THESE SLIDES ARE RELATED TO ANATOMY AND PHYSIOLOGY,BSN GENERIC 1 ST YEAR 1ST SEMESTER

1. Anatomy And Physiology
Unit: II-Homeostasis & Adaptation
2/14/2024 1
Faculty ASAIN INSTITUTE of Nursing & HEALTH SCIECNES :
AFTAB JAN MENGAL
BS Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB SP(ICU) BSFB
from Lumhs jamshoro

2. Tips for being successful in
study
• Please Give a Chance of Rest To Your Mobile Phone During Lecture
• Do not whisper or talk during lecture is going in the class
• Do not ask any question during lecture it make distraction between
study and lecture if you have any question just note it down in your
note book after end of the lecture we will make question and
answering session
• And question should be related to lecture, do not ask question out of
lecture it make time wasting in class
2/14/2024
Faculty of ASAIN INSTITUTE of Nursing & HEALTH
SCIECES : AFTAB JAN MENGAL BS Post
RN,DOT,DGN,IPC,PHELOBOTMIST, PB SP(ICU) BSFB
from Lumhs jamshoro 2

3. OBJECTIVE
At the completion of this unit, learners will be able
to
1. Define the term homeostasis
2. Discuses the factors which affect homoeostasis
3. Define feedback mechanism and its
components
4. Discuss the role of feedback mechanisms in
2/14/2024 3
Faculty of AINHS: AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro

4. Homeostasis
Homeo > same : stasis = standing
Process of maintaining a controlled , stable internal
environment is called homeostasis
2/14/2024 4
Faculty of AINHS: AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro
Homeostasis must be maintained for normal body
functioning and to sustain life
Homeostasis imbalance ----- a disturbance resulting
in disease

5. Homeostasis
 literally means ‘’same state ‘’
Refers to the process of keeping the inter body environment in a steady state
when the external environment is changed
2/14/2024 5
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro
Ability of organism to maintain a relative stable internal environment involving
continuous monitoring and regulating multiple parameters and coordinating the
response to minimize the disturbance to organism
Changes can do occur but the magnitude of the changes must be small and
stay within narrow limits

6. Factors Affecting Homeostasis
 metabolic activities constantly taking place inside the body as a
result as a result unwanted chemicals are produce
2/14/2024 6
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro
 secondly the external environment or the conditions in which an organism lives
may vary greatly even over a brief period.
Temperature,
acidity,
salts,
water,
are some of the external factors to which an organism must adjust in order to
surviv

7. Two major systems involved
2/14/2024 7
Faculty of Asian institut of Nursing and halth scincs:
AFTAB JAN MENGAL BS Post
RN,DOT,DGN,IPC,PHELOBOTMIST, PB SP(ICU) BSFB
from Lumhs jamshoro

8. Discuss the role of feedback mechanisms in
maintaince of homeostasis Homeostasis with
examples
 A feedback mechanism is a physiological regulation system in a living
body that works to return the body to its normal internal state, or commonly
known as homeostasis. In nature, feedback mechanisms can be found in a
variety of environments and animal types. In a living system, the feedback
mechanism takes the shape of a loop, which aids in maintaining
homeostasis.
2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro
8

9. cont... feedback mechnism
 Feedback mechanism is a loop system in which the system responds to perturbation
either in the same direction (positive feedback) or in the opposite direction (negative
feedback). In a biological sense, a feedback mechanism involves a biological process,
a signal, or a mechanism that tends to initiate (or accelerate) or to inhibit (or slow
down) a process.
 An example: of a positive feedback loop is the onset of contractions in childbirth.
When a contraction begins, the hormone oxytocin is released into the body to stimulate
further contractions. As for the negative feedback loop, an example is the regulation of
blood glucose levels. If blood glucose levels continue to raise it may result in diabetes.
In fact, there are many biologic processes that use negative feedback to maintain
homeostasis or dynamic equilibrium
2/14/2024
Faculty of AINHS: AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 9

10. CONT...
 The feedback mechanism is triggered when the system undergoes a change
that causes an output. The biochemical control system in living beings is
made up of a variety of components,
 including chemicals, genes, and their regulatory connections.
 When the activation of one component leads to the activation of another, the
interaction between the components is said to be positive. If the activation of
one component results in the inactivation of another, it is labeled as negative.
 The term “feedback mechanism” was first used in cybernetics to characterize
a control system’s ability to change its output in response to an input.
 There are two types of feedback mechanisms; these are positive and
negative feedback mechanisms.
2/14/2024
Faculty Asian institute of nursing and health
sciences of Nursing : AFTAB JAN MENGAL
BS Post RN,DOT,DGN,IPC,PHELOBOTMIST,
PB SP(ICU) BSFB from Lumhs jamshoro 10

11. 2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 11

12. Homeostasis
•Stable operating conditions in the internal environment
•Three components interact
2/14/2024 12
Faculty of ainhs : AFTAB JAN MENGAL BS Post
RN,DOT,DGN,IPC,PHELOBOTMIST, PB SP(ICU) BSFB from Lumhs jamshoro
Structure (input into the
system
The response to the stimulus leads to changes the
is fed back to the receptor, in negative feedback the
response of the system cancels or counter act the
effect of the original stimulus
Response
System’s output

13.  The three common components of a
feedback loop are the
 1. Receptor (sensor),
 2. Control center (integrator or
comparator),
 3. Effectors. A sensor, or commonly
known as a receptor, detects and
transmits a physiological value to the
control center. The value is compared to
the typical range by the control center. If
the value deviates significantly from the
set point, the control system stimulates an
effector. A change is caused by an
effector, which causes the situation to be
reversed and the value to return to its
2/14/2024
Faculty of AINHS: AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 13

14. Cont…………..
1.Receptors
 Responds to changes in the environment (stimuli)
 Sends information to control center
2/14/2024 14
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro
2.Control center
Determines set point
Analyzes information
Determines appropriate response
3. Effector
Provides a means for response to the stimulus

15. 2/14/2024 15
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro

16. 2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 16

17. Role of Feedback mechanism and maintenance of
homeostasis with example
 Feedback mechanism is a loop system in which the system responds to
perturbation either in the same direction (positive feedback) or in the opposite
direction (negative feedback). In a biological sense, a feedback mechanism
involves a biological process, a signal, or a mechanism that tends to initiate
(or accelerate) or to inhibit (or slow down) a process. An example of a positive
feedback loop is the onset of contractions in childbirth. When a contraction
begins, the hormone oxytocin is released into the body to stimulate further
contractions. As for the negative feedback loop,
 Example is the regulation of blood glucose levels. If blood glucose levels
continue to rise it may result in diabetes. In fact, there are many biologic
2/14/2024 17

18. Feedback mechanism
Positive feedback
Increase the original stimulus to push the variable
farther
In the body only occurs in blood clotting and birth of a
baby
2/14/2024 18
Faculty of the Rising Star School of Nursing :
AFTAB JAN MENGAL BS Post
RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro

19. Feedback loops are commonly divided into two main types;
opened-loop mechanism and closed-loop mechanism.
 1. Positive feedback loops occur when a change in one direction is
followed by another change in the same direction. A sensor, or commonly
known as a receptor, detects and transmits a physiological value to the
control center. Positive feedback loop examples can result in uncontrolled
conditions since a change in an input generates reactions that cause
further modifications in the same manner. Even if the components of a loop
(receptor, control center, and effector)are not immediately recognizable, the
term “positive feedback” is widely accepted when a variable has the ability
to increase itself. Positive feedback is often damaging, however, there are
a few occasions where it can help people function normally when used in
moderation.
2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 19

20. 2/14/2024 20
Faculty of AINHS : AFTAB JAN MENGAL BS Post
RN,DOT,DGN,IPC,PHELOBOTMIST, PB SP(ICU) BSFB
from Lumhs jamshoro

21. Hire …wire Artist Model
Variable – position of body
Set point- directly over the wire
Sensor – nerve receptors
(eyes , inner ears, muscle stretch receptors etc
Integrator- brain
Effectors- skeletal muscles
High-wire artist use
Negative feedback to maintain constant
position on wire relatively
2/14/2024 21
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro

22.  Negative feedback loops occur when a change in one direction produces
a change in the other. For instance, a rise in a substance’s concentrations
produces feedback, which causes the substance’s content to reduce.
Negative feedback loops are mechanisms that seem to be naturally stable.
When combined with the many stimuli that can affect a variable, negative
feedback loops usually result in the value oscillating about the set point.
Negative feedback loop examples include Temperature and blood Glucose
level regulation
2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 22

23. Feedback
Mechanism
Negative feedback
 Includes most homeostatic control
mechanisms
Shuts off the original stimulus or
reduces its intensity
Works like a household thermostat
2/14/2024 23
Faculty AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro
Correcting
mechanism comes
into play
Correcting mechanism
comes into play
Correcting
mechanism comes
into play
Stress
Stress
Return to optimum
Return to optimum
------ Optimal environment …………………………………………..

24. Negative feedback in body temperature control:
(a) Events comparable to those shown in figure (a) occur in the regulation of body
temperature; a control center in the brain functions as a thermostat with a sat point
37’C, if body temperature climbs above 37’2-C heat loss is increased through
enhanced blood flow to the skin and increased sweating.
(b) The thermoregulatory centers keeps body temperature oscillating within an access
usually between 37’7-2’c
2/14/2024 24

25. Steps in a negative feedback
mechanism
The negative feedback system works in a similar way to the positive feedback loop in
that it is activated by stimuli and eventually leads to modifications that tend to cancel
out those impulses. The following is a summary of the overall procedure:
1. Stimulation. The development of stimuli as a result of physiological
parameter deviations from the normal value is the initial stage in the negative
feedback loop. Physiological parameters can deviate from the norm in either direction.
2. Reception. The control unit receives changes in physiological parameters
through a variety of receptors located throughout the body. Nerves and other thermo
receptors are examples of common receptors engaged in stimulus transmission.
2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 25

26. CONT...
 3. Processing. The brain serves as the loop’s control unit, determining
whether a change in a physiological parameter necessitates loop activation
or inhibition. The brain sends out signals to erase the alterations in different
ways depending on the direction of departure.
 4. Counteract on the stimulus. The control unit sends out signals at
the end of the loop to cancel out the impacts that cause changes in
physiological variables. Changes can take several forms and be directed at
different sections of the body.
2/14/2024
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 26

27. 2/14/2024
Faculty of the Rising Star School of Nursing :
AFTAB JAN MENGAL BS Post
RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro 27

28. 2/14/2024 28
Faculty of AINHS : AFTAB JAN MENGAL BS
Post RN,DOT,DGN,IPC,PHELOBOTMIST, PB
SP(ICU) BSFB from Lumhs jamshoro