This document provides an introduction to physiology by defining key terms and concepts. It can be summarized as follows: Physiology is defined as the study of the functional activities and mechanisms of biological bodies. The document distinguishes between teleological and mechanistic approaches to explaining physiological processes. It also discusses different levels of structural organization in the human body and describes the 11 major organ systems, including their definitions, functions, and key organs. Finally, it explains the concept of homeostasis - the body's ability to maintain stable internal conditions - and provides an example of homeostatic regulation in response to changes in external temperature.

1. TOPIC 1
INTRODUCTION TO
PHYSIOLOGY

2. LEARNING OUTCOME
At the end of this lecture, students should be able to:
• State the definition of physiology, teleological, mechanistic and homeostasis
• List different field of physiology
• Describe the level of human structural organization
• Explains different types of human body systems
• Explains the homeostasis regulation and it example.

3. WHAT IS PHYSIOLOGY?
• Physiology is the science of studying the functional
activities and its mechanisms in biological body.
• For example: why can heart automatically beat?
• Physiology derived from two Greek words:
• Physis= nature
• Logos= study

4. FUNCTION AND PROCESS: TELEOLOGICAL VS
MECHANISTIC APPROACH TO SCIENCE
Teleological: explains purpose of a physiological process
• What is purpose or function?
• Why does something exist?
• Why does it need to be done?
• Example: shivering elevates a low body temperature
Mechanistic: explain in terms of cause and effect of physiological process.
• What are processes involved?
• How does something work?
• Example: when body temperature drops below normal, a reflex pathways causes
involuntary oscillating skeletal muscle contractions which produce heat.

5. DISTINGUISH BETWEEN PROCESS & FUNCTION
PROCESS
•How do we breath?
•How does blood flow?
•How do RBCs transport O2?
FUNCTION
Why do we breath?
Why does blood flow?
Why do RBCs transport O2?

6. FIELD OF PHYSIOLOGY
VIRAL PHYSIOLOGY
BACTERIAL
PHYSIOLOGY
CELLULAR
PHYSIOLOGY

7. FIELD OF PHYSIOLOGY
PLANT PHYSIOLOGY
HUMAN
PHYSIOLOGY

8. HUMAN PHYSIOLOGY
• In human physiology, we attempt to
explain the specific characteristics
and mechanisms of human body
that make it a living being.

9. THE IMPORTANCE OF PHYSIOLOGY
• Understanding human body
• Diagnosis
• Understanding research and applications to practice

10. LEVELS OF STRUCTURAL ORGANIZATION

12. BODY SYSTEMS
• Groups of organs that perform
related functions and interact to
accomplish a common activity
essential for survival of the whole
body
• Do not act in isolation from one
another
• Human body has 11 systems.

13. CARDIOVASCULAR SYSTEM
DEFINITION
The heart and the vessels that carry blood or blood
constituent (lymph) through the body.
FUNCTIONS
i. Transport respiratory gases, nutrients, wastes,
and hormones
ii. Protect against disease and fluid loss
iii. Helps regulate body temperature and acid-base
balance
KEY ORGANS
Heart, blood vessels (arteries, veins, and capillaries),
and blood.

14. DIGESTIVE SYSTEM
DEFINITION
The body organs that render ingested foods
absorbable
FUNCTIONS
Mechanically and chemically breaks down foods
for cellular use and eliminates undigested
wastes.
KEY ORGANS
Mouth, teeth, tongue, oesophagus, stomach,
pancreas, liver, small intestine, large intestine
(colon), rectum, and anus.

15. ENDOCRINE SYSTEM
DEFINITION
The hormone-producing glands (hypothalamus,
pineal gland, pituitary gland, thyroid,
parathyroid, thymus, adrenal gland, pancreas,
ovaries, testes)
FUNCTIONS
Controls and integrates body functions via
hormones secreted into the bloodstream
KEY ORGANS
Pituitary gland, thyroid gland, adrenal glands,
and pancreas.

16. INTEGUMENTARY SYSTEM
DEFINITION
The integumentary (skin) and structured derived from
it (hair, nails and oil sweat glands)
FUNCTIONS
i. Protects the body
ii. Regulates body temperature
iii. Eliminates waste
iv. Receives certain stimuli (tactile, temperature and
pain)
KEY ORGANS
Skin, hair, and nails.

17. LYMPHATIC SYSTEM
DEFINITION
Consist of the lymphatic vessels, lymph nodes, and other
lymphatic organs
FUNCTIONS
i. Removes foreign substances from blood and lymph
ii. Combat disease
iii. Maintain tissue fluid balance
iv. Absorb dietary fats from the digestive tracts
KEY ORGANS
Spleen, thymus, tonsils, lymph nodes, and lymphatic
vessels.

18. MUSCULAR SYSTEM
DEFINITION
Skeletal muscle of the body and their tendinous
attachment
FUNCTIONS
i. Effects body movements
ii. Maintains postures
iii. Produces body heat
KEY ORGANS
Muscles and tendons.

19. NERVOUS SYSTEMS
DEFINITION
Brain, spinal cord, nerves, and sensory organs such as
the eye and the ear
FUNCTIONS
i. Detects and responds to changes internal and
external environments
ii. Enables reasonings and memory
iii. Regulates body activities
KEY ORGANS
Brain, spinal cord, ganglia, nerves, and sensory
organs.

20. REPRODUCTIVE SYSTEM
DEFINITION
The organs that produce, store, and transport
reproductive cells (gametes, or sperm and ova)
FUNCTIONS
Reproduce the organism, produce sex hormones
KEY ORGANS
Fallopian tubes, uterus, vagina, testes, ductus
(vas) deferens, urethra, penis, and prostate.

21. RESPIRATORY SYSTEM
DEFINITION
The body organs concerned with movement or
respiratory gases (O2 and CO2) to and from pulmonary
blood (the blood within lungs)
FUNCTIONS
i. supplies oxygen to the blood
ii. Eliminates carbon dioxide
iii. Helps to regulate acid-base balance
KEY ORGANS
Mouth, nose, nostrils, sinuses, pharynx, cilia, trachea,
larynx, diaphragm, lungs, bronchi, alveoli

22. SKELETAL SYSTEM
DEFINITION
Bones, cartilage and ligaments (which steady the
bones at the joints)
FUNCTIONS
i. Provide body support and protections
ii. Permit movement and leverage
iii. Produce blood cells (haematopoiesis)
iv. Store minerals
KEY ORGANS
Bones, joints, and ligaments.

23. URINARY SYSTEM
DEFINITION
The organs that operate to remove wastes from the
blood and to eliminate urine from the body
FUNCTIONS
i. Remove various wastes from the blood
ii. Regulates the chemical composition, volume and
electrolyte balance of the blood
iii. Helps maintain the acid-base balance of the
body
KEY ORGANS
Kidneys, ureters, bladder, and urethra.

24. ORGAN SYSTEMS
INTERRELATIONSHIP
• All cells depend on
organ systems to meet
their survival needs
• Organ systems work
cooperatively to
perform necessary life
functions

25. HOMEOSTASIS
• Homeostasis is a mechanism that
maintains a stable internal
environment despite the changes
present in the external environment.
• The body maintains homeostasis by
controlling a host of variables
ranging from body temperature,
blood pH, blood glucose levels to
fluid balance, sodium, potassium
and calcium ion concentrations.

26. HOMEOSTATIC REGULATION
• This process of adjustment (called homeostatic regulation)
involves:
1. Receptor: which receives information about change in the
environment
2. Control centre: which receives and processes information from the
receptor
3. Effector: which responds to signals from the control centre by either
opposing or enhancing the stimulus.

28. EXAMPLE OF HOMEOSTASIS IN ACTION
AN EXAMPLE OF HOMEOSTASIS IN ACTION
RECEPTOR Cutaneous receptor of the skin
CONTROL CENTRE Brain
EFFECTOR Blood vessels and sweat glands in the skin
The skin has receptors that detect changes in temperature. If the external temperature
rises or drops below the equilibrium, the control center sends signals to the blood
vessels and sweat glands in our skin to react accordingly. If the temperature is too hot,
the blood vessels dilate (vasodilation) and cause a drop in the body temperature.
Moreover, sweat glands produce sweat to accompany vasodilation. If the external
temperature is too cold, the blood vessels constrict (vasoconstriction) and enable the
body to retain heat.

29. HOMEOSTASIS BREAKDOWN
• The failure of homeostasis function in an internal environment will
result in illnesses or diseases.
• In severe cases, it can lead to death and disability.
• Factors can affect homeostasis:
i. Genetics
ii. Physical condition
iii. Diet and nutrition
iv. Venoms and toxins
v. Psychological health
vi. Side effects of medicines and medical procedure.

30. THANK YOU