CHAPTER 3: CELLS AND TISSUES

CHAPTER 3: CELLS AND TISSUESMicroscope Lab: Letter e

Anatomy of a Generalized CellDid you hear?! QUIZ tomorrow on these structures and functions!

Anatomy of a Generalized Cell: QUIZ

VOYAGE INSIDE THE CELL 15 min

Cell DiversityThere are seven primary types of cells found in humans. These types are defined by what they do.

REFER to TXT Figure 3.7 pg 65 and descriptions found in text.1. Cells that connect body parts.

A. FibroblastElongated shapeFibrous Lots of Rough ER Big Golgi Complex


REFER to TXT Figure 3.7 pg 65 and descriptions found in text.1. Cells that connect body parts.

B. ErythrocyteRed blood cellsCarries oxygenConcave shape provides extra surface area to take on oxygen No organelles


REFER to TXT Figure 3.7 pg 65 and descriptions found in text.Cells that cover and line body organs.

Epithelial CellHexagonal shapePack into sheets Intermediate filaments Resists tearing


REFER to TXT Figure 3.7 pg 65 and descriptions found in text.3. Cells that move organs and body parts. A. Skeletal and Smooth muscle cells.

Elongated shape Lots of contractile filaments Flash:Insane Feats of Strength


REFER to TXT Figure 3.7 pg 65 and descriptions found in text.4. Cells that store nutrients. Fat Cells

Made of a cell that becomes filled with a lipid droplet. www.blobs.orgEmpty CellFilled CellTeenage Obesity 30:00 http://player.discoveryeducation.com/index.cfm?guidAssetId=9F3F8962-C7F4-49F5-8D7A-15C990C343D3&blnFromSearch=1&productcode=US#


REFER to TXT Figure 3.7 pg 65 and descriptions found in text.Cells that fight disease

Macrophage Cells Contain lots of lysosomes and use pseudopods (false feet) to capture disease units.www.blobs.orgFlash: Macrophage Cytokine Releaserelfe.com


Cells that gather information and control body functions.

Nerve Cells (Neurons) Have long extensions called Processes that receive and send messages.www.blobs.org


7. Cells used for reproductionEgg Cells (Oocyte)Female reproductive cell

Sperm Cells Male reproductive cellwww.blobs.org

Membrane TransportSolution = homogeneous mixture of two or more components.Solute = the substance present in the smallest amount in the solution.Example: Kool-Aid dissolved in WaterWater is the solvent. Kool-Aid is the solute.Intracellular Fluid = fluid within the cellInterstitial Fluid = fluid around the outside of the cellContains nutrients, regulatory substances like hormones, salts, waste products.Each cell pulls what it needs from the interstitial fluid and deposits waste into the interstitial fluid.

Membrane is made of special kind of lipid phospholipidssplit personalityMembrane is a double layer phospholipid bilayer lipidrepelled by waterattracted to waterphosphateMembrane Transport

Semi-permeable membraneCell membrane controls what gets in or outNeed to allow some materials but not all to pass through the membrane semi-permeable (semi partly)only some materials can get in or outaaH2OsugarlipidssaltwasteSo what needs to get across the membrane?O2Membrane Transport

Crossing the cell membraneWhat molecules can get through the cell membrane without doors or help?fats and oils can pass directly through lipidsaltaaH2Osugarwastebutwhat about other stuff?Membrane Transport

Cell membrane protein channelsNeed to make doors through membrane protein channels allow substances in & outspecific channels allow specific material in & outH2O channel, salt channel, sugar channel, etc.inside celloutside cellwastesaltH2OaasugarMembrane Transport

Channels are made of proteinsproteins both like water & like lipidsbi-lipidmembraneprotein channels in bi-lipid membraneMembrane Transport

Protein channels (cont.)Proteins act as open doors in the membranechannels to move specific molecules through cell membraneHIGHLOWConcentration gradientSugar moleculesMembrane Transport

Simple Diffusion Move from HIGH to LOWinside celloutside cellWhich way will these fat molecules move?fatfatfatfatfatfatfatfatfatfatfatfatfatfatLOWHIGHMembrane Transport

Facilitated DiffusionMove from HIGH to LOW through a channel inside celloutside cellsugarsugarsugarsugarsugarsugarsugarsugarsugarsugarsugarWhich way will sugar move?sugarsugarLOWHIGHMembrane Transport

Membrane TransportFiltration = movement of water and solutes across a membrane as a result of hydrostatic pressure usually exerted by the blood.

Cells may need to move molecules against concentration gradient need to pump uphillfrom LOW to HIGH using energySolute PUMPRequires ATPATP

Membrane TransportBulk TransportExocytosis = movement of substances OUT of the cell.Endocytosis = movement of substances INTO the cell.

Movement of Water Across Cell Membrane

Osmosisdiffusion of water from high concentration of WATER to low concentration of wateracross a semi-permeable membraneHighLowMembrane Transport

Maintaining HomeostasisCell survival depends on balancing water uptake & water lossfreshwaterbalancedsaltwaterMembrane Transport

Cell ProcessesMitosis = Division of one cell into two identical cells.Interactive Mitosis http://www.cellsalive.com/mitosis.htm

Cell ProcessesProtein Synthesis =Processes that use DNA to create proteins.

BODY TISSUES: EPITHELIAL TISSUESTissues = groups of cells that are similar in structure and functionEpithelium: (epithe = covering) tissues of linings, coverings or glandsFunctions:ProtectionAbsorptionSecretion

Characteristics:1. Fit closely together.Held together by desmosomes and tight junctions.Always have one free edge called the apical surface that is exposed to the bodys exterior or an organ cavity.Lower surface rests on a basement membrane which it secretes.Avascular = No blood supply of their own.Regeneration = ability to make more of themselves.

BODY TISSUES: EPITHELIAL TISSUESSimple Epithelium = one layer of cellsStratified Epithelium = more than one layer of cellsPseudostratified Epithelium = one layer that looks like two.

Squamous = flatCuboidal = short cubesColumnar = tall columns

BODY TISSUES: EPITHELIAL TISSUESSimple Squamous EpitheliaCharacteristics: One layer. Look like floor tiles. Found in membranes where filtration or exchange of substances occurs.

Examples: Lining of air sacs in lungs. Walls of capilaries. Serosae = slick membranes lining the body cavity and covering organs.Why would this type of tissue need to be thin?

BODY TISSUES: EPITHELIAL TISSUESSimple Cuboidal EpitheliaCharacteristics: One layer. Look like cubes packed together. Found in glands and ducts.

Examples:Salivary glandsPancreasKidney tubules

BODY TISSUES: EPITHELIAL TISSUESSimple Columnar EpitheliaCharacteristics: One layer. Look like columns packed together. Found in body cavities. Goblet Cells = produce lubricating mucus.

Examples:Digestive tractMucosae = lining of body cavities that open to exterior.

BODY TISSUES: EPITHELIAL TISSUESPseudostratified Columnar EpitheliaCharacteristics: One layer. Looks like two layers because some cells are shorter than others. (pseudo = false) Functions in absorption and secretion. Some have cilia.

Examples:Respiratory tractciliante-serveur.univ-lyon1.fr

BODY TISSUES: EPITHELIAL TISSUESStratified Squamous EpitheliaCharacteristics: Multiple layers. Most common stratified tissue. Cells at free edge are squamous. Cells at basement membrane can be columnar or cuboidal. Found where abuse or friction occurs.

Examples:EsophagusMouthOuter skin

BODY TISSUES: EPITHELIAL TISSUESStratified Cuboidal or Columnar EpitheliaCharacteristics:Multiple layers.Rare.Found in ducts of large glands.

Examples:Salivary glandsnte-serveur.univ-lyon1.fr

BODY TISSUES: EPITHELIAL TISSUESTransitional EpitheliaCharacteristics:Multiple layers.Highly modified.Forms lining of a few organs.

Examples:BladderUretersUrethrante-serveur.univ-lyon1.fr

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueCartilage tissue: softer than bone, more flexible.Hyaline cartilage = lots of collagen fibers hidden by rubbery matrix that looks like glass (hyalin = glass).

Function: LarynxRibs to breastboneEnds of bones at jointsFetal bones

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueCartilage tissue: softer than bone, more flexible.Elastic cartilage Fibrocartilage = highly compressible cushionlike discs between vertebrae.

Function: Vertebral cushioning

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueDense Connective/Fibrous tissue: collagen matrix.Fibroblasts = fiber-forming cells between collagen fibers.Strong, rope-like structures.Tendon = attaches skeletal muscles to bones.Ligament = attaches bones to bones.

Function: Connections

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueAreolar tissue: Most widely distributed. Soft, pliable. Acts as a glue to hold organs together and in their places. Lamina propria = areolar tissue that underlies all mucosa epithelium. Looks like mostly space (aerola = small open space)

Function: Cushions and protectsAbsorbs waste materials

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueAdipose tissue:Commonly called FAT.Areolar tissue in which fat cells predominate.

Function: Subcutaneous layer under skin.InsulationProtection

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueReticular Connective tissue:Associated with reticular cells (similar to fibroblasts).

Function: Forms Stroma (framework) that supports free blood cells in lymph nodes, spleen, and bone marrow.

BODY TISSUES: CONNECTIVE TISSUESTypes of Connective TissueBlood:Also called vascular tissue.Made of blood cells surrounded by blood plasma (fluid).

Function: Transports oxygen, nutrients, water, etc.

BODY TISSUES: MUSCLE TISSUES Highly Specialized to contract or shorten. Elongated. Also called muscle fibers.

Function: Produces movement.

BODY TISSUES: MUSCLE TISSUESSkeletal Muscle: connective sheets attached to skeleton voluntarily controlled cells are long, cylindrical, and multinucleate (many nuclei)

Function: Movement

BODY TISSUES: MUSCLE TISSUESCardiac Muscle: Found only in heart. Has striations. Fit together at intercalated disks (like clasped fingers). Gap junctions allow ions to pass freely from cell to cell which produces electrical beat. Involuntary muscle.

Function: Pumps blood.

BODY TISSUES: MUSCLE TISSUESSmooth Muscle: Also called visceral muscle. No striations. Found in walls of hollow organs (stomach, blood vessels, uterus, etc.) Makes cavity of organ smaller or larger. Peristalsis = wavelike motion that keeps food moving through the digestive system.

Function: Pushes substances through an organ along a specific pathway.

Peristalsis http://www.mennellmedia.co.uk/VideoProjects/Peristalsis/Peristalsis.html

BODY TISSUES: NERVOUS TISSUESNervous Tissue: Neurons = cells making up nervous tissues. Neurons receive and conduct electrical impulses in the form of chemicals. Has supporting cells to help protect and insulate.

FUNCTION: Irritability and conductivity.

TISSUE REPAIR How tissue repair works:

Regeneration = replacement of destroyed tissue by the same kind of cells.

Fibrosis = repair by the formation of scar tissue.Scar tissue = connective tissue used for repair.Method of repair depends on1. type of tissue damaged2. severity of the injury

Generally speaking, clean cuts (incisions) heal better than ragged tears (lacerations).

BODY TISSUES: NERVOUS TISSUESWound healing:

Capillaries become permeable.Clotting agents enter wound area.http://adam.about.com/care/Blood-clotting-animation.htm3. Clot exposed to air forms a scab.Refer to pg 85 Fig 3.21


Granulation Tissue forms. (Pink tissue composed of mostly capillaries that grow into the damaged area.)

Phagocytes in granulation tissue will dispose of clot and tissues that are no longer needed.


6. Fibroblasts synthesize collagen fibers (scar tissue) to fill in the gap.Matrix fibers (blue) Growth factors (green)Smooth muscle protein (red)


Surface epithelium regenerates under the scab.

Scab detaches.

New epithelium covers underlying scar tissue (scar tissue may be visible or not).

NOTE: Scar tissue cannot perform the function of the tissue it has replaced.

DEVELOPMENTAL ASPECTS OF CELLS AND TISSUESLife begins as a single celland that cell gives rise to a wide variety of cells.

DEVELOPMENTAL ASPECTS OF CELLS AND TISSUESMost cells (except neurons) continue to divide until puberty.

Skin and intestinal cells regenerate continually.

Liver cells will regenerate as needed.

Heart and nerve cells become amitotic (cannot replace lost cells).

DEVELOPMENTAL ASPECTS OF CELLS AND TISSUESAging begins once maturity is reached.Aging man http://www.dlwaldron.com/ageproganimat.htmlEnvironmental factors can affect the aging process.

DEVELOPMENTAL ASPECTS OF CELLS AND TISSUESOther modifications of cells and tissue can occur at any time.

Neoplasm = cells that fail to stop multiplyingBenign = nonspreadingMalignant = spreading

Hyperplasia = enlargement of tissues/organsex. Anemia leads to bone marrow hyperplasiaex. Breast enlargement during pregnancyHemangioma The large red mass within the tongue most likely represents a benign neoplasm of blood vessels--a "hemangioma." Hemorrhage is the most common complication of such lesions

HyperplasiaHyperplasia of the vaginal area in a canine.

Hyperplasia of breast during pregnancy.

DEVELOPMENTAL ASPECTS OF CELLS AND TISSUESAtrophy = decrease in size

Can occur if the tissue loses its normal stimulation.Atrophied brain (left side) of patient with Huntingtons disease.Atrophied bone marrow due to osteoporosis.

A new locus for recessive distal spinal muscular atrophy

CSI: Autopsy 3:55 http://video.nationalgeographic.com/video/player/science/health-human-body-sci/human-body/real-csi-sci.htmlCanine Bone Repair 2:49 http://www.myvnn.com/page.asp?id=39&media_type=11&story_id=105Assignment:TXT pg 89 1-11 TXT pg 90 At the Clinic #1 and #3

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CHAPTER 3: CELLS AND TISSUES