F_Chapter 15: Urinary System Flashcards
This organ alone perform the functions of the urinary system
Why? what’s the function of the other organs in the urinary system?
Kidneys
Other organs in the urinary system only provide temporary storage for urine or serve as transportation channels to carry it from the kidneys to the outside of the bod
What gland are found on the top of the kidney
Adrenal gland
a long tube that delivers the urine created by the kidney into the bladder
Ureter
storage site of urine temporarily
until it goes out of the urethra
Urinary Bladder
delivers urine to the outside
urethra
Kidneys are just floating inside t body, but it doesn’t move around because it is anchored to the surrounding tissues, organs, and blood vessels through the
what protective layer of the kdiney??
Renal Fascia
This structure captures all the urine created from the renal cortex into the medulla
and then the pelvis. It goes into the bladder
Renal Pelvis
Structures within the renal pelvis that will help capture urine created
Calyces
Assists in capturing and draining urine
the part where there are a lot of
blood vessels. part where it is being held; where filtration happens; blood gets filtered out
Renal Cortex
Filtrate being created by the renal cortex is pushed down to the _____
renal pyramids
The capillary bed in the renal kidney
Gets blood from the approaching _____________- (the artery before it)
Glomerulus
Gets blood from the approaching Cortical Radiate Artery
Most capillary beds function for absorption but the glomerulus functions for ________
Filtration
Most Important Capillary/ Blood Vessel
- Peritubular Capillaries
- Glomerulus
What structure of the nephron is more important?
What are the functions of each structure?
Renal Corpuscle is more important
Renal Tubule only helps in delivery of urine
________ is important in creating urine because it involves the principle of filtration
Blood pressure
This structure captures “filtrate” being filtered by glomerulus
Bowman’s Capsule (Glomerular Capsule)
Last part of the renal tubule, where all
the final adjustments are being done
What are these final adjustments? What do you call the substance that goes out in this part?
Collecting Duct
it release and absorbs molecules to create the final product. After everything, the product that goes out is called the URINE
What do you call the substance that goes out of the glomerulus?
Filtrate
Size of the kidney? (structure) What are its 3 protective layers?
The kidney is about the size of a large bar of soap
Three protective layers:
(1) Fibrous Capsule – transparent layer, gives glistening appearance
(2) Perirenal Fat Capsule – fatty mass, cushions the kidneys
(3) Renal Fascia – mostsuperficial layer of dense fibrous connective tissue; anchor
3 regions of the Kidney?
(1)Renal Cortex – the outer region
(2)Renal Medulla – deep to the cortex; has renal pyramids
(3)Renal Pelvis – funnel-shaped tube; continuous with the ureter
This is are extensions of the renal pelvis that form “drains” that enclose the tips of the pyramids
What is its main function?
Calyces (Calyx)
Collect urine which continuously drain from the tips of the pyramids into the renal pelvis
How do kidneys contribute to blood supply?
What does it do to the blood? How many % blood supply passes through?
Kidneys continuously cleanse the blood and adjust its composition
Approximately 25% of the total blood supply of the body passes through the kidneys each minute
this supplies the kidney w/ oxygenated & nutrient-rich blood
What is the flow of blood?
Renal Artery
Aorta –> Renal Artery –> Segmental artery –> Interlobar artery –> Arcuate artery –> Cortical radiate artery –> Afferent arteriole –>
–>GLOMERULUS (capillaries) –> Efferent arteriole –> PERITUBULAR capillaries
–> Cortical radiate vein –> Arcuate vein –> Interlobar vein –> Renal vein –> Inferior vena cava
Structural and Functional units of each kidney
* Responsible for forming urine
What are its 2 main structures?
NEPHRONS
Each nephron consists of two main structures:
(1) Renal Corpuscle
(2) Renal Tubule
a structure of nephrons that consists of a glomerulus and the Bowman’s capsule
What is a glomerulus? What is the bowman’s capsule? (describe structure)
RENAL CORPUSCLE
* Glomerulus is a knot of capillaries
* Bowman’s Capsule (Glomerular Capsule) is a hollow structure
encloses the glomerulus
The inner layer of the capsule found in the renal corpuscle is made up of?
What are found in the openings between these structures? What are its functions?
podocytes
Podocytes have foot processes that intertwine with each other
The openings between these podocytes are filtration slits that allow the podocytes to create a porous membrane which is ideal for filtration
a structure of nephron that Extends from the glomerulus, then it coils and twists forming a hairpin loop and then coil and twist again before entering the collecting duct
The collecting ducts run ______________ (what direction?)
and they deliver _________________ into _________?
RENAL TUBULE
- Collecting Ducts run downwards to the medullary pyramids
- Collecting Ducts deliver the FINAL urine product into the calyces and renal pelvis
FLOW OF URINE
(1) Glomerulus → (2) Proximal Convoluted Tubule (PCT) → (3) Loop of Henle →(4)Distal Convoluted Tubule →(5) Collecting Duct
Types of Nephrons according to location
- Cortical Nephrons
- Juxtamedullary Nephrons
a) Cortical Nephrons – make up majority of the nephrons; almost entirely in the cortex
b) Juxtamedullary Nephrons – situated close to the cortex-medulla junction
Type of nephron
make up majority of the nephrons; almost
entirely in the cortex
Cortical nephrons
This is where Majority of blood vessels, nephrons that contain glomerulus (capillaries), and filtration process are/occurs
Cortical Nephron (Renal Cortex)
Type of nephron
situated close to the cortex-medulla junction
Juxtamedullary Nephrons
NEPHRON-ASSOCIATED CAPILLARY BEDS: (2)
- glomerulus
- peritubular capillary bed
A NEPHRON-ASSOCIATED CAPILLARY BED fed by the afferent arteriole; and feeds into the efferent arteriole
Glomerulus
A structure that is TECHNICALLY not part of the kidney because it is just an extension of the cardiovascular system
Glomerulus
Reason why we don’t have blood loss/ blood volume doesn’t lower even when the kidney filters 25% of our blood every minute
Most of the filtrate (~99%) is eventual reabsorbed by the renal tubule cells and returned to blood.
Criteria for Glomerular filtration
<70K Daltons
positively charged
A NEPHRON-ASSOCIATED CAPILLARY BED Specialized for the filtration of blood
Glomerulus
In the glomerulus capillary bed. the afferent arteriole has a larger diameter than the efferent, resulting in______________
How does the result contribute to the fluid and small solutes?
The afferent arteriole has a larger diameter than the efferent, resulting in a much higher blood pressure in the glomerular capillaries
This pressure forces fluid and small solutes out of the blood into the glomerular capsule
Most of the filtrate in the glomerulus capillary bed (~99%) is eventually ________________ by the
renal tubule cells and _________
what happens to the filtrate basically
Most of the filtrate (~99%) is eventually reabsorbed by the renal tubule cells and returned to blood
A nephron-associated capillary bed that arises from the efferent arteriole that drains the glomerulus. This is composed of low-pressure, porous vessels adapted for absorption instead of filtration
Peritubular Capillary Bed
A Nephron-associated Capillary bed that Cling closely to the whole length of the renal tubule –reabsorbs filtered solutes and water
What are these solutes and water basically? (What are only reabsorbed?)
Peritubular Capillary Bed
Only reabsorbs the essential nutrients including glucose, amino acids, & salts (Na+) and WATER
What happens to the nutrients reabsorbed through the peritubular capilalry bed?
eventually returned to the heart for redistribution
Essential Nutrients Include: glucose, amino acids, & salts (Na+)
3 main Process involved in Urine formation
What waste is poorly reabsorbed by urine formation?
I. GLOMERULAR FILTRATION
II. TUBULAR REABSORPTION
III. TUBULAR SECRETION
NITROGENOUS WASTES are poorly reabsorbed, if at all
A Nonselective, passive process in which fluid passes from the blood into the bowman’s capsule
What is the overall role of the glomerulus in this process?
Glomerular filtration
Glomerulus acts as a filter
Principle followed by glomerular filtration?
What happens when blood pressure drops?
Follows a pressure gradient, wherein the capillaries have high pressure and the bowman’s capsule has lower pressure.
If blood pressure drops, glomerular pressure becomes inadequate and filtrate formation will stop
During glomerular filtration, what do you call the fluid once it is in the capsule?
Once in the capsule, the fluid is now called a filtrate – essentially blood plasma without blood proteins
This structure is technically already part of
tubules. Nothing really differentiates it from the convoluted tubule except for the fact that it surrounds the glomerulus
Bowman’s Capsule
Mechanism of glomerular filtration which prevents negatively charged particles from passing through
Shield of negativity
“Shields glomerulus from all the negativities in the world”
In the tubular reabsorption, The filtrate contains a mixture of?
waste & essential substances
Process of urine formation that begins as soon as the filtrate enters the proximal convoluted tubule (PCT)
TUBULAR REABSORPTION
Tubular Reabsorption
they are “transporters”, taking up needed substances from the filtrate and then passing them out into the extracellular space in which they are absorbed by peritubular capillary blood
Most reabsorption happens in ________ and is done through?
tubule cells
Most reabsorption happens in the Proximal convoluted tubule and is done through an active transport process
During tubular reabsorption, what are usually completley reabsorbed?
Glucose, Amino Acids, and Salts and WATER
Essentially tubular reabsorption in reverse. What substances in this process are secreted out from the peritubular capillaries and into the tubule cells to be eliminated through urine?
TUBULAR SECRETION
Some substances such as Hydrogen and Potassium Ions and creatinine, and Drug metabolites are “secreted” out from the peritubular capillaries and into the tubule cells to be eliminated through the urine
These substances are waste products that remain after glomerular filtration
These substances are waste products that remain after glomerular filtration
Some substances such as Hydrogen and Potassium Ions and creatinine
How does the mechanism of tubular secretion influence blood?
This mechanism is also an additional means to control blood pH
Tubule cells have few membrane carriers to reabsorb these substances because we do not need them. What do you call these substances?
Common examples of thse substances include?
Nitrogenous waste/ products
o Urea – formed by the liver as an end product of protein
breakdown when amino acids are used to produce energy
o Uric Acid – released when nucleic acids are metabolized
o Creatinine – associated with creatinine metabolism in muscle
tissue
Nitrogenous waste product
formed by the liver as an end product of protein
breakdown when amino acids are used to produce energy
Urea
Nitrogenous waste product
released when nucleic acids are metabolized
Uric acid
Nitrogenous waste product
associated with creatinine metabolism in muscle tissue
Creatinine
In 24 hours, the kidneys filter about ______ L of blood plasma
In the same 24 hours, only about ______ L of urine are produced
Hence ______ and ______ are DIFFERRENT
In 24 hours, the kidneys filter about 150 to 180 L of blood plasma
In the same 24 hours, only about 1.0 to 1.8 L of urine are produced
Hence, filtrate and urine are DIFFERENT
contains everything that blood plasma does (except proteins) but by the time it reaches the collecting ducts, this has lost most of its water and essential nutrients
If it has lost most of its water and essential nutrients, what remains? What are these “remains” made up of?
Filtrate
What remains, urine, is just a combination of nitrogenous wastes and unneeded or excess substances
Characteristic of a Freshly voided urine
generally clear and pale (straw) to deep
yellow
the pigment responsible for the normal yellow color of urine
this pigment results from?
Urochrome
pigment results from Hemoglobin destruction
Describe urine when its formed? How about once it gets out?
When formed, urine is sterile, and its ODOR is aromatic
Once it gets out, it gets contaminated with bacteria and starts developing an ammoniacal odor
Urine pH?
What results in a more acidic urine?
What results in a more alkaline pH?
Urine pH is slightly acidic (pH 6.0)
- A meat-based diet would result in a more acidic urine
- A vegetarian diet would give a more alkaline pH
Alkaline urine is an indication of?
bacterial infection
What solutes are normally found in urine?
What substances are not normally found?
- Solutes normally found in urine – Sodium, Potassium, Urea, Uric Acid, Creatinine, Bicarbonate ions
- Substances not normally found in urine – glucose, blood proteins, RBCs, WBCs, hemoglobin, bile
Abnormal urinary constituents and the name of their condition
- Glucose - Glycosuria
- Proteins - Proteinuria (Albuminuria)
- Pus - Pyuria
- RBCs - Hematuria
- Hemoglobin - Hemoglobinuria
- Bile pigment - Bilirubinuria
Possible cause of this condition:
- Excessive intake of sugary foods (nonpathological)
- Diabetes mellitus (pathological)
Glycosuria
Possible cause of this condition:
- Physical exertion, pregnancy (nonpathological)
- Glomerulonephritis, hypertension (pathological)
Proteinuria
Possible cause of this condition: Urinary tract infection
Pyuria
Possible cause of this condition: Bleeding in the urinary tract (due to trauma, kidney stones, infection)
Hematuria
Possible cause of this condition: Transfussion reactions, hemolytic anemia
Hemoglobinuria
Possible cause of this condition: Liver disease (hepatitis)
Bilirubinuria
Slender tubes which connect the kidney to the bladder. Its superior end is continuous with the renal pelvis
Ureters
Smooth muscle layers in the walls of the ureter propels urine by?
through what action/movement mechanism
peristalsis
Urine is prevented from going back by?
small valve-like folds of bladder mucosa
Smooth collapsible, muscular sac that stores urine temporarily
Urinary Bladder
The urinary bladder mucosa is made up of ________ (type of tissue). The bladder wall also contains three layers of smooth muscle – collectively the __________
The urinary bladder mucosa is made up of transitional epithelium. The bladder wall also contains three layers of smooth muscle –
collectively the detrusor muscle
A moderately filled bladder holds about ____ mL of urine but it is capable of holding more than _______
A moderately filled bladder holds about 500 mL of urine but it is capable of holding more than twice the amount
A thin-walled tube that carries urine by peristalsis from the bladder to the outside of the body
Urethra
an involuntary sphincter that keeps the urethra closed when urine is not being passed
Internal urethra sphincter
voluntary sphincter, allows controlled urination
External Urethral Sphincter
Length of urethra in men vs women:
In men, the urethra is longer – about 20 cm or 8 inches
In women, the urethra is about 3 to 4 cm (1.5 inches) long
The urethra opens at the __________, after traveling down its length (male)
The external orifice of the urethra lies _______ (women)
The urethra opens at the tip of the penis after traveling down its length
The external orifice of the urethra lies anterior to the vaginal opening
Function of urethra in males and females?
Urethra of the male has 2 functions: carry both urine and sperm; but never at the same time
In women, it only has 1 function: carry urine out of the body
If body is to remain properly hydrated, __________ (physiology of maintaining water and electrolye balance)
it cannot lose more water than it takes in
Where do most water intake come from? How about the small amount?
Most water intake comes from fluids and foods we ingest in our diet
However, small amount is produced during cellular metabolism
the driving force for water intake
THIRST MECHANISM
An increase in plasma solute content of 2 to 3% excites highly sensitive cells in the hypothalamus known as ________
these will in turn activate the ________
osmoreceptors
These osmoreceptors will in turn activate the hypothalamic thirst center
What organ regulates the amount of water going in and out, depending on the body’s state of hydration?
Kidney
Major regulators of the amount of water that go in and out of the body
Major regulators are Antidiuretic Hormone (ADH) and
Aldosterone
Imbalance
Abnormally low urinary output
* Between 100 and 400 mL/day
What happens when it becomes <100mL/day
OLIGURIA
Anuria if it becomes < 100mL/day
What does a low urinary output indicate?
In what imbalance is this found?
Low urinary output indicates that the glomerular blood pressure is too low to cause filtration
Oliguria
Imbalance that may result from transfusion reactions and acute inflammation or from injuries to the kidney
Anuria
What imbalance?
When urine becomes extremely concentrated, solutes such as uric acid salts form crystals that precipitate in the renal pelvis
this is more commonly known as?
RENAL CALCULI
Kidney stones
What imbalance?
Excruciating pain radiates from the area as the sharp calculi is being forced to move out
RENAL CALCULI
Causes and treatment for Renal Calculi
Causes: frequent bacterial infection, urinary retention, alkaline urine
Treatment: Surgery, non-invasive lithotripsy uses soundwaves to shatter calculi
What imbalance?
Improper toileting habits (wiping from back to front) can carry fecal bacteria into the urethra
URETHRITIS
In Urethritis, Since the urethra is continuous with the rest of the urinary tract organs, it can easily ascend the tract and cause ___________ or even ____________
these 2 are generally termed as
bladder inflammation (cystitis) or even kidney inflammation (pyelonephritis)
These inflammation and infection is generally termed as a Urinary Tract Infection (UTI)
Symptoms of Urethritis
Symptoms include dysuria (painful urination), urinary agency and frequency, fever, cloudy or blood-tinged urine
When kidneys are involved, what are the common symptoms observed?
When kidneys are involved, back pain & a severe headache are common
What imbalance?
When ADH is not released, huge amounts of very dilute urine (up to 25 liters/day) flush from the body day after day
DIABETES INSIPIDUS
Diabetes Insipidus is caused by many things, mainly revolve around an injury or destruction of the ______ or the ____
injury or destruction of the hypothalamus or the posterior pituitary gland
What imbalance?
Can lead to severe dehydration and electrolyte imbalances
* Affected individuals are always thirsty and must drink fluids almost continuously to maintain normal fluid balance
DIABETES INSIPIDUS
Inflammation of the glomerulus
GLOMERULONEPHRITIS
What imbalance?
Childhood streptococcal infections, such as strep throat and scarlet fever may cause inflammatory damage to the kidneys if
the original infections are not treated promptly and properly
GLOMERULONEPHRITIS
In glomerulonephritis, the glomerulus is inflamed as a result of being clogged with
________ resulting from the strep infection
The glomerulus is inflamed as a result of being clogged with antigen- antibody complexes resulting from the strep infection
A mixture of waste and essential substances
filtrate
In what part of the tube system does reabsorption start?
What is pushed out and what is taken by the body?
Proximal convoluted tubule (PCT)
Waste is pushed out and essential substances are taken by the body
these are the transporters ” taking up needed substances from the filtrate and then passing them out into the extracellular space in which they are absorbed by peritubular capillary blood
Tubule cells
Most reabsorption happens in the
PCT (Proximal Convoluted tube)
Most require ATP (Active transport process)
What will happen If the filtrate level that goes out of the glomerulus is 185 mg/dL glucose ?
what do you call the term used to indicate the capacity of these cells
filtrate, that is beyond the reabsorption capacity of the cell (cells seen in
proximal convoluted tubule) will cause them to get overwhelmed, so they can’t reabsorb
everything.
It will be mixed with urine. Thus, people with DM have urines that are positive for glucose because their glucose level is beyond the renal threshold found in their filtrat
Renal Threshold (160-180 mg/dL)
Glomerulus is not a perfect filter, thus what is the second way to remove the waste produucts found in the blood?
Through tubular secretion: secreted out from the peritubular capillaries into the tubule cells to be eliminated through urine
Tubular secretion is also an additional means to control blood pH but it is not a blood buffer, why?
how does it control blood pH
blood buffers need to be molecules
It secretes H+ ions
What filtrates are reabsorbed and secreted in the Proximal convoluted tube
Give their reabsorption method of transport
REABSORBED:
- NaCl (active)
- HCO3- (active)
- H2O (passive)
- Glucose and amino acids (active)
SECRETED: (all active)
- Some drugs and poisons
- H+
What is reabsorbed in the nephron loop (descending loop)
passive reabsorption of H2O
What is reabsorbed in the nephron loop (ascending loop)
BOTH Active & Passive reabsorption of NaCl
What are Reabsorbed and secreted in the Distal tube?
- NaCl reabsorbed (active)
- K+ and drugs secreted (active)
What are reabsorbed and secreted ini the Collecting Duct?
Reabsorbed:
- H2O (passive)
- NaCl (active)
- Urea (passive)
Secreted:
- K+ (active)
Nitrogenous waste products are poorly reabsorbed, if all. what is an example of a waste reabsorbed by the body
In what part is it reabsorbed?
Urea
Reabsorbed in the Collecting Duct
How is creatinine made
Muscle tissue releases creatine then it becomes/converted to creatinine
Muscle tissue, although made up of protein, is different from urea. How?
Protein breakdown in urea is from DIETARY PROTEIN
when should you drink water?
When you’re thirsty
L of filtrate and L of urine produced?
150-180 L of filtrate REABSORBED
1.0-1.8 L of urine PRODUCED
What happens to bilirubin when it goes to the Urine?
It becomes the Urochrome
How does the ammoniacal odor of the urine develop?
Breakdown of bacteria
What is the major pathological reason for proteinuria?
The Glomerulus is damaged so all big stuffs go out (like protein)
What happens to the filter system when you have pyuria?
Bacteria can destroy the entire filter systems
When does urine get contaminated with bacteria?
when it reaches near and on the external genetalia (urethra)
Why are Women are more prone to Urinary Tract Infection?
the urethra is closer to the bladder
and Bad Hygiene: back to front
True or False
Small amount of water is produced during cellular metabolims thus processcess in cells create water
T
Assuming 2.5 L intake of water. What percentage is from beverages, food, and metabolism?
60% beverages
30% food (water molec)
10% metabolism
Around how many percent of our average intake of water per day turns into urine?
What happens to the remaining percentage?
60% (1.0-1.8L)
● Remaining 40%:
○ 4% to feces
○ 8% to sweat
○ 28% to skin and lungs (breathing)
Relative increase Vs. Absolute increase of plasma solutes
**Relative increase: **Water molecules lower (Ex. Urinating a lot without drinking water)
Absolute increase: Eating a lot of salty foods
When this increases, the thirst mechanism is activated
Solutes/Plasma solutes
In what part does the Antidiuretic hormone reabsorb water?
Collecting duct
2 causes why the Hypothalamic thirst center activates
- Dry mouth
- Osmoreceptors in hypothalamus
What happens when you have high plasma solutes (2)
- decrease saliva (neg feedback)
- Osmoreceptors activate (regulat BP)
3 Responsible Mechanisms that respond to Falling systemic blood pressure/volume
- RAAS
- Sympathetic NS
- ADH/AVP
Pathway for increasing blood pressure through AVP/ADH
- Hypothalamic osmoreceptors
- Posterior Pituitary (could also be activated by Angiotensin II in blood)
- ADH
- Collecting ducts (become more permeable)
- H2O reabsorption
- Increased blood volume
- Increased BP
Pathway for increasing blood pressure through Sympathetic NS
- Inhibits baroreceptors in blood vessels
- Sympathetic NS (activates JG cells of kidneys)
- Systemic arterioles
- Vasoconstriction
- Increased Peripheral Resistance
- Increased blood volume
- Increased BP
Pathway for increasing blood pressure through RAAS
- Reduced filtrate volume or solute content in renal tubules
- Juxtaglomerular cells of kidneys (by Sympathetic NS) —-release renin
- Renin (enzyme catalyze angiotensinogen to angiotensin I)
- Angiotensin II iformed in blood
5A. Systemic Arterioles 5B. Adrenal Cortex
6A. Vasoconstriction 6B. Aldosterone
7A. Peripheral Resistance 7B. Kidney tubules - Increase Na+ reabsorption and H2O
- Increased blood vol
- Increased BP
enzyme that activates the inactive angiotensinogen into angiotensin I
renin
For Angiotensin I → II, it needs what enzyme (found in lungs)
ACE enzyme (Angiotensin Converting Enzyme)
this does not only activate adrenal cortex, but as well as posterior pituitary to release more AVP
Angiotensin II
Falling systemic blood pressure inhibits _____________- in bood vessels and this activates the sympathetic NS
Baroreceptors: Pressure receptors
2 stimuli for the JG cells to release renin
- Reduced BP from low filtrate volume/solute content
- Sympathetic NS
3 functions of RAAS (Angiotensin II)
- Activate Posterior Pituitary
- Vasoconstriction
- Stimulate adrenal cortex to release aldosterone (increase aldosterone=more sodium=more water)
The point where the kidney can’t handle or
function; it is too damaged to function
Treatment for this?
Renal Failure
Dialysis [Artificial Kindey] will filter blood in place of kidne
