The functions of the urinary system are to filter plasma and eliminate waste, regulate blood volume in blood pressure, blood pH, osmolarity and electrolyte, balance and red blood cell production.
Metabolic waste is waste produced by the body.
Nitrogenous waste is the most toxic
Blood urea nitrogen is the measurement of nitrous waste in blood
The body excretes a mini different ways for example respiration excrete CO2 digestive, excretes cholesterol/Bill Rubin and the urinary excretes metabolic waste toxins, drugs, access salts and hydrogen
The kidneys receive 20% of carbon monoxide
The functional unit of a kidney is a nephron, and there are about 1.2 million per kidney
Nephrons have two sets of arteries and two sets of capillaries
Nephrons are a series of tubes and associated capillaries
The cortical nephron’s make up about 85% of all nephrons.
They are mostly in the cortex and have a short nephron loop.
Juxtamedullary nephrons make up about 15%. They have a long nephron loop in the medulla increase and osmolarity gradient to concentrate the urine.
Through the nephron the stuff travels from the renal capsule to the proximal convoluted tubule to the nephron loop to the distal convoluted tubule into the ureter
The renal corpuscle is a physical connection between blood and tubules and consists of the glomerulus and the glomerular capsule
The renal corpuscle acts to filter the blood
20% of plasma is filtered through the renal corpuscle
Urine is formed through steps, the first step being glomerular filtration which creates a plasma-like filtrate of the blood. The second step is tubular reabsorption, which removes useful solute from the filtrate and return them to the blood, and along with that step is tubular secretion, which removes ways from the blood and add them to the filtrate, and then the last step is water conservation which removes any water from the urine and returns it to the blood, which concentrates the waste
Filtration pressure moves from high to low
The pressure is higher than the so fluid is filtered out into capsule
About 20% of fluid in plasma gets filtered
Reno auto regulation is the ability of nephrons to adjust its own blood flow to maintain its own GFR despite changes in blood pressure
Renal autoregulation starts with myogenic mechanism, which is based on fact that smooth muscle contracts when it’s stretched
A high blood pressure in efferent arterial can lead to an increased stretch in the afferent arterial which leads to base construction and a lower pressure, which will maintain the GFR despite the blood pressure
Next tubular glomerular feedback is the fluid flow in tubes is sensed in communicate communicated back to after arterial next to sympathetic nervous system causes vasoconstriction of afferent arterial
Which lowers GFR
Peritubular caps returns H2O and solute from tubular fluid to blood
Most reabsorption occurs in the proximal convoluted tube, which is about 65% in overall 99% of filtrate is reabsorbed
Substance that do get reabsorbed or H2O ions, such as NA K CL nutrients such as glucose and vitamins
If all transporters are occupied some, so you will not be reabsorbed and just appear in the urine substance that need protein carriers have a transport maximum, for example, diabetes mellitus substances that weren’t filtered move from peritubular caps into tubular fluid
the purpose is to dispose of substances at a higher rate than filtration
Most secretion occurs in the proximal convoluted tube
Things that are secreted are drugs and toxins, metabolic waste, hydrogen, and potassium
Reabsorption and secretion in the proximal convoluted tube is not regulated
Sodium is regulated by aldosterone and a NP in the distal convoluted tube
Aldosterone and ANP have opposite effects
H2O follows NA by osmosis so if a high amount of NA is reabsorbed than a high amount of H2O is reabsorbed which leads to a change in the blood volume in blood pressure
The path of urine starts in the kidney goes to the ureter into the bladder and through the urethra to outside the body
Renin-Angiotensin-Aldosterone (RAA) - When blood volume/BP drops: RAA increases Na+ and H2O
reabsorption to increase BP
High renin means high ang I which means high ang II
Effects of inch two are widespread vasoconstriction, causing high blood pressure, increased aldosterone, causing high sodium reabsorption in the distal convoluted tub Effects of inch two are widespread vasoconstriction, causing high blood pressure, increased aldosterone, causing high sodium reabsorption in the distal convoluted tubule, and high ADH causing an increase in h2o reabsorption
This will result in high sodium and water retention and less excreted
Causing high blood volume and blood pressure
Atrial natriuretic peptide Atrial naturalistic peptide is anti-aldosterone
when blood pressure and blood volume rises ANP decreases NAN H2O absorption in order to decrease blood pressure When blood pressure and blood volume rises a NP decreases NAN H2O absorption in order to decrease blood pressure
High blood pressure leads to an increased stretch in the right atrium, causing a high ANP
Effects of a NPR dilation of the African arterial and constriction of the effort arterial which leads to high GFR, low aldosterone, low ADH, low and a reabsorption in distal convoluted tubules directly
This results in a low sodium and water retention, which means more water secreted, and there is a decrease in the blood volume in blood pressure
Osmolarity gradient in the medulla is important for H2O reabsorption
The long nephron tube of JM nephron create an osmolarity gradient in renal medulla
The countercurrent multiplier is the nephron loop and it creates a gradient. It has an ascending limb that transports salt out, and it is impermeable to water. The descending lab is impermeable salt, but permeable to H2O the H2O diffuses out because of the high salt.
The effect is multiplied as fluid move through the loop
The countercurrent exchanger is the VA Rector and it maintains the gradient
The osmolarity gradient is used in the collecting duct to concentrate urine
ADH inserts water channels into collecting duct to increase H2O absorption
The number of H2O channels is regulated by ADH
A high level means more water channels, aquaporins, which leads to H2O flowing out by diffusion, which means urine can be concentrated
ADH helps restore the blood volume a low blood pressure means high ADH can lead to high aqua fortis, causing high water reabsorption leading to high blood volume in blood pressure
Factors that increase a blood pressure or blood blood volume is sns renin ang II and aldosterone, ADH and low GFR
Factors that decrease blood volume in blood pressure are ANP and high GFR
ADH also regulates plasma osmolarity, which is the main function, the only way to disconnect H2O reabsorption from NA reabsorption and regulate plasma molarity
For example, X H2O assumption can lead to low plasma molarity, causing a decrease of firing of receptors in the hypothalamus. This causes a decrease of ADH and a low number of Aquaphor Rhynn causing a high H2O excretion while NA reabsorption not being affected, this can affect high plasma osmolarity
The characteristics of urine are colorless to Amber color, clear, distinct odor, gravity, osmolarity, pH. They should not contain protein, glucose, white blood cells or blood.
Diuretic is any chemical that increases your volume such as caffeine and alcohol
Diabetes mellitus is the failure to absorb all glucose, causing more H2O to excrete due to osmosis
Diabetes insipidus is no ADH or response to ADH leading to a high H2O excretion