chronic renal failure signs and symptoms

Signs and symptoms of chronic renal failure

Early stages of CRF are often asymptomatic.
Symptoms are common when the serum urea concentrations exceed 40mmol/l but many patients develop uraemic symptoms at lower levels of serum urea.

Symptoms include:
malaise, loss of energy
loss of appetite
insomnia
nocturia and polyuria due to impaired concentrating ability
itching
nausea, vomiting and diarrhoea
paraesthesiae due to polyneuropathy
Bone pain due to metabolic bone disease
Paraesthesiae and tetany due to hypocalaemia
Symptoms due to salt and water retention- peripeheral or pulmonary oedema
Symptoms due to anaemia
Amenorrhoea in women, erectile dysfunction in men

In more advanced uraemia ( serum urea >50-60 mmol/l), symptoms are more severe, and CNS symptoms are common
mental slowing, clouding of consciousness,seizures
myoclonic twitching


anaemia: pallor, lethargy, breathlessness on exertion
platelet abnormality: epitaxis, bruising
skin: pigmentation, pruritus( itching)
GI tract: anorexia, nausea, vomiting, diarrhoea
Endocrine/ gonads: amenorrhoea, erectile dysfunction, infertility
CNS: coma, confusion, fits
CVS: uraemic pericarditis, hypertension, peripheral vascular disease, heart failure causing oedema
Renal: nocturia, polyuria, salt and water retention causing oedema
Renal osteodystrophy: osteomalacia, muscle weakness, bone path, hyperparathyroidism, osteosclerosis

Spleen

Spleen
– an ovoid, purplish, pulpy mass about the size of one’s fist
– located in the left upper quadrant
– protected by the 9th – 11th ribs
– functions:
1. prenatal: haematopoietic organ
2. site of lymphocyte proliferation, immune surveillance and response
3. identifying, removing and destroying expended red blood cells and broken-down platelets
4. recycling iron and globin
5. serves as a blood reservoir, storing RBCs and platelets
– most vulnerable organ: a sudden marked increase in intra-abdominal pressure (eg. impalement on the steering wheel of a car) can cause the thin capsule and overlying peritoneum of the spleen to burst, rupturing the spleen, leading to intraperitoneal haemorrhage.
– NOT NECESSARY TO SUSTAIN LIFE

Splenectomy
Definition: surgical removal of a diseased or damaged spleen

When do you need splenectomy?
1. Emergency – trauma to the spleen with uncontrolled bleeding
– spontaneous rupture (extremely rare)
2. Elective – idiopathic thrombocytopenia purpura
– congenital or acquired haemolytic anaemia
– thrombosis of the splenic blood vessels
– portal hypertension and hypersplenism
– hereditary spherocytosis
– lymphoma (enlarged spleen)

2 methods:
1. Open surgery – an abdominal incision of almost 12 inches is made, cutting through muscle
and tissue. Spleen is located and removed. Hospitalization following the
surgery may be up to a week, with a 3-4 week recuperation period.
2. Laparoscopic surgery – 3-4 small incisions are made, one for insertion of the laparoscope and
the others for specially designed surgical instruments. Patients are
usually hospitalized for 1-2 days, have less postoperative pain, and a
shorter recovery time.

Effects and prognosis of splenectomy:
1. no serious effects because most of its functions are assumed by other reticuloendothelial organs (eg. the liver and bone marrow)
2. greater susceptibility to infections (bacteria) – reduced by giving special vaccinations at least 2 weeks prior to the elective surgery (pneumococcal pneumonia, meningococcal A and C). Booster vaccinations may be needed. Children usually take daily doses of penicillin until they are 16 years old. If surgery is an emergency, vaccines are given after the operation.
3. complete recovery is anticipated in the absence of other severe injuries and medical conditions, usually 4-6 weeks
4. patients should seek medical attention even for minor illnesses such as sinus infections or sore throats, because antibiotics may be required

Sources:
http://www.nlm.nih.gov/medlineplus/ency/article/002944.htm
http://www.theuniversityhospital.com/cdtv/html/videosurgeryprocedures/spleen.htm

(Posted by: Vivian)

alcohol effect on kidney function

Gross and Microscopic changes
• Alcohol alters the form and structure of the kidney
• The basement membrane of glomerulus become abnormally thickened and was characterized by cell proliferation
• Further changes included enlarged and altered cells in kidney tubules
• These effects alter the ability of the kidneys to function normally.

Rate of blood flow
• The rate of blood flow through the kidneys is an important determinant of the amount of filtration of the blood and absorption of substances from the blood that can take place.
• Various effects of alcohol have been reported including both increased and reduced blood flow.
• These effects seem to be related to whether or not the person also had liver disease and in animal models which species of animal was used.


Effect on electrolytes balance
• Alcohol’s on electrolyte balance has major implications for the satisfactory functioning of the cells of the body
• As a prime example, the cells of the brain and particularly neurons are highly dependent upon proper amounts of sodium, potassium, chloride, and calcium being available.
• Disruption in the proper flow and availability of these electrolytes alters the ability of the neurons to function which leads to modifications in behavior and the ability of the brain to regulate other bodily processes.

Effect of Ethyl Alcohol on Electrolytes

Problem Major Cause(s)
Low sodium level (hyponatremia Massive intake of solute-free fluid (beer

Low potassium level (hypokalemia) Dietary deficiency, gastric losses, leaky membranes, shifts from extracellular to intracellular

Low phosphorus level (hypophosphatemia) Dietary deficiency, malabsorption, increased cellular uptake
Low magnesium level (hypomagnesemia) Dietary deficiency, malabsorption, phosphorus deficiency




Fluid
• Alcohol can produce urine output within 20 minutes of consumption
• It inhibit the secretion of Anti-Diuretic Hormone(ADH) which promotes the concentration of urine by inducing the kidney to conserve water
• Under this condition, the urine become diluted and electrolytes concentration in blood simultaneously arised
• Ages makes a difference in how rapidly the body escape from alcohol’s ADH suppressive effect
• People with older age than 50 escape quicker from the ADH suppressive effect than their younger counterparts. It is thought that sensitivity to increase electrolytes concentration is enhanced with age





Acid-Base Balance
• Proper acid-base balance (i.e. hydrogen ion concentration) is crucial to the proper functioning of most of the body’s metabolic reactions.
• The kidneys play an important role in regulating this acidity, thus the rate at which metabolic processes proceed.
• Examples of alcohol-related acid-base disturbances include low levels of phosphate, which may result from hyperventilation during withdrawal from alcohol and cases of alkalosis which may be a result of severe vomiting after binge drinking.
• The latter sickness leads to losses of fluid, salt, and stomach acid.
• A potential serious condition known as alcoholic ketoacidosis is another disorder associate with abnormally high blood acidity
• This is characterized by the accumulation of ketone bodies, which is produced in the liver as a reserve fuel for brain and muscle tissues
• Typically, this happen to chronic alcohol abuser following a severe binge in which they consume alcoholic beverages and nothing else over the several days

Blood pressure
• Chronic alcohol consumption can lead to accumulation of both fluid and solutes, thereby increasing of the volume of overall body fluid
• This can contribute to high blood pressure
• Clinical studies of hypertensive patients show that reducing alcohol intake lower the blood pressure
• The mechanism responsible for this effect is not well established. However, study has showed that alcohol’s influence on blood pressure may be attributable, at least in part, to its effect on the production of hormones that act on the kidneys to regulate fluid balance or that act on blood vessels to constrict them.

Contributed by Lawrence Oh

Pathophysiology of renal failure (Powerpoint Slides for Download)

Copyright Reserved. For personal use only.

Pathophysiology of Kidney Failure

by JI KEON LOOI

Acute Kidney Failure
http://www.mayoclinic.com/health/kidney-failure/DS00280
Acute kidney failure is the sudden loss of your kidneys' ability to perform their main function — eliminate excess fluid and waste material from your blood. When your kidneys lose their filtering ability, dangerous levels of fluid and waste accumulate in your body.
Acute kidney failure is most common in people who are already hospitalized, particularly people who need intensive care. Acute kidney failure tends to occur after complicated surgery, after a severe injury or when blood flow to your kidneys is disrupted.
Loss of kidney function may also develop gradually over time, with few signs or symptoms in the early stages. In this case, it's referred to as chronic kidney failure. High blood pressure and diabetes are the most common causes of chronic kidney failure.
Acute kidney failure can be serious and generally requires intensive treatment. Unlike the chronic form, however, acute kidney failure is reversible and if you're otherwise in good health you should recover normal kidney function within a few weeks. If acute kidney failure occurs in the context of severe chronic illness — a heart attack, stroke, overwhelming infection or multiorgan failure — the outcome is often worse.
Prerenal
Prerenal problems are among the most common causes of acute kidney failure. Examples of problems that may leave your kidneys with an insufficient blood supply to function properly include:
§ Extremely low blood pressure. Severe bleeding, infection in the bloodstream (sepsis), dehydration or shock can all lead to a drastic drop in blood pressure that prevents an adequate amount of blood from reaching your kidneys. These conditions tend to occur after a traumatic injury or as a risk of major surgery.
§ Poor heart function. If your heart isn't functioning at full capacity, such as during a heart attack or with congestive heart failure, the result can be reduced blood flow to your kidneys.
§ Low blood volume. Severe dehydration — which can be brought on by prolonged vomiting or diarrhea, heatstroke or major burns — results in excessive loss of fluid, diminishing the volume of blood in your body and the amount available to your kidneys.
RenalConditions that may affect the structure and function of the kidney itself, potentially leading to acute kidney failure, include:
§ Disorders that reduce blood supply in your kidneys. Any number of disorders can lead to decreased blood supply in your kidneys, which can lead to organ damage and acute kidney failure. One example is atheroembolic kidney disease.
Atheroembolic kidney disease can occur when masses of cholesterol and cellular debris (plaques) accumulate in arteries and harden in a process called atherosclerosis. If a plaque is injured or disturbed — cardiac catheterization, a procedure used to conduct diagnostic tests and treatments on the heart, is a common cause — pieces of it may break off into your bloodstream and move throughout your body. These moving pieces are called emboli. When these emboli move to your kidneys, the cholesterol emboli accumulate in small blood vessels (arterioles). Within the arterioles, these emboli can produce severe inflammation, leading to decreased blood supply and acute kidney failure.

Other causes of reduced blood supply include a blood disorder called idiopathic thrombocytopenic purpura, development of blood clots in kidney vessels, a reaction to a blood transfusion, or a sudden onset of severe high blood pressure (malignant hypertension).
§ Hemolytic uremic syndrome. This condition, which is associated with certain strains of Escherichia coli (E. coli) bacteria, is a leading cause of acute kidney failure in infants and young children. The bacterium causes inflammation of the intestine. It also produces a toxin that causes damage and swelling in the lining of blood vessels, especially the small blood vessels (glomerular capillaries) in the kidneys. As red blood cells travel through the damaged blood vessels, they're often broken apart (hemolysis). This complex condition may result in acute kidney failure.
§ Inflammation in the kidneys. Acute kidney failure may result from sudden inflammation of the spaces between the glomeruli and the tubules (acute interstitial nephritis) and inflammation of the glomeruli (acute glomerulonephritis). Acute interstitial nephritis is usually associated with an allergic reaction to a drug. Examples include certain antibiotics — especially streptomycin or gentamicin — and common pain medications, such as aspirin and ibuprofen (Advil, Motrin, others). Antibiotics pose a greater risk of acute kidney failure for people who already have liver or kidney disease or who use diuretics or other drugs that affect your kidneys.
Acute glomerulonephritis may be associated with immune diseases, such as lupus or IgA nephropathy (Berger's disease). It may also follow an infection in another part of your body, such as strep throat, infection of a heart valve (endocarditis), typhoid fever, syphilis and malaria. Viruses that cause AIDS, mononucleosis, mumps, measles or hepatitis also may trigger glomerulonephritis.
§ Toxic injury. Because the main purpose of your kidneys is to filter toxins from your body, your kidneys are particularly vulnerable to toxic injury. Exposure to toxic substances — such as excessive amounts of alcohol, cocaine, heavy metals, solvents and fuels — can induce acute kidney failure. Certain drugs also have the potential to injure the tubules in your kidneys, including chemotherapy drugs and contrast dyes used in medical tests, such as arteriography. Contrast dyes are a common cause of acute renal failure, especially in people with diabetic kidney disease or multiple myeloma, a type of cancer.
PostrenalPostrenal causes of acute kidney failure are generally related to obstruction of the flow of urine out of your kidneys on the way out of your body. This may occur at the level of the tubes that lead from your kidneys to your bladder (ureters), or at the bladder level (urethral obstruction).
§ Ureter obstruction. Kidney stones in both ureters (or in a single ureter if only one kidney is functioning) or tumors pushing in on the ureters can cause obstruction at this level.
§ Bladder obstruction. In the bladder, the most common cause of obstruction in men is an enlarged prostate, which causes obstruction at the bladder outlet. Other obstructive bladder causes, in both men and women, include a bladder stone, blood clot, tumor or a nerve disorder that prevents the bladder from contracting properly
Chronic Renal Failure
slowly progressive loss of renal function over a period of months or years and defined as an abnormally low glomerular filtration rate, which is usually determined indirectly by the creatinine level in blood serum.
§ Diabetes. Diabetes mellitus is a leading cause of chronic kidney failure in the United States. Chronic kidney failure is related to both type 1 and type 2 diabetes.
§ High blood pressure (hypertension). Untreated or inadequately treated high blood pressure is another common cause of chronic kidney failure in the United States. The added force of elevated blood pressure exerted on the glomeruli can cause damage and scarring. When this happens, the nephrons containing the damaged glomeruli eventually lose their ability to filter waste from your blood.
§ Obstructive nephropathy. This occurs when urine outflow is blocked over time by an enlarged prostate, kidney stones or tumors, or by vesicoureteral reflux, a condition that results from urine backing up into your kidneys from your bladder. The backflow pressure in your kidneys reduces their function.
§ Kidney diseases. These include clusters of cysts in the kidneys (polycystic kidney disease), kidney infection (pyelonephritis) and inflammation of the glomeruli (glomerulonephritis), a condition that causes your kidneys to leak protein into your urine and damages nephrons.
§ Kidney (renal) artery stenosis. This is a narrowing or blockage of the kidney artery before it enters your kidney. In older adults, blockages often result when fatty deposits accumulate under the lining of the artery walls (atherosclerosis). Kidney artery stenosis can also affect young women in the form of a condition known as fibromuscular dysplasia, which causes the walls of the arteries to become thicker. Both conditions are often associated with high blood pressure.
§ Toxins. Ongoing exposure to fuels and solvents, such as carbon tetrachloride, and lead — in lead-based paint, lead pipes, soldering materials, jewelry and even alcohol distilled in old car radiators — can lead to chronic kidney failure.

http://www.mayoclinic.com/health/kidney-failure/DS00682/DSECTION=1
http://en.wikipedia.org/wiki/Chronic_renal_failure

Complications, Management & Prognosis

End stage renal failure/ stage 5 kidney disease/ established renal failure

• When kidney function is so bad that pt is likely to die within weeks or months unless special treatment such as dialysis or transplantation is given

Complications:
Pericarditis, cardiac tamponade
Congestive heart failure
Hypertension
Platelet dysfunction
Gastrointestinal loss of blood; duodenal or peptic ulcers
Hemorrhage
Anemia
Hepatitis B, hepatitis C, liver failure
Decreased functioning of white blood cells and immune system
Infection
Peripheral neuropathy
Seizures
Encephalopathy, nervous system damage, dementia
Weakening of the bones, fractures, joint disorders
Permanent skin pigmentation changes
Skin dryness, itching/scratching with resultant skin infection
Changes in glucose metabolism
Changes in electrolyte levels
Decreased libido, impotence
Miscarriage, menstrual irregularities, infertility http://www.nlm.nih.gov/medlineplus/ency/article/000500.htm#Complications

Treatment:

• Your treatment before end stage
  Usually kidney failure develops slowly, and at first you may not have noticed anything. Gradually most people begin to feel tired, lose their appetite and may start to itch. Some get swollen ankles or develop high blood pressure. You may have to get up several times during the night to go to the toilet. Initially, you will be treated CONSERVATIVELY. The aim is to keep you feeling well, and to delay or even prevent the need for dialysis.
  This form of treatment uses drugs and diet. You may find that you are prescribed a number of different drugs particularly those which are aimed at controlling blood pressure like ACE inhibitors. Your diet plays a very important part in looking after your kidneys and helping you feel well. You will receive advice from a dietitian - this may involve reducing the amount of protein (small amounts of meat, fish, eggs, poultry, cheese and milk) and salt in your diet, and sometimes other advice too.

http://renux.dmed.ed.ac.uk/EdREN/EdRenINFObits/CRFLong.html#anchor31913728

http://renux.dmed.ed.ac.uk/EdREN/EdRenINFObits/Dialysis_ESRFLong.html

• End-stage treatment

1. Peritoneal dialysis (CAPD, APD)

Treatment that can usually be carried by you in your own home or at work.

a) CAPD - which stands for Continuous Ambulatory Peritoneal Dialysis - happens throughout the day, at home or at work, while the person goes about his or her daily life. Between 1.5 and 3 litres of fluid is run in four times a day, exchanging for the fluid from the previous exchange. This takes about 30-40 minutes.

b) APD - Automated Peritoneal Dialysis - in which the dialysate solution is changed by a machine, at night, while you are asleep. The machine will exchange 8-12 litres over 8-10 hours and then leave 1-2 litres to dwell during the day.

What is the Peritoneal Dialysis Fluid?

Peritoneal dialysis fluid is a sugar (glucose) solution containing other salts. Bags come in 3 strengths (1.36%, 2.27% and 3.86% or light, medium and heavy) - the "heavier" the bag (ie.3.86%), more water will be removed from the body.

If you have a lot of fluid in the body, you would use heavy bags to remove fluid. If you are dehydrated, you would use some light bags so that the dialysis does not remove fluid.

The sugar solution can be a problem for diabetic patients and changes in therapy may be needed. New solutions are being developed - Protein or starch.

How good is peritoneal dialysis?

Peritoneal dialysis can provide good, efficient dialysis but needs to be monitored carefully. It needs to be performed daily with breaks only because of unusual circumstances.

The nurses and doctors will measure how effectively the dialysis is being performed and change the volume and strength of the fluids.

If good dialysis cannot be achieved it is important to think about a change - from CAPD to APD or to haemodialysis.

What are the problems with peritoneal dialysis?

• There can be problems with fluid leaks in the groin or around the catheter when dialysis starts. These problems can be managed easily.
• Infections are the major risk - either in the exit site or most importantly in the tummy itself, peritonitis. This shows as tummy pain, a fever and a cloudy fluid bag. It is important to ring the kidney unit immediately if a cloudy bag develops. Peritonitis is treated with antibiotics added to the bags and may need admission to hospital for a few days. Rarely, the infection may be so bad that the catheter has to be removed.
• In the long term, there can be a thickening of the peritoneal membrane so that it does not work efficiently. The dialysis fluid may need to be changed or switched to haemodialysis.

http://www.kidneypatientguide.org.uk/site/pd.php

2. Haemodialysis = a form of dialysis in which the blood is cleaned outside the body by a machine which passes the blood across a filter.

• Usually at a dialysis centre.
• Home haemodialysis also available - need comprehensive training in order to become confident and self-reliant. Some alterations to your home’s plumbing and electricity supply may also be needed.

How does it work?

• This form of dialysis removes waste products from the blood by passing it out of the body, through a filtering system (dialyser) and returning it, cleaned, to the body.
• While in the filtering system, the blood flows through tubes made of a membrane that allows the waste products (which are much smaller than blood cells) to pass out through it.
• The waste products pass through the membrane into a dialysis solution (dialysate), then out of the machine. The "clean" blood is carried on through and returned safely to the body.
• This happens over and over again throughout the dialysis session. Each time the "clean" blood is returned to the body, it picks up more waste products from the cells it circulates through, and brings these newly-collected toxins back to the dialyser to be removed.
• Fresh dialysate is passed through continuously, to make the rate of the cleaning process as fast as possible.
• As well as cleaning the blood, the dialysis machine also removes excess water. This part of the process is called ultrafiltration which can be done separately without dialysis.
• It takes about 4 hours (perhaps more) to complete a good session of haemodialysis, which needs to be done 3 times a week.

http://www.kidneypatientguide.org.uk/site/HD.php

3. Kidney transplant

Kidney transplants have revolutionised life for many people with kidney failure. Dialysis only keeps you OK - a successful transplant restores your health. The best treatment by far if it is suitable for you.

Medical staff will discuss transplantation with you. For the majority of patients transplantation is the ultimate goal, but for some, particularly those with other medical conditions, long-term dialysis may be the best option.

If transplantation is an option for you, you will undergo a series of blood tests and X-rays. After this, you will be referred to a transplant surgeon for further assessment. At this stage you will be given more information about the actual procedure.

Most patients receive a kidney from someone who has died in hospital, usually on a life support machine. However the best transplants come from living people - who must be a close relative, or in certain cases, a partner or close friend. Live donor transplants can be carefully planned, instead of coming as a surprise at any time, and the kidney is proved in advance to be very healthy.

The transplanted kidney is placed in one or other groin beneath the skin and muscle. As with most operations, you may feel a bit groggy for a couple of days.

All being well, you will soon be up and about and home within a couple of weeks.

The number of kidneys required greatly exceeds the number available, and you may have to wait a long time (sometimes years) before a kidney suited to your blood group and tissue type is found. Some patients, however, are lucky and get a kidney transplant within a few months. The type or place of treatment is irrelevant - the time you wait depends entirely on availability and suitability of the organ available. It is not a queue - it is to some extent a matter of luck.

To prevent your body rejecting the new kidney, you will have to take some special immunosuppressive drugs for kidney diseases.These are tailored to each individual's requirements, but you will need to take at least one anti-rejection drug every day for as long as you have the transplant. Go to http://renux.dmed.ed.ac.uk/EdREN/EdRenINFObits/ISdrugs.html for more information on immunosuppressive drugs in renal disease.

There is no need for a special renal diet following a transplant. You will, however, be advised about a healthy diet containing not too much sugar or salt, plenty of fruit, vegetables and fibre, but with less fat, particularly animal fat. You will be encouraged to maintain a healthy weight for your height.

http://renux.dmed.ed.ac.uk/EdREN/EdRenINFObits/TransplantShort.html

4. No dialysis

The best option for some people may be not to have dialysis

- reasons will be discussed in presentation, or look up the link below:

http://renux.dmed.ed.ac.uk/EdREN/EdRenINFObits/NoRRTshort.html

by your keynote speaker:-p

Shantz

Anatomy and Physiology of the Kidneys and Nephron

Anatomy of the Kidneys:

- Lie against the posterior wall of the abdomen at level T12 to L3.
- Right kidney lower than left due to the liver.
- Convex lateral surface and concave medial surface with hilum, where it receives the renal nerves, blood vessels, lymphatic vessels and urter.
- Protected by 3 layers; from superficial to deep- the fibrous renal fascia, the adipose capsule and the renal capsule
- Renal parenchyma (glandular tissue that forms the urine) appears C-shaped in frontal section and encircles a medial space, the renal sinus (occupied by blood and lymphatic vessels, nerves and urine-collecting structures)
- Parenchyma divided into outer cortex and inner medulla.
- Extension of cortex into the medulla called renal columns; divides the medulla into renal pyramids
- Each pyramid conical with a broad base facing the cortex and the blunt tip, called the papilla facing the sinus
- Each papilla is nestled in a minor calyx, which drains the urine and 2-3 minor calices converge to form a major calyx.
- 2-3 major calices then converge to form the renal pelvis which continues inferiorly as the ureter.

Functions of the kidney

- Filter blood plasma, separate metabolic wastes from the useful chemicals and eliminate the waste while returning the rest to the bloodstream
- Regulate blood volume and pressure by eliminating or conserving water as necessary
- Regulate osmolarity of body fluids by controlling the relative amounts of water and solutes eliminated
- Secrete enzyme rennin, which activates the hormonal mechanisms that control blood pressure and electrolyte balance
- Secrete hormone erythropoietin, which controls the RBC count and oxygen carrying capacity of the blood
- Function with the lungs to regulate PCO2 and acid-base balance of the body fluids
- Contribute to calcium homeostasis through their role in synthesizing clacitriol (active form of Vitamin D)
- Detoxify free radicals and drugs with the use of peroxisomes
- Carry out gluconeogenesis in times of starvation by deaminating amino acids

Anatomy of the nephron

- Functional unit of the kidney
- Each kidney contains 1.2 million nephrons
- Each nephron consists of 2 principal parts: the renal corpuscle (where blood plasma is filtered) and the long renal tube (that processes the glomerular filtrate into urine).
- Renal corpuscle consists of the glomerulus (ball of capillaries) enclosed in a two-layered glomerular capsule or Bowman’s capsule
- Renal tubule consists of the Proximal Convoluted Tubule, the Nephron Loop or the Loop of Henle, the Distal Convoluted Tube


NB: blue box: reabsorption/ pink box: secretion

Basic Physiology of the Different parts of the Nephron

Renal corpuscle

Glomerular filtration occurs here. It is a process in which water and solutes in the blood plasma pass from the capillaries of the glomerulus into the capsular space of the nephron to form the glomerular filtrate

Proximal Convoluted Tubule (PCT)

The PCT reabsorbs about 65% of the glomerular fluid back into the peritubular capillaries, while it also removes some substances from the blood and secretes them into the tubule for disposal in the urine.

Nephron Loop

The primary function of the nephron loop is to generate a salinity gradient that enables the collecting duct to concentrate the urine and conserve water.

Distal Convoluted Tubule (DCT)

Fluid reabsorption that is subjected to hormonal control (particularly by aldosterone, Atrial Natriuretic Peptide, Antidiuretic Hormone and parathyroid hormone) takes place here.

NB - Some terms to take note of:
Glomerular filtrate: Fluid in the glomerular capsular space
Tubular fluid: Fluid from the PCT to the DCT; different from the Glomerular filtrate due to substances removed or added by the tubule cells
Urine: fluid will be called urine once it enters the collecting ducts


Source: Saladin, Anatomy & Physiology 3rd Ed, Chap23

Contributed by: John Lee