Tissues: Epithelia, Connective Tissue, and Muscle PDF

Tissues: Epithelia, Connective Tissue, and Muscle Gregory Casey, PhD, LMT, AOBTA-CP Dept. of Cell Biology and Anatomy Lions Eye Center Room 747 LSU Health Sciences Center New Orleans, La Marieb: 64-102 Questions: E-Mail: [email protected]...

Tissues: Epithelia, Connective Tissue, and Muscle Gregory Casey, PhD, LMT, AOBTA-CP Dept. of Cell Biology and Anatomy Lions Eye Center Room 747 LSU Health Sciences Center New Orleans, La Marieb: 64-102 Questions: E-Mail: [email protected]  Learning Objectives By the end of this lecture students should be able to: 1. Classify the four basic tissue types in the human body. 2. Organize the characteristics, classifications, specific features, and brief functions of epithelial tissue. 3. Identify the cellular components of epithelial cells. 4. Identify the components, functions, and characteristics of connective tissue 5. Classify the basic types and specialized kinds of connective tissue in the human body. 6. Identify the cellular and non-cellular structures of connective tissue. 7. Briefly describe three types of muscle tissue. 8. Compare and contrast locations of different tissues in the same region.  Epithelia* Connective Tissue* Muscle* Nervous * = Link to tissue description Nervous tissue only included here The Human Body has 4 basic tissue types 1. Epithelium – Mucous membrane, Skin GI tract – Lining of the blood vessels, body cavity, organs 2. Connective Tissue – Connective Tissue Proper – Bone – Blood – Cartilage 3. Muscle – Cardiac – Skeletal – Smooth 4. Nervous Tissue  Epithelia Sheet of cells that interfaces between two different environments. Serous Linings Gut Lining Blood Vessels Skin, Hair, & Nails Return to Basic Tissue Slide  Characteristics of Epithelia Composed almost entirely of cells! Specialized junctions to hold cells together. Polarity – Apical: toward the surface – Basal: part of the cell that rests on a basal lamina Supported by connective tissue. Avascular – Receive oxygen and nutrients via diffusion Highly regenerative – Constantly dividing and replacing old epithelial cells Classification of Epithelia Squamous – Flat cell Cuboidal – Cube like cell Columnar – Taller than wide Classification of Epithelial Layers Simple – One layer of cells – Act as a filtration barrier, secretion, absorption, propel substances Stratified – Protection Simple Squamous Epithelium Example: Alveoli – Allows for diffusion and filtration Types of Epithelium Index Simple Cuboidal Epithelium Example: Kidney Tubules – Allows for secretion & absorption Types of Epithelium Index Simple Columnar Epithelium Example: Stomach Mucosa – Allows for absorption, secretion of substances. Has cilia. Types of Epithelium Index Stratified Squamous Epithelium Example: Esophagus – Protection from abrasion Types of Epithelium Index Stratified Cuboidal Epithelium Example: Parotid Duct – Protection Types of Epithelium Index Stratified Columnar Epithelium Example: Male urethra – Protection, secretion Types of Epithelium Index Return to Type of Epithelium Pseudostratified Epithelium Transitional Epithelium  Other Types of Epithelium Pseudostratified Columnar Epithelium – Considered a single epithelial layer, but not all of its cells reach the apical surface. – Respiratory Epithelium Transitional Epithelium – Resembles stratified cuboidal, but changes depending on the distention of urinary organs such as the bladder. Return to Other Types of Epithelium Types of Epithelium Index  Cellular Components of Epithelial Cells Cell Surface Features – Apical Microvilli Cilia – Lateral Cell Junctions Desmosomes Gap Junctions – Basal Hemidesmosomes Basement membrane Intracellular – Cytoskeleton framework Microfilaments (small) Intermediate filaments (medium) Microtubules (large) Cell Surface Features of Epithelium Apical Side Lateral Side Basal Side  Cell Surface Features Apical side surface – Interfaces with another environment – Can have modifications related to function Lateral side surface – Junctional complexes and specific microstructures with adjacent cells Basal side surface – Junctional complexes – Interfaces with underlying connective tissue Apical modification: Microvilli – Contains a core of actin microfilaments – Maximize surface area for absorption – Help to anchor mucus sheets Apical modification: Cilia Whip-like extensions that propels mucus or particles across the epithelial surface Arranged in Microtubule doublets A Cilium contains a basal body at its base on the apical membrane Cell Surface Features of Epithelium Lateral Side  Cell Junctions Zonula occludens (Tight Junctions) – Plasma membrane proteins on the lateral side of one cell fuse with those of an adjacent cell – Prevents molecules from passing in between cells Zonula adherens (Adhesive Belt Junctions) – Transmembrane linker proteins that attach to actin microfilaments bind to adjacent cells. – Reinforces Zonula occludens and form a tight junctional complex. Lateral Border Microstructures Cell Surface Features of Epithelium Desmosomes  Desmosomes – Cytoplasmic side: circular plaque – More robust cellular junction – Attach to other cells by fusion of linker proteins – Intracellular Intermediate filaments insert on each plaque – Resists mechanical stress so cells are not pulled apart from each other. Lateral Border Microstructures Cell Surface Features of Epithelium Gap Junctions  Gap Junctions – Tunnel-like Junction that allows passage of small molecules or ions from one cell to an adjacent cell. Lateral Border Microstructures Cell Surface Features of Epithelium Hemidesmosomes and basement membrane Basal Side Cell Surface Features of Epithelium Hemidesmosomes – Identical to desmosomes but will attach to the basal lamina/Basement membrane. – Resists mechanical stress so cells are not pulled apart from underlying connective tissue  Without Basement membrane, epithelial regeneration is more difficult. Basement membrane Cell Surface Features of Epithelium Apical modification Junctional complexes & specific microstructures Basement membrane Connective Tissue  Intracellular Microstructures Cytoskeleton Microfilaments Intermediate Microtubules Filaments  Framework of the Cytoskeleton Microfilaments = Contractile protein actin – Involved in muscle contraction and intracellular movement. Helps form the cell’s cytoskeleton Intermediate filaments = Protein fibers – Stable cytoskeletal elements. Resist tension Microtubules = Cylindrical proteins made of tubulin – Support and give the cell shape, involved in intracellular and cellular movements.  Connective Tissue Cartilage Blood CT Proper Adipose Bone Return to Basic Tissue Slide  Connective Tissue Cells Extracellular Matrix Figure 5.1b, Histology by Ross, Kaye, & Pawlina  Function Of Connective Tissue Binding, support, and compartmentalization Hydration – Holds body fluids Transportation - nutrients, wastes Defense Energy Storage  Characteristics Of Connective Tissue Cell – Fibroblast* – secretes extracellular matrix proteins and the ground substance – Immune Cells – Battle Infections Extracellular Matrix Proteins – Collagen* – High tensile strength; tough – Elastin* – High stretchability; low tensile strength; long & thin – Reticular* – Thin branched collagen that forms delicate networks Ground Substance – Proteoglycans & Glycosaminoglycans – soak fluid up like a sponge Hyaluronic acid Chondrotin sulfate Types of Connective Tissue Proper Loose Connective Tissue Few collagen fibers Abundant ground substance Dense Connective Tissue – Irregular Dense Connective Tissue Mostly collagen fibers Sparse ground substance – Regular Dense Connective Tissue Densely and orderly packed fibers Sparse ground substance  Connective Tissue Proper Loose CT Dense CT Areolar CT Adipose CT Reticular CT  Areolar Connective Tissue Mast Cells Elastic Fibers Collagen Fiber Fibroblast Nuclei Human Anatomy 5th ed. Marieb, Brief Atlas Plate 11 Areolar Connective Tissue Human Anatomy 6th ed. Marieb, Figure 4-10b  Subtypes of Loose Connective Tissue – Areolar (typical) Supports and binds other tissue Holds body fluids (ground substance) Site of fighting infection Return to Basic Tissue Slide Adipose Connective Tissue Nucleus of Adipocyte Fat Droplet Human Anatomy 5th ed. Marieb, Brief Atlas Plate 12  Types of Adipose Connective Tissue WHITE FAT (UNILOCULAR): Adult type; In superficial fascia (hypodermis), organ and joint fat pads, etc.; For protection, temperature regulation, and storage BROWN FAT (MULTILOCULAR): Fetal type; Located between scapulae etc.; Provide energy for temperature regulation in the newborn Used in hibernation by bears  Subtypes of Loose Connective Tissue – Adipose Type of areolar connective tissue that stores nutrients White Fat = stores nutrients Brown Fat = used to produce heat and consumes nutrients (occurs in babies and bears) Return to Basic Tissue Slide Reticular Connective Tissue Reticular Fibers Human Anatomy 5th ed. Marieb, Brief Atlas Plate 12 Reticular Connective Tissue Human Anatomy 6th ed. Marieb, Figure 4-10d  Reticular CT found in Spleen Lateral Surface Medial Surface Return to Basic Tissue Slide Figure 13.35 A & B,Thieme Atlas of Anatomy  Subtypes of Loose Connective Tissue – Reticular Loose ground substance Fibers form a network Provides framework for structures: ex. liver, spleen, bone marrow, lymph node, Return to Basic Tissue Slide  Connective Tissue Proper Loose CT Dense CT Areolar CT Irregular CT Regular CT Adipose CT Reticular CT Dense Irregular Connective Tissue Collagen Fiber (not arranged) Fibroblast Nuclei Human Anatomy 5th ed. Marieb, Brief Atlas Plate 14  Dense Irregular Connective Tissue Return Human Anatomy 6th ed. Marieb, Figure 4-10e  Subtypes of Dense Connective Tissue – Dense Irregular CT Much more collagen than areolar connective tissue Collagen is irregularly arranged Resist strong tensions from different directions Gives resiliency to the dermis layer of skin Makes up fibrous capsules Return Dense Regular Connective Tissue Collagen Fiber (arranged) Fibroblast Nuclei Human Anatomy 5th ed. Marieb, Brief Atlas Plate 15  Dense Regular Connective Tissue Return Human Anatomy 6th ed. Marieb, Figure 4-10f  Subtypes of Dense Connective Tissue – Dense Regular CT Much more collagen than areolar connective tissue Collagen fibers are arranged in parallel with each other Poorly vascularized Makes up ligaments, tendons, aponeuroses, and deep investing fascia of muscles. Return  Muscle Tissue Cardiac Smooth Skeletal Striated No Striations Striated Uninucleated Uninucleated Multinucleated Involuntary Involuntary Voluntary Return to Basic Tissue Slide Comparison Different Tissues in Mammary Gland Tissue Loose (Areolar CT) Stratified cuboidal epithelium Dense (Irregular CT) Figure 5.3, Histology by Ross, Kaye, & Pawlina  Skin Layer Composed of Tissue types Epidermis - Stratified Squamous epithelium Dermis - Areolar CT wraps nerves & blood vessels - Dense Irregular CT allows for resiliency of skin - Smooth muscle - Nervous tissue - nerves Hypodermis - Areolar CT - Adipose CT Human Anatomy 5th ed. Marieb, Figure 5.1  Questions? E-mail: [email protected] Office: Lions Eye Center Room 747