This document discusses the four main types of tissues found in animals: epithelial, connective, nerve, and muscle tissue. Epithelial tissue forms protective barriers and lines body cavities and organs. Muscle tissue consists of elongated muscle cells that contract and relax to enable movement through skeletal muscles, with some muscles being voluntary and others involuntary. Nervous tissue contains neurons that transmit electrical signals to coordinate bodily functions.

3. • Multicellular (large) organisms function more
efficiently if cells become specialized for
specific functions.
• There are four types of tissues found in
animals: epithelial, connective, nerve, and
muscle tissue.
• Sponges do not have tissues.

5. Epithelial Tissue
(Covering)
• Tightly-joined closely-packed cells
• One side of exposed to air or internal
fluid, other side attached to a basement
membrane
• Covers outside of the body and lines
internal organs and cavities
• Barrier against mechanical injury,
invasive microorganisms, and fluid loss
• Provides surface for absorption,
excretion and transport of molecules

9. • The muscular tissue are made of muscle cells and these cells
are elongated and large sized , so they are also called the
muscle fibres
• The movement of the body or limbs are brought about by
the contraction and relaxation of the contractile protein
present in the muscle cells.
• Most of the muscular tissue is attached to the bones and
hence are called the skeletal muscles
• The movement of the muscles can be controlled as well as
uncontrolled
• The type of muscles in which the movement is under our
control are called the voluntary muscles
• And the type of muscles where the movement cannot be
controlled are called the involuntary muscles

11. Nervous
tissue