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Tissue. Chapter 4. Link. Tissues. Tissue: 4 Primary Tissue Types Epithelial Connective Muscle Nervous. http://www.stegen.k12.mo.us/ tchrpges / sghs / ksulkowski /images/20_Simple_Columnar_Epithelial_Tissue.jpg. Match Tissue Type to Function. Epithelial Connective Nervous Muscle. - PowerPoint PPT Presentation
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Tissues
• Tissue:
• 4 Primary Tissue Types1. Epithelial2. Connective3. Muscle4. Nervous
http://www.stegen.k12.mo.us/tchrpges/sghs/ksulkowski/images/20_Simple_Columnar_Epithelial_Tissue.jpg
Match Tissue Type to Function
1. Epithelial
2. Connective
3. Nervous
4. Muscle
A. Supports, protects, binds other tissues together
B. Internal communication
C. Contracts to cause movement
D. Forms boundaries between different environments, protects, secretes, absorbs, filters
Epithelial Tissue (Epithelium)
• Two main types (by location):1. Covering and lining epithelium2. Glandular epithelium
http://www.bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/goblet%20cells%20.jpg
Forms boundaries b/w different environments
Functions of Epithelial Tissue
• Protection• Absorption• Filtration• Excretion• Secretion• Sensory reception
Characteristics of Epithelial Tissue
1. Cells have polarity2. Are composed of closely packed cells3. Supported by a connective tissue reticular
lamina (under the basal lamina)4. Avascular but innervated 5. High rate of regeneration
Classification of Epithelia
• Ask two questions:
1. How many layers? 1 = simple epithelium>1 = stratified epithelium
Classification of Epithelia
2. What type of cell?• Squamous• Cuboidal• Columnar
Note: if stratified, name according to apical layer of cells!
Overview of Epithelial Tissues
• For each of the following types of epithelia, note:– Description– Function– Location
Simple Epithelia
• Single cell layer (usually very thin)• Concerned with:
– Absorption– Secretion– Filtration
• NOT concerned with: protection• Simple squamous, simple cuboidal, simple
columnar, pseudo stratified columnar
Simple Squamous Epithelium• Description
• Function
• Location
Photomicrograph: Simple squamous epitheliumforming part of the alveolar (air sac) walls (125x).Note: ENDOTHELIUM AND MESOTHELIUM
• Description
• Function
• Location
(b) Simple cuboidal epithelium
Photomicrograph: Simple cuboidalepithelium in kidney tubules (430x).
Simple Cuboidal Epithelium
(c) Simple columnar epithelium
Photomicrograph: Simple columnar epitheliumof the stomach mucosa (860X).
Simple Columnar Epithelium• Description
• Function
• Location
(c) Simple columnar epitheliumPseudostratified Columnar Epithelium• Description
• Function
• Location
Photomicrograph: Pseudostratified ciliatedcolumnar epithelium lining the human trachea (570x).
Stratified Epithelium
• 2+ cell layers• Regenerate from below• More durable than simple epithelia• Major role: Protection
Stratified Squamous Epithelium• Description
• Function
• Location
Photomicrograph: Stratified squamous epitheliumlining the esophagus (285x).
Stratified Cuboidal Epithelium• Description
• Function
• Location
Stratified Columnar Epithelium
http://www.sciencephoto.com/image/115414/large/C0051252-Stratified_columnar_epithelium,_urethra-SPL.jpg
• Description
• Function
• Location
Transitional Epithelium
• Description
• Function
• Location
Photomicrograph: Transitional epithelium lining the urinary bladder, relaxed state (360X); note the bulbous, or rounded, appearance of the cells at the surface; these cells flatten and become elongated when the bladder is filled with urine.
Glandular Epithelia
• Gland: one or more cells that secretes and aqueous fluid
• Classified by:– Site of product release
• Endocrine• Exocrine
– Relative number of cells forming the gland• Unicellular• Multicellular
GlandsEndocrine
• Ductless glands • Secrete hormones that
travel through lymph or blood to target organs
• Examples: Thyroid Gland, Pituitary Gland
• Covered in Ch. 16
Exocrine• Secrete products into
ducts• Secretions released
onto body surfaces (skin) or into body cavities
• Examples: mucous, sweat, oil, and salivary glands
More numerous!
Unicellular Exocrine Glands
• Goblet cell and Mucous cell– Mucin -> mucous
Multicellular Exocrine Glands
• Composed of a duct and a secretory unit• Classified according to:
1. Duct type • Simple• Compound
2. Structure of secretory units• tubular• alveolar• tubuloalveolar
Figure 4.5
Compound duct structure(duct branches)
Simple tubular
ExampleIntestinal glands
Simple branchedtubular
ExampleStomach (gastric)glands
Compound tubularExampleDuodenal glands of small intestine
Compound alveolarExampleMammary glands
SimplealveolarExampleNo importantexample in humans
Simple branchedalveolar
ExampleSebaceous (oil)glands
Compoundtubuloalveolar
ExampleSalivary glands
Tubularsecretorystructure
Alveolarsecretorystructure
Surface epithelium Duct Secretory epithelium
Simple duct structure(duct does not branch)
Modes of Secretion
Merocrine• Products are secreted
by exocytosis • pancreas, sweat and
salivary glands
Holocrine• Products are secreted
by rupture of gland cells • sebaceous (oil) glands
Connective Tissue
• Most abundant and widely distributed tissue type
• Four main classes1) Connective Tissue Proper2) Cartilage3) Bone Tissue4) Blood
See Table 4.1
Major Functions of Connective Tissue
1) Binding and Support2) Protection3) Insulation4) Stores reserve fuel5) Transports
Characteristics of Connective Tissue
• Connective tissues have:– Mesenchyme as their common tissue of origin– Varying degrees of vascularity– Cells separated by nonliving extracellular matrix
(ground substance and fibers) • 3 Structural Elements
– Ground substance– Fibers– Cells
Structural Elements of Connective Tissue
• Ground substance– Medium through which solutes diffuse between
blood capillaries and cells– Components:
• Interstitial fluid• Adhesion proteins (“glue”) • Proteoglycans
–Protein core + large polysaccharides–Trap water -> viscosity
Structural Elements of Connective Tissue
• Connective Tissue Fibers– Collagen (white fibers)
• Strongest and most abundant type• Provides high tensile strength
– Elastic (yellow fibers)• Networks of long, thin, elastin fibers that allow
for stretch/recoil– Reticular
• Short, fine, highly branched collagenous fibers
Structural Elements of Connective Tissue
• Cells (see table 4.1)– Mitotically active and secretory cells = “blasts”
• Fibroblasts, chondroblasts, osteoblasts, hematopoietic stem cells
– Mature cells = “cytes”• Chondrocytes, osteocytes
– Other cell types• Fat cells, white blood cells, mast cells, and
macrophages
Figure 4.7
Macrophage
Fibroblast
Lymphocyte
Fat cellMast cell
Neutrophil
Capillary
Cell types Extracellularmatrix
Fibers• Collagen fiber• Elastic fiber• Reticular fiber
Ground substance
Connective Tissue: Embryonic
• Mesenchyme—embryonic connective tissue– Gives rise to all other connective tissues – Gel-like ground substance with fibers and star-
shaped mesenchymal cells
Connective Tissue Proper
• Types:– Loose connective tissue
• Areolar• Adipose• Reticular
– Dense connective tissue
• Dense regular• Dense irregular• Elastic
Loose Connective: Areolar
• Description
• Function
• Location
Photomicrograph: Areolar connective tissue, asoft packaging tissue of the body (300x).
CONNECTIVE TISSUE PROPER
Loose Connective: Adipose
• Description
• Function
• Location
Photomicrograph: Adipose tissue from thesubcutaneous layer under the skin (350x).
CONNECTIVE TISSUE PROPER
Loose Connective: Reticular• Description
• Function
• Location
Photomicrograph: Dark-staining network of reticularconnective tissue fibers forming the internal skeletonof the spleen (350x).
CONNECTIVE TISSUE PROPER
Dense Connective: Dense Regular
• Description
• Function
• Location
Photomicrograph: Dense regular connectivetissue from a tendon (500x).
CONNECTIVE TISSUE PROPER
Dense Connective: Dense Irregular
• Description
• Function
• Location
Photomicrograph: Dense irregularconnective tissue from the dermis of theskin (400x).
CONNECTIVE TISSUE PROPER
Dense Connective: Elastic
• Description
• Function
• Location
Photomicrograph: Elastic connective tissue inthe wall of the aorta (250x).
CONNECTIVE TISSUE PROPER
Connective Tissue: Cartilage
• Stands up to both compression and tension• No nerve fibers, avascular• 80% water• Chondroblasts – produce new matrix• Chondrocytes – mature cartilage cells
– Found in small groups in lacunae
Hyaline Cartilage• Description
• Function
• Location
Photomicrograph: Hyaline cartilage from the trachea (750x).
CARTILAGE
Elastic Cartilage• Description
• Function
• Location
Photomicrograph: Elastic cartilage from the human ear pinna; forms the flexible skeleton of the ear (800x).
CARTILAGE
Fibrocartilage• Description
• Function
• Location
Photomicrograph: Fibrocartilage of anintervertebral disc (125x). Special stainingproduced the blue color seen.
CARTILAGE
Connective Tissue: Bone• Description
• Function
• Location
Photomicrograph: Cross-sectional view of bone (125x).
Connective Tissue: Blood• Description
• Function
• LocationPhotomicrograph: Smear of human blood (1860x); two white blood cells (neutrophil in upper left and lymphocyte in lower right) are seen surrounded by red blood cells.
Nervous Tissue• Description
• Function
• Location
Photomicrograph: Neurons (350x)
Muscle Tissue
• Highly cellular, well vascularized• Movement• Types
1. Skeletal2. Cardiac3. Smooth
Skeletal Muscle• Description
• Function
• Location
Photomicrograph: Skeletal muscle (approx. 460x).Notice the obvious banding pattern and thefact that these large cells are multinucleate.
MUSCLE TISSUE
Cardiac Muscle• Description
• Function
• Location
Photomicrograph: Cardiac muscle (500X); notice the striations, branching of cells, and the intercalated discs.
MUSCLE TISSUE
Smooth Muscle• Description
• Function
• Location
Photomicrograph: Sheet of smooth muscle (200x).
MUSCLE TISSUE
Epithelial Membranes
• Cutaneous membrane (skin)• Mucous membranes
– Mucosae• Line body cavities open to the exterior (e.g., digestive
and respiratory tracts)
• Serous Membranes– Serosae—membranes (mesothelium + areolar
tissue) in a closed ventral body cavity• Parietal serosae line internal body walls• Visceral serosae cover internal organs
Figure 4.11b
Mucosa ofnasal cavity
Mucosa oflung bronchi
Mucosa ofmouth
Esophaguslining
(b) Mucous membranes line body cavitiesopen to the exterior.
Figure 4.11c
Parietalpericardium
Visceralpericardium
(c) Serous membranes line body cavitiesclosed to the exterior.
Parietalperitoneum
Visceralperitoneum
ParietalpleuraVisceralpleura
Steps in Tissue Repair
• Inflammation• Organization and Restored Blood Supply• Regeneration and Fibrosis
Figure 4.12, step 1
Scab
Blood clot inincised wound
Epidermis
Vein
Inflammatorychemicals
Inflammation sets the stage:• Severed blood vessels bleed and inflammatory chemicals are
released.• Local blood vessels become more permeable, allowing white
blood cells, fluid, clotting proteins and other plasma proteinsto seep into the injured area.
• Clotting occurs; surface dries and forms a scab.
Migrating whiteblood cell
Artery
1
Figure 4.12, step 2
Regeneratingepithelium
Area ofgranulationtissueingrowth FibroblastMacrophage
Organization restores the blood supply:• The clot is replaced by granulation tissue, which restores
the vascular supply.• Fibroblasts produce collagen fibers that bridge the gap.• Macrophages phagocytize cell debris.• Surface epithelial cells multiply and migrate over the
granulation tissue.
2
Figure 4.12, step 3
Regeneratedepithelium
Fibrosedarea
Regeneration and fibrosis effect permanent repair:• The fibrosed area matures and contracts; the epitheliumthickens.• A fully regenerated epithelium with an underlying area ofscar tissue results.
3
Developmental Aspects• Primary germ layers: ectoderm, mesoderm,
and endoderm– Formed early in embryonic development– Specialize to form the four primary tissues
• Nerve tissue arises from ectoderm• Muscle and connective tissues arise from mesoderm• Epithelial tissues arise from all three germ layers