Histology Histology Salt Lake Community College Salt Lake Community College BIO 2325 BIO 2325 Compiled by: Benjamin Sparks(Anatomy Laboratory Assistant) Compiled by: Benjamin Sparks(Anatomy Laboratory Assistant) Edited by: Claudia Gonzales (Anatomy Laboratory Assistant) Edited by: Claudia Gonzales (Anatomy Laboratory Assistant)
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HistologyHistologySalt Lake Community CollegeSalt Lake Community College
• Epithelium is a tissue composed Epithelium is a tissue composed of cells that line the cavities and of cells that line the cavities and surfaces of structures throughout surfaces of structures throughout the bodythe body
How to Identify EpitheliumHow to Identify Epithelium
1. Determine how many layers of cells .1. Determine how many layers of cells .
A. 1-Layer = SimpleA. 1-Layer = Simple
B. More than one layer = StratifiedB. More than one layer = Stratified
2. Determine the shape of those cells (squamous, 2. Determine the shape of those cells (squamous, cuboidal, columnar)cuboidal, columnar)
• Structure: Single layer of thin, flat, irregularly-shaped Structure: Single layer of thin, flat, irregularly-shaped cells resembling floor tiles; the single nucleus of each cell cells resembling floor tiles; the single nucleus of each cell bulges at its centerbulges at its center
• Function: Rapid diffusion, filtration, and some secretion Function: Rapid diffusion, filtration, and some secretion in serous membranesin serous membranes
• Location: Air sacs in lungs (alveoli); lining lumen of blood Location: Air sacs in lungs (alveoli); lining lumen of blood vessels (endothelium); serous membranes of body vessels (endothelium); serous membranes of body cavities (mesothelium)cavities (mesothelium)
• Structure: Multiple layers of cells; basal cells typically are Structure: Multiple layers of cells; basal cells typically are cuboidal or columnar, while apical (superficial) cells cuboidal or columnar, while apical (superficial) cells appear squamous; more superficial cells are dead and appear squamous; more superficial cells are dead and filled with the protein keratinfilled with the protein keratin
• Function: Protection of underlying tissueFunction: Protection of underlying tissue
• Location: Epidermis of the skinLocation: Epidermis of the skin
• Structure: Multiple layers of cells; basal cells typically are Structure: Multiple layers of cells; basal cells typically are cuboidal or polyhedral, while apical (superficial) cells are cuboidal or polyhedral, while apical (superficial) cells are squamous; surface cells are alive and kept moistsquamous; surface cells are alive and kept moist
• Function: Protection of underlying tissueFunction: Protection of underlying tissue
• Location: Lining of oral cavity, part of pharynx, Location: Lining of oral cavity, part of pharynx, esophagus, vagina and anusesophagus, vagina and anus
• Structure: Single layers of cells about as tall as they are Structure: Single layers of cells about as tall as they are wide; spherical, centrally located, often round, nucleuswide; spherical, centrally located, often round, nucleus
• Function: Absorption and secretionFunction: Absorption and secretion
• Location: Thyroid gland follicles; kidney tubules; ducts Location: Thyroid gland follicles; kidney tubules; ducts and secretory regions of many glandsand secretory regions of many glands
• Structure: Two or more layers of cells; cells at the apical Structure: Two or more layers of cells; cells at the apical surface are cuboidalsurface are cuboidal
• Function: Protection and secretionFunction: Protection and secretion
• Location: Found in large ducts in most exocrine glands Location: Found in large ducts in most exocrine glands and in some parts of the male urethraand in some parts of the male urethra
• Structure: Single layer of tall, narrow, ciliated cells; Structure: Single layer of tall, narrow, ciliated cells; oval-shaped nucleus oriented lengthwise in the basal oval-shaped nucleus oriented lengthwise in the basal region of the cell; goblet cells may be presentregion of the cell; goblet cells may be present
• Function: Secretion of mucin and movement of mucus Function: Secretion of mucin and movement of mucus along apical surface of epithelium by action of cilia; along apical surface of epithelium by action of cilia; oocyte movement through uterine tubeoocyte movement through uterine tube
• Location: Lining of uterine tubes and larger Location: Lining of uterine tubes and larger bronchioles of respiratory tractbronchioles of respiratory tract
• Structure: Single layer of columnar cells, often with oval-Structure: Single layer of columnar cells, often with oval-shaped nuclei oriented lengthwise in cell; may contain shaped nuclei oriented lengthwise in cell; may contain goblet cells; apical surface may have microvilligoblet cells; apical surface may have microvilli
• Function: Absorption, secretion; secretion of mucin. Function: Absorption, secretion; secretion of mucin.
• Location: Lining most of GI tractLocation: Lining most of GI tract
• Structure: Two or more layers of cells; cells at the apical Structure: Two or more layers of cells; cells at the apical surface are columnarsurface are columnar
• Function: Protection and secretionFunction: Protection and secretion
• Location: Rare; found in large ducts of some exocrine Location: Rare; found in large ducts of some exocrine glands and in some regions of the male urethraglands and in some regions of the male urethra
• Structure: Single layer of cells with varying heights Structure: Single layer of cells with varying heights that appears multilayered; all cells connect to the that appears multilayered; all cells connect to the basement membrane, but not all cells reach the basement membrane, but not all cells reach the apical surface. Ciliated form has goblet cells and apical surface. Ciliated form has goblet cells and cilia; nonciliated form lacks goblet cells and ciliacilia; nonciliated form lacks goblet cells and cilia
• Function: Protection; ciliated form also involved in Function: Protection; ciliated form also involved in secretion of mucin and movement of mucus across secretion of mucin and movement of mucus across surface by ciliary actionsurface by ciliary action
• Location: Ciliated form lines most of the Location: Ciliated form lines most of the respiratory tract, including nasal cavity, part of the respiratory tract, including nasal cavity, part of the pharynx, larynx, trachea, bronchi. Non-ciliated is pharynx, larynx, trachea, bronchi. Non-ciliated is rare and lines epididymis and part of male urethra.rare and lines epididymis and part of male urethra.
• Structure: Epithelial appearance varies, depending on Structure: Epithelial appearance varies, depending on whether the tissue is stretched or relaxed; shape of cells whether the tissue is stretched or relaxed; shape of cells at apical surface changes; some cells may be at apical surface changes; some cells may be binucleatedbinucleated
• Function: Distention and relaxation to accommodate Function: Distention and relaxation to accommodate urine volume changes in bladder, ureters, and urethraurine volume changes in bladder, ureters, and urethra
• Location: Lining of the urinary bladder, ureters, and Location: Lining of the urinary bladder, ureters, and part of urethra part of urethra
Transitional EpitheliumTransitional Epithelium
Transitional EpitheliumTransitional Epithelium
Transitional EpitheliumTransitional Epithelium
Connective TissueConnective Tissue
• Connective tissue is the most diverse tissue. It is Connective tissue is the most diverse tissue. It is widespread although not exposed to the outside of the widespread although not exposed to the outside of the body. Except for cartilage, it is highly vascular. It has body. Except for cartilage, it is highly vascular. It has widely scattered cells with lots of space between each widely scattered cells with lots of space between each cell.cell.
• Functions: Protection (bone, fat), support (bone, Functions: Protection (bone, fat), support (bone, cartilage), binding together (tendons, ligaments), cartilage), binding together (tendons, ligaments), storage of fat (bone marrow), disease fighting (blood), storage of fat (bone marrow), disease fighting (blood), and production of certain blood cells.and production of certain blood cells.
BloodBlood
• Structure: Contains erythrocytes, leukocytes, and platelets; Structure: Contains erythrocytes, leukocytes, and platelets; soluble (dissolved) protein fibers and a watery ground soluble (dissolved) protein fibers and a watery ground substance form a fluid extracellular matrix called plasmasubstance form a fluid extracellular matrix called plasma
• Function: Erythrocytes transport oxygen and some carbon Function: Erythrocytes transport oxygen and some carbon dioxide. Leukocytes initiate and control immune response. dioxide. Leukocytes initiate and control immune response. Plasma contains clotting elements to stop blood loss. Plasma contains clotting elements to stop blood loss. Platelets help with blood clotting. Plasma transports Platelets help with blood clotting. Plasma transports nutrients, wastes, and hormones throughout the bodynutrients, wastes, and hormones throughout the body
• Location: Primarily within blood vessels (arteries, veins, Location: Primarily within blood vessels (arteries, veins, capillaries) and the heart; leukocytes are also located in capillaries) and the heart; leukocytes are also located in lymphatic organs and can migrate to infected or inflamed lymphatic organs and can migrate to infected or inflamed tissue in the bodytissue in the body
• Structure: Gel-like substance with scattered reticular Structure: Gel-like substance with scattered reticular fibers, fibroblasts, white blood cells and extracellular fibers, fibroblasts, white blood cells and extracellular matrixmatrix
• Function: Provides supportive framework for some Function: Provides supportive framework for some spleen, lymph nodes, thymus, and bone marrow.spleen, lymph nodes, thymus, and bone marrow.
• Location: Forms functional portion (stroma) of lymph Location: Forms functional portion (stroma) of lymph nodes, spleen, thymus, bone marrownodes, spleen, thymus, bone marrow
• Structure: Closely packed adipocytes (fat cells); nucleus Structure: Closely packed adipocytes (fat cells); nucleus squeezed to one side by large fat dropletsqueezed to one side by large fat droplet
• Function: Stores energy; protects, cushions, and Function: Stores energy; protects, cushions, and insulatesinsulates
• Location: Subcutaneous layer; covers and surrounds Location: Subcutaneous layer; covers and surrounds some organssome organs
• Structure: Densely packed, parallel collagen fibers; Structure: Densely packed, parallel collagen fibers; fibroblast nuclei squeezed between layers of fibers; fibroblast nuclei squeezed between layers of fibers; scarce ground substancescarce ground substance
• Function: Attaches muscle to bone and bone to bone; Function: Attaches muscle to bone and bone to bone; Resists stress applied in one directionResists stress applied in one direction
• Location: Forms tendons, most ligamentsLocation: Forms tendons, most ligaments
• Structure: Freely branching elastic fibers+; fibroblast Structure: Freely branching elastic fibers+; fibroblast cells occupy some spaces between fiberscells occupy some spaces between fibers
• Function: Allows stretching of some organsFunction: Allows stretching of some organs
• Location: Walls of elastic arteries, trachea, bronchial Location: Walls of elastic arteries, trachea, bronchial tubes and suspensory ligaments of penis; forms true tubes and suspensory ligaments of penis; forms true vocal cordsvocal cords
• Structure: Predominantly collagen fibers, randomly Structure: Predominantly collagen fibers, randomly arranged and clumped together; fibroblasts in spaces arranged and clumped together; fibroblasts in spaces among fibers; more ground substance that in dense among fibers; more ground substance that in dense regular connective tissueregular connective tissue
• Function: Withstands stresses applied in all directions; Function: Withstands stresses applied in all directions; durabledurable
• Location: Dermis; periosteum covering bone; Location: Dermis; periosteum covering bone; perichondrium covering cartilage, and organ capsulesperichondrium covering cartilage, and organ capsules
• Structure: Compact bone: Calcified matrix in osteons Structure: Compact bone: Calcified matrix in osteons (concentric lamellae arranged around a central canal (concentric lamellae arranged around a central canal containing blood vessels)contains osteocytes is lacunae containing blood vessels)contains osteocytes is lacunae and canaliculiand canaliculi
• Function: Supports soft structures; protects vital Function: Supports soft structures; protects vital organs; provides levers for movement; stores calcium organs; provides levers for movement; stores calcium and phosphorus.and phosphorus.
• Location: Bones of the bodyLocation: Bones of the body
Compact BoneCompact Bone
Compact BoneCompact Bone
Compact BoneCompact Bone
Identify the structures at the arrows.
Compact BoneCompact Bone
Canaliculi
Central Canal
Osteocyte in Lacunae
Hyaline CartilageHyaline Cartilage
• Structure: Glassy appearing extracellular matrix; Structure: Glassy appearing extracellular matrix; lacunae house chondrocytes; usually covered by lacunae house chondrocytes; usually covered by perichondriumperichondrium
• Function: Smooth surfaces for movement at joints; Function: Smooth surfaces for movement at joints; model for bone growth; supports soft tissuemodel for bone growth; supports soft tissue
• Location: Most of fetal skeleton; covers articular ends Location: Most of fetal skeleton; covers articular ends of long bones; costal cartilage; most of the larynx, of long bones; costal cartilage; most of the larynx, trachea, and nosetrachea, and nose
• Structure: Readily visible, parallel collagen fibers in Structure: Readily visible, parallel collagen fibers in extracellular matrix; lacunae house chondrocytes; no extracellular matrix; lacunae house chondrocytes; no perichondriumperichondrium
• Function: Resists compression; absorbs shock in some Function: Resists compression; absorbs shock in some jointsjoints
• Structure: Contains abundant elastic fibers; elastic fibers form Structure: Contains abundant elastic fibers; elastic fibers form web-like mesh around lacunae with chondrocytes; web-like mesh around lacunae with chondrocytes; perichondrium presentperichondrium present
• Function: Maintain structure and shape while permitting Function: Maintain structure and shape while permitting extensive flexibilityextensive flexibility
• Location: External ear; epiglottis of the larynxLocation: External ear; epiglottis of the larynx
Elastic CartilageElastic Cartilage
Elastic CartilageElastic Cartilage
Chondrocyte in Lacunae
Identify the structures at the arrows.
Elastic CartilageElastic Cartilage
Elastic CartilageElastic Cartilage
Elastic CartilageElastic Cartilage
Elastic CartilageElastic Cartilage
Muscle TissueMuscle Tissue
• Cells are long and narrow and are called fibersCells are long and narrow and are called fibers
• Functions through contraction in motion, posture, and Functions through contraction in motion, posture, and heat productionheat production
How to Identify MuscleHow to Identify Muscle
1. Look for the differences in the types of tissues (Look at 1. Look for the differences in the types of tissues (Look at what is in bold on the following slidewhat is in bold on the following slide
2. Look for the structures that are particular to that type 2. Look for the structures that are particular to that type of muscle tissue onlyof muscle tissue only
Muscle TissueMuscle TissueType of Muscular Tissue
Skeletal Muscle Smooth Muscle Cardiac Muscle
Shape of Fibers Elongated; blunt ends
Elongated, Tapered ends
Elongated; Blunt ends
Nucleus: # and Location
Multinucleated, peripheral
Uninucleated, central Uninucleated, central
Striated or Non-striated
Striated Non-striated Striated
Branched or Unbranched
Unbranched Unbranched Branched (Bifurcated and Intercalated Discs)
Involuntary of Voluntary
Voluntary Involuntary Involuntary
Location in Body Attached to bones Walls of hollow, internal organs, and tubes
Only in wall of Heart (Myocardium)
Speed of Contraction Fastest Slowest Intermediate
Ability to Remain Contracted
Least Greatest Intermediate
Smooth Muscle TissueSmooth Muscle Tissue
• Structure: Cells are fusiform (spindle-shaped), short, Structure: Cells are fusiform (spindle-shaped), short, non-striated, and contain one centrally located nucleusnon-striated, and contain one centrally located nucleus
• Function: Involuntary movements and motion; moves Function: Involuntary movements and motion; moves materials through internal organsmaterials through internal organs
• Location: Walls of hollow internal organs, such as vessels, Location: Walls of hollow internal organs, such as vessels, airways, stomach, bladder, uterusairways, stomach, bladder, uterus
Smooth Muscle TissueSmooth Muscle Tissue
Smooth Muscle TissueSmooth Muscle Tissue
Note: The tissue is Non-striated
Skeletal MuscleSkeletal Muscle
• Structure: Fibers are long, cylindrical, striated, parallel, Structure: Fibers are long, cylindrical, striated, parallel, and unbranched; fibers are multinucleated with nuclei and unbranched; fibers are multinucleated with nuclei along peripheryalong periphery
• Function: Moves skeleton; responsible for voluntary Function: Moves skeleton; responsible for voluntary body movements, locomotion, heat productionbody movements, locomotion, heat production
• Location: Attaches to bones or sometimes to skin (e.g. Location: Attaches to bones or sometimes to skin (e.g. facial muscles); also found in the voluntary sphincters-facial muscles); also found in the voluntary sphincters-lips, urethra, anuslips, urethra, anus
Skeletal MuscleSkeletal Muscle
Skeletal MuscleSkeletal Muscle
Identify the structures at the arrows.
Skeletal MuscleSkeletal Muscle
(Multiple) nuclei
striations
Cardiac MuscleCardiac Muscle
• Structure: Cells are short, bifurcated, and striated, with Structure: Cells are short, bifurcated, and striated, with one or two centrally located nuclei; intercalated discs one or two centrally located nuclei; intercalated discs between cellsbetween cells
• Function: Involuntary contraction and relaxation pump Function: Involuntary contraction and relaxation pump blood in heartblood in heart
• Structure: Contains neurons with rounded or stellate Structure: Contains neurons with rounded or stellate cell bodies and an axon and dendrites extending from cell bodies and an axon and dendrites extending from the cell body; glial cells lack such extensive fibrous the cell body; glial cells lack such extensive fibrous processesprocesses
• Function: Function: NeuronsNeurons: Responsible for control; : Responsible for control; information processing, storage, and retrieval; internal information processing, storage, and retrieval; internal communication. communication. Glial CellsGlial Cells: Support and protect : Support and protect neuronsneurons
• Location: Brain, spinal cord, and nervesLocation: Brain, spinal cord, and nerves
Nervous TissueNervous Tissue
Nervous TissueNervous Tissue
Nervous TissueNervous Tissue
Nervous TissueNervous Tissue
Layers of the IntegumentLayers of the Integument
Integument ModelIntegument Model
Key to Integument ModelKey to Integument Model• 1 - Stratum corneum1 - Stratum corneum