Transcript water & waste - St Aidans High School

WATER & WASTE
WATER is crucial to our survival.
Whilst we can go a month without
food, we can only survive a few days
without water.
Our body contains a lot of water – if you took all the
water out of our bodies (the liquid used in blood etc
and the fluid inside cells) it would probably amount to
around 90%
of our weight!
Gaining Water
Our bodies gain water in three
different ways.
1. Water from Drinking
2. Water from Food
3. Water from Cell Respiration

food + oxygen  carbon dioxide + water
Losing Water

1.
2.
3.
4.
Our bodies lose water in four
different ways.
Water in Sweating
Water in Breathing
Water in Urine
Water in Faeces
Water Balance
 Most mammals are not designed to
store water, and so they need to have
a constant supply.
 Therefore the water we gain each
day must equal the water we lose.
Total Water Gain = Total Water Loss
Water and Waste -The Kidney
Structure and Function of Kidney
Structure
Kidneys
Function
Control water balance and filter
the blood
Renal Artery
Carries blood towards the
kidneys
Renal Vein
Carries blood away from the
kidneys
Ureter
Carries urine from the kidney to
the bladder
Bladder
Temporary store of urine
Function of the Kidneys

The Kidneys have two main
functions, which are:
1. Maintaining a water balance.
2. Getting rid of poisonous waste
substances from within the body
(Urea).
Urea
 The poisonous waste Urea is made in our
_________.
liver
 It is made when excess _______
amino _______
acids
are broken down.
 The urea is then transported by the blood
removed
to the kidneys were it is __________.
Function of the Kidneys

The Kidneys carry out its two functions
through two processes, which are:
1.
Filtration
2. Reabsorption

These processes take place in millions of
nephrons
tiny filtering units called __________.
Nephron
From renal
artery
Glomerulus
Bowman’s capsule
Glucose
•_______
Water
•_______
Salt
•_______
urea
•_______
all filtered
out
Collecting
duct
glucose
_________
reabsorbed
Blood Capillary
Water
__________
And ______
salt
reabsorbed
Final urine =
Urea
__________
Some salt
__________
Some water
__________
to renal
vein
To the URETER
Nephron
 The Glucose, Water, Salt and Urea which
are filtered out of the Glomerulus into the
Bowmans Capsule are referred to as the
G___________
F____________.
lomerular
iltrate
 The final Urine is then transported to the
B____________
via the U_________.
ladder
reter
Water Regulation - ADH
 ADH - Anti-Diuretic Hormone
 It is produced by the P_________
ituitary gland in
the brain.
 ADH controls the volume of water
reabsorbed into the blood.
Level ADH
Volume of Water
Volume of Urine
Reabsorbed into Blood
Produced
High
High
Low
Low
Low
High
Water Regulation - ADH
 When the body is dehydrated, for example
in hot climates, during vigorous exercise, or
by the consumption of salty foods then the
blood will have a low water concentration.
 The pituitary gland in the brain will
produce a _____
high level of ADH, which
causes a ______
large volume of water to be
reabsorbed to rehydrate the body.
small volume of urine
 Therefore only a ______
is produced.
Water Regulation - ADH
 However, if the body is overly hydrated
for example through drinking large volumes
of liquid then the blood will have a high
water concentration.
 The pituitary
________ gland in the brain will
produce a ______
level of ADH.
low
 This results in a lower
_____ level of water to
be reabsorbed and so a ______
large volume of
urine is produced.
Kidney Failure & Treatment

If both kidneys stop working due to
either disease or damage this is known as
idney
ailure
T_____
F_________.
otal K_________
There are two ways of treating kidney
failure, which are:
1. D_________
on a kidney machine.
ialysis
2. A kidney T____________.
ransplant

Kidney Failure & Treatment
 List some of the benefits of Dialysis and
Kidney Transplants.
 List some of the limitations of Dialysis and
Kidney Transplants.
Benefits
Limitations
Transplant Patient can live a
normal life
Not dependant on a
machine
Patient can eat and
drink normally
Tissue rejection may
cause new kidney to
fail.
Patient on special
drugs for life.
Drugs may make
patients weak.
Not enough kidneys
available
Kidney
Machine
 Restricted diet
 Patient must always
be near machine
 Machines break
down.
 No drugs
 Availability of
machines only limited
by money
Saves lives
How Dialysis Works
•The blood is bathed in a rinsing fluid which is carefully
designed to have the same concentration of useful
substances as the blood
•Therefore only waste materials will diffuse out of the
blood.
Urea