Week 10-Urinary system Flashcards
Describe the specific functions of urinary system (functions of the kidneys)
Forming urine-remove nitrogenous waste from blood
control blood volume/pressure
Control osmolarity of blood
Controls what solutes stay or get peed out
Control Ph
What does the nephron do?
functional unit
Filter blood
Form urine from filtered blood
What are the 2 types of nephrons?
cortical-85%
juxtamedullary-15%
Describe the 3 processes (glomerular filtration, reabsorption and secretion) involved in urine formation—what affect will these processes have on the content of the urine?
Filtration
First-filters substances from blood
Water, electrolytes, waste products, glucose and amino acids go from glomerulus into glomerular capsule
Will not let rbc, wbc, platelets or albumin get into gc
Describe the 3 processes (glomerular filtration, reabsorption and secretion) involved in urine formation—what affect will these processes have on the content of the urine?
Reabsorbtion
Happens second-returns necessary substances into blood
Filtered substances get reabsorbed into blood(normally are “good stuff”)
Some water, some electrolytes, all glucose, amino acids back into blood
Describe the 3 processes (glomerular filtration, reabsorption and secretion) involved in urine formation—what affect will these processes have on the content of the urine?
Secretion
Also happens second-secreting unwanted substances into tubes for excretion
Substances go directly from blood into tubule
(typically “bad stuff” that you want to pee out, like nitrogenous wastes, drugs, potassium and hydrogen )
What is the GFR (Glomerular Filtration Rate)?
Amount of filtrate formed in all nephrons in both kidneys per minute
Why does the GFR need to be constant?
Needs to be constant so you can maintain proper kidney functions
In urinalysis—what are the physical properties of urine?
Volume
Color
Ph
Specific gravity
Odor
What is the clinical significance if urine output is too low or absent?
Can lead to kidney failure
can indicate kidney disease, dehydration, or circulatory shock
What is the clinical significance if the Specific Gravity
if too high, you could be peeing out too many substances-too concentrated
dehydration, kidney disease, or other conditions affecting solute concentration.
What are the substances that are normally found in urine (chemical composition of urine)?
urea, creatinine, and uric acid (nitrogenous wastes)
electrolytes and other solutes.
Which substances are nitrogenous wastes?
uric acid
urea
ammonia
Creatinine
How are these wastes produced in the body?
Nitrogenous wastes are produced through protein metabolism and nucleic acid breakdown.
Name general substances reabsorbed in the tubule (these are substances returned to the blood)
Some water, some electrolytes, all glucose, amino acids
Name general substances secreted in the tubule (these are substance that are added to the tubule to be excreted in urine)
H+-Hydrogen
K+-Potassium
Nitrogenous wastes(waste products)
drugs.
What types of abnormal urinalysis findings are present in: Type I Diabetes,
glucose, ketones
What types of abnormal urinalysis findings are present in: Acute renal failure
albumin
foamy coke colored- Rbc
low output
What types of abnormal urinalysis findings are present in: UTI
wbc
microbes
rbc
Function of renin and effect on urine, blood volume and blood pressure
is important in making angiotensin ll-activates RAAS
will increase blood volume/pressure
function of angiotensin ll and effect on urine, blood volume and blood pressure
causes release of ADH and aldosterone
will increase blood volume/pressure
Function of ANP and effect on urine, blood volume and blood pressure
will decrease reabsorption of sodium/water
(pee out more sodium/water)
lower blood volume/pressure
increase urine volume
Function of Aldosterone and effect on urine, blood volume and blood pressure
Will increase soduim and water reabsorption
(pee less sodium/water)
raise blood volume/pressure
Describe the RAAS (Renin-Angiotensin Aldosterone System)
-hormone system that regulates blood pressure
Try to prevent you from dying of low blood pressure and going into shock/death
How does ADH affect the osmolarity of the blood?
Blood volume=Blood pressure
Increased ADH= more blood volume/pressure and lower urine volume/pressure
Lower ADH=less blood volume/pressure and higher urine blood volume/pressure
Describe how ADH can regulate blood osmolarity
Increased ADH
-decreases blood osmolarity
-concentrates urine
decreased ADH
-increases blood osmolarity
-dilutes urine.
What is the effect of ADH on the concentration of urine?
Will take water out of urine and put into blood-causing concentrated urine
will decrease volume/pressure of urine and increase volume and pressure of blood
Describe how a diuretic works-What does diuretic affect and what is the result?
Decrease reabsorption of sodium and water
Will increase urine volume so you can pee more
What do the BUN and plasma creatinine blood tests indicate?
If these are high numbers= poor kidney function
if numbers are low= good kidney function
Describe renal plasma (creatinine) clearance
kidney’s ability to remove substances from blood
what does it mean if renal plasma clearance is LOW?
Low renal plasma clearance indicates poor kidney function or kidney failure.
Describe the micturation reflex (this is an autonomic reflex)
Allow you to pee when bladder is full
detrusor muscle contracts and the internal urethral sphincter relaxes, leading to the release of urine from the bladder
What is the purpose of dialysis?
external way to clean out plasma by removing nitrogenous wastes from body
return clean plasma to body
Albumin
damage to filtration membrane due to injury or disease/infections, high BP, toxins
Ketones
primarily diabetes mellitus but also anorexia/starvation, low carb diet
Microbes
infections in the urinary tract—urine should be sterile
Glucose
primarily diabetes mellitus but also stress which causes release of epinephrine/norepinephrine and cortisol
Crystals
salts that precipitate out—found in a person with a kidney stone
Red blood cells
acute inflammation from disease or kidney stones, tumors, trauma and kidney disease
White blood cells
result of response to infection—called pyuria
