What renal process occurs at the renal corpuscle?
What are the three forces acting at the glomerulus that are responsible for the formation of filtrate?
1- Glomerular hydrostatic pressure 2- Colloid osmotic pressure (opposite force to glomerular hydrostatic pressure - sucking force due to proteins and RBC) - not as strong as 1 3- Capsular hydrostatic pressure
What are the forces in mmHg of the three pressures acting upon the glomerulus? 1- Glomerular hydrostatic pressure 2- Colloid osmotic pressure 3- Capsular hydrostatic pressure
1- Glomerular hydrostatic pressure - 55mmHg 2- Colloid osmotic pressure - 30mmHg 3- Capsular hydrostatic pressure - 15mmHg
Which of the three forces acting upon the glomerulus is equivalent to blood pressure?
Glomerular hydrostatic pressure
Which of the three forces acting upon the glomerulus is a consequence of proteins in the blood?
Colloid osmotic pressure
Which of the three forces acting upon the glomerulus is generated by fluids in the glomerular capsule?
Capsular hydrostatic pressure
These three forces acting at the glomerulus are responsible for the formation of filtrate. What is the not filtration pressure and what equation defines net filtration pressure (NFP)?
NFP is the pressure that is responsible for making the filtrate. This pressure needs to be a plus. The equation is Glomerular hydrostatic pressure - (Colloid osmotic pressure + Capsular hydrostatic pressure) NFP = 55 - (30+15) = 10
What is the definition of glomerular filtration rate?
The amount of filtrate by all nephrons in both kidneys. = 120 - 125mls per min
How does a decrease in blood pressure effect GFR, urine out put and Glomerular hydrostatic pressure?
Reduced glomerular hydrostatic pressure, reduced GFR and reduced urine.
How does an increased in blood pressure effect GFR, urine out put and Glomerular hydrostatic pressure?
increased glomerular hydrostatic pressure, increased GFR and increased urine.
If blood pressure is decreased how do the kidneys compensate for this?
Causes a reduction in GFR dilate afferent arteriole increase glomerular blood flow Increase Glomerular Hydrostatic pressure Increased GFR
If blood pressure is increased how do the kidneys compensate for this?
Causes an increase in GFR constrict afferent arteriole reduce glomerular blood flow reduce hydrostatic pressure reduce GFR
Explain the events that occur when there is a reduction in arterial pressure.
A reduction in arterial pressure --> inhibits baroreceptors --> increases sympathetic NS activity --> Kidneys produce Renin --> Renin turns angiotensinogen (produced in liver) to angiotensin I --> ACE (in the lungs) turns angiotensin I into angiotensin II --> angiotensin II acts on 4 areas - Causes Adrenal cortex to secrete aldosterone which in Na+ reabsorption --> increases H2O absorption - Increases ADH release by posterior pituitary --> increased water reabsorption - Increases thirst via hypothalamus --> increased water intake - Vasoconstriction increasing peripheral resistance All of these factors increase blood volume and therefore mean arterial pressure
Briefly describe the three processes involved in the production of urine.
• Glomerular Filtration - involves the transfer of soluble components such as water and waste from the blood into the glomerulus. • Tubular Reabsorption - involves the absorption of molecules, ions, and water that are necessary for the body to maintain homeostasis from the glomerular filtrate back into the blood. • Tubular Secretion - involves the transfer of hydrogen ions, creatinine, and drugs from the blood into the collecting duct.
What is the name of the vessel that feeds blood into the kidneys?
Cortical radiate artery
What is the name of the vessel that leads into the glomerular capsule?
What part of the nephron is likely to be damaged by hypertension?
Names the following structures.
1- Renal corpuscle (glomerular capsule + Glomerulus)
2- Proximal convoluted tubule
3- thin descending segment
4- Think ascending segment
5- thick ascending segment
6- Distal convoluted tubule
7- collecting duct
Where are these structures located in relationto the sections of the kidney?
Cortex - renal corpuscle, proximal tubule, distal tubule
Medula - descending thin loop of henle, ascending thin loop on henle, section of the ascending think loop of henle.
What are the two type of nephrons, which is there most of and where are they located?
Cortival nephrons (85%) - located almost entirely in within the cortex
Juxtamedullary nephrons (15%) - located near the cortex-medulla junction
Where to the preitubular capillaries arise from?
Peritubular capillaries arise from efferent arterioles draining the ______?
The peritubular capillaries arise from efferent arterioles draining the glomerulus, they also_____ __ ___ ___ the tubules?
absorb solutes and water from the tubules
What does the juxtaglomerular apparatus do and where is it located?
The juxtagolmerular apparatus regulates the blood flow and filtration rate of each nephron.
It is located between the renal corpuscle and the distal convoluted tubule of the same nephron
What cells are part of the juxtaglomerular complex?
Net filtration pressure that forms filtrate is the blance of ____ _____ ____ against the combined forces of ______ ____ _____ and ____ ____ ____.
glomerular hydrostatic pressure
colloid osmotic pressure
capsular hydrostatic pressure
How is water reaborbed by the PCT?
1- Na+ is actively pumped from the filtrate into the peribulular capillary. Water always follows Na+. Water therefore also moves from the fitrate into the peribubular capillary. And glucose follows water.
What substances remain in the filtrate?
Urea, creatinine, uric acid,
not all - sodium chloride and potassium choride
Different areas of the tubules have different aborpative capabilities. What are they in which regions?
Proximal convoluted tubule - most active in reabsorption
Descending limb of the loop of Henle - Water
Ascending limb of the loop on Henle - electrolytes (no water)
Distat convoluted tubule and Collecting duct - Na+ and water reabsorption regulated by hormones (aldosteronem antiduretic hormone and ariterial natriuertic peptide)
What is the purpose of tubular secretion?
To dispose of unwanted solutes, rids the body of excess K+ and controls blood pH.
Where does tubular secretion occur and where does it occur most?
Sercretion occurs most in the proximal convoluted tubule. Also occurs in the collecting ducts and distal conviluted tubules.
How are the componens of urine formed?
Urea, Creatinine, Uric acid.
Urea - Breakdown of amino acids
Creatinine - metabilite of creatine phosphate
Uric Acid - product of nucleic acid metabilism
WHat are the threee layers of th bladder?
- outer adventitia
- detrusor muscle
- inner mucosa (highly folded to allow for exspansion
what is the function of the detrusor muscle?
When the bladder is stretched, this signals to the parasympathetic nervous system to contract the detrusor muscle. This encourages the bladder to expel urine through the urethra.
Facilitates in emptying the bladder.
What is the difference between the internal uretral sphincter and the external ureteral sphincter?
The internal urethral sphincter in involuntary and formed from the detrusor muscle
The external urthral spincter is voluntary and is formed by skeletal muscle.
What factors influence urine production?
1 - BP
2- Increase in blood concertration - Increase in osmolarity --> release of ADH --> less urine produced
3- An increase/decrease in ambient temperature
4- Diet / water intake
5- Diuretics can increase urine volume
6- Emotions --> increased BP --> changes in GFR
What is the yellow colour in urine caused by?
What is urine's normal range of pH?
4.6 to 8.0
What is unrine's normal ranges for specific gravity?
1.001 ro 1.035