introduction to physiology n.
Skip this Video
Loading SlideShow in 5 Seconds..
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 32


  • Uploaded on

INTRODUCTION TO PHYSIOLOGY. LECTURE--------1 DR ZAHOOR ALI SHAIKH. What is Physiology ?. Physiology deals with functions of the body. Central aim is to keep the HOMEOSTASIS that is to keep the INTERNAL- ENVIORNMENT of the cell constant, so that cells can work.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'INTRODUCTION TO PHYSIOLOGY' - chenoa

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
introduction to physiology




what is physiology
What is Physiology ?
  • Physiology deals with functions of the body.
  • Central aim is to keep the HOMEOSTASIS that is to keep the INTERNAL- ENVIORNMENT of the cell constant, so that cells can work.
levels of organization in the body
Levels of organization in the Body
  • Cells are basic units of life.
  • Cell is the smallest unit which is capable of carrying out the processes associated with life.
basic cell function
Basic Cell Function
  • Obtaining food and O2from the surrounding.
  • Perform chemical reaction to use food and O2

Food + Oxygen = CO2+ H2O+Energy

  • Eliminate CO2 and other waste products.
  • Synthesize protein.
  • Exchange of material through cell membrane.
specialized function of cells
Specialized Function of cells
  • Digestive System - secrete digestive enzymes
  • Muscle Cells - Muscle contraction
  • Nerve Cell - send electrical impulses

Cells are organized in Tissues, Organs, Systems and finally Body.

  • Cells of similar structure and function are organized in Tissues .
types of tissue
  • There are FOUR types of Tissue

1- Muscle Tissue

2- Nervous Tissue

3- Epithelial Tissue

4- Connective Tissue

1 muscle tissue
1. Muscle Tissue
  • Muscle Tissue - for contraction
  • THREE types of Muscles :

1– Skeletal Muscle

2– Cardiac Muscle

3– Smooth Muscle

2 nervous tissue
  • Nervous Tissue – Specialized cells for initiation and transmission of Electrical impulses
  • Brain
  • Spinal cord
  • Nerves
3 epithelial tissue
3. Epithelial Tissue
  • Two types

1. Epithelial lining e.g. Skin, Digestive system

2. Secretary glands e.g. Salivary glands

glands two types
Glands – Two types
  • Exocrine - Having duct e.g. salivary gland
  • Endocrine - Ductless e.g. Thyroid gland
4 connective tissue
4. Connective Tissue
  • Connective tissue connects, supports the body
  • e.g. Tendon - attach skeletal muscle to bone

Elastin - helps in stretching and recoil of the lungs

  • Organs are composed of tissues (Two or more types ) to perform a particular function.
  • E.g. stomach has all four primary tissues i.e. Epithelial, Muscle, Nervous and connective tissue.
body systems
  • Organs make the body system.
  • Each system works to perform related functions and is essential for survival of body.
  • E.g. – Digestive system works for digestion and absorption.
total body
  • Composed of organ systems linked together structurally and functionally.
concept of homeostasis
  • Body cells work in INTERNAL ENVIRONMENT that surrounds the body.
  • What is Internal Environment ?
  • It is aqueous(watery) Extracellular Fluid (Interstitial fluid ) with which body cells are in direct contact it is outside the cell but not inside the cell.
extracellular fluid ecf
Extracellular Fluid (ECF)
  • What is Extracellular Fluid (ECF) ?
  • ECF consists of

-Plasma (fluid portion of blood) and Interstitial fluid

(which surrounds the cells)

  • Materials are exchanged between the plasma and interstitial fluid across the capillary membrane e.g. O2 and nutrition go from plasma to interstitial fluid than to cell
  • Same way waste products go from cell to Interstitial fluid to plasma.
homeostasis continued
HOMEOSTASIS (continued)
  • Homeo = Same
  • Stasis = Stay
  • Cells can only work when Internal environment (cell surrounding) physical and chemical state is within narrow physiological limits.
  • Homeostasis is essential for survival of each cell.
homeostasis continued1
HOMEOSTASIS (continued)
  • All body system work for Homeostasis so that body can function.
  • How body keeps Internal environment constant.
  • E.g.- If CO2 increases – it affects respiration(increased) to get rid of increased CO2

-when cold outside, our body temperature decreases than shivering occurs to increase the body temperature.

homeostasis continued2
HOMEOSTASIS (continued)
  • For Homeostasis, Following factors are to be maintained constant:

-supply of nutrient

-concentration of O2 and CO2

-waste product concentration

-pH as acidity affects enzyme activity

-concentration of water and electrolytes

- Temperature, narrow limit 35-38c

- plasma volume and Blood pressure

body systems1
Body Systems
  • ELEVEN Body Systems work for Homeostasis :

1. Circulatory system

2. Digestive system

3. Respiratory system

4. Urinary system

5. Skeletal system

6. Muscular system

body systems cont
Body Systems (CONT)

7. Integumentary system- skin, hair, nails, sweat glands, temperature regulation

8. Immune system

9. Nervous system

10. Endocrine system

11. Reproductive system

feedback mechanism
  • Feedback refers to responses made after a change has been detected [response has taken place].
  • There are two types of feedback mechanism:

1. Negative Feedback

2. Positive Feedback

negative feedback
  • In Negative Feedback, response occurs to restore to the normal (by moving the factors in the opposite direction of its initial change).
  • Example:

1. If CO2 increases in the body, there will be respiratory stimulation which will try to wash out CO2 and bring it back to the normal. It is Negative Feedback mechanism.

negative feedback1
  • Example ( cont )

2. If blood sugar decreases, body will try to increase blood sugar. It is Negative Feedback mechanism.

positive feedback
  • Positive Feedback mechanism amplifies (increases) the initial change, so that initial change is increased.
  • Example:

If temperature increases, Positive Feedback will increase it more.

  • In body Positive Feedback is not common, but Positive Feedback does occur in our body under certain circumstances.
positive feedback1
  • Positive Feedback birth of baby:

Here hormone Oxytocin causes powerful contraction of uterus. As contraction push the baby against cervix (exit of the uterus), the resultant stretching of the cervix sends message to brain(posterior pituitary) and causes release of more Oxytocin, which causes even stronger uterine contractions. Positive Feedback does not stop until baby is born.

what you should know from this lecture
What you should know from thisLecture
  • What is Physiology ?
  • What is Homeostasis?
  • What is Internal Environment of the cell?
  • What are the functions of cell?

- General

- Specialized

  • Organization of the body

Cell – Tissue – Organs – System – Body

  • Feedback Mechanism

- Negative and Positive