The Animal Tissues

Asst. Professor à MVPs Institute of Pharmaceutical Sciences,Nashik
18 Jan 2021

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The Animal Tissues

  1. The Tissue Prof. Amol B. Deore Department of Physiology MVPS Institute of Pharmaceutical Sciences, Nashik
  2. Tissue •A group of cells similar in form, structure and embryonic origin which coordinate to perform a specific function is called a simple tissue. •Various tissues combine together in an orderly manner to form large functional units called organs. •Number of organs work in coordination and give rise to organ-system.
  3. A tissue is a group of similar cells which are specialized for a particular function. The branch of science that deals with the microscopic study of tissues is called histology.
  4. •Epithelial tissue: (Covering tissues. These tissues are present for protection) •Connective tissue: (Supporting tissues. These tissues help in binding different body Structures) •Muscular tissue: (Contractile tissues. These tissues help in movements and locomotion) •Nervous tissue: Conducting tissues. These tissues help in conduction of nerve impulses.) The fundamental types of body tissues
  5. Epithelial tissue •General position: It covers the outer surface of all the organs of the body and also lines the cavities of all the hollow organs of the body. •Structure: Epithelium consists of closely packed cells arranged in continuous sheets, in either single or multiple layers.
  6. The attachment between the epithelium and the connective tissue is a thin layer called the basement membrane. Epithelial tissue can be named according to shape, arrangement, or function.
  7. Functions of epithelial tissue •Epithelial tissue functions in four ways: •It protects underlying tissues; it absorbs nutrients; it secretes hormones, mucus, and enzymes; and it excretes waste material like urea in sweat
  8. •Simple Epithelium •It consists of single layer of cells. •Stratified Epithelium •Stratified epithelium has two or more layers of cells. Because of this, it is more durable and can better protect underlying tissues. Classification of Epithelium
  9. Epithelial tissue is classified as follows • Simple epithelium • Simple squamous epithelium • Simple cuboidal epithelium • Simple columnar epithelium • Pseudostratified columnar epithelium • Stratified epithelium • Stratified squamous epithelium • Stratified cuboidal epithelium • Stratified columnar epithelium • Transitional epithelium
  10. SIMPLE EPITHELIUM •It consists of single layer of cells. It is further divided in four types as follows.
  11. Simple Squamous Epithelium •This tissue made up of a single layer of flat cells. The nucleus of each cell is oval and is located centrally. •Location: skin, the heart, blood vessels and lymphatic vessels, body cavities, and alveoli (air sacs) of lungs. Functions •They act as outer layer skin to protect the body against microbial attack. •Filtration of blood in the kidneys. •Diffusion of gases like oxygen and carbon dioxide in lungs. Basement membrane
  12. Simple Cuboidal Epithelium •This tissue made up of cube-shaped cells. •The nucleus are usually rounded and centrally located. •Location: the thyroid gland and kidneys tubules, retina, ovaries and secretary parts of certain glands. Functions •Absorption, secretion and protection.
  13. Simple Columnar Epithelium • The cells of simple columnar epithelium appear like columns, with oval nuclei near the base. • They found in the ducts, digestive tract (especially the intestinal and stomach lining), parts of the respiratory tract, reproductive system and glands. • Non-ciliated simple columnar epithelium • Ciliated simple columnar epithelium. Functions • Secretion of mucus as a lubricant for the linings of the digestive, respiratory, and reproductive tracts, and the urinary tract. • Cilia also help move oocytes expelled from the ovaries through the fallopian tubes into the uterus.
  14. Pseudostratified Columnar Epithelium • It is made up of several layers columnar epithelium but the nuclei are located at various depths. • Even though all the cells are attached to the basement membrane in a single layer, some cells do not extend to the superficial surface. Locations • The linings of throat, trachea, and bronchi of the lungs consist of mucous glands which secrete mucus which traps foreign particles and the cilia sweep away mucus for elimination from the body. Functions • Lubricant and provide protection
  15. STRATIFIED EPITHELIUM •Stratified epithelium has two or more layers of cells. •Because of this, it is more durable and can better protect underlying tissues.
  16. Stratified Squamous Epithelium •It is made up of several layers of polyhedral cells. •It is found in our mouth cavity, skin, esophagus and vagina Functions •Protection of skin from the harmful rays of the sun and certain chemicals. •Protection of underlying tissue from scratch as food moves through the tract.
  17. Stratified Cuboidal Epithelium •This is a fairly rare type of epithelium in which cells in the superficial layer are cuboidal. •It is found in sweat glands, salivary glands and mammary glands Functions •Secretion •Sweat glands excrete waste products such as urea. •Salivary gland secretes saliva •Mammary gland secretes milk
  18. Stratified columnar epithelium •Usually the basal layers consist of irregular shaped cells; only the superficial layer has cells are columnar in shape. •It is found in male urethra and ducts of certain glands Functions •Protection and secretion
  19. Stratified Transitional Epithelium •It is made up of several layers of closely packed, polyhedral, flexible, & easily stretched cells. •It is present only in the urinary system (the ureters, the urinary bladder, and the upper part of the urethra). Functions •Contraction and relaxation: it permits expansion of urinary bladder because of its elasticity. •It allows the urinary bladder to stretch to hold urine without rupturing.
  20. CONNECTIVE TISSUE •Most abundant and widely distributed tissues in the body. •Functions: •It binds together, supports, and strengthens other body tissues; •protects and insulates internal organs; serves as the major transport system within the body (blood).
  21. Connective tissue consists of ground substance and fibers; matrix with few cells. It is highly vascular tissue with nerve supply. Connective tissues are comprised of different cells like •fibroblast, •macrophages, •plasma cells, •mast cells, •adipocytes, and •white blood cells. Matrix contains collagen fibers, elastic fibers and reticular fibers.
  22. •Areolar Connective tissue •Adipose Tissue •Fibrous Connective tissue •Hyaline Cartilage •Fibrocartilage •Elastic Cartilage •Bone (Osseous) Tissue •Blood Classification of connective tissue
  23. Areolar Connective tissue •It contains several types of cells, including fibers (collagen, elastic, and reticular) and several kinds of cells (fibroblasts, plasma cells, macrophages, adipocytes, and mast cells) embedded in a semifluid matrix. •It is found in subcutaneous layer of the skin; and around blood vessels, nerves, and body organs. Functions •Supports both nerve cells and blood vessels. •It provides strength and elasticity. •Areolar tissue also (temporarily) stores glucose, salts, and water.
  24. Adipose Tissue •Adipose tissue contains adipocytes; with peripheral nucleus. •They are specialized for the storage of fats and triglycerides. Location •Adipose cells are found throughout the body: in the skin layer, around the kidneys, behind the eye socket, within padding around joints, and in the yellow bone marrow.
  25. Functions • Adipose tissue is a good insulator and can therefore reduce heat loss through the skin, act as an energy reserve. • It is a major energy reserve and generally supports and protects various organs. • This tissue stores fat. • It acts as protective material tissue, cushions, supports, and protect the body.
  26. Fibrous Connective tissue •It is made up of closely packed white collagen fibers. Collagen fibers arranged in bundles. •Fibrous tissue is flexible, but not elastic. This tissue forms ligaments (attach bone to bone) and tendons (attach skeletal muscle to bone). Functions •Ligaments are strong, flexible bands which hold bones firmly together at the joints. •Tendons are white, shiny bands attaching skeletal muscles to the bones.
  27. Hyaline Cartilage •It consists of a strong gel and chondrocytes. •Hyaline cartilage is found on the ends of long bone surfaces, ribs, larynx, trachea, bronchi and bronchial tubes. Functions •It provides movement of joints, flexibility and support. •The hyaline cartilage that attaches the upper seven pair of ribs to the sternum.
  28. Fibrocartilage •It consists of chondrocytes and bundles of collagen fibers within the matrix. •It is located within intervertebral discs and pubic symphysis between the pubic bones. Functions •It is a strong, flexible, supportive substance, found between bones and wherever great strength (and a degree of rigidity) is needed.
  29. Elastic Cartilage • In this tissue, chondrocytes are located in thread like network of elastic fibers within the matrix. • It is located inside the auditory ear tube, external ear, epiglottis, and larynx. Functions • Give support and maintains shape
  30. Bone (Osseous) Tissue •Bone tissue contains intercellular matrix which is calcified by the deposition of mineral salts (like calcium carbonate & Calcium phosphate). •Calcification of bone gives strength. The entire skeleton is composed of bone tissue. Functions •The skeleton of the body made up of bones which support and protect underlying soft tissue parts and organs. •It serves as attachments for skeletal muscles.
  31. Blood • Blood is a fluid connective tissue made up of blood cells and plasma. • Plasma consists of water with variety of dissolved substances like nutrients, wastes, enzymes, plasma proteins, hormones, respiratory gases, and ions. • The blood cells are three types: • Red blood cells, (Erythrocytes) • White blood cells (Leukocytes) & • Platelets (Thrombocytes)
  32. Functions • Erythrocytes transport oxygen and carbon dioxide. • Leukocytes promote phagocytosis of foreign microbes and involved in allergic reactions and immunity. • Thrombocytes are essential for the blood clotting.
  33. MUSCLE TISSUE •Muscle tissue consists of fibers to generate force of contraction. •As a result, muscular tissue produces body movements, maintains posture, and generates heat. •Based on location and certain structural and functional characteristics, muscle tissue is classified in to three types: •Smooth, Skeletal and Cardiac muscle.
  34. Smooth Muscle • Smooth muscle is non-striated because it does not contain striations (bands) of skeletal muscles. • Smooth muscle cells are single nucleated and spindle-shaped. • Its movement is involuntary. • It makes up the walls of the blood vessels, eye pupil, the stomach intestine, gallbladder, urinary bladder, and reproductive tract, airways of lungs, and lymphatic vessels. Functions • These provide for involuntary movement. • Examples include the movement of materials along the digestive tract, controlling the diameter of blood vessels and the pupil of the eyes.
  35. Cardiac Muscle •It is striated (having a cross-banding pattern), involuntary (not under conscious control) muscle. •It makes up the walls of the heart. •Cardiac muscle fibers are branched containing a single nucleus that is located centrally. •Cardiac muscle fibers are attached to each other by intercalated discs, which contain gap junctions and desmosomes. •Gap junctions provide a route for quick conduction of action potential of muscle throughout the heart.
  36. Functions •Cardiac muscle contraction pumps the blood though the heart into systemic circulation
  37. Skeletal Muscle •It is striated. The muscle fibers contain altering light and dark bands. The skeletal muscle is voluntary, because it is under conscious control. •Skeletal muscles are attached to the skeleton (bones, tendons and other muscles). Functions •These muscles are attached to the movable parts of the skeleton. •They are capable of rapid, powerful contractions which allow voluntary movement.
  38. NERVOUS TISSUE •The nervous system consists of only two principal types of cells: neurons and neuroglia. •Neurons (or nerve cells) are sensitive to various stimuli. •They convert stimuli into electrical signals called nerve impulses and conduct these impulses to other neurons, to muscle tissue, or to glands.
  39. Neuroglia cells are nerve cells that support and protect the neurons. Nerve cells (neurons) are the working units of the nervous system that generate and transmit nerve impulses.
  40. Neuron • Neurons consist of three elementary parts: a cell body, dendrites and axons. • The cell body contains the nucleus and other organelles. • Dendrites are highly branched and usually short cell extensions. They are the major input portion of a neuron. • The axon of a neuron is a single, thin, cylindrical process that may be very long. • It is the output portion of a neuron, conducting nerve impulses toward another neuron.
  41. Neuroglia •Neuroglia’s do not generate or conduct nerve impulses, these cells do have many significant supportive functions.
  42. Summary
  43. Thanking you