Histology and Physiology PDF

HumanChapter Anatomy4:&Histology Physiology Second Edition Chapter 04 Histology PowerPoint® Lectures created by Suzanne Pundt, University...

HumanChapter Anatomy4:&Histology Physiology Second Edition Chapter 04 Histology PowerPoint® Lectures created by Suzanne Pundt, University of Texas at Tyler Copyright © 2019, 2016 Pearson Education, Inc. All Rights Reserved  What is Histology Histology – study of normal structures of tissues (group of structurally and functionally related cells and their external environment; together perform common functions) All tissues share two basic components: 1. Discrete population of cells; related in structure and function 2. Extracellular matrix (ECM) – surrounding material  Background on tissues Tissues = group of structurally and functionally related cells AND their external environment, that perform common function. Types of tissue: Epithelial tissues (epithelia) Connective tissues Muscle tissues Nervous tissues  The Extracellular Matrix Definition: substances in liquid, thick gel, or solid form that surround cells of tissue. Functions: Provides tissues with strength Directs cells Regulates cells Two main components 1. Ground Substance 2. Protein fiber  The Extracellular Matrix (Ground Substance) Definition: extracellular fluid with water, nutrients, and ions 3 families of macromolecules 1. Glycosaminoglycans (GAGs)= concentration gradient for ECM- water into cells by osmosis 2. Proteoglycans- barrier for diffusion- protects from microorganisms 3. Cell-adhesion molecules (CAMs)-adhere cells- normal tissue architecture  The Extracellular matrix (Protein Fibers) Definition: embedded within ground substance, enormous tensile strength 3 protein fiber types: 1. Collagen fibers- resistant tension and pressure 2. Elastic fibers- stretch without breaking 3. Reticular fibers- traps foreign cells Review: Cell Junction another way cells bind to one another; neighboring cell’s plasma membranes are linked by integral proteins  Types of Cell Junction Tight junctions hold cells closely together; space Gap junctions between is impermeable to small pores formed by protein channels movement of macromolecules between adjacent cells; allow small substances to flow freely between each Desmosomes (linking integral cell’s cytoplasm proteins) allow for materials in extracellular fluid to pass through space between cells Epithelial Tissue Epithelial tissues are avascular (lack blood vessels; must obtain oxygen and nutrients by diffusion from deeper tissues); limits thickness  Epithelial tissues Function: Protection= Mechanical and thermal injury Immune defenses= Physical barrier Secretion= oils and hormones Transport into other tissues= selectively permeable membrane Sensation= nerve supply  Classification of Epithelia Classified by 2 ways 1. Number of cell layer 1 layer= simple epithelia 2 + layers= Stratified epithelia 2. Shape of the cell Squamous cell- Flattened Cuboidal Cell- short (looks like a cube) Columnar cell- Tall and elongated (skyscraper) Covering & Lining Epithelia on inner and outer body surfaces; each cell shape may be in varying thicknesses in broad, flat sheets; termed membranes when basement membrane is included  Simple Epithelia types Simple squamous epithelium Function: Location: air sacs of lung Rapid diffusion of substance (oxygen, carbon dioxide, fluids, specific segments of kidney and ions) tubules lining blood vessels  Simple Epithelia types Simple cuboidal epithelium Function: Location: thin enough for rapid substance segments of renal tubules diffusion respiratory passages ducts of many glands thyroid gland  Simple Epithelia types Simple Columnar Epithelium Function: Location: Secretion Small intestines Excretion Uterine tubes Absorption Segments of respiratory tract  Simple Epithelia types Pseudostratified columnar epithelium Function Location help trap and transport Segments of respiratory tract particles (trachea) Nasal cavity  Stratified Epithelium (think board) Keratinized stratified squamous Nonkeratinized stratified squamous epithelium epithelium Function: protects the body Function: provide protection against various external and serve as a lining or covering influences, such as mechanical for moist internal cavities of the stress, radiation, and microbial body penetration Location: mouth, throat, Location: Skin esophagus, anus, and vagina  Nonkeratinized stratified Keratinized stratified squamous squamous epithelium  Stratified Epithelium Stratified cuboidal epithelium Function: Location: secretion and protection Sweat glands *Rare in the body*  Stratified Epithelium Stratified Columnar Epithelium Function Location protection of underlying tissues Male urethra with multiple layers of epithelial cornea of eye cells salivary glands Rare in the body*  Stratified Epithelium Transitional Epithelium Function Location flatten allows tissues to stretch urinary system; lines interior of kidney, ureters, urinary bladder, and urethra Gland Definition: structure of epithelial origin; synthesizes and secretes product from designated secretory cells 2 mechanisms 1. Endocrine= secrete products (hormones) 2. Exocrine glands= release Gland (Goblet Cell) Function Location secrete mucus, thick sticky liquid in digestive and respiratory that protects underlying tracts epithelium Connective Tissue Widely distributed in body, Connect tissues and organs to one another, Components of internal architecture of some organs Connective Tissue: Definition and Function Function: Connecting and binding= anchor together Support= weight of body Protection= internal organs, shock absorption, immune system Transport= blood  Connective Tissue Proper Fibroblast Function: contributes to the formation of connective tissue; most common resident cell Location: in our skin and in our tendons.  Connective Tissue Proper Phagocytes immune system cells Function: ingest foreign substances, microorganisms, and dead or damaged cells by phagocytosis Location: All over the body  Connective Tissue: Loose Connective Tissue Proper Function Location Contains and supports blood vessels Beneath epithelium of skin, in vital to avascular epithelial tissues; membranes lining body cavities, and houses immune system cells within walls of hollow organs  Connective Tissue Dense IRREGULAR Connective Tissue Function Location provides strength, making the skin dermis of the skin, surrounding organs resistant to tearing by stretching and joints forces from different directions. predominantly disorganized collagen bundles  Connective Tissue Dense REGULAR Connective Tissue Function Location supports, protects, and holds tendons and ligaments bones, muscles, and other tissues and organs in place  Connective Tissue Dense Regular Elastic Connective Tissue Or Elastic Tissue Function Location allows the tissue to return to its In walls of organs that must original length after stretching stretch to function (large blood vessels and certain ligaments)  Connective Tissue Reticular Tissue Function Location Forms fine networks that lymph nodes and spleen support small structures such as blood and lymphatic vessels Forms part of basement membrane; supports all epithelia and internal structure of liver and bone marrow forms weblike nets that trap old and foreign cells  Specialized Connective Tissue Adipose Tissue Function Location Fat storage (major energy reserve of All over the body body) Insulation (retains warmth) Shock absorption and protection fat-storing adipocytes and surrounding fibroblasts and ECM  Specialized Connective Tissue Hyaline Cartilage Function Location helps your bones move end of bones in joints, linking smoothly past each other in sternum to ribs, framing sections your joints of respiratory tract, and in nose  Specialized Connective Tissue Fibrocartilage Function Location provides the tough material of the between bones of fibrous joints intervertebral discs forms articular discs that improve fit of bones in joints filled with bundles of collagen fibers; little room for ground substance in ECM  Specialized Connective Tissue Elastic Cartilage Function Location supports parts of your body that need external ear assists with detection of to bend and move to function. sound in air larynx assists with production of sound Allows tissue to vibrate  Specialized Connective Tissue Bone Function Location tension increases osteoblast activity Bone (all over the body) and bone deposition compression increases osteoclast activity and bone resorption  Specialized Connective Tissue Blood In Blood you can find: Plasma Protein- transport of substances and blood clotting Erythrocytes- bind to and transport oxygen throughout body Leukocytes- function in immunity Platelets cell fragments- major role in blood clotting  Muscle tissue (Overview) Definition: specialized for contraction; turn chemical energy of ATP into mechanical energy of movement Main component of muscle tissue is muscle cell (myocyte) Function: excitable (respond to electrical or chemical stimulation) Contract and relax  Muscle Tissue Skeletal Mostly attached to skeleton; contraction produces body movement; striated Skeletal muscle must be stimulated by nervous system to contract; under voluntary control Most skeletal muscle cells (fibers) are long, extending to almost entire length of whole muscle  Muscle Cardiac Function Location responsible for the contractility Heart of the heart and, therefore, the pumping action  Muscle Tissue Smooth Function Location consists of smooth muscle cells In walls of nearly every hollow organ blood vessels contractions are involuntary Eyes skin and ducts of certain glands  Nervous Tissue Location Function Nervous System (Brain, Spinal Cells of the nervous system are Cord, and Nerves) highly specialized to transmit electrical impulses around the body.