Dr. ANAND SRINIVASAN

 Student at the end of the class should be able to :  Identify different types of epithelia types and list examples.  Identify different types of cartilage and list examples.  Identify the microanatomtical aspects of bone and correlate with clinical conditions.

 Tissues :  Consists of large number of cells  Classified based on size, shape and functions  Epithelial tissue  Connective tissue  Muscle tissue  Nervous tissue

 Group of tissue that covers the body and lining cavities, hollow organs and tubes.  Functions  Protection  Secretion  Absorption  Cells lie on basement membrane  Less matrix (intercellular substance)

 Simple : single layer of cells  Simple squamous  Simple cuboidal  Simple columnar  Pseudostratified ciliated columnar  Stratified : several layers of cells  Stratified squamous keratinized epithelium  Stratified squamous non keratinized epithelium  Transitional epithelium

 Single layer of flattened cells  E.g. lining epithelium of heart, blood vessels, alveoli of lungs.

 Cube shaped cells lying on a basement membrane  E.g. Proximal convoluted tubule of nephron, Thyroid follicle

 Single layer of cells, rectangular in shape, on a basement membrane  E.g. lining epithelium of Stomach, Intestines

 Single layer of cells on basement membrane but has its cell nuclei similar to stratified epithelium  E.g. Trachea

 Composed of number of layers of cells  Superficial layer are squamous  2 types  KERATINIZED ▪ Superficial layer consists of dead epithelial cells that contain a protein ‘KERATIN’ ▪ Found on dry areas ▪ E.g. Skin  NON KERATINIZED ▪ Superficial layer does not contain keratin ▪ Found on wet areas ▪ E.g. Oesophagus, Cornea

 Several layers of pear shaped cells  E.g. Urinary bladder, ureter, urethra

 Specialised dense connective tissue  Cartilage cells are called “Chondrocytes” Cartilage HyalineElasticFibro

 Chondrocytes  Small groups  Within cell nests  Solid & smooth matrix  E.g.  Costal cartilage  Larynx, trachea and bronchi

 Yellow elastic fibers  More flexible  E.g.  Pinna or ear lobe  Epiglottis

 Dense white collagen fibers  Less flexible  E.g.  Intervertebral disc  Ligaments

Dr. ANAND SRINIVASAN

 Bone is a connective tissue  Rigid because the matrix is infiltered with inorganic salts mainly calcium.  Is covered by thin vascular layer - PERIOSTEUM - involved in bone growth & repair – preserved during surgery.

 Formation of new bone  Found on the bone surface

 Present in bones  Embedded in bony matrix surrounded by lacuna & canaliculi  Derived from osteoblasts

 Resorption of bone

 Consists of cells called “Osteocytes”  Each bone made of units called “Osteons / Haversian system”  Central canal through which blood vessels pass “Haversian canal”  Series of cylindrical plates of bone “Lamellae”  Between adjacent lamellae there are “Lacunae”  Lacunae are connected to each other by “Canaliculi”

 Vitamin D  Absorption of Calcium from intestine  Rickets

 Human Anatomy and Physiology – Ross and Wilson