Upload
hamid-naseem
View
2.664
Download
6
Embed Size (px)
DESCRIPTION
about functioning of kidney and dialysis methods
Citation preview
ARTIFICIAL KIDNEY
HAMID NASEEMMD SOHRAB ANSARI
Department of Electrical engineering
Outlines Introduction Function of the Kidney Working of Kidney Bowman’s Capsule Reabsorption by Kidney Dialysis Types of Dialysis How does dialysis work? References
Introduction
Human Possess Two Kidneys
Situated at the back of the abdominal cavity
Each kidney is connected to a tube called the ureter which empties into the urinary bladder
Each kidney is supply by a renal artery which supplies urea and oxygen
Each is also supply with a renal vein that leaves the kidney with the correct levels of urea, salts & water.
Function of the Kidney
Remove undesirable substances from the blood plasma:
• Toxins• Metabolism wastes• Excess of ingested water• Excess of mineral salts
Regulate the Acidity of blood
25% of the blood flows through the kidneys (1,2 l/min)
Terminology
Blood is filtered in the Nephrons
The cortex of kidney contains about 1million Nephrons
Nephron consists of Renal Corpuscle & Renal Tubule
The main filter of the Nephron is Glomerulus which is
located within the Bowman's Capsule
How Kidney Works
Supplied with blood from
Renal Artery
Inside it splits into many
fine Capillaries
Each capillary supplies
blood to hundreds of
thousands of tiny filtration
units called Nephrons
B
RENAL CORPUSCLE: SITE WHERE BLOOD IS FILTERED
B
1. Glomerulus brings a large surface area of blood capillaries in close contact with Bowman’s capsule
2. Liquid filtered from blood under pressure (filtration)
3. Glomerular filtrate produced containing:
- Water- Glucose- Salts- Urea
(Protein molecules and red bloodcells do not pass into tubule asthey are TOO BIG!!!!)
Blood travels through narrow capillary towards renal veinGlomerular
filtrate
Filtration
Blood from renal artery enters wide capillary
Bowman’s Capsule
Reabsorption by Kidney Once the main components of Glomerulur filtrate enter
the bloodstream, they are no longer in bloodstream
If nothing more happened in the Nephron then all the useful stuff would be lost in the urine!
Therefore, Glucose, Water and some Salts need to be reabsorbed!
Dialysis Process of removing waste products and excess fluid
from the body Also controls blood pressure and helps body to keep
proper balance of chemicals such as potassium, sodium, and chlorine.
There are two methods:
Hemodialysis (HD)
Peritoneal dialysis (PD).
How does dialysis work? It uses a membrane as a filter and a solution called
dialysate to regulate the balance of fluid, salts and minerals carried in the bloodstream.
The toxins pass from the blood through the membrane and into the dialysate to be taken away.
These toxins would normally be filtered by the
kidneys and taken away in urine.
Hemodialysis
The process takes place outside the body
A dialysis machine pumps small amounts of blood
out of the body and through a filter called an artificial
kidney or Dialyzer.
The Dialyzer filters extra fluid & wastes from blood.
The Blood is then pumped back into the body.
• Fig. Hemodialysis setup
Dialyzer
Dialyzer contd…
The dialyzer is a large container containing thousands
of small fibers through which blood is passed.
Fluid, called dialysate, is added to the Dialyzer to :
i. Help filter out extra fluid and wastes
ii. Add chemicals that your body uses
The Dialysate is pumped around the fibers. The fibers
allow wastes and extra fluids to pass from blood into the
solution, which carries them away.
Complications of Hemodialysis
Peritoneal Dialysis
The process takes place inside the body.
A tube (catheter) is inserted into the abdomen during
operation.
Special dialysis fluid is drained into the abdomen.
Excess waste and water pass from the blood into the fluid
and after a few hours the fluid is drained out.
PD as a Three-step process:
Types of Peritoneal Dialysis
1) Continuous Ambulatory Peritoneal Dialysis
Involves 3 main steps
FILL
A bag of solution called dialysate is put
into the abdomen through the catheter
The bag holds about 2 quarts of fluid
It takes about 10 to 20 minutes to fill
When the bag is empty, it can be clamped
off
DWELL
The solution stays in the abdomen 4 to 6 hours. While the solution is in the abdomen, extra fluid and wastes
move from the blood and into the solution.
DRAIN
Using gravity, the solution is then drained
out of the body into a drain bag. The drained fluid is much like urine and
will be clear yellow.
2) It takes about 10 to 20 minutes to drain.
2) Continuous Cycling Peritoneal Dialysis
Involves same fill, dwell and drain cycles.
But the dwell time is shorter and a machine does the
exchanges.
The dwell time is about 1½ hours.
The machine is set up and the person is connected to the
machine for 8 to 10 hours during the night.
Hemodialysis Peritoneal Dialysis
Slower
Requires less equipment
Causes fewer physiologic
adverse reactions
Requires professionals
Faster
Requires more equipment
More physiologic adverse
reactions
Can be performed by patient
itself
Hemodialysis v/s Peritoneal Dialysis
THANK YOU