Cell Physiology Basics Youtube Lecture Handout

Glide to success with Doorsteptutor material for UGC : Get detailed illustrated notes covering entire syllabus: point-by-point for high retention.

Download PDF of This Page (Size: 1.2M)

Get video tutorial on: https://www.youtube.com/c/Examrace


  1. Functional organization of cells.

  2. Milieu Interieur

  3. Cell Physiology.

  4. Transport through cell membrane.

  5. Membrane Potential

Image of Amazing But True For General Physiology

Image of Amazing but True for General Physiology

Levels of Organization Chart

Levels of Organization Chart

Milieu Interieur

  • Claude Bernard a French Physiologist coined the term Milieu interieur in 1949.

  • Milieu Interieur also called internal environment of body and is formed by extracellular fluid.

A Simple Cell

Image of Water And Nutrients For Simple Cell

Image of Water and Nutrients for Simple Cell

Cells are capable of living, growing, and performing their special functions so long as the constancy of internal environment is maintained

Image of Blood In Capillaries For Simple Cell

Image of Blood in Capillaries for Simple Cell

Important Factors to be Kept Constant

  • pH

  • Temperature

  • Nutrients, hormones, oxygen (supply)

  • Electrolytes

  • Water

  • Removal of metabolic waste products

Image of Important factors to be kept constant

Image of Important Factors to be Kept Constant


  • The term was introduced by W.B. Cannon an American scientist in 1932

  • Definition: is maintenance of chemical & physical conditions of internal environment (extracellular fluid) constant for optimal functions of the cells

Homeostatic Control Systems

  • It includes various mechanisms involving almost all systems of body.

  • The mode of operation of various systems is through 'feedback' mechanism.

Image of Homeostatic Control Systems

Image of Homeostatic Control Systems

Feedback Mechanisms

Feedback mechanisms include

  • Variable

  • Sensor

  • Integrator

  • Effector

Image of Feedback mechanisms

Image of Feedback Mechanisms

Feedback mechanisms operate by

  • Negative feedback

  • Positive feedback

Negative Feedback Mechanisms

Most of the control systems act by it

  • It maintains stability of various factors

  • If a factor changes, the control system tries to push the factor in opposite direction so as to bring it back to normal

  • Regulation of Bp., temp., etc.

Image of Negative feedback mechanisms

Image of Negative Feedback Mechanisms

Image of Thyroid Hormone Signaling Pathway (source)

Image of Thyroid Hormone Signaling Pathway (Source)

Positive Feedback Mechanisms

  • These mechanisms most of the time do not favour stability

  • The disturbance is increased further which can be fatal at times

  • Thus a vicious cycle sets

Image of Positive feedback mechanisms

Image of Positive Feedback Mechanisms

At times it is helpful also eg.

  • Generation of action potential

  • During child birth

  • Clot formation

Image of Generation of Action Potential

Image of Generation of Action Potential

Stretching of Cervix Release More Oxytocin

Image of Stretching of Cervix Release More Oxytocin

Two Big Systems Are Involved

  • Nervous system: via nerve impulses

  • Rapid but,

  • Short

  • Endocrinal: via production of hormones

  • Slow but,

  • Prolonged

Cell Physiology

  • Cell (L-store room) described by Robert Hooke

  • He had fabricated microscope in the middle of seventeenth century

  • He observed them in a piece of cork

  • Smallest structural and functional unit

Diameter is.

Developed by: