3. INTRODUCTION
Various functions are going inside our body and
inside the body of all living organisms which are
necessary to maintain the living being.
The maintenance functions of living organisms
must go on even when they are not doing
anything particular. The processes which
together perform this maintenance job are life
processes.
4. CONTD….
It is generally regarded that there are seven signs of life
that all living things (organisms) have in common (from
bacteria to plants to animals).
They are:
Nutrition/feeding
Growth
Movement
Respiration/breathing
Reproduction
Sensitivity
Excretion
6. INTRODUCTION
Nutrition is the process of getting energy from
outside sources.
The process of nutrition is to break down these
sources to release energy.
The process of getting nutrition can vary from
organism to organism and is affected by the
external environment.
7. CLASSIFICATION
On the basis of mode of getting food, organisms can
be classified as follows:
Autotrophs
Heterotrophs
8. AUTOTROPHS
They make their own food.
All green plants are autotrophs. For example,
green leaves contain a pigment called
“chlorophyll”, which makes them green.
The process of food preparation in plants is
called Photosynthesis that involves making of
glucose with the help of carbon dioxide and
water in the presence of sunlight.
6CO2 + 6 H2O --------C6H12O6 + 6O2
9. HETEROTROPHS
Those organisms which are
dependent on other organisms
for their food are called heterotrophs.
For example, some animal, like humans
have complex digestive system to break
the food into basic constituents to make
them fit for oxidation.
10. CONTD…
Human digestive system includes:
Intake of food
Digestion of food
Assimilation of food, and
Expulsion of waste products.
12. INTRODUCTION
All living things grow, even when they are
mature. Immature organisms grow new cells to
enable them to grow to their mature size. This is
achieved through cell division.
When new cells form, the nucleus makes a copy
of itself and then divides to form two new cells
and this type of cell division is known as
mitosis.
13. CONTD…
Cellular healing: the reparative process begins
at approximately with same time as the injury
and is interwoven with inflammation.
Healing proceeds after the inflammatory debris
has been removed.
Healing may occur by regeneration in which the
gradual repair of the defect occurs by
proliferation of cells of the same type as those
destroyed or by replacement.
15. INTRODUCTION
All living things move to some extent and this is
perhaps most obvious with animals.
Plants, however, do move as well, for instance,
when buds open. Many plants also follow the
path of the Sun through the sky during the day.
Movement is important for gathering nutrition
and to evade predators.
16. CONTD…
Movement can also be internal, such as the
movement of the heart muscles or the
muscles that push food through the
digestive system. The energy for much of
this movement comes from respiration.
18. INTRODUCTION
Respiration is a means of releasing
energy from food.
Respiration occurs in the mitochondria.
Aerobic respiration requires oxygen and is the
reason why humans and other animal breathe.
The food normally used is the sugar, glucose.
19. CONTD…
Aerobic respiration can be summarized with a
chemical equation:
glucose + oxygen------ carbon dioxide + water [+ energy]
C6H12O6 + 6 O2 ---------6CO2+ 6 H2O [+ energy]
The energy released is used for a variety of
chemical and other processes, including
digestion and movement.
20. CONTD...
Organisms can also respire anaerobically
(without oxygen). This releases less energy than
aerobic respiration and so organisms that can do
both will tend to respire aerobically as much as
possible.
Humans can respire both aerobically and
anaerobically.
When we exercise, the oxygen supply can be
insufficient to supply our energy needs through
aerobic respiration alone. Hence we start to
respire anaerobically as well.
21. CONTD...
A number of organisms only respire
anaerobically, such as yeast. It is this process
that we exploit in bread-making and brewing.
In the strictest sense this is really only limited to
animals with lungs. The lungs are the organs that
some animals possess (mammals, birds, reptiles
and adult amphibians) to extract oxygen from
the air and to release carbon dioxide into the air.
Other organisms exchange oxygen for carbon
dioxide in other ways (for instance, the gills of
fish).
23. INTRODUCTION
It is the biological process by which new
“offspring” individual organisms are produced
from their “parents”. Reproduction is a
fundamental features of all known life; each
individual organism exists as the result of
reproduction.
24. METHODS OF REPRODUCTION
The known methods of reproduction are
broadly grouped into two main types.
Sexual reproduction
Asexual reproduction
26. ASEXUAL REPRODUCTION
An individual can reproduce without
the involvement of another individual of that
species. The division of a bacterial cell into two
daughter cells is an example of asexual
reproduction.
Asexual reproduction, is not, however, limited to
single-celled organisms. Most plants have the
ability to reproduce asexually.
28. INTRODUCTION
Sensitivity is an important function of organisms
that helps them to survive in their environment.
Plants are sensitive to gravity, hence their roots
grow downwards and they can obtain water.
They are also sensitive to light, which is why
their leaves point towards the light. In these
cases gravity and light are stimuli.
29. CONTD…
The five human senses that we all come to
learn have helped to ensure our survival
over thousands of generations:
sight
hearing
smell
taste
touch/feeling
31. INTRODUCTION
Excretion is simply the removal of waste. All
organisms produce waste substances that they
need to get rid of. The build up of such waste
can be hazardous to the cell.
Examples of this include:
the removal of carbon dioxide made by
respiration. Carbon dioxide is weakly acidic and
if it were allowed to build up, the resulting
increase in acidity would affect the chemistry of
the cell and the structure of proteins within it.
33. INTRODUCTION
Homeostasis is derived from the latin word “homeo”
means constant and “stasis” means “stable”.
The human body manages a multitude of highly complex
interactions to maintain balance or return systems to
functioning within a normal range. These interactions
within the body facilitate compensatory changes
supportive of physical and psychological functioning.
This process is essential to the survival of the person and
to our species.
An inability to maintain homeostasis may lead to death
or a disease, and this condition is known as homeostatic
imbalance.
34. DEFINITION
Homeostatic mechanism can be defined as “the
property of a system, either open or closed, that
regulates its internal environment and ends to
maintain a stable, constant condition. Multiple
dynamic equilibrium adjustment and regulation
mechanisms make homeostasis possible.”
( Claude Bernad and Walter Cannon)
35. HOW HOMEOSTASIS ACHIEVED
To maintain cells, tissues and entire organisms within
their biological tolerance limits, various mechanism have
evolved.
These may be:
Structural: the animal or plant has particular physical
features which help its survival in an otherwise hostile
environment.
Functional: the metabolism of the animal or plant is able
to adjust to changes in conditions as they are detected.
Behavioural: the actions and interactions of the
individual, either alone or with others, help it to survive
in its particular environment.
36. CONTROL MECHANISM
All homeostatic control mechanisms have at
least three interdependent components for the
variable being regulated:
The receptor,
Control centre, and
An effector
37. CONTD…
When the receptor senses a stimulus
Sends information to control centre
Control centre determines an appropriate response to the
stimulus
Control centre then send signals to effectors that receives signal
from the control centre
After receiving signal, a change occurs to correct the deviation
by enhancing it with positive feedback or depressing it with
negative feedback.
38. THIS IS MRS NERG
Can you
remember
what each of
the letters in
her name
stand for ?
39. BIBLIOGRAPHY
Khan S. Yaseen & Basheer P. Shabeer
“comprehensive textbook of Advanced Nursing
Practices” published by EMMESS publications,
page no. – 189 to 193
Gulani k.k.” community health
nursing”published by Kumar publications.
Park K. “ preventive & social medicine”
published by Bhanot publications.
www.wikipedia.com
