CHARACTERISTICS OF THE LIVING HUMAN ORGANISM

CHARACTERISTICS OF THE LIVING HUMAN ORGANISM



SIX MOST IMPORTANT LIFE PROCESSES OF HUMAN BODY

1. METABOLISM

2. RESPONSIVENESS

3. MOVEMENT

4. GROWTH

5. DIFFERENTIATION

6. REPRODUCTION


1. METABOLISM

Sum of all the chemical processes that occur in the body

The two  phases of metabolism are 

1. catabolism

2. anabolism

CATABOLISM

catabol= throwing down

- ism = a condition

                                                             the breakdown of complex chemical substances into simpler components

2. ANABOLISM

anabol= raising up

                                                          the building up of complex chemical substances from smaller, simpler components



EXAMPLE

             Digestive processes catabolize/ split proteins in food into amino acids

             These amino acids are used to anabolize/ build new proteins that make up body structures such as muscles and bones. 


2. RESPONSIVENESS

is the body's ability to detect and respond to changes.
  

a. Example for a change in internal environment

                          A decrease in body temperature represents a change in internal environment 
 

b. Example for a change in external environment

             turning head towards the sound of a squealing brakes


DIFFERENT CELLS IN THE BODY RESPOND TO ENVIRONMENTAL CHANGES IN DIFFERENT WAYS

EXAMPLE

a. NERVE CELLS

                                 - respond by  generating electric signals known as nerve impulses/ action potentials

b. MUSCLE CELLS

                                - Respond by contracting,
                                                               which generates force to move body parts. 


   
3. MOVEMENT

                                 includes motion of 

                                                      the whole body
                                                      individual organs
                                                      single cells
                                                      even tiny structures inside cells


4. GROWTH

                         Increase in body size that results from 

                                               an increase in the size of existing cells
                                               an increase in the number of cells
                                                 or BOTH

Also a tissue sometimes increase in size due to an increase in the amount of material between cells

EXAMPLE

In a growing bone, mineral deposits accumulate between bone cells, causing the bone to grow in length and width.


5.  DIFFERENTIATION 

                                    Development of a cell from an unspecialized to a specialized state.


STEM CELLS

                        Unspecialized precursor / ancestor cells, which can divide and give rise to cells that undergo differentiation are known as stem cells


THROUGH DIFFERENTIATION , A FERTILIZED EGG/ OVUM DEVELOPS INTO AN EMBRYO, THEN INTO A FETUS, AN INFANT, CHILD AND FINALLY AN ADULT.

  egg/ ovum  -  embryo -  fetus -  infant -  child -  adult.


6. REPRODUCTION

                  a. formation of new cells for 
                                                              tissue growth
                                                                 repair
                                                                    or
                                                              replacement

                  b. production of a new individual