— Maintaining homeostasis through the regulation of
fluid and electrolytes and removing wastes through
the formation of urine.
ž Other important functions:
— Regulation of acid-base balance
— Control of blood pressure
— Renal clearance
— Regulation of RBC production
— Synthesizing vitamin D to the active form
— Secreting prostaglandins
— Regulating calcium and phosphorus balance.
Nephron
ž Each kidney has
about 1 million
nephrons
ž Two types
— Cortical nephrons
— Juxtamedullary
nephrons
FUNCTIONS OF THE
NEPHRON
1. Filtering plasma
through the
glomerulus
2. Reabsorb and
secrete substances
along tubular tract.
3. Form a filtrate (urine)
that is protein free.
4. Regulate filtrate
formation to
maintain body fluid
volume, electrolyte
composition, and pH
within limits.
URINE FORMATION
1. Glomerular Filtration
2. Tubular Reabsorption
3. Tubular Secretion
4. Excretion
GLOMERULAR
FILTRATION
ž This is the movement of fluid and
solutes out of the glomerulus, across the
glomerular capillary membrane, and into
Bowman’s capsule.
ž The filtrate that is formed here should NOT
contain any red blood cells or protein.
ž Filtrate contains mostly water, NaCl, K+,
bicarbonate, glucose, amino acids,
creatinine and urea
GLOMERULAR FILTRATION
PRESSURES
ž Rate of glomerular filtration is
affected by capillary pressure.
ž Capillary hydrostatic pressure
(CHP) is the main force
responsible for pushing water
and solutes into Bowman’s
capsule.
ž CHP is opposed by hydrostatic
pressure in Bowman’s space and
the effective oncotic pressure of
blood in the glomerular capillary.
ž Net filtration pressure is the sum
of all these forces combined.
GLOMERULAR FILTRATION
RATE
ž This is the measurement of how much
blood passes through glomeruli, each
minute.
ž 90-120 mL/min
ž The rate of glomerular filtration is
affected by the net filtration pressure in
the glomeruli.
TUBULAR SECRETION AND
REABSORPTION Proximal Convoluted
Tubule
ž This is where most of the
nephron’s reabsorption and
secretion occurs.
ž Reabsorbed: K+, NaCl,
H2O, amino acids,
glucose, and bicarbonate.
ž Secreted: uric acid and
foreign substances.
TUBULAR SECRETION AND
REABSORPTION
Loop of Henle
ž Urine can be concentrated
or diluted here
— Descending loop: water is
— Ascending loop: NaCl is
reabsorbed
reabsorbed.
ž Uromodulin: protein
produced by the loop
of henle that binds to
pathogens and prevents
UTIs, protects the tubule
from injury, and against
kidney stone formation.
TUBULARE SECRETION AND
REABSORPTION
Distal Tubule
ž Distal tubule: where the
final adjustments of urine
composition are made.
— Reabsortion: Na+, water (in
the presences of ADH) and
bicarbonate
.
— Secretion: K+, urea, H+,
ammonia, and metabolites are
secreted into the tubule
ž The distal tubule contributes
to the regulation of acid-base
balance.
You May Also Find These Documents Helpful
-
Process blood and form urine as a waste to be excreted. Eliminating toxins, metabolic wastes excess ions from blood. Regulation of blood volume and…
- 1088 Words
- 5 Pages
Good Essays -
Mr. Newman is a 49 year old male who has hematuria, fever and severe flank pain. He also has bilateral lumbar tenderness, bilateral renal enlargement, liver enlargement, ankle and facial edema, skin pallor, and lung sounds suggest pulmonary edema.…
- 702 Words
- 3 Pages
Better Essays -
15. What is a substance normally found in urine that closely reflects the glomerular filtration rate?…
- 988 Words
- 4 Pages
Powerful Essays -
Introduction: In this lab we will learn how the kidney processes blood and produces urine.…
- 668 Words
- 3 Pages
Satisfactory Essays -
The renal system is also known as the urinary system. It consists of the kidneys, ureters, bladder, and the urethra. The function of the renal system is to remove liquid waste from the blood and keep salts and other substances in the blood. The kidneys remove urea from blood by filtering. Besides filtering and eliminating wastes, the system also maintains homeostasis of water, ions, pH, acid and blood pressure. The renal system is a major homeostatic system because it maintains electrolyte balance, acid-base, and fluid balance; excrete nitrogenous wastes.…
- 89 Words
- 1 Page
Satisfactory Essays -
| Whole-wheat bread is preferable because it is likely to contain several nutrients not added to white bread.…
- 2600 Words
- 11 Pages
Good Essays -
a. Active transport of solutes is the primary cause of medullary osmotic gradient. Describe, for example, ion activities along the ascending loop of Henle in the kidney medulla. This is the active transport of Na+ ions drives passive reabsorption of Cl- ions. Addition of these ions to the interstitial fluids of the medulla increases its osmolarity.…
- 837 Words
- 4 Pages
Powerful Essays -
A 45- year- old female nonsmoker has had a cough for the last six months. With the patient placed under intravenous sedation, a bronchoscope was passed in the patient’s oral cavity. Primary structures of upper area visualized and found to be normal. The transbronchial area was examined. A biopsy sample was taken of the lobe. The patient had minimal blood loss. The bronchoscope was then removed, and the patient returned to the outpatient area in satisfactory condition.…
- 667 Words
- 3 Pages
Good Essays -
* Other symptoms that may occur is headache, gastrointestinal distress, and the odor of ammonia on the breath.…
- 508 Words
- 3 Pages
Satisfactory Essays -
* What is happening to Ms. Jones’s kidneys, and why is it causing the observed symptom?…
- 391 Words
- 2 Pages
Satisfactory Essays -
USC Liver Transplant Program And Center For Disease, Postoperative Complications Rejection, First Published 1999, Information Retrieved 5/1/2010, http://www.surgery.usc.edu/divisions/hep/patientguide/rejection.html…
- 835 Words
- 4 Pages
Good Essays -
Because we synthesized the two most common kidney stones, calcium oxalate and calcium phosphate, we will focus on those two in the discussion of formation, treatment, and prevention. Calcium stones like calcium oxalate and calcium phosphate stones form when urine is “supersaturated with the constituent ions that comprise the stone” (Figge). This means, when urine is supersaturated with calcium and oxalate ion that type of stone is more likely to form. This supersaturation results from the ionic activity of Ca^(2+) and oxalate and Ca^(2+) and PO_4^(2-) is greater than the solubility of product for calcium oxalate and calcium phosphate (Figge). There can be various reasons for this supersaturation of ions. Concentrations of unbound calcium, oxalate and phosphate ions, urine pH, and other chemical presences can lead to calcium stones (Figge). Though kidney stone formation can be quite complicated, the formation of them is largely a solubility equilibrium problem where Le Chatelier’s Principle comes into play. Consider calcium oxalate stones that form from oxalic acid reacting with calcium ions.…
- 1458 Words
- 6 Pages
Good Essays -
He is already aware of it, but to clarify he needs to come prepared to do a sheep kidney dissection and also answer questions based on the excretory system (including, structure, function and health issues). Focus is on the internal structure of the kidney.…
- 63 Words
- 1 Page
Satisfactory Essays -
* Calcium stones are most common. They are more common in men between age 20 - 30. Calcium can combine with other substances, such as oxalate (the most common substance), phosphate, or carbonate, to form the stone. Oxalate is present in certain foods such as spinach. It's also found in vitamin C supplements. Diseases of the small intestine increase your risk of these stones.…
- 250 Words
- 1 Page
Satisfactory Essays -
Pyelonephritis is an inflammation of the kidney and upper urinary tract that usually results from noncontiguous bacterial infection of the bladder. It is a renal disorder that involves the pyelum, pelvis or the parenchymal tissues which commonly known as pyelitis. A more severe form of the disease, on the other hand is called urosepsis. The common bacteria that usually found in patient with this disease are E-coli, staphylococcus, and streptococcus. Most kidney infections result from lower urinary tract infections, usually bladder infections. Bacteria can travel from the vagina or rectal area (anus) into the urethra and bladder. Lower urinary system infections may spread to the kidneys, causing pyelonephritis. When you have a bladder infection, the usual mechanism that prevents urine from flowing back to the kidneys does not work properly. This problem can allow infected urine to move into the kidneys and cause a kidney infection that will bring damage to the kidney. Pyelonephritis can either be acute or chronic.…
- 3360 Words
- 14 Pages
Powerful Essays