Principles of Organisation

• Cells are the fundamental units of life, each designed to perform specialised functions through a process called DIFFERENTIATION.
• These specialised cells combine to form TISSUES, which then group to create ORGANS.
• Multiple organs work together to form ORGAN SYSTEMS within larger multicellular organisms.

Tissues:

• A TISSUE is a group of cells with similar structures and function that work together to carry out specific jobs. Examples in mammals include:
  • Muscular tissue: Responsible for movement by contracting and relaxing.
  • Glandular tissue: Produces and releases substances like enzymes and hormones.
  • Epithelial tissue: Covers the surfaces of the body, such as the inside of the gut.

 Organs:

• Organs are complex structures composed of different tissues, each contributing to the organ's overall function.
  • For instance, the HEART is an organ that contains muscular tissue for PUMPING BLOOD around the body

Organ Systems: The Teamwork of Organs

• An ORGAN SYSTEM is a group of ORGANS working together to perform complex functions for the organism's survival.
  • The CIRCULATORY SYSTEM is an example of an organ system