Urinary System Flashcards
What is the role of the kidneys
the main excretory organ
What is the role of the ureters
transport urine from the kidneys to bladder
What is the role of the urinary bladder
holds urine temporarily until excretion
What is the role of the urethra
a tube from the bladder that allows urine to leave the body
What are the 6 functions of the kidneys
1) regulation of water volume and solute concentration
2) balance pH
3) aids in ridding the body of metabolic wastes, toxins, and drugs
4) endocrine functions ( renin and erythropoietin)
5) activates vitamin d
6) aids in making glucose
What is the purpose of renin
regulates blood pressure
What is the purpose of erythropoietin
regulate the production of RBC
What causes a low urine output
dehydration
blood loss
diarrhea
enlarged prostate
What causes a high urine output
diabetes
alcohol
caffeine
drugs
What is urine? percentage of water? percentage of solutes? How much do we produce?
minimum 500 mL/day
normal range 1-2 L
95% water
5% solutes
What solutes are present in urine
urea
nitrogenous waste
other solutes: sodium, potassium, phosphate, sulfate, calcium, magnesium, and bicarbonate
What are 2 nitrogenous waste
uric acid ( from nucleic metabolism) creatinine ( from skeletal muscle)
What is urea
break down of amino acids from the liver
What are 4 trace substances found in urine
1) cells
2) proteins
3) ketones
4) blood
What do the presence of trace substance indicate?
1) cells: might indicate a UTI
2) PROTEINS: might indicate damage to kidneys
3) ketones: indicates fat metabolism / diabetes
4) blood: menstruations or severe UTI
What color is urine usually and what gives its color?
urine is normally pale to deep yellow
urochrome gives its color ( produced from rbc destruction)
What does urine to have a ammonia smell to it
due to urea being converted by bacteria
What is the normal pH of urine
slightly acidic (6) range from 4.5-8
What causes more acidic urine
diets rich in whole wheat or meat
What causes more alkaline urine (5 things)
citrus fruits vegetables dairy products constant vomiting bacteria infection
What is specific gravity and what is the normal range
ratio of the mass of the substance compared to the mass of an equal volume of distilled water
1.003-1.032
How are the kidneys situated compared to one another
right lower than the left ( due to liver)
Define renal hilum
medial side. places where ureters, renal blood vessels, lymphatic and nerves enter and exit
What are the 3 internal layers of the kidney
renal cortex
renal medulla
renal pelvis
Define the renal cortex
superficial layer
define renal medulla
middle layer; contains cone shaped renal pyramids
Describe the renal pyramids
separated
tips of the pyramids are called papilla
Define the renal pelvis
tube/central cavity that connects to ureter
What are the 2 structures of the internal kidneys
minor and major calyces
Define the minor calyces
drain pyramids at papillae
Define major calyces
collect urine from minor
carry urine from renal pelvis
What is the direction of urine flow
renal pyramids minor calyces major calyces renal pelvis ureter
Define the nephron
the structural unit that form urine
over 1 million in the kidney
2 parts: renal corpuscle and renal tubule
Why do women get UTI more frequently compared to males
sexually active
poor bathroom habits
Define Bowman’s Capsule
a bulb that contains bundled arterioles
double layered [ visceral( inside) and parietal ( outside) ]
simple squamous
Describe the visceral layer of bowman’s capsule
made of cells with small slits
slits allow for flow of fluids and solutes
cells positively charged and prevent entrance to negative charged molecules
Define what the glomerulus is
bundle arteries in bowman’s capsule
afferent vessels enter and efferent vessels exit
What is the purpose of bundling in the glomerus
slows down the flow of blood
What effects do the PSNS plays on the glomerus
vagus
vasodilation of arterioles
more urine output
What effects does the SNS has on the glomerus
vasoconstriction of the arterioles
less urine output
What are the 3 parts of the renal tubule
1) proximal convoluted tubule ( PCT)
2) NEPHRON LOOP
3) DISTAL CONVOLUTED TUBULE ( dct)
What is the function of the proximal convoluted tubule
functions in reabsorption and secretion
What is the function of the nephron loop
comparable to the pipes under a sink > descends then ascends
used for reabsorbing water
What is the function of the Distal Convoluted Tubule ( DCT)
functions mostly in secretion with bits of reabsorption
What is the function of the nephron collecting duct
1) receive the filtrate from many of the nephrons
2) run through the medullary pyramids
3) fuse together to deliver urine from papillae to minor calyces
What are the 2 types of nephrons
1) cortical nephrons ( 85%)
2) juxtamedullary nephrons ()
What is the cortical nephrons
almost all the cortex
What are juxtamedullary nephron?
long nephron loops
through the medulla
produce concentrated urine
What type of capillaries do cortical nephrons have and what is the function
peritubular capillaries
wound around the cortical nephron
low pressure capillaries for absorption of water and solutes
What type of capillaries do juxtamedullary nephrons and what is there function
Vasa recta
wrapped around the long nephron loop
long and thin walled
helps concentrate urine
What are the 3 steps of forming urine
1) Glomerular filtration
2) tubular reabsorption
3) tubular secretion
1. 5 L of urine made from 180L of processed fluids
Why does filtration occur in the glomerular filtration step? What can be filtered and what can’t be filtered?
bowman’s capsule
filtration happens because large molecules are not able to flow out of the arterioles
CAN DIFFUSE INTO THE CAPSULE SPACE: water, nitrogenous waste, nutrients, salts
CAN’T DIFFUSE: blood cells, platelets, plasma proteins
What occurs during tubular reabsorption
water, nutrients, and salt molecules are pumped from tubules into the capillary network around the nephron using active transport
What are the three steps to tubular reabsorptions and where do they occur
1) Proximal Convoluted Tubule
2) Loop of Henle ( Ascending and Descending)
3) Distal Convoluted Tubule and Collecting Duct
What is reabsorbed and not absorbed in the proximal convoluted tubule
reAbsorbed ( into the capillaries): 100% of glucose, 2/3rds water,sodium Not reabsorbed( stay in urine) : some water, nitrogenous waste, excess salt
What is reabsorbed and not in the loop of henle
DESCENDING: water reabsorbing ( highly permeable)
not permeable to ions
ASCENDING: highly permeable to ions
impermeable to water
What is absorbed and not absorbed in the Distal convoluted tubule and collecting duct
normally impermeable
reabsorption can change with hormonal influences ( ex. anti-diuretic hormone increase water reabsorption)
What can and cant be secreted in tubular secretion
movement of molecules and ions from capillaries into tubules for urine excretion
drugs ( antibiotics), hormones, metabolic waste ( urea/creatinine) and H+ and K+ ions
What does RAAS stand for and what is the purpose
Renin-Angiotensin Aldosterone System
regulate arterial blood pressure by changing the solute concentration and water reabsorption/ secretion
What hormone gets released when blood pressure is high?what 3 things does it cause?
Atrial Natriuretic Hormone ( ANH) released by myocardiocytes increase water and sodium excretion decrease water and sodium reabsorption inhibit renin secretion
caused by excess sodium concentration in blood
Define ureters and its function
prevent the backflow of urine
urine entering the ureters trigger smooth muscle to push it down to the bladder
strength and frequency of smooth muscle contraction based on the amount of urine
What are diuretics and what are examples of some. How do they work?
substances that increase urine flow
ex. alcohol and caffeine
alcohol inhibits the secretion of ADH
caffeine decreases reabsorption of sodium
What are kidney stones? What size are they? How can they be treated?
crystallization of calcium, magnesium, and uric acid salts
most stones under 5mm will pass
> 5mm can cause blockage
ultrasonic waves can break up the stones
What are the 3 regions to the male urethra
prostatic urethra
intermediate part
spongy
How long is the prostatic urethra
1cm long
runs through the prostate
How long is the intermediate urethra
2 cm long
runs from prostate to penis
How long is the spongy urethra
15 cm long
through the penis
What are the 2 functions of the male urethra
1) carries semen
2) carries urine out of the body
What are the 3 parts to urination/ micturition
1) detrusor contracts
2) internal urethral sphincter opens
3) external urethral sphincter opens
What controls the urination/ micturition
detrusor and internal sphincter controlled via ANS
external sphincter controlled via somatic
Define what the urethra is?
how many spincters?
how long is the female urethra?
how long is the male urethra?
thin walled muscular tube
have 2 spincters: internal and external sphincters
female urethra: 3-4 cm long
male urethra: 20 cm long
where is the internal urethra sphincter located
at the bladder-urethra junction
Define the external urethra sphincter
made of skeletal muscle
controlled voluntary
How does the bladder change shapes depending on how filled it is
when empty bladder is pyramid shaped
moderately filled: 5 in long and can hold 500mL of urine
Max capacity: 800-1000 mL
What are the 4 layers of the bladder
1) Mucosa ( inner): urothelium
2) connective tissue
3) thick smooth tissue : detrusor
4) fatty layer
What is the urinary bladder
a muscular sac that can collapse
How many opening does the bladder have
3 opening for the ureters and urethra in the inferior half of the bladder
contains the region called trigone where infection mostly occur
What happens when blood pressure is low (5 steps)
1) renin ( enzyme) is released from kidney
2) renin stimulate pathway to create angiotensin
3) Stimulates thirst centers in brain and release aldosterone
4) Aldosterone increases sodium reabsorption ( increase water reabsorption)
5) increase pressure
What does angiotensin induce
vasoconstriction
Define aldosterone
released from the adrenal gland
promotes sodium reabsorption in nephron tubules
What other hormone can renin stimulate
Antidiuretic Hormone ( ADH)/ Vasopressin
released from hypothalamus
inhibits diuresis ( urine output)
increase water reabsorption
