Chapter 26 & 27 - The Urinary System Flashcards
What are the 4 components of the urinary system?
Kidneys (2), Ureters (2), Urinary bladder (1), Urethra (1)
Name the 8 functions of the kidneys
Regulation of the BLOOD IONIC COMPOSITION, Regulation of the PH of blood, regulation of the BLOOD VOLUME, regulation of BLOOD PRESSURE, maintenance of BLOOD OSMOLARITY, production of HORMONES, regulation of blood GLUCOSE LEVEL, EXCRETION of wastes and foreign substances.
For the kidneys to regulate the pH in blood, what happens?
The kidneys excrete H+ into urine and conserve bicarbonate ions and HCO3
To regulation the blood volume, what do the kidneys do?
They conserve or eliminate blood in the urine
How do the kidneys help to regulate blood pressure?
They secrete the enzyme renin which raises blood pressure
How do the kidneys help to maintain the blood’s osmolarity?
The separately regulate the the loss of water and solutes in urine.
The kidneys produce what 2 hormones?
Calcitriol & erythropoietin
This hormone is an active form of vitamin D which helps in the absorption of calcium from food in the GI tract into the blood.
Calcitriol
This hormone stimulates the production of blood cells.
Erythropoietin
How do the kidneys help to regulate the blood glucose level?
They can synthesize glucose from certain amino acids during gluconeogenesis
This is the process by which non-carbohydrate sources are used to make glucose; this glucose can be released into the blood as needed.
Gluconeogenesis
Ammonia and urea are wastes from the breakdown of?
Amino acids
Bilirubin results from the breakdown of?
Hemoglobin
Creatinine results from the breakdown of?
Creatine phosphate in muscle
Uric acid results from the breakdown of?
Nucleic acids
Kidneys excrete wastes by forming?
Urine
Paired reddish kidney-bean shaped organ
Kidney
What is the position of the kidneys?
Retroperitoneal (posterior) to the peritoneum of the abdominal cavity and at the level of the lumbar vertebrae
Which kidney is slightly lower than the other? Because?
The right / the space occupied by the liver
The kidneys regulate what 3 things within blood? They produce?
The composition, volume, pressure / urine
A typical adult kidney is how long? Wide? Thick?
4-5 inches / 2-3 inches wide / 1 inch thick
The fissure at the concave medial part of the kidney from which the ureter, blood vessels (renal artery & renal vein), lymphatic vessels, and nerves exit?
The renal hilum
What are the 3 layers of tissue that surround each kidney?
renal fascia, adipose capsule, renal capsule
This tissue layer surrounding the kidneys is a superficial layer, a thin layer of connective
Renal fascia
This is the middle layer of tissue surrounding each kidney that is composed of fatty tissue and protects the kidneys.
Adipose tissue
This is the deep layer of tissue surrounding the kidneys. It is composed of connective tissue and is continuous with the outer coat of the ureter. It protects the kidney and maintains its shape.
Renal capsule
Internally, the kidneys have superficial outer layer that is called? A deeper inner layer called? Which one is usually darker colored than the other?
Renal cortex / renal medulla / the medulla is generally darker
These are cone-shaped and are found in the renal medulla
Renal pyramids
The pointed end of each renal pyramid is called?
Renal papillae
These are the portions of the renal cortex that extends between the renal pyramids?
Renal columns
This is the functional unit of the kidneys and produces urine.
Nephron
Each has about how many nephrons?
About 1 million
These nephrons are found primarily in the cortex and make up what percentage of nephrons?
80-85%
These nephrons extend from the cortex into the medulla and make up 15-20% of nephrons.
Juxtamedullary nephrons
Urine drains from a nephron through ducts that lead to cuplike structures called?
Calyces
This calyx is small and more numerous (8-18 per kidney)? This calyx is larger and less numerous (2-3 per kidney)
Minor calyx / major calyx
Name the order in which urine flows.
Renal papillae ➡ minor calyx ➡ major calyx ➡ becomes urine ➡ renal pelvis ➡ ureter ➡ urinary bladder.
Where does urine flow first?
Minor calyx
After passing through the minor calyx, urine flows into?
The major calyx
From the major calyx, urine drains into a single large cavity called?
The renal pelvis
This is a cavity within the kidney that contains part of the renal pelvis, the clayces, and branches of the renal blood vessels and nerves.
Renal sinus
2 parts of a nephron
Renal corpuscle & renal tubule
The part of a nephron where blood plasma is filtered.
Renal corpuscle
The renal corpuscle consists of what 2 parts?
Glomerulus and glomerular (bowman’s) capsule
This is the capillary network of the renal corpuscle (a cluster of capillaries around the end of a kidney tubule where waste products are filtered from the blood).
Glomerulus
This part of the renal corpuscle that surrounds the capillaries?
Glomerular (bowman’s) capsule
Part of the nephron where the filtered fluid passes.
Renal tubule
The renal tubule of a nephron consists of what 3 parts?
Proximal convoluted tubule, loop of henle, distal convoluted tubule.
The renal corpuscle and both convoluted tubules lie within what part of the kidney?
The renal cortex
The loop of henle lies within which part of the kidney? It returns to?
Extends into the medulla and returns to the renal cortex
Cortical nephrons have what size loops of henle?
Short
Juxtamedullary nephrons have what size loops of henle?
Long
The distal convoluted tubules of several nephrons empty into?
A collecting duct
Collecting ducts unite to form? This drain into?
Papillary ducts / minor clyces
These form the entire wall of the Bowman’s capsule, renal tubule, and wall ducts
a single layer of epithelial cells
The number of nephron cells is?
constant from birth
Will new nephrons form is they are injured or diseased?
no
If one kidney is surgically removed, what happens?
The remaining kidney enlarges and eventually is able to filter blood at about 80% of the rate of two normal kidneys
From the renal pelvis, the urine passes out of the kidneys through?
the ureters
A ureter is a tube that carries urine from each kidney to?
the urinary bladder
how long is a ureter?
10-12 inches
This type of contraction of the walls of the ureters push urine towards the bladder. What also contributes?
Peristaltic contractions / pressure and gravity
The 3 layers of the ureters
mucosa, muscularis, adventitia
This layer of the ureter is the deepest layer. It is a mucous membrane with transitional epithelium (stretches) and an underlying lamina propria of connective tissue mucus that protects the cells in the walls from acidic pH of urine.
mucosa
This middle layer of the ureter wall is composed of an inner layer of longitudinal muscles and an outer layer of circular muscles (opposite that of the GI tract which has inner circular and outer longitudinal). The distal end of the ureters have an additional longitudinal muscle layer outside of the circular muscles.
muscularis
This is the superficial layer of the wall of the ureters. It is made of connective tissue and contains blood vessels, lymphatic vessels, and nerves.
adventitia
This is a hollow muscular organ that temporarily stores urine.
urinary bladder
The bladder does this as it fills with urine. What happens once the bladder is full?
stretches / empties
From the urinary bladder, urine passes through this before it heads out of the body through?
urethra / external urethral orifice
In the floor of the urinary bladder is a small triangular area called?
trigone
The trigone contains the openings from? (2)
ureters & internal urethral orifice
this is the opening into the urethra
internal urethral orifice
The trigone is smooth in appearance but the rest of the urinary bladder has folds in the mucosa called?
rugae
The wall of the urinary bladder has the same 3 layers as?
the ureters
What allows the urinary bladder to stretch?
transitional epithelium
The muscularis of the urinary bladder has the three layers of muscle arranged like that of?
the distal ureters
involuntary circular, smooth muscle forms this which surrounds the internal urethral orifice
involuntary circular smooth muscle
This is composed of skeletal muscle and is located inferior to the internal urethral sphincter
external urethral sphincter
What is the outermost layer of the urinary bladder?
The adventitia of connective tissue
Pressure builds up within the bladder as it?
fills with urine
The pressure from urine within the bladder compresses the ureters to prevent?
the urine from flowing back up towards the kidneys
Despite the pressure that compresses the openings of the ureters, this can still happen?
microorganisms can still spread to the kidneys and cause infection
This is a small tube leading from the internal urethral orifice in the floor of the urinary bladder to the exterior of the body.
Urethra
This is the passageway for discharging urine from the body. It also discharges semen in males.
The urethra
The opening of the urethra to the exterior of the body is?
external urethral orifice
How long is the female urethra?
1.5 inches
The male urethra is how long?
8 inches
The 3 main regions of the male urethra
Prostatic, membranous, spongy
This part of the urethra passes through the prostate.
prostatic
The part of the urethra passess through the deep muscles of the perineum.
membranous
This part of the urethra passes through the penis
spongy urethra
The discharge of urine from the urinary bladder is called?
micturition (urination)
When the volume of urine within the bladder reaches about this much, the pressure stimulates stretch receptors in the wall.
200-400 mL
The stretch receptors send nerve impulses to?
the micturition center.
Where is micturition center located?
in the sacral region of the spinal cord
Parasympathetic impulses travel from the micturition center to the wall of the bladder which causes it to contract and cause?
The urethral sphincter to relax.
The maturation center also inhibits somatic motor neurons that innervate the skeletal muscle in the external urethral sphincter causing?
it to relax
What occurs as the external urethral sphincter relaxes?
urination
The cerebral cortex allows us to do what to our urine for a limited period of time. How does this work?
hold it / by exerting voluntary control over the external urethral sphincter and pelvic floor muscles.
oxygenated blood is carried to the kidneys by?
the right and left renal arteries
the right and left renal arteries branch from?
the abdominal aorta
within each kidney, the renal arter divides into?
several levels of smaller arteries (segmental, interlobar, arcuate, interlobular)
interlobular arteries enter the renal cortex and branch into?
afferent arterioles
Each nephron receives one afferent arteriole which divides into a tangled, ball-shaped capillary network called?
glomerulus
From the glomerulus, the capillaries reunite to form?
an efferent arteriole
efferent arterioles divide to form these which surround the renal tubule part of the nephron
peritubular capillaries
this consists of long capillaries that loop into the medulla of some nephrons
vasa recta
the peritubular capillaries reunite to form several levels of these? (2)
venules (peritubular) and small veins (interlobular, arcuate, interlobar)
Deoxygenated blood exits the kidneys through?
right and left renal veins
The right and left renal veins lead to?
the inferior vena cava
to produce urine, nephrons and collecting ducts perform these 3 basic processes
glomerular filtration, tubular reabsorption, tubular secretion
This is the first step of urine production, water and most solutes move across the wall of glomerular capillaries into the Bowman’s capsule and then into the renal tubule.
glomerular filtration
During this process of urine production, as filtered fluid passes through the various tubules and collecting ducts, materials such as wastes, drugs, and excess ions are secreted into the fluid from the blood.
tubular secretion
The passage of water and small solutes from the blood in the glomerular capillaries into the Bowman’s capsule is called?
glomerular filtration
Most plasma proteins and blood cells do not pass from the blood because?
they are too large
The blood pressure in the glomerular capillaries is normally higher?
than the pressure in the capsule
The difference in pressure between the glomerular capillaries and the capsule forces the fluids and small solutes out of?
the blood
This is the use of pressure to force fluids and solutes through a membrane.
filtration
The amount of filtrate formed in all of the renal corpuscles of both kidneys each minute is called?
Glomerular filtration rate (GFR)
The GFR averages how much in males and how much in females?
males: 180 liters/day
females: 150 liters/day
The level of GFR filtration helps to maintain?
homeostasis
most of the filtrate from filtration returns to the bloodstream during tubular reabsorption, though, so how many liters are actually excreted as urine per day?
1-2 liters
Dialtion and constriction of these affect the GFR
afferent arterioles
Dilation increases blood flow into the glomerulus which increases?
glomerular blood pressure and GFR
Constriction decreases blood flow into the glomerulus which decreases?
glomerular blood pressure and GFR
Through this the kidneys can help to maintain a nearly contant GFR.
renal autoregulation
blood flow to the glomerulus can be automatically?
increase and decreased as needed.
In some kidney diseases, glomerular capillaries are damaged affecting their? This can cause?
permeability Oplasma proteins can pass into the capsule from the glomerulus) / edema
An abnormally high amount of interstitial fluid
edema
The return of most of the filtered water and many of the filtered solutes to the bloodstream are called?
tubular reabsorption
Normally, what percentage of filtered water is reabsorbed by osmosis?
99%
Most solutes are reabsorbed by what process?
both active and passive
epithelial cells all along the renal tubule and ducts carry out? Which contributes the most?
reabsorption / proximal convoluted tubule
The reabsorbed substances return to the blood as it flows through?
the peritubular capillaries (and vasa recta in some nephrons)
The transfer of materials from the blood (and tubule cells) into tubular fluid is called?
tubular secretion
The secreted substances from tubular secretion include? (4)
ions (hydogen & potassium), ammonium ions NH4, creatinine, and certain drugs
The secretion of hydrogen ions during tubular secretion helps to control?
blood pH
The secretion of the other substances during tubular secretion does what?
eliminates them from the body.
What affects the extent of Na+ Cl- and water reabsorption as well as K+ secretion by the renal tubules
several hormones
The most important regulators of electrolyte reabsorption are the hormoens?
angiotensin II and aldosterone
This is a major hormone that regulates water reabsorption
antidiuretic hormone (ADG or vasopressin)
This is a hormone that inhibits both electrolyte and water reabsorption
atrial natriuretic peptide (ANP)
When blood volume and blood pressure decrease, as during dhydration or hemorrhage, what happens to the walls of the afferent arterioles?
they are stretched less
These are smooth muscle fibers in the walls of the afferent arterioles that secrete the enzyme renin into the blood.
juxtaglomerular cells
What also causes renin to be released?
sympathetic stimulation
Renin converts angiotensinogen into?
angiotensin I
This is a plasma protein produced by the hepatocytes of the liver.
angiotensinogen
After angiotensinogen is converted into angiotensin I, it is converted by another enzyme into this which is the active form of the hormone.
angiotensin II
Angiotensin II has what 3 main effects in the kidneys?
- it decreases the GFR
- enhances reabsorption in the proximal convoluted tubule
- stimulates the cortex of the adrenal gland to release aldosterone
Angiotensin II decreases the GFR by causing?
vasoconstriction of the afferent arterioles.
angiotensin II enhances reabsorption of what in the proximal convoluted tubule?
Na+, Cl-, and water
angiotensin II stimulates the cortex of the adrenal gland to release?
aldosterone
This is a mineralocorticoid which regulates the homeostasis of two mineral ions, Na+ and K+. This hormone stimulates the collecting ducts to absorb more Na+ and Cl- and secrete more K+
aldosterone
angiotensin II causes less water to be excreted which increases?
blood volume
antidiuretic hormone (ADH) is produced by? it is released by?
hypothalamus and released by the posterior pituitary gland
This hormone stimulates water reabsorption from the kidney tubules into the blood and vasoconstriction of the arterioles.
antidiuretic hormone (adh)
the water reabsorption from the kidney tubules into the blood and vasoconstriction of arterioles from ADH, results in? (2)
decreased urine production, concentrated urine, and increased blood pressue.
What inhibits the secretion of ADH and causes frequent urination?
antidiuretic hormone (ADH)
A large increase in blood volume causes release of of this from the atria of the heart (as stretching occurs)
atrial natriuretic peptide (ANP)
This causes decreased reabsorption of Na+ and water and suppresses secretion of aldosterone and ADH
atrial natriuretic peptide (ANP)
The decreased reabsorption of Na+ and water and suppression of secretion of aldosterone and ADH results in? In addition, the urine has an increased amount of?
increased urine output and decreased blood volume and pressure / Na+
This is a condition where urine has an increased amount of Na+
natriuresis
Low blood Ca2+ levels stimulate the parathyroid glands to release?
parathyroid hormone (PTH)
parathyroid hormone (PTH) stimulates cells in the renal tubules to reabsorb this into the blood.
Ca2+
parathyroid hormone inhibits HPO4 2- (phosphate) reabsorption causing?
phosphate excretion
The analysis of the properties of urine is?
urinalysis
normal urine output is about how many liters a day?
1-2
the pH range of urine is? high proteins diets do what to urine?
4.6-8.0 / increase acidity
What is the percentage breakdown of urine?
95% water, 5% electrolytes, cellular wastes, and substances such as drugs
Normal urine is free of?
protein
Solutes normally in urine include?
urea, creatinine, uric acid, urobilinogen
this is from protein breakdown
urea
this is from creatine phosphate and is the breakdown within muscles
creatinine
this is from the nucleic acid breakdown
uric acid
this is from hemoglobin breakdown
urobilinogen
abnormal components of urine include?
albumin, glucose, red blood cells, microbes
this is a plasma protein generally too large to be filtered out of the blood
albumin
this abnormal component found in urine is usually reabsorbed
glucose
if these are found in urine, they indicate the presence of blood due to inflammation or disease
red blood cells
These are bacteria, protozoans, or fungi
microbes
body fluids make up what percentage of total body weight in an adult? They can make up to what percentage of the body weight of an infant?
55-60% / 75%
Body fluids are mixtures of of solutes within a solvent called?
solution
The concentration of body fluids varies depending on?
conditions within the body
About 2/3 of body fluid is the fluid within cells called?
intracellular fluid
1/3 of body fluid is the fluid outside cells called?
extracellular fluid
About 80% of extracellular fluid is?
interstitial fluid
This is fluid that fills the spaces between the cells of a tissue
interstitial fluid
What percentage of interstitial fluid is blood plasma?
20%
These membranes separate body fluids. Give an example.
Selectively permeable / plasma membrane
Water moves into and out of cells by?
osmosis
What determines which direction osmosis occurs?
The concentration of solutes in the body fluids
What happens to the percentage of water that makes up body weight as we age?
decreases
The main source of body fluid is?
that which is ingested by the mouth
Generally, fluid intake should balance?
fluid output (by sweating, urination)
Body fluids contain many dissolved suchstances like? (2)
electrolytes and nonelectrolytes
Electrlytes are compounds that have how many ionic bonds?
one
This is a chemical bond formed between ions or charged atoms?
ionic bond
These are positively charged ions? These are negatively charged ions?
Cations / anions
Charged atoms have gaind or lost these which are negatively charged subatomin particles.
electrons
Electrolytes are capable of conducting?
an electric current
What happens to electrolytes when dissolved in fluid such as water?
they dissociate into ions.
Examples of electrolytes include mostly?
inorganic compunds such as acids, bases, and salts
Nonelectrolytes are compounds formed with these chemical bonds formed between atoms that share electron pairs.
covalent bonds
When dissolved in water, what happens to nonelectrolytes?
they do not dissociate in water to form ions and do not conduct an electric current
Examples of organic compounds (which do contain carbon) include?
glucose and urea
Many electrolytes are essential?
minerals
Which is more numerous: electrolytes or nonelectrolytes?
electrolytes
Because electrolytes are more numerous than nonelectrolytes, they control?
osmosis
Electrolytes help maintain what for normal cell activity?
acid-base balance
Because they carry an elecrical current, electrolytes are important in?
NERVE impulse conduction, MUSCLE contraction, and SECRETION of some hormones and neurotransmitters
The number of ions in a volume of fluid (concentration) is indicated in?
milliequivalents per liter
Name the 6 most important ionds include?
Sodium, potassium, calcium, magnesium, chloride, phosphate
What is the most abundant extracellular ion?
sodium
Sodium makes up what percentage of extracellular cations?
90%
Why is sodium found in greater outside the cells?
Because of the sodium-potassium pump and its active tranports of Na+ out of cells and K+ into cells
Na+ is needed for what 2 things?
Nerve impulses conduction and muscle contraction
Na+ creates osmotic pressure in extracellular fluid which causes water to do what?
follow it
Na+ is also involved in these which prevent drastic pH changes in body fluids
buffer systems
pH can be lost from the body through what things?
perspiration, vomiting, diarrhea, diuretic use, and burns
What do most individuals usually exceed?
The body’s normal daily requirements of sodium ions
What do the kidney’s do with excess Na+? What do they do when levels are low?
excrete excess and conserve when levels are low
This occurs when Na+ levels are high in the blood.
hypernatremia
This occurs when levels are low in the blood.
hyponatremia
This is the most abundant intraceulluar cation
potassium
What two things is potassium needed for?
nerve impulse conduction and muscle contraction
Abnormal levels of K+ in the blood can cause what problems?
with cardiac functioning
This occurs when K+ levels are high in the blood. It can cause death from heart fibrillation, involuntary varfiac muscle contractions.
hyperkalemia
This occurs when levels are low in the blood. It can result from vomiting, diarrhea, diuretic use, and/or kidney disease.
hypokalemia
This is the most abundant ion in the body
calcium
This is mainly an extracellular electrolyte foud in the skeleton and teeth as a mineral sald (combined with phosphate HPO42-)
calcium
What perentage of calcium is found in the form HPO42-?
98%
What other two places can a small amount of Ca2+ (calcium) be found?
the blood, muscle cells and the fluid around them
What is the structural component of bones and teeth?
Ca2+
Calcium is also involved in what 3 things?
Blood clotting, muscle contraction, and the release of neurotransmitters.
This occurs when Ca2+ levels in the blood are high.
hypercalcemia
This occurs when Ca2+ levels in the blood are low?
hypcalcemia
As phosphate levels go up, what happens to calcium levels?
they go down
Magnesium is what kind of electrolyte?
intracellular
Where can magnesium be found in mostly? Also in?
50% in bone & 45% fluid inside of the cells
Magnesium (Mg2+) activates the enzymes needed to?
metabolize carbohydrates and proteins
Magnesium is also involved in the structure of?
DNA, RNA, and ribosomes
What does magnesium trigger? It is also involved in? (2)
the sodium potassium pump, involved in nervous system and muscular activity, and in myocardial functioning
This occurs when levels of Mg2+ in the blood are high.
hypermagnesemia
This occurs when levels of Mg2+ in the blood are low
hypomagnesemia
This is the main extracellular anion of the body.
Chloride
Chloride is important to osmosis because it determines?
which direction water moves by osmosis
Chloride is also found in combination with?
hydrogen to form hydrochloric acid (HCI) in the gastric glands of the stomach
This occurs when there are high levels of Cl- in the blood
hyperchloremia
This occurs when there are low levels of Cl- in the blood.
hypochloremia
Phosphate is what kind of electrolyte?
an intracellular electrolyte
What percentageof the phosphate in an adult is in the bones and teeth as calcium phosphate salts.
85%
The remainder 15% of phosphate can be found?
Combined with lipids (phospholipids) to form cellular membranes and is found in DNA, RNA, and ATP
Besides sodium what is also involved in buffer systems of the body?
phosphate (HPO42-)
This occurs when there are high levels of phosphate in the blood
hyperphosphatemia
This occurs when there are low levels of HPO42- in the blood.
hypophosphatemia
The acid-base balance in body fluids depends on?
hydrogen ion concentration
Solutions with more H+ than OH- are considered? They have what pH level?
acids and have a pH of less than 7
Solutions with more OH- than H+ are considered? They have a pH of?
bases (alkaline) and have a pH of more than 7
What is the pH of extracellular fluid including the blood is normally?
7.35-7.45
Various metabolic activities in the body produce H+ ionj, so the body tends to produce more?
acids than bases
To deal with pH changes, the body has these which are chemical substances that resist changes in pH. The make strong acids and bases weaker.
buffers
These two systems also help in keeping the pH of fluids in the body at about 7.4
respiratory and urinary system
What happens to the pH level if there is a raise in the CO2 levels?
raises and body fluids become more alkaline
What happens to the pH levels if there is an increase in CO2 in body fluids (as a result of cellular respiration)
lowers and body fluids become more acidic
The CO2 in blood reacts with water to form? Therefore what else can change the pH of body fluids?
carbonic acid / changes in the rate and depth of breathing
An increase in breathing rate and depth (hyperventilation) does what to the pH since CO2 is exhaled?
raises the pH
A decrease in breathing rate and depth (hypoventilation) does what to the pH since CO2 accumulates
decreases the pH
The pH of body fluids can affect the rate of?
breathing rate
If the blood becomes more acidic, the breathing rate increases as a way to?
get rid of CO2
If the blood becomes more alkaline, what happens to the breathing rate?
decreases
The kidneys carry out this which involves adding materials to the filtrate during urine formation.
tubular secretion
As the blood becomes more acidic,what do the kidney’s do?
They excrete more H+ to raise the pH of the blood (the pH of urine is about 6, on average)
What do the kidneys to if the blood pH needs to be lowered? How often does this happen? Why?
Less H+ is excreted / this does not happen often, though, because bodily processes tend to make body fluids acidic
If the pH of the blood decreases below 7.35, what occurs?
acidiosis
Acidosis causes?
CNS depression and an individual can go into a coma and even die
If the pH of the blood increases above 7.45, what occurs?
alkalosis
What can happen if alkalosis occurs?
causes CNS excitation and an individual can experience nervousness, muscle spasms, convulsions, and even death
This is a physiological response to an acid-base imbalance that attempts to normalize blood pH
compensation
