Tissues Ch. 4

Tissues Tissues - A group of cells similar in structure and serve a similar, specialized function 4 major categories of tissues: 1.Epithelial – Covering 2.Connective – Support 3.Muscle – Movement 4.Nervous – Communication and Control

1. Epithelial Tissue A.Covers body surfaces B.Lines body cavities and ducts C.Forms glands YOUR VISIBLE SKIN, LINING OF GUT, LINING OF BLOOD VESSELS, RESPIRATORY PASSAGES, DUCTS, JUST ABOUT ANY SURFACE AREA-NOSE, EAR,EYE

2. Connective Tissue A.Protects and supports body and organs B.Binds tissues together C.Stores energy D.Insulates E.Transport substances

3. Muscle Tissue Allows for movement through active generation of force

4. Nervous Tissue Initiates, transmits, and interprets impulses that coordinate the body

Epithelial Tissue

Epithelial Tissue – Characteristics 1.Cells closely packed with very little extracellular space. 2.All have specialized cell to cell contact a)Tight junctions b)Desmosomes

3. Polarity – have top (apical surface) and bottom (basal surface) – Epithelial Tissue (ET) is always attached to connective tissue (CT) via – Basement membrane: point of attachment for ET and CT, made-up of Basal lamina – glycoproteins from ET + collagen fibers Reticular lamina – glycoproteins from CT + collagen fibers Non-cellular! Epithelial Tissue – Characteristics Apical surface Basal surface

4. Avascular – no blood supply – Get nutrients from blood vessels in underlying connective tissue 5. High regeneration rate (like zombies) – mitosis to replace lost cells Epithelial Tissue – Characteristics

6. Specializations a. cilia- hairlike projections, help propel substances ex. nasal cavity, trachea b. microvilli – extensions of plasma membrane, increase surface area (greatly increases absorption of nutrients ex. small intestines Epithelial Tissue – Characteristics LC2

Epithelial Tissue – Arrangement and Shape A.Arrangement 1.Simple – single layer of cells 1.Minimal wear and tear locals or diffusion surfaces 2.Stratified – 2+ layers of cells 1.High wear and tear 3.Pseudostratified – single layer of cells that looks stratified 4.Transitional – many layers; cells can stretch (ie. “transitions”) B.Shape 1.Squamous – scale-like 2.Cuboidal – cube 3.Columnar - column

nucleus shape reflects that of the cell

TypesFunctionLocation 1) Simple Squamous 2) Simple Cuboidal 3) Simple Columnar 4) Pseudostratified columnar 5) Stratified Squamous 6) Stratified Cuboidal 7) Stratified Columnar 8) Transitional

Endothelium - forms lining in heart, blood vessels and lymphatic vessels Mesothelium - simple squamous epithelium of serous membranes (serosa)

MESOTHELIOMA cancer of cells forming mesothelium most often caused by exposure to asbestos pleura (lines lungs, thoracic cavity)

TypesFunctionLocation 1) Simple SquamousDiffusion/Filtration Air sacs of lungs, lymph & blood vessels, serosae, lining of heart 2) Simple Cuboidal 3) Simple Columnar 4) Pseudostratified columnar 5) Stratified Squamous 6) Stratified Cuboidal 7) Stratified Columnar 8) Transitional

1)LINES SMALL GLANDS AND DUCTS OF SMALL GLANDS 2)KIDNEY TUBULES THAT ABSORB WATER

TypesFunctionLocation 1) Simple SquamousDiffusion/Filtration Air sacs of lungs, lymph & blood vessels, serosae, lining of heart 2) Simple CuboidalSecretion/Absorption Kidney tubule, ducts & secretory part of small glands, and ovaries 3) Simple Columnar 4) Pseudostratified columnar 5) Stratified Squamous 6) Stratified Cuboidal 7) Stratified Columnar 8) Transitional

OVIDUCTS - CILIATED Endometrium-composed of simple columnar epithelium and layer of connective tissue

TypesFunctionLocation 1) Simple SquamousDiffusion/Filtration Air sacs of lungs, lymph & blood vessels, serosae, lining of heart 2) Simple CuboidalSecretion/Absorption Kidney tubule, ducts & secretory part of small glands, and ovaries 3) Simple ColumnarSecretion/Absorption Digestive tract, gallbladder, oviducts, some regions of uterus 4) Pseudostratified columnar 5) Stratified Squamous 6) Stratified Cuboidal 7) Stratified Columnar 8) Transitional

TypesFunctionLocation 1) Simple SquamousDiffusion/Filtration Air sacs of lungs, lymph & blood vessels, serosae, lining of heart 2) Simple CuboidalSecretion/Absorption Kidney tubule, ducts & secretory part of small glands, and ovaries 3) Simple ColumnarSecretion/Absorption Digestive tract, gallbladder, oviducts, some regions of uterus 4) Pseudostratified columnar Secretion Trachea, upper respiratory tract 5) Stratified Squamous 6) Stratified Cuboidal 7) Stratified Columnar 8) Transitional

TypesFunctionLocation 1) Simple SquamousDiffusion/Filtration Air sacs of lungs, lymph & blood vessels, serosae, lining of heart 2) Simple CuboidalSecretion/Absorption Kidney tubule, ducts & secretory part of small glands, and ovaries 3) Simple ColumnarSecretion/Absorption Digestive tract, gallbladder, oviducts, some regions of uterus 4) Pseudostratified columnar Secretion Trachea, upper respiratory tract 5) Stratified SquamousProtection keratinized = skin nonkeratinized = mouth, esophagus, vagina 6) Stratified CuboidalProtection Ducts of large glands 7) Stratified ColumnarProtection Male urethra, pharynx 8) Transitional

LOOKS LIKE NONKERATINIZED STRATIFIED SQUAMOUS EPITHELIUM- LG AND ROUND AT apical surface SO CAN STRETCH WITHOUT CELLS BREAKING APART FROM ONE ANOTHER

TypesFunctionLocation 1) Simple SquamousDiffusion/Filtration Air sacs of lungs, lymph & blood vessels, serosae, lining of heart 2) Simple CuboidalSecretion/Absorption Kidney tubule, ducts & secretory part of small glands, and ovaries 3) Simple ColumnarSecretion/Absorption Digestive tract, gallbladder, oviducts, some regions of uterus 4) Pseudostratified columnar Secretion Trachea, upper respiratory tract 5) Stratified SquamousProtection keratinized = skin nonkeratinized = mouth, esophagus, vagina 6) Stratified Cuboidal (RARE) Protection Ducts of large glands (Sweat, mammary, salivary) 7) Stratified Columnar (RARE) Protection Male urethra, pharynx 8) TransitionalStretches Ureters, bladder, urethra LC3

Epithelial Tissue – Glands One or more cells that make and secrete a product -Endocrine – produce hormones and secrete into bloodstream via exocytosis -Exocrine – secrete product onto body surfaces (skin) or into body cavities.

USUALLY CUBOIDAL OR COLUMNAR IN SHAPE GLANDULAR EPITHELIUM SECRETES INTO – A DUCT, OR A FREE SURFACE, OR THE BLOOD Endocrine glands are ductless – Hormones = messenger chemicals Exocrine-ex. Sweat, mammary, salivary, sebaceous (oil) among others Epithelial Tissue – Glands

Structural Classification of Exocrine Glands 1. Unicellular – mucous and goblet cells Produce mucin; glycoprotein that dissolves in water when secreted forming mucus Secret product by exocytosis Goblet cell

2.Multicellular - consist of a duct and secretory unit Duct type – Simple = unbranched duct – Compound = branched duct Secretory Unit – Alveolar (acinar) = secretory cells form small sacs – Tubular = secretory cells form tubes – Tubuloalveolar = alveolar + tubular Structural Classification of Exocrine Glands

LC4

Functional Classification of Exocrine Glands *Based on how product is secreted 1.Holocrine – “ whole membrane rupturing” Ex. Sebaceous glands, clogged = pimple 2.Apocrine – “membrane budding” with vesicles Mammary milk lipids 3. Merocrine – secrete their products by exocytosis as they are produced, mammary non-fat Ex. Sweat and salivary glands