tissue level of organization

Question Answer
Four tissue categories Epithelium, Connective, Muscle and Nervous
Structure of simple squamous epithelium one cell layer, flat, tightly bound, each cell attaches to basement membrane
Function of simple squamous epithelium Rapid diffusion, filtration, some secretions in serous membranes
Location of simple squamous epithelium Air sacs of lungs (alveoli), lining of heart chambers and lumen of blood vessels (endothelium), serous membranes of body cavities (mesothelium)
Structure of simple cuboidal epithelium Single layer of cells – same height and width, spherical nucleus that is centrally located.
Function of simple cuboidal epithelium Absorption and secretion
Location of simple cuboidal epithelium Thyroid gland follicles, kidney tubules, ducts of secretory regions of most glands, surface of ovary
Structure of nonciliated simple columnar epithelium Single layer of columnar cells that appear multi layered, microvilli at apical surface, oblong nucleus nearer basal layer, may contain goblet cells
Function of nonciliated simple columnar epithelium Absorption and secretion, secretion of mucin
Location of nonciliated columnar epithelium Lining of most of digestive tract, stomach lining does not contain goblet cells
Structure of non keratinized stratified squamous epithelium multi layered cells, basel cells usually cuboidal or polyhedral, apical cells are squamous, surface cells alive and kept moist
Function of non keratinized stratified squamous epithelium Protection of underlying tissue – moist
Structure of keratinized stratified squamous epithelium multi layered, basal typically cuboidal or polyhedral, apical are squamous, dead and filled with keratin proteins
Function of keratinized stratified squamous epithelium Protect underlying tissue – dead
Location of non keratinized stratified squamous epithelium Lining of oral cavity, part of pharynx, esophagus, vagina, and anus
Location of keratinized stratified squamous epithelium Epidermis of skin
Characteristics if epithelial tissue Cellularity, polarity-apical, basal, lateral; attachment-basement membrane, avascularity, innervation
Functions of epithelial tissue Physical protection, selective permeability, secretions, sensations
Another term for tight junction zonula occludens
Structure of tight junction encircles epithelial cells near apical surface, attaches with PLASMA MEMBRANE PROTEINS
Another term for adhering junction Zonula adherens
Structure of adhering junction deep to tight junctions, extensive zones of MICROFILAMENTS that extend from cytoplasm through plasma membrane
Function of tight junction Seals intercellular space so materials pass through cell not btwn cell.
Function of adhering junction provide passageway for materials to continue path to basal layer, only means of support for apical layer
Another term for Desmosomes macula adherens
Structure of desmosomes A snap btwn adjacent epithelial cells, each cell provides one half of junction, PROTEIN FILAMENTS, INTERMEDIATE FILAMENTS, PROTEIN PLAQUE
Function of desmosomes Provides resistance to mechanical stress at a single point, does not encircle cell
Structure of Gap Junction formed across intercellular gap btwn neighbor cells, connexions-6 TRANSMEMBRANE PROTEINS make a pore, pore is a direct passageway for small molecules to travel cell to cell, ions, glucose, amino acids
Function of Gap junction Provides passageway for small molecules to travel btwn cells, ions-coordinates cellular activities, glucose, amino acids
Structure of pseudostratified columnar epithelium Single layer varying heights appear multilayered, all cells attach to basement membrane, not all reach apical layer, ciliated-contain goblet cells, non ciliated-no goblets and no cilia
Function of pseudostratified columnar epithelium Protection;ciliated, secretion of mucin, movement of mucin across surface
Location of pseudostratified columnar epithelium Ciliated; lines most of respiratory tract, nasal cavity, part of pharynx, larynx, trachea, bronchi
Structure of Transitional epithelium Cells appearance varies in shape depending on stretched or relaxed, apical cells change shape, some may be binucleated
Function of transitional epithelium Distention and relaxation to accommodate urine volume
Location of transitional epithelium Lining of urinary bladder, ureters, and part of urethra
Characteristics of connective tissue Cells, protein fibers, ground substance
Functions of connective tissue Physical protection, support structural framework, binding of structures, storage, transport, immune protection
Mesenchyme first type of connective tissue – embryonic stage-spindle shaped-stem cells
Types of cells in connective tissue fibroblast, adipocyte, chondrocyte, osteocyte
Types of protein fibers in connective tissue collagen, elastic and reticular
Structure of collagen Long, unbranched, extracellular fibers, strong, flexible, resistant to stretching, 25% of body's protein,
Function of collagen Able to withstand enormous forces in one direction
Structure of elastic fibers -elastin thinner, coiled,
Function of elastic fibers stretch and return to normal shape (lungs)
Structure of reticular fibers thinner, coated with glycoprotein, branching, interwoven, tough but flexible abundant in stroma
Function of reticular fibers mesh like framework allows for physically support organs and resist external forces
Function of mesenchymal cells Divide in response to injury to produce new connective tissue
Fibroblast abundant, large, relatively flat cells, often with tapered ends
Function of fibroblast Produce fibers and ground substance of the extracellular matrix
Adipocytes Fat cells, single layer lipid droplets, cellular components pushed to one side
Function of adipocytes Store lipid reserves
Fixed macrophages large cells derived from monocytes in blood, resides in extracellular matrix after leaving blood
Function of macrophages To phagocytize foreign materials
Structure of Areolar connective tissue Abundant vascularized ground substance-gel like, scattered fibroblasts, elastic fibers, collagen fibers
Function of Areolar connective tissue Surrounds protects tissues and organs, loosely binds epithelial tissue to deeper tissue, provides nerve and bloodvessel packing
Location of Areolar connective tissue Subcutaneous layer and surrounds organs
Structure of Adipose connective tissue closely packed, nucleus to one side, slightly vascularized stores lipids
Function of Adipose connective tissue Stores energy, protects, cushions and insulates
Structure of Dense regular connective tissue Densely packed, parallel collagen fibers, fibroblast, nuclei squeezed btwn layers of fibers, scarce ground substance, looks like lasagna
Function of Dense regular connective tissue Attaches bone to bone and muscle to bone, resists stress applied in one direction
Location of Dense regular connective tissue Tendons and ligaments
Structure of Hyaline cartilage Glassy appearing matrix, lacunae house chondrocytes usually covered by perichondrium
Function of Hyaline cartilage Smooth surfaces provide for movement at joints, model for bone growth, supports soft tissue
Location of Hyaline cartilage Fetal skeleton, covers articular ends of long bones, most of larynx, trachea and nose
Structure of fibrocartilage Readily visible, parallel collagen in matrix, lacunae house chondrocytes and no perichondrium
Function of Fibrocartilage Resists compression, absorbs shock in some joints
Location of Fibrocartilage Internal vertebral discs, pubis symphysis, menisci of knee joints
Structure of Elastic cartilage Contains abundant elastic fibers, form a web like mesh around lacunae, chondrocytes and perichondrium
Function of Elastic cartilage Maintains structure and shape while permitting extensive flexiblity
Location of Elastic cartilage Ears and Epiglottis of larynx
Structure of compact bone Calcified matrix, Osteons-concentric lamellae, central canal, canaliculi, lacuna
Function of compact bone Supports soft tissue, protects vital organs, levers for movement, stores calcium and phosphorus
Location of Compact bone bones of the body
Structure of Fluid connective tissue – Blood Erythrocytes, leukocytes, platelets, plasma
Function of Fluid connective tissue – Blood transport, control immune response, clotting,
Function of erythrocytes Transport oxygen and some carbon dioxide
Function of leukocytes Initiate and control immune response
Function of platelets Responsible for blood clotting
Function of Plasma Transports waste, hormones, and nutrients
Location of Fluid connective tissue – Blood Blood vessels-arteries, veins, capillaries
Classification of muscle tissue Skeletal, cardiac, smooth
Structure of skeletal muscle tissue fibers are long, cylindrical, striated, parallel, unbranched, multinucleated-located along the periphery
Function of skeletal muscle tissue Moves skeleton responsible for voluntary body movements, locomotion, and heat production
Location of Skeletal muscle Attaches to bone, sometimes skin (facial muscles) voluntary muscles of sphincter, lips urethra, and anus
Structure of cardiac muscle Cells are short, bifurcated, striated, one or two centrally located nuclei, intercalated discs
Function of cardiac muscle Involuntary contraction and relaxation of heart, pumps blood
Location of Cardiac muscle Heart wall (myocardium)
Structure of Nervous tissue Neurons, rounded stellate cell bodies, axon, dendrite, glial cells- lack extensive fibrous processes
Location of Nervous tissue Brain, spinal cord, and nerves
Function of Nervous tissue Information processing, storage, retrieval, internal communication
Function of Glial cell Supports and protects neurons

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