Life processes and homeostatic mechanism

2. ADVANCED NURSING PRACTICE
SEMINAR
Submitted by :
Dimple Warrior
M.Sc. 1st Year

3. WHAT ARE LIFE PROCESSES?
The maintenance functions of living organisms must go on even
when they are not doing anything particular. Various functions
are happening inside our body and inside the body of all living
organisms . These functions are necessary to maintain the living
being. The maintenance job has to go on. The processes which
together perform this maintenance job are the life processes.

5. 1. NUTRITION
It is the process of getting energy from outside sources. Next
process of nutrition is to break down these sources to release
energy. Process of getting nutrition can vary from each
organism and is affected by the external environment.

6. BASED ON MODE OF NUTRITION , ORGANISMS
ARE CLASSIFIED AS FOLLOWS :-

7. AUTOTROPHS
• An autotroph or primary producer is an organism that produces complex
organic compounds (such as carbohydrates, fats, and proteins) using
carbon from simple substances such as carbon dioxide, generally using
energy from light (photosynthesis) or inorganic chemical reactions
(chemosynthesis).Autotrophs do not need a living source of carbon or
energy and are the producers in a food chain, such as plants on land or
algae in water.
• Some autotrophs, such as green plants and algae, are phototrophs,
meaning that they convert energy from sunlight into chemical energy in
the form of glucose. Others, including methanogens, are chemotrophs,
which use organic or inorganic chemical compounds as a source of
energy.

10. EXPERIMENT TO TEST PLANT LEAF FOR
STARCH

11. HETEROTROPHS
• The organisms that cannot produce their own food, instead take nutrition from other
sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs
are primary, secondary and tertiary consumers, but not producers. Living organisms that
are heterotrophic include all animals and fungi, some bacteria and many parasitic plants.

12. HUMAN DIGESTIVE SYSTEM
Functions :
1. Intake of food
2. Digestion of food
3. Assimilation of food
4. Expulsion of digested
waste products

13. 2. RESPIRATION
• A process in living organisms involving the production of energy, typically with the intake
of oxygen and the release of carbon dioxide from the oxidation of complex organic
substances.

15. 3. EXCRETION
• Excretion is a process by which metabolic waste is eliminated from an organism. In
vertebrates this is primarily carried out by the lungs, kidneys and skin.[1] This is in
contrast with secretion, where the substance may have specific tasks after leaving the
cell. Excretion is an essential process in all forms of life. For example, in mammals urine
is expelled through the urethra, which is part of the excretory system. In unicellular
organisms, waste products are discharged directly through the surface of the cell.
• During life activities such as cellular respiration, several chemical reactions take place in
the body. These are known as metabolism. These chemical reactions produce waste
products such as carbon dioxide, water, salts, urea and uric acid. Accumulation of these
wastes beyond a level inside the body is harmful to the body. The excretory organs
remove these wastes. This process of removal of metabolic waste from the body is
known as excretion.

18. 4. GROWTH AND REPAIR

19. CELLULAR DIVISION AND PROCESS

20. 5. REPRODUCTION

21. • Reproduction (or procreation or breeding) is the biological
process by which new individual organisms – "offspring" – are
produced from their "parents". Reproduction is a fundamental
feature of all known life; each individual organism exists as the
result of reproduction.
• Sexual reproduction has many drawbacks, since it requires far
more energy than asexual reproduction and diverts the
organisms from other pursuits, and there is some argument
about why so many species use it.

24. • Homeostasis is the physiological process by which the internal systems of the body (Eg.
Blood pressure, Body temperature, Acid base balance) are maintained at equilibrium
despite variations in the external conditions. Homeostasis refers to the maintenance of
the constant internal environment of the body.
• homeo = same; Stasis = standing.
• The word ‘homeostasis’ was introduced by Walter B Canon in 1930.
• Biologist Bernard enlightened the fact that multicellular organisms including man live in
a perfectly organized and controlled internal environment, which he called ‘milieu
interieur’.
• Internal environment in the body is ECF in which the cell live, it is the fluid outside the
cell and it constantly moves throughout the body.
• Human beings depends upon the constant maintenance of internal environment within
the physiological limits.

25. • The concept of homeostasis forms basis of physiology because it
explain why various physiological functions are able to maintained
by or within normal range and in case if any function deviates from
this range how it is brought back to normal.
• For the functioning of homeostatic mechanism, the body must
recognize the deviation of any physiological activity from the normal
limits.
• In the body sensors sense the deviation and alert the integrating
centre, this center sends the information to the concern effectors to
either accelerate or inhibit the activity so that the normalcy is
restored.

26. IMPORTANCE
• A stable internal environment allows on organism to be
independent of changes in the external environment.
• To maintain internal environment of organisms especially
higher vertebrates in a steady and balanced state.
• To establish optimum condition of organisms.

27. NEED
• Conditions outside our body are changing all the time, but condition
within our body must be kept constant. Eg. pH and body temperature.
WHY?
• Ensure that enzymes do not do not get inactivated or denatured since
enzymes only work within a certain temperature range.

28. COMPONENTS OF HOMEOSTATIC SYSTEM
• Homeostatic system in the body acts through self-regulating device,
which operate in a cyclic manner.
• This cycle includes four components.
• 1) Sensors or detectors , which recognize the deviation .
• 2) Transmission of this message to a control centre.
• 3) Transmission of information from the control centre to the effectors for
correcting the deviation.
• 4) Effectors , which correct the deviation.

30. MECHANISM OF ACTION OF HOMEOSTATIC
SYSTEM
1. Homeostasis is an important characteristic of living things.
2. Maintaining a stable internal environment which requires adjustments
as condition change inside and
3. outside the cell.
4. The maintenance of the system within a cell is called homeostatic
regulation.
5. The continuous adjustments are made to meet the set point.
6. Homeostasis is regulated by feedback mechanism.

31. FEEDBACK REGULATION
• Homeostatic mechanism in the body is responsible for maintaining the normalcy of various body
systems.
• Whenever there is any change in behavioural pattern of any system, the effectors bring back the
normalcy either by inhibiting and reversing the change depending upon requirement of the
situation, this is achieved by means of feedback signals.
• Feedback is a process in which some proportion of the output signal of a system is passed back
to the input
• This is done more often intentionally in order to control the behaviour pattern of the system,.
• Whenever any changes occurs, system receives and react to two types of feedback
1. Negative feedback
2. Positive feedback