column and within the walls of the bronchial tubes. Specialised Connective Tissues are classified as cartilage, bones and blood. The intercellular material of cartilage is solid and pliable and resists compression. Cells of this tissue (chondrocytes) are enclosed in small cavities within the matrix secreted by them (Figure .
). Most of the cartilages in vertebrate embryos are replaced by bones in adults. Cartilage is present in the tip of nose, outer ear joints, ear pinna, between adjacent bones of the vertebral column, limbs and hands in adults. Bones have a hard and non-pliable ground substance rich in calcium salts and collagen fibres which gives strength to the bones.
It is the main tissue that provides structural frame to the body. Bones support and protect softer tissues and organs. The bone cells (osteocytes) are present in the spaces called lacunae . Limb bones, such as the long bones of the legs, serve weight- bearing functions.
They also interact with skeletal muscles attached to them to bring about movements. The bone marrow in some bones is the site of production of blood cells. Blood is the fluid connective tissue containing plasma, red blood cells (RBC), white blood cells (WBC) and platelets. It functions as the transport medium for the cardiovascular system, carrying nutrients, wastes, respiratory gases throughout the body.
You will learn more about blood in Chapter . Figure . Specialized Connective Tissues &ROODJHQILEHUV &DUWLODJHFHOO &KRQGURF\WH &DUWLODJH %RQH &RPSDFWERQHWLVVXH %RQHFHOO 2VWHRF\WH %ORRG %& :%& 3ODWHOHWV %ORRG %& :%& 3ODWHOHWV You are looking at a slide of a tissue through the compound microscope and you see striped branching cells that connect with one another. What type of muscle are you viewing?
XI Std Biology-Zoology Chapter- (Figure . ). Cell junctions hold them together and they are bundled together in a connective tissue sheath. The walls of internal organs such as the blood vessels, stomach and intestine contain this type of muscle tissue.
Smooth muscles are ‘involuntary’ as their functions cannot be directly controlled. Unlike the smooth muscles, skeletal muscles can be controlled by merely thinking. Cardiac Muscle