Lesson 2.3 Tissues Chapter 2: Cells and Tissues

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Tissues are groups of cells with similar structure that join together to perform a common function - the study of tissues is Histology - tissues are classified into four main types; 1. Epithelial – lines and cover 2. Connective - supports 3. Muscle – generates force 4. Nerve – conveys information Types of Tissues

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. I.Epithelial Tissue - Epithelia – tissues that cover the body and line body cavities - Gland – tissues that secrete chemicals - endocrine gland tissue – secrete to other parts inside the body - exocrine gland tissue – secrete to outside world Epithelial Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. - Four main functions of Epithelial Cells: 1. protect body from physical damage 2. control what enters and leaves the body 3. provide sensory input 4. secrete various substances Epithelial Cell Shapes

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. -Apical surface – faces the outside world or lumen of a body cavity connected to outside world -Basal surface – faces deeper body cells Epithelial Cell Shapes

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Epithelia: Cell Layers and Shapes - Epithelia are classified by: 1. layers Simple = one layer Stratified = multiple layers 2. shape Squamous = almost flat Cuboidal = height equal to width Columnar = tall and skinny IF multiple layers not same shape = classified as shape of the most apical cells Epithelial Cell Shapes

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. simple –one layer stratified –more than one layer other –transitional stretchable Epithelial Cell Arrangement

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Simple Epithelia -Simple Squamous = single layer of flattened cells, allow for rapid diffusion (thin) + gas-exchanging cavities = alveoli in lungs + lining of abdominal cavity + endothelium, single layer, lining blood vessels/heart -Simple Cuboidal = single layer typically involved in secretion or absorption + surround tubules in kidneys and secretory glands - Simple Columnar = single layer, secretory or absorptive + linings of ducts in kidneys, stomach and intestine + may contain microvilli to increase surface area Epithelial (Simple)

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Stratified Epithelia - Stratified Squamous – where mechanical and chemical protection is most needed + skin – outside surfaces (apical) are dead and dying cells along with protein keratin. Provides a waterproof barrier to combat dehydration. + other apical surfaces include; mouth, throat, esophagus, anus, rectum - Stratified Cuboidal = (rare) duct of sweat gland - Stratified Columnar = (rare) duct linings of pancreas and salivary glands Epithelial (Stratified)

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Epithelial (other) Transitional epithelia does not fit the other classifications Example: Bladder

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Glands – epithelial cells that secrete a substance(s) 1. Exocrine gland – secretes products to outside world a. unicellular exocrine glands – isolated cells in lining of respiratory and digestive tracts they secrete mucus to form protective cover over epithelium Epithelial Glands

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. b. multicellular exocrine glands – two parts, secretory cells that make product and duct cells that connect gland cells to surface of epithelium c. simple duct structure = single or compound – can be tubular or alveolar (spherical) 2. Endocrine gland secrete to interstitial space (spaces between tissues) Epithelial Glands

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. True or False? 1. Connective tissue provides support. 2. Transitional epithelial stretches. 3. Cuboidal cells are flat. 4. Stratified means more than one layer. 5. Epithelial glands secrete substances. Review and Assessment

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. functions –strengthens the body and organs –protects internal organs –maintains the shape of organs –provides rigid framework for muscles to pull fibers –collagen –reticular –elastic Connective Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. connective tissue proper –wide variety of locations and functions –plays a role in immune defenses cartilage –provides support and flexibility –minimizes friction bone tissue (osseous tissue) –provides framework, protects organs, supports body blood –provides transportation, regulation, and protection –carries oxygen and nutrients, and carbon dioxide Classes of Connective Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. connective tissue proper – loose –dense cartilage bone Types of Connective Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. loose connective tissue –areolar – under epithelium –reticular – spleen –adipose – fat Loose Connective Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. dense connective tissue –regular dense–tendons –irregular dense–dermis –dense elastic–large artery walls Dense Connective Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. chondroblasts hyaline –ends of long bones elastic –external ear fibrocartilage –intervertebral discs Cartilage

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. osseous tissue –protects organs –supports the body Bone

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. skeletal cardiac smooth Types of Muscle Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. central nervous system peripheral nervous system glial cells neurons Nerve Tissue

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Match the following with 1–4 below: skeletal, collagen, nervous tissue, elastic cartilage. 1. muscle tissue type 2. external ear 3. fiber 4. glial cells Review and Assessment