Structure of The Kidney. Objectives 1)Define the term excretion and explain the importance of...
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Structure of The Kidney. Objectives 1)Define the term excretion and explain the importance of removing waste material from the body 2)Describe the process
Objectives 1)Define the term excretion and explain the
importance of removing waste material from the body 2)Describe the
process which forms urea from amino acids 3)Describe the general
structure of the kidney, the nephron, and associated blood
vessels
Slide 3
Excretion What waste material do we produce? What waste
material do we produce? CO 2 released through lungs Feces released
through digestive tract Urine released through kidneys All are
poisonous materials (toxins) All are poisonous materials (toxins)
Where do they come from? Where do they come from? CO 2 cellular
respiration Feces material not absorbed by body Urine forms from
urea; produced by the liver from excess amino acids
Slide 4
It All Starts In The Liver After absorption, food molecules are
assimilated After absorption, food molecules are assimilated
Assimilation to become a useful part of a cell or organ
Assimilation to become a useful part of a cell or organ Roles of
the Liver Roles of the Liver 1)Glycogen is made from excess blood
glucose 2)Amino acids used to make proteins 3)Fatty acids/glycerols
are made into fat 4)Form cholesterol from fat 5)Excess amino acids
deaminated; forms urea
Slide 5
Deamination: Forming Urea What are our major sources of energy?
What are our major sources of energy? Carbohydrates, Fats, and
Proteins How are carbs and fats stored? Proteins? How are carbs and
fats stored? Proteins? Glycogen and fat (adipose tissue)
Deamination removal of for amino group from an amino acid to form a
keto acid and ammonia (NH 3 ) Deamination removal of for amino
group from an amino acid to form a keto acid and ammonia (NH 3 )
Keto acids can form glucose and fat Ammonia is toxic
Slide 6
Deamination: Forming Urea To prevent damage from ammonia build
up, ammonia instantly combines with CO 2 and produce urea and H 2 O
To prevent damage from ammonia build up, ammonia instantly combines
with CO 2 and produce urea and H 2 O Urea passes from the liver
into the blood plasma and then filtered out through the kidneys
Urea passes from the liver into the blood plasma and then filtered
out through the kidneys Uric Acid minor nitrogenous excretory
product made from the breakdown of DNA Uric Acid minor nitrogenous
excretory product made from the breakdown of DNA
Slide 7
Structure of the Urinary System Renal artery takes unfiltered
blood to kidneys Renal artery takes unfiltered blood to kidneys
Renal vein takes filtered blood from kidneys Renal vein takes
filtered blood from kidneys Kidney bean-shaped network of filtering
units called nephrons Kidney bean-shaped network of filtering units
called nephrons Ureter carries urine from kidneys to bladder Ureter
carries urine from kidneys to bladder Bladder elastic storage area
for urine Bladder elastic storage area for urine Urethra carries
urine from bladder to outside the body Urethra carries urine from
bladder to outside the body
Slide 8
Layers of a Kidney 2 main roles of kidneys: 2 main roles of
kidneys: 1)Removal of urea 2)Regulating water levels, ion levels,
and pH of blood (homeostasis) Capsule tough outer layer to protect
kidney from damage Capsule tough outer layer to protect kidney from
damage 3 main areas of a Kidney 3 main areas of a Kidney Cortex
contains all glomerulus, renal capsules, and area where
ultrafiltation occurs Cortex contains all glomerulus, renal
capsules, and area where ultrafiltation occurs 1)Medulla contains
kidney tubules and collecting ducts, and area where reabsorbtion
occurs 2)Pelvis where all collecting ducts meet to carry waste away
through ureters
Slide 9
K L M N O Glomeruli Cortex Collecting ducts Medulla Pelvis
Slide 10
Structure of a Nephron Nephron (kidney tubule) filtration unit
a kidney Nephron (kidney tubule) filtration unit a kidney Renal
(Bowmans) capsule cup-shaped site where arterial blood is filtered
Renal (Bowmans) capsule cup-shaped site where arterial blood is
filtered Blood comes in from arteriole Glomerulus splitting
capillaries in capsule to increase filtering rate Filtered blood
leaves through the arteriole
Slide 11
Ultrafiltration Renal capsule filters urea, H 2 O, and small
molecules from the blood Renal capsule filters urea, H 2 O, and
small molecules from the blood Reabsorption pulls important
molecules and H 2 O back into blood 3 layers of Filtration walls
inside renal capsule have small gaps; only small molecules get
through 3 layers of Filtration walls inside renal capsule have
small gaps; only small molecules get through Blood cells are too
big Blood pressure helps force waster material through filter and
out of the blood (125 ml/min) Blood pressure helps force waster
material through filter and out of the blood (125 ml/min)
Slide 12
Reabsorption What inside the filtrate? What inside the
filtrate? Urea Water Glucose Na + / Cl-; Ions What do we need back?
What do we need back? Glucose and Ions Capillaries wrapped about
nephrons reabsorb glucose and ions into the blood Capillaries
wrapped about nephrons reabsorb glucose and ions into the blood
Water is reabsorbed in the collecting ducts depending on your blood
water levels Water is reabsorbed in the collecting ducts depending
on your blood water levels Hydrated clear/light yellow Dehydrated
dark yellow
Slide 13
Kidney Failure What happens when the kidneys shut down? What
happens when the kidneys shut down? Urea builds up in body Toxic
levels effect organs; death What can cause kidneys to fail? What
can cause kidneys to fail? Physical damage Blood clots; blockage in
tubes Kidney Stones Toxins; Alcohol and Drugs Genetics; DNA Disease
How do we know kidneys are damaged? How do we know kidneys are
damaged? Blood in urine Large proteins in urine Pain and
illness
Slide 14
Living With One Kidney What does living with one kidney mean?
What does living with one kidney mean? More urea in blood Higher
blood pressure More stress on remaining kidney Toxins have longer
effects; alcohol and drugs Greater chance of losing other kidney
What options do you have if you lose both kidneys? What options do
you have if you lose both kidneys? 1)Dialysis 2)Kidney
Transplant
Slide 15
Kidney Dialysis Kidney dialysis machine filtering blood outside
the body Kidney dialysis machine filtering blood outside the body
1)Machine draws out blood from vein 2)Inside machine; blood passes
by several dialysis membranes; Urea drawn out of blood into
dialysis fluid (dialysate). How? Diffusion 3) Dialysis fluid is
contains salt and sugar. Why? No diffusion; glucose/salts stays in
blood 4) Filtered blood returns to body vein 3-4 hours; 2-3 times a
week 3-4 hours; 2-3 times a week What diet must you have? What diet
must you have? Low-Protein = Less Urea
Slide 16
Kidney Transplant Kidney Transplant surgically replacing the
damaged kidney with the healthy kidney of a donor Kidney Transplant
surgically replacing the damaged kidney with the healthy kidney of
a donor What are the major difficulties with transplants? What are
the major difficulties with transplants? 1)Donor match kidney must
be excepted by body (donor should be related to you or similar in
DNA) Drugs can lower white blood count to help kidney acceptance
Might get really sick 2)Dangerous surgeries always have a risk of
killing the patient 3)Expensive lots of money needed to get kidney
and pay the hospital; plus after hospital care