Animal Cells and Tissues PDF

WEEK 6: Animal Cells and Tissues September 2024 | Prepared by: Daniel Lance R. Nevado Organization of the Vertebrate Body The vertebrate body has four levels of organization: (1) cells, (2) tissues, (3) organs, and (4) organ systems. Tissues – an organized groups of cells that are sim...

WEEK 6: Animal Cells and Tissues September 2024 | Prepared by: Daniel Lance R. Nevado Organization of the Vertebrate Body The vertebrate body has four levels of organization: (1) cells, (2) tissues, (3) organs, and (4) organ systems. Tissues – an organized groups of cells that are similar in structure and function. Germ layers - the cells of the growing embryo differentiate into the three fundamental embryonic tissues. From the innermost to the outermost layers, these are the endoderm, mesoderm, and ectoderm. Organization of the Vertebrate Body In adult vertebrates, there are four principal kinds of tissues: (1) epithelial; (2) connective tissue, (3) muscle tissue, and (4) nerve tissue. Organs and Organ System provide specialized functions Organs are body structures composed of several different types of tissues that form a structural and functional unit. An organ system is a group of organs that cooperate to perform the major activities of the body. Epithelial Tissue An epithelial membrane, or Epithelium forms a barrier epithelium (plural, epithelia), covers Epithelial membranes thus provide a every surface of the vertebrate body. barrier that can impede the passage Epithelial membranes can come of some substances, while facilitating from any of the three germ layers. the passage of others. The epidermis, derived from The epithelial lining of the digestive ectoderm, constitutes the outer tract, in contrast, must allow portion of the skin. selective entry of the products of An epithelium derived from digestion, while providing a barrier endoderm lines the inner surface to toxic substances. of the digestive tract, The epithelium of the lungs must The inner surfaces of blood allow for the rapid diffusion of gases into and out of the blood. vessels derive from mesoderm. Epithelial Regeneration Structure of Epithelial Tissue Epithelium possesses remarkable Epithelial tissues attach to regenerative powers, constantly underlying connective tissues by a replacing its cells throughout the fibrous membrane. life of the animal. The secured side of the epithelium is This ability to regenerate is useful called the basal surface, and the in a surface tissue because it free side is the apical surface. constantly renews the surface and also allows quick replacement of the protective layer should damage or injury occur. Cell junction in Animal ❑Tight Junctions: seal between adjacent cells. Tight junctions between skin cells make us watertight by preventing leakage between cells in our sweat glands ❑Desmosomes (anchoring junction)- function like rivets, fastening cells together into strong sheets. Sites of strong cell adhesion. ❑Gap Junction: channels for communication between adjacent cells. EPITHELIUM TISSUE ❑It is the tissue that covers the internal and external surface throughout the body. ❑External - outer layer of skin ❑ Internal – lining of cavities such as the digestive tract, airways, and blood vessel etc., Epithelial types reflect their function Epithelial tissue are classified according ff. Number of cell layer: ▪ Simple epithelium- composed of single layer of cells ▪ Stratified epithelium- composed of multiple layer of cells Shape of cell ▪ Squamous- flat shape ▪ Cuboidal- cube-like (about as tall are they are wide) ▪ Columnar- Tube-like (taller than they are wide) Simple Squamous Epithelium SIMPLE SQUAMOUS EPITHELIAL TISSUE LOCATIONS| Simple squamous epithelial tissue a. Part of kidney Simple squamous epithelial tissue of lungs (alveoli) b. Outer layer of intestine c. Cornea (part of eye) Simple Cuboidal Epithelium SIMPLE CUBOIDAL EPITHELIUM Simple Columnar Epithelium Simple columnar epithelial tissue of intestine Simple columnar epithelial tissue of stomach Stratified Squamous Epithelium Stratified Cuboidal Epithelium Stratified Columnar Epithelium Pseudostratified Columnar Epithelium Transitional Epithelium Connective Tissue They have abundant extracellular Connective tissues derive from material because their cells are spaced widely apart. embryonic mesoderm and occur in many different forms. Two major class of connective Tissue: connective tissue proper, which further divides into loose ( fewer fibers, more ground substance) and dense connective tissues (more fiber, less ground substance) special connective tissues, which include cartilage, bone, and blood. Connective Tissue They have abundant extracellular Extracellular materials material because their cells are spaced ❑ Protein fibers widely apart. ❑ Collagen- (glue producing)-microscopic ropes that are flexible but resist to stretching ❑ Elastic fiber- it is like coiled metal bed spring, after being stretched they can recoil to their original shape ❑ Ground substance- shapeless background against which collagen fibers are embedded. Composed of proteoglycans ❑ Cells of connective tissue ❑ Fibroblast- cells that form fibers and ground substance (blast-produce, cyte-maintin, clast- breakdown ❑ Mast cell- non-motile cells that release chemical such as histamine ❑ Macrophages- large white blood cells (motile) that ingest foreign substance including microorganism ❑ Adipocytes- fat cells Function of Connective Tissue ❑ Enclosing and Separating tissue ❑ Storing compound ❑ Connective tissue separates ❑ Adipose fats stores high-energy muscles, arteries, veins, and molecules and bones store nerves from one another minerals (calcium and phosphate) ❑ Connecting tissue to one another ❑ Cushioning and insulating ❑ Tendons connects muscle and ❑ Adipose tissue protects the bones together, ligaments that tissue and provide insulating connect bone together layer beneath the skin. ❑ Supporting and moving parts of the body ❑ Skeletal system of the body provide a rigid support for body, semi cartilage (nose, ears and joints) Function of Connective Tissue ❑ Enclosing and Separating tissue ❑ Storing compound ❑ Connective tissue separates ❑ Adipose fats stores high-energy muscles, arteries, veins, and molecules and bones store nerves from one another minerals (calcium and phosphate) ❑ Connecting tissue to one another ❑ Cushioning and insulating ❑ Tendons connects muscle and ❑ Adipose tissue protects the bones together, ligaments that tissue and provide insulating connect bone together layer beneath the skin. ❑ Supporting and moving parts of the body ❑ Skeletal system of the body provide a rigid support for body, semi cartilage (nose, ears and joints) Loose and Dense Connective Tissue Loose and Dense Connective Tissue Ground Substance Loose Connective Tissue Loose Connective Tissue Loose Connective Tissue Dense Connective Tissue Special Connective Tissue: Cartilage Special Connective Tissue: Cartilage Special Connective Tissue: Bone  Special Connective Tissue: Blood Unique connective tissue because it matrix is liquid allowing the cell to move through the vessels. Muscle Tissue Vertebrates possess three kinds of muscle: smooth, skeletal, and cardiac Skeletal and cardiac muscles are also known as striated muscles because their cells appear to have transverse stripes when viewed in longitudinal section under the microscope. The contraction of each skeletal muscle is under voluntary control, whereas the contraction of cardiac and smooth muscles is generally involuntary. Muscle Tissue: Smooth Muscle Muscle Tissue: Skeletal Muscle Muscle Tissue: Cardiac Muscle Nerve Tissue axon – single extension of Cells include neurons and their cytoplasm that conducts impulses supporting cells, called neuroglia. away from the cell body. Neurons are specialized to produce and conduct electrochemical events, or impulses. Most neurons consist of three parts: a cell body, dendrites, and an axon. cell body (soma) – contains the nucleus. Dendrites – thin, highly branched extensions that receive incoming Two division stimulation and conduct electrical of Nervous impulses to the cell body. System Nervous Tissue: Sensory Neurons Nervous Tissue: Motor Neurons Nervous Tissue: Interneurons WEEK 6: Animal Cells and Tissues September 2024 | Prepared by: Daniel Lance R. Nevado