due to pressure from the filtrate fluid in the capsular space.
capsular pressure
The ___ is also an inward pressure that opposes filtration. It is due to the osmotic pressure of plasma proteins in the glomerular capillaries.
colloid osmotic pressure
The combination of the three pressures is called ___
filtration pressure.
In a normal kidney, is glomerular capillary pressure is greater than the combination of capsular and colloid osmotic pressure?
Yes
Intense sympathetic stimulations, like those that occur during circulatory shock or vigorous exercise, will it significantly decrease filtrate formation and urine volume?
Yes
One of the dangers of ___ is that renal blood flow can be so low that the kidneys suffer from a lack of O2.
circulatory shock
___ is the transport of water and solutes from the filtrate into the blood.
Tubular reabsorption
Water movement in the kidney is governed by ___. It is the movement of water toward solutions with higher solute concentrations or high osmotic pressure.
osmosis
___ is the net movement of solutes down their concentration gradient.
Diffusion
The ___ convoluted tube is the site of the majority of reabsorption.
proximal
___ is the movement of nonfiltered substances from the blood into the filtrate.
Tubular secretion
The kidney’s ability to control the volume and concentration of the urine depends on three factors:
Countercurrent mechanisms
Medullary concentration gradient
Hormonal mechanism
A ___ is one where fluid in separate structures flows in opposite directions relative to each other. As the fluids pass by each other, materials can be exchanged between the fluids.
countercurrent mechanism
The interstitial fluid of the medulla of the kidney has a higher solute concentration than that of the cortex. This is called the ___
medullary concentration gradient.
Three major hormonal mechanisms are involved in regulating urine concentration and volume:
Renin-angiotensin-aldosterone mechanism
Antidiuretic hormone (ADH) mechanism
Atrial natriuretic hormone (ANH) mechanism
The ___ mechanism is initiated under low blood pressure conditions.
renin-angiotensin-aldosterone
When blood pressure decreases, cells of the juxtaglomerular apparatuses in the kidneys secrete the enzyme ___.
renin
Upon secretion, renin enters the blood and converts ___, a plasma protein produced by the liver, to angiotensin I.
angiotensin
___ is an enzyme produced by capillaries of organs such as the lungs. It converts angiotensin I to angiotensin II.
Angiotensin-converting enzyme (ACE)
___ increases blood pressure and increases the sensation of thirst and salt appetite. It also stimulates the adrenal cortex to secrete aldosterone.
Angiotensin II
___ stimulates an increase in the reabsorption of Na+ and Cl- in the distal convoluted tubules and collecting ducts.
Aldosterone
___ is secreted by neurons in the posterior pituitary when the concentration of the blood or the interstitial fluid increases.
Antidiuretic hormone (ADH)
___ promotes water conservation in the kidneys by increasing the permeability of the distal convoluted tubules and collecting ducts to water.
ADH
A low blood solute concentration inhibits ADH secretion, which reduces or increases urine volume?
Reduces it
An increased blood pressure triggers the ___
atrial natriuretic hormone (ANH) mechanism.
___ is secreted from cardiac muscle cells in the right atrium when blood pressure in the right atrium increases above normal. It acts on the kidneys to decrease Na+ reabsorption. It increases urine volume while reducing blood volume and blood pressure.
ANH
ANH is secreted from ___ when blood pressure increases above normal. It acts on the kidneys to decrease Na+ reabsorption. It increases urine volume while reducing blood volume and blood pressure.
cardiac muscle cells in the right atrium
The ___ are small tubes that carry urine from the renal pelvis of the kidney to the posterior inferior portion of the urinary bladder.
ureters
The ___ is a hollow, muscular container that lies in the pelvic cavity just posterior to the pubic symphysis. It stores urine.
urinary bladder
The urinary bladder can hold from a few mL to a maximum of about ___
1000 mL.
_ is an inflammation of the urinary bladder that usually results from a bacterial infection. E coli is the most common cause of this.
Cystitis
The ___ is the tube that carries urine from the urinary bladder to the outside of the body.
urethra
The triangle-shaped portion of the urinary bladder located between the opening of the ureters and the opening of the urethra is called the ___.
trigone
___ cells lines both the ureters and the urinary bladder.
Transitional epithelium
___ is the presence of blood in the urine.
Macrohematuria
___ is where a catheter is inserted into the bladder to view the wall and collect cells which are then examined under a microscope to look for abnormalities in appearance.
Cystoscopy
___ is a live, attenuated strain of Myocobacterium bovis, the bacterium that causes tuberculosis in cattle.
Bacillus Calmette-Guerin
___ is another name for kidney stones. The majority of kidney stones consist of mainly calcium oxalate.
Renal calculus
___ is a common treatment for kidney stones. It uses an ultrasound to pulverize kidney stones into small particles that can pass easily through the ureter.
Lithotripsy
_ is the act of urinating. It is activated by the stretch of the urinary bladder wall.
Micturition
Water intake is controlled by neurons in the hypothalamus collectively called the ___.
thirst center
___ ions are the dominant ions in the extracellular fluid.
Sodium
___ is the recommended intake amount for daily sodium ions
2.4 grams
___ is secreted by the parathyroid glands when blood CA2+ levels are too low.
Parathyroid hormone (PTH)
___ is secreted by the parafollicular cells of the thyroid gland. This lowers extracellular CA2+ levels.
Calcitonin
___ are chemicals that resist a change in pH of a solution when either acids or bases are added to the solution.
Buffers
___ occurs when the blood pH falls below 7.35.
Acidosis
___ occurs when the respiratory system is unable to eliminate adequate amounts of CO2 from the blood.
Respiratory acidosis
___ occurs from excess production of acidic substances, such as lactic acid and ketone bodies.
Metabolic acidosis
___ occurs when the blood pH increases above 7.45.
Alkalosis
___ results from hyperventilation as can occur in response to stress.
Respiratory alkalosis
___ usually results from the rapid elimination of H+ from the body.
Metabolic alkalosis
___ is the inflammation of the filtration membrane within the renal corpuscle, causing increased membrane permeability.
Glomerulonephritis
___ often occurs 1-3 weeks after a severe bacterial infection, such as strep throat. This normally subsides after several days.
Acute glomerulonephritis
___ is a long-term and progressive process whereby the filtration membrane thickens and is eventually replaced by connective tissue and the kidneys become nonfunctional.
Chronic glomerulonephritis
___ occurs when damage to the kidney is rapid and extensive. This leads to accumulation of wastes in the blood and may eventually lead to death in 1-2 weeks if renal failure is complete.
Acute renal failure
___ results from permanent damage to so many nephrons that the remaining nephrons are inadequate for normal kidney functions.
Chronic renal failure
