lOMoAR cPSD| 12768992
REGULATION OF INTERNAL ENVIRONMENT
An organism is affected by changes in its internal environment that
is conditions within its own body. Every organism has self-regulatory
mechanisms which help to maintain its internal environment within the
ranges needed for normal metabolism. The maintenance of a fairly
constant state of the internal environment is known as homeostasis.
In animals, the kidney, liver, skin, brain and hormones
(substances secreted by endocrine glands) help in maintaining constant
internal environment while in plants auxins (e.g. gibberellins and
cytokinin) also help in maintaining constant internal environment.
NOTE: The structure of the kidney has been treated under the excretory
system of mammal.
Functions of the kidneys
The kidneys perform some functions like excretion,
osmoregulation acid-base balance of the body but the major functions
are excretion and osmo-regulation.
a) Excretion:- the kidneys are responsible in removing waste products from
the body to the environment.(see SS2 note on mechanism of excretion).
b) Osmoregulation:- this is a process by which an organism regulates the
balance of the ratio of water to salts in its body fluids. The kidneys
regulate the osmotic concentration of blood plasma and in doing so keep
the environmental conditions of each individual cell of the body fairly
constant. This is done in two ways:
i) When the osmotic concentration of the blood plasma is higher than that
of the cell contents i.e. when substances like sugar, mineral salts,
amino acids and other plasma solute are present in large amounts. The
kidneys reduce the concentration by extracting some of these substances
from the blood and excrete them.
ii) When the osmotic concentration of the blood plasma is lower than that
of the cell contents i.e. the plasma solutes are present in small
amount. The kidneys extract more water instead of the plasma solute
thereby increasing the osmotic concentration of the blood plasma.
c) Maintenance of acid-base balance: the acid-base balance in the body is
also maintained by the kidneys. When the body fluids become acidic,
more acid is excreted by the kidneys with the urine. The kidneys
prevent the excessive loss of bases at the same time. When the
concentration of a base becomes higher, more salts will be excreted
with the urine.
1
, lOMoAR cPSD| 12768992
Diseases of the kidneys, effects and remedy
Certains conditions that can affect the functioning of the
kidneys include diseases, drugs, changes in normal habit or physical
injury and temperature. Some of the diseases of the kidneys include
glomerular nephritis or bright’s disease, kidney stones or renal
calculi, diuresis and oedema or dropsy.
a) Glomerular nephritis (Bright’s disease) is a condition in which the
blood vessels (glomerulus) in Bowman’s capsule become inflamed and
porous. This inflammation makes the blood vessels not to carry out the
function of ultrafiltration completely. It can be caused by bacterial
infection.
Effects
1)inflammation of the kidneys
2)amino acids are present in urine
3)weakness of the body 4) fever and pains
Remedy
1) Use of dialysis
2) Kidney transplant
3) Use of antibiotics
b) Kidney stones (renal calculi): it is caused by some disease growths
within the tubules or by deposition of hard masses of calcium or
minerals. This may also occur when the intake of water is low, the salt
intake is high or the urine is abnormally acidic or alkaline. Kidney
stones are the narrowing of the kidney tubules by certain substances
that block the tubules.
Effects
1) Obstructs the passage of urine
2) Pain is experienced on passing out urine
3) Severe abdominal pain is experienced
4) It can cause high blood pressure, fever, chills and blood in urine.
Remedy
(1) Surgery called nephrectomy can be performed or microsurgery.
REGULATION OF INTERNAL ENVIRONMENT
An organism is affected by changes in its internal environment that
is conditions within its own body. Every organism has self-regulatory
mechanisms which help to maintain its internal environment within the
ranges needed for normal metabolism. The maintenance of a fairly
constant state of the internal environment is known as homeostasis.
In animals, the kidney, liver, skin, brain and hormones
(substances secreted by endocrine glands) help in maintaining constant
internal environment while in plants auxins (e.g. gibberellins and
cytokinin) also help in maintaining constant internal environment.
NOTE: The structure of the kidney has been treated under the excretory
system of mammal.
Functions of the kidneys
The kidneys perform some functions like excretion,
osmoregulation acid-base balance of the body but the major functions
are excretion and osmo-regulation.
a) Excretion:- the kidneys are responsible in removing waste products from
the body to the environment.(see SS2 note on mechanism of excretion).
b) Osmoregulation:- this is a process by which an organism regulates the
balance of the ratio of water to salts in its body fluids. The kidneys
regulate the osmotic concentration of blood plasma and in doing so keep
the environmental conditions of each individual cell of the body fairly
constant. This is done in two ways:
i) When the osmotic concentration of the blood plasma is higher than that
of the cell contents i.e. when substances like sugar, mineral salts,
amino acids and other plasma solute are present in large amounts. The
kidneys reduce the concentration by extracting some of these substances
from the blood and excrete them.
ii) When the osmotic concentration of the blood plasma is lower than that
of the cell contents i.e. the plasma solutes are present in small
amount. The kidneys extract more water instead of the plasma solute
thereby increasing the osmotic concentration of the blood plasma.
c) Maintenance of acid-base balance: the acid-base balance in the body is
also maintained by the kidneys. When the body fluids become acidic,
more acid is excreted by the kidneys with the urine. The kidneys
prevent the excessive loss of bases at the same time. When the
concentration of a base becomes higher, more salts will be excreted
with the urine.
1
, lOMoAR cPSD| 12768992
Diseases of the kidneys, effects and remedy
Certains conditions that can affect the functioning of the
kidneys include diseases, drugs, changes in normal habit or physical
injury and temperature. Some of the diseases of the kidneys include
glomerular nephritis or bright’s disease, kidney stones or renal
calculi, diuresis and oedema or dropsy.
a) Glomerular nephritis (Bright’s disease) is a condition in which the
blood vessels (glomerulus) in Bowman’s capsule become inflamed and
porous. This inflammation makes the blood vessels not to carry out the
function of ultrafiltration completely. It can be caused by bacterial
infection.
Effects
1)inflammation of the kidneys
2)amino acids are present in urine
3)weakness of the body 4) fever and pains
Remedy
1) Use of dialysis
2) Kidney transplant
3) Use of antibiotics
b) Kidney stones (renal calculi): it is caused by some disease growths
within the tubules or by deposition of hard masses of calcium or
minerals. This may also occur when the intake of water is low, the salt
intake is high or the urine is abnormally acidic or alkaline. Kidney
stones are the narrowing of the kidney tubules by certain substances
that block the tubules.
Effects
1) Obstructs the passage of urine
2) Pain is experienced on passing out urine
3) Severe abdominal pain is experienced
4) It can cause high blood pressure, fever, chills and blood in urine.
Remedy
(1) Surgery called nephrectomy can be performed or microsurgery.
