unit 3: cells and tissues ch. 3, 5. cell basics cells are the basic unit of structure and function...

UNIT 3: CELLS AND UNIT 3: CELLS AND TISSUESTISSUES

CH. 3, 5CH. 3, 5

Cell BasicsCell Basics

Cells are the basic unit of structure and Cells are the basic unit of structure and function of living thingsfunction of living thingsPancreas produces insulinPancreas produces insulin

Individual acinar cells produce the protein insulin Individual acinar cells produce the protein insulin and dump into blood stream and dump into blood stream action is the result action is the result of individual cellsof individual cells

Bone is collection of osteocytes – bone cellsBone is collection of osteocytes – bone cellsStructure is repeating units of bone cellsStructure is repeating units of bone cells

Cell Basics - OrganellesCell Basics - Organelles NucleusNucleus – controls cellular activity; – controls cellular activity;

contains DNAcontains DNA ChromatinChromatin – uncoiled strands of DNA – uncoiled strands of DNA

MitochondriaMitochondria – powerhouse of the – powerhouse of the cell; site of aerobic respirationcell; site of aerobic respiration

RibosomesRibosomes – site of protein synthesis – site of protein synthesis Can be attached to ER or free floating Can be attached to ER or free floating

in cytoplasmin cytoplasm CentrosomeCentrosome – microtubules arranged – microtubules arranged

in “T” formation involved in cell in “T” formation involved in cell reproductionreproduction

a.k.a centriolesa.k.a centrioles LysosomeLysosome – contains digestive – contains digestive

enzymes enzymes Phagocytes (WBC)Phagocytes (WBC)

PeroxisomePeroxisome – contains catalase to – contains catalase to decompose hydrogen peroxide into decompose hydrogen peroxide into water and oxygenwater and oxygen HH22OO22 H H22O + OO + O22

Endoplasmic reticulumEndoplasmic reticulum – folds of – folds of interior membranesinterior membranes

Smooth – lipid, carb metabolism; Smooth – lipid, carb metabolism; detoxificationdetoxification

Rough – protein synthesis (ribosomes Rough – protein synthesis (ribosomes attached)attached)

Golgi AppartusGolgi Appartus – packages, modifies – packages, modifies proteins; gets ready for transportproteins; gets ready for transport

VesicleVesicle – membrane bound storage – membrane bound storage unitunit

CytoskeletonCytoskeleton – microtubules and – microtubules and microfilaments that provide a microfilaments that provide a framework for cell shapeframework for cell shape

ciliacilia – short, hair-like projections – short, hair-like projections Move substance across surfaceMove substance across surface Respiratory and Female Reproductive Respiratory and Female Reproductive

SystemsSystems FlagellaFlagella – longer, hair/tail like – longer, hair/tail like

projectionprojection Used for cellular locomotion - spermUsed for cellular locomotion - sperm

Movement of Materials Into and Movement of Materials Into and Out of the CellOut of the Cell

Diffusion – passive (no energy) process of materials moving from a Diffusion – passive (no energy) process of materials moving from a high concentration to a lower concentrationhigh concentration to a lower concentration Diffusion of gases (ODiffusion of gases (O22/CO/CO22) between blood an air (in lungs; alveoli) and ) between blood an air (in lungs; alveoli) and

between blood and tissues (capillaries)between blood and tissues (capillaries) Facilitated diffusion – diffusion through a proteinFacilitated diffusion – diffusion through a protein

Uses protein channel in cell membrane to get across barrierUses protein channel in cell membrane to get across barrier Osmosis – diffusion of waterOsmosis – diffusion of water

Hypertonic – higher concentration of solutesHypertonic – higher concentration of solutes Hypotonic – lower concentration of solutesHypotonic – lower concentration of solutes

Water will always flow towards hypertonic env.Water will always flow towards hypertonic env. A cell with 5% solute concentration is placed in distilled water A cell with 5% solute concentration is placed in distilled water gains water gains water A cell with 5% solute concentration is placed in sea water (15%) A cell with 5% solute concentration is placed in sea water (15%) loses loses

waterwater Filtration – uses differences in hydrostatic (water) pressure to drive Filtration – uses differences in hydrostatic (water) pressure to drive

materials across membranematerials across membrane Urinary system; capillary bedsUrinary system; capillary beds

Movement of Materials Into and Movement of Materials Into and Out of the CellOut of the Cell

Active Transport – use of energy (ATP) to drive materials from an Active Transport – use of energy (ATP) to drive materials from an area of lower concentration to an area of higher concentrationarea of lower concentration to an area of higher concentration Ion/proton pumpsIon/proton pumps Na+/K+ pump – necessary for establishing correct ionic concentrations Na+/K+ pump – necessary for establishing correct ionic concentrations

on both sides of a cell membraneon both sides of a cell membrane 3 Na+ out 3 Na+ out 2 K+ in2 K+ in Causes a buildup of Na+ out and K+ inCauses a buildup of Na+ out and K+ in

Endocytosis – bulk transport into the cellEndocytosis – bulk transport into the cell Pinocytosis – cell “drinking”Pinocytosis – cell “drinking”

Membrane indents Membrane indents liquids flow in liquids flow in membrane seals off membrane seals off fluid filled fluid filled vesicle formsvesicle forms

Phagocytosis – cell “eating”Phagocytosis – cell “eating” Membrane extends arms out Membrane extends arms out surrounds large solid particle surrounds large solid particle seals off seals off

forms vesicleforms vesicle Usually will fuse wit h lysosome to dissolve/digest contentsUsually will fuse wit h lysosome to dissolve/digest contents

Exocytosis – opposite of endocytosis; move large materials out Exocytosis – opposite of endocytosis; move large materials out

Cell ReproductionCell Reproduction Mitosis – making genetically identical cellsMitosis – making genetically identical cells

multicellular growth and repairmulticellular growth and repair Meiosis – making gametes with half the genetic Meiosis – making gametes with half the genetic

informationinformation Two gametes fuse to form zygote Two gametes fuse to form zygote mitosis reproduces copies mitosis reproduces copies

of zygote many times to form trillions of cells of babyof zygote many times to form trillions of cells of baby Phases of MitosisPhases of Mitosis

Interphase – individual cell growth; DNA replicationInterphase – individual cell growth; DNA replication Prophase Prophase \\ MetaphaseMetaphase \ organizes DNA and separates \ organizes DNA and separates AnaphaseAnaphase / chromosomes to opposite sides / chromosomes to opposite sides TelophaseTelophase / of cell/ of cell

Cytokinesis – division of cytoplasm and cell itselfCytokinesis – division of cytoplasm and cell itself

Cell ReproductionCell Reproduction Control of Cell Cycle – different tissues must reproduce at different Control of Cell Cycle – different tissues must reproduce at different

ratesrates If cells reproduce slower than normal tissue death If cells reproduce slower than normal tissue death holes result holes result

(stomach ulcers, skin lesions)(stomach ulcers, skin lesions) If cells reproduce to fast, tumors can result If cells reproduce to fast, tumors can result

Psoriasis – skin cells reproduce too fastPsoriasis – skin cells reproduce too fast Controlled by genes Controlled by genes

Cancer – loss of a cell’s ability to control the rate at which it divides; Cancer – loss of a cell’s ability to control the rate at which it divides; mitosis too fastmitosis too fast Problems with genes:Problems with genes:

Tumor Suppressor genes – usually turned on to slow cell division downTumor Suppressor genes – usually turned on to slow cell division down Caner results when genes are inactivatedCaner results when genes are inactivated

Oncogenes – normally turned offOncogenes – normally turned off Cancer results when genes are activatedCancer results when genes are activated

Tumor – a mass of unspecialized cellsTumor – a mass of unspecialized cells Benign – non-cancerousBenign – non-cancerous Malignant – cancerousMalignant – cancerous

Damages healthy tissue by: 1) nutrients flow to tumor, starve out Damages healthy tissue by: 1) nutrients flow to tumor, starve out healthy tissue; 2) pressure damage (can cut off blood flow)healthy tissue; 2) pressure damage (can cut off blood flow)

Metastasis – spread of cancer to other body partsMetastasis – spread of cancer to other body parts Usually associated with lymph and vascular systemsUsually associated with lymph and vascular systems Only takes 1 cancer cell to start new tumor (mitosis produces genetically Only takes 1 cancer cell to start new tumor (mitosis produces genetically

identical cells)identical cells)

Types of TissuesTypes of Tissues

Tissues – different types of cells working together for a Tissues – different types of cells working together for a common purposecommon purposeKinds:Kinds:

1)1) Epithelial Tissue – covering for organs, cavities and surfaces Epithelial Tissue – covering for organs, cavities and surfaces in generalin general

2)2) Connective Tissue – supports or binds different organs Connective Tissue – supports or binds different organs togethertogether

a)a) Can be used to fill spaces as wellCan be used to fill spaces as wellb)b) Can be very different in make-up: bone and blood are both types Can be very different in make-up: bone and blood are both types

of C. T.of C. T.

3)3) Muscle tissue – tissue specialized for contractile motionMuscle tissue – tissue specialized for contractile motiona)a) Skeletal, smooth and cardiacSkeletal, smooth and cardiac

4)4) Nervous tissue – tissue specialized for conduction of impulsesNervous tissue – tissue specialized for conduction of impulses

Epithelial TissuesEpithelial Tissues General CharacteristicsGeneral Characteristics

Acts as a coveringActs as a covering Free surface – opens to outsideFree surface – opens to outside Basement membrane – attached to surface that it is coveringBasement membrane – attached to surface that it is covering

Usually lacks blood vessels (Avascular)Usually lacks blood vessels (Avascular) Must be nourished via diffusion from underlying tissuesMust be nourished via diffusion from underlying tissues

Must reproduce rapidly; continually being replacedMust reproduce rapidly; continually being replaced Cells are tightly packed with little intercellular material between themCells are tightly packed with little intercellular material between them Function – covering, barrier, protectionFunction – covering, barrier, protection

Also can be specialized for secretion, absorption and excretionAlso can be specialized for secretion, absorption and excretion Important Terms for ClassificationImportant Terms for Classification

Simple – single row of cellsSimple – single row of cells Stratified – many layersStratified – many layers Squamous – short, flat cellsSquamous – short, flat cells Cuboidal – box-like shapeCuboidal – box-like shape Columnar – tall, elongated cellsColumnar – tall, elongated cells Ciliated – cilia on free surfaceCiliated – cilia on free surface

Epithelial TissuesEpithelial Tissues

Simple Squamous EpSimple Squamous Ep.. Single row of flattened cellsSingle row of flattened cells Thinnest of coveringsThinnest of coverings Allows substances to pass freely Allows substances to pass freely important for areas that important for areas that

need diffusion to happen between tissuesneed diffusion to happen between tissues Alveoli (air sacs) in lungs; capillary blood vesselsAlveoli (air sacs) in lungs; capillary blood vessels

Simple Cuboidal EpSimple Cuboidal Ep.. Single row of square shaped cellsSingle row of square shaped cells Central, spherical nucleiCentral, spherical nuclei Ovaries, kidney tubules, ducts of salivary glands, pancreas and Ovaries, kidney tubules, ducts of salivary glands, pancreas and

liverliver Simple Columnar Ep.Simple Columnar Ep.

Single layer of tall, elongated cellsSingle layer of tall, elongated cells Nuclei usually at same level, near basement membraneNuclei usually at same level, near basement membrane Digestive System – specialized for secretion and absorptionDigestive System – specialized for secretion and absorption

Microvilli – tiny folds on surface to increase absorptive surface areaMicrovilli – tiny folds on surface to increase absorptive surface area Goblet Cells – specialized cells for secreting mucusGoblet Cells – specialized cells for secreting mucus


Pseudostratified Columnar EpPseudostratified Columnar Ep.. Appear (pseudo- = fake) to be layered, but actually only a single layer of Appear (pseudo- = fake) to be layered, but actually only a single layer of

columnar cellscolumnar cells Nuclei are at different levels in cellsNuclei are at different levels in cells all cells reach basement membraneall cells reach basement membrane

Respiratory tract – cells line trachea, bronchi and larger bronchiolesRespiratory tract – cells line trachea, bronchi and larger bronchioles Ciliated – cilia on free surface act to move substances across surfaceCiliated – cilia on free surface act to move substances across surface Contain goblet cells for mucus productionContain goblet cells for mucus production

Also found in reproductive tubes to move female sex cells Also found in reproductive tubes to move female sex cells Stratified Squamous EpStratified Squamous Ep..

Many layers of flattened cellsMany layers of flattened cells Cuboidal cells near basement membrane; flattened near free surfaceCuboidal cells near basement membrane; flattened near free surface

Cells reproduce near basement membrane; flattened as they are pushed awayCells reproduce near basement membrane; flattened as they are pushed away Epidermis of skinEpidermis of skin

Keritinization – older cells accumulate “keratin” – protein that hardens and waterproofs Keritinization – older cells accumulate “keratin” – protein that hardens and waterproofs the cellsthe cells

Also lines cavities that open directly to outside world: mouth, vagina, anal canalAlso lines cavities that open directly to outside world: mouth, vagina, anal canal Stratified Cuboidal EpStratified Cuboidal Ep..

Two or three layers of cuboidal cellsTwo or three layers of cuboidal cells Generally lines lumen (cavity of a tube)Generally lines lumen (cavity of a tube) Larger gland ducts – mammary, sweat, salivary and pancreasLarger gland ducts – mammary, sweat, salivary and pancreas Ovarian follicles (Female Rep. Sys.) and seminiferous tubules (Male Rep. Sys.)Ovarian follicles (Female Rep. Sys.) and seminiferous tubules (Male Rep. Sys.)


Stratified Columnar EpStratified Columnar Ep.. Many layers of columnar cellsMany layers of columnar cells

Cells near basement membrane are cuboidal; elongate as they reach free Cells near basement membrane are cuboidal; elongate as they reach free surfacesurface

Male urethra, Vas Deferens, parts of pharynxMale urethra, Vas Deferens, parts of pharynx Transitional Ep.Transitional Ep.

Specialized layers to respond to changes in tensionSpecialized layers to respond to changes in tension Must be able to expand when organ expands and tighten when organ Must be able to expand when organ expands and tighten when organ

emptiesempties Bladder and passages of urinary systemBladder and passages of urinary system

Glandular EpGlandular Ep.. Cells that are specialized to produce and secrete substances into tubes Cells that are specialized to produce and secrete substances into tubes

(ducts) or body fluids(ducts) or body fluids ExocrineExocrine – secrete into ducts that lead to internal or external surfaces – secrete into ducts that lead to internal or external surfaces

See Classification Types – P141See Classification Types – P141 Simple, compound, tubular, alveolarSimple, compound, tubular, alveolar Also classified by how they secreteAlso classified by how they secrete

MerocrineMerocrine – substance only – substance only ApocrineApocrine – substance + part of cell cytoplasm – substance + part of cell cytoplasm HolocrineHolocrine – substance + all of cell interior – substance + all of cell interior

EndocrineEndocrine – secrete directly into body fluids (commonly blood) – secrete directly into body fluids (commonly blood) Endocrine glands revisited in Ch. 13Endocrine glands revisited in Ch. 13

Connective TissueConnective Tissue

General CharacteristicsGeneral Characteristics Most abundant by weightMost abundant by weight Main function – bind structures togetherMain function – bind structures together

Also provide support and protection; framework; fill spaces; store fat; Also provide support and protection; framework; fill spaces; store fat; produce blood cells; protect against infections; help repair tissue damageproduce blood cells; protect against infections; help repair tissue damage

Cells generally farther apart with lots of intercellular material (matrix)Cells generally farther apart with lots of intercellular material (matrix) Matrix can vary from solid, to semi-solid, to liquidMatrix can vary from solid, to semi-solid, to liquid

Cells usually able to reproduce – how fast depends on blood supplyCells usually able to reproduce – how fast depends on blood supply Cell TypesCell Types

Resident cells – numbers of cells are relatively constantResident cells – numbers of cells are relatively constant Wandering cells – increase in numbers when neededWandering cells – increase in numbers when needed Fibroblast – cells that produce fibersFibroblast – cells that produce fibers Macrophages – specialized for phagocytosisMacrophages – specialized for phagocytosis Mast Cell – produces compounds histamine and heparineMast Cell – produces compounds histamine and heparine

Histamine – associated with inflammatory responseHistamine – associated with inflammatory response Heparin – helps prevent blood clottingHeparin – helps prevent blood clotting


Fiber TypesFiber Types Collagenous Fibers – tough, dense protein fibersCollagenous Fibers – tough, dense protein fibers

Made of collagen – long parallel bundlesMade of collagen – long parallel bundles White fibersWhite fibers Great tensile strength – resist pulling forcesGreat tensile strength – resist pulling forces Dense – many; loose – few and spread outDense – many; loose – few and spread out

Regular – all fibers in similar directionRegular – all fibers in similar direction Irregular – fibers are arranged in all directionsIrregular – fibers are arranged in all directions

Elastic Fibers – made of protein elastinElastic Fibers – made of protein elastin Weaker than collagenous but can return to original shapeWeaker than collagenous but can return to original shape Vocal cords and respiratory passagesVocal cords and respiratory passages Yellow fibersYellow fibers

Reticular Fibers – thin, single strands of collagen fibersReticular Fibers – thin, single strands of collagen fibers Highly branched for a delicate frameworkHighly branched for a delicate framework


Loose Fibrous C. T.Loose Fibrous C. T. Delicate thin membranesDelicate thin membranes Fibroblasts spread out – produce collagenous and elastic fibersFibroblasts spread out – produce collagenous and elastic fibers Binds skin to underlying tissueBinds skin to underlying tissue Highly vascularHighly vascular

Adipose C. T.Adipose C. T. Specialized loose C. T. for fat storageSpecialized loose C. T. for fat storage Looks like big marshmallows; filled with fat; nucleus squeezed against sideLooks like big marshmallows; filled with fat; nucleus squeezed against side Beneath skin, between muscles, around kidneys, behind eyeballsBeneath skin, between muscles, around kidneys, behind eyeballs

Dense Fibrous C. T. Dense Fibrous C. T. Mostly fibers; few actual cellsMostly fibers; few actual cells Can be regular Can be regular tendons and ligaments tendons and ligaments

Slow to heal b/c of poor vascularizationSlow to heal b/c of poor vascularization Can be irreguar Can be irreguar dermis of skin dermis of skin

Elastic C. T. Elastic C. T. Parallel stands or branching networks of elastic fibersParallel stands or branching networks of elastic fibers Ligamente flava – attachments between adjacent vertebraeLigamente flava – attachments between adjacent vertebrae Larger arteries, airwaysLarger arteries, airways

Reticular C. T.Reticular C. T. Thin, collagenous fibers arranged in 3-D networkThin, collagenous fibers arranged in 3-D network Walls of liver, spleen and lymphatic organsWalls of liver, spleen and lymphatic organs


Cartilage – rigid connective tissueCartilage – rigid connective tissue Provides support, framework, attachment, protection of Provides support, framework, attachment, protection of

underlying tissues, structural model for developing bonesunderlying tissues, structural model for developing bones Composed mainly of collagenous fibersComposed mainly of collagenous fibers Chondrocytes – cartilage cellsChondrocytes – cartilage cells

Lacunae – spaces that chondrocytes occupyLacunae – spaces that chondrocytes occupy Perichondrium – covering of cartilagePerichondrium – covering of cartilage

Provides blood to cartilage (which is avascular; slow healing)Provides blood to cartilage (which is avascular; slow healing) Hyaline – most common typeHyaline – most common type

Ends of bones, soft part of nose, supporting rings of respiratory Ends of bones, soft part of nose, supporting rings of respiratory systemsystem

Bone forms from this during developmentBone forms from this during development Elastic – more flexible than hyalineElastic – more flexible than hyaline

External ears and larynxExternal ears and larynx Fibrocartilage – shock absorber with many collagenous fibersFibrocartilage – shock absorber with many collagenous fibers

Intervertebral disksIntervertebral disks


Bones (osseous tissue) – solid connective tissueBones (osseous tissue) – solid connective tissue Solid matrix due to calcium phosphate and calcium carbonate Solid matrix due to calcium phosphate and calcium carbonate

(mineral salts)(mineral salts) Attachments for muscles, leverage, protection, inorganic salt Attachments for muscles, leverage, protection, inorganic salt

storagestorage Osteons – basic repeating unit of boneOsteons – basic repeating unit of bone

Osteonic (Haversion) canal – central tubeOsteonic (Haversion) canal – central tube Osteocytes – bone cellsOsteocytes – bone cells Lacunae – space that bone cells occupyLacunae – space that bone cells occupy Canaliculi – cytoplasmic extensions that connect osteocytesCanaliculi – cytoplasmic extensions that connect osteocytes

Blood – liquid connective tissueBlood – liquid connective tissue Cells suspended in liquid plasmaCells suspended in liquid plasma Red blood cells, white blood cells, plateletsRed blood cells, white blood cells, platelets Hematopoietic tissue – blood cell forming tissueHematopoietic tissue – blood cell forming tissue

Red bone marrow found in spaces of bonesRed bone marrow found in spaces of bones Reticuloendothelial tissue – largely phagocytic tissueReticuloendothelial tissue – largely phagocytic tissue

Found in blood, brain, lungs, bone marrow, spleen, liver and Found in blood, brain, lungs, bone marrow, spleen, liver and lymph glandslymph glands

Muscular TissueMuscular Tissue Elongated cells (fibers) specialized for contractionElongated cells (fibers) specialized for contraction Skeletal:Skeletal:

Voluntary, striated, movement of body partsVoluntary, striated, movement of body parts Fibers contain many nuclei and mitochondria; very longFibers contain many nuclei and mitochondria; very long

Smooth:Smooth: Involuntary, non-striated, movement of walls of internal organs Involuntary, non-striated, movement of walls of internal organs

(digestive, blood vessels, urinary etc.)(digestive, blood vessels, urinary etc.) Cardiac:Cardiac:

Involuntary, striated, self-exciting, rhythmic beating of heartInvoluntary, striated, self-exciting, rhythmic beating of heart Intercalated disks – hold cardiac cells togetherIntercalated disks – hold cardiac cells together

Nervous Tissue:Nervous Tissue: Tissue specialized to transmit electrochemical messages (nervous Tissue specialized to transmit electrochemical messages (nervous

impulses) throughout the bodyimpulses) throughout the body Neurons – functional cell of nervous systemNeurons – functional cell of nervous system

Dendrites – receiving endDendrites – receiving end Cell bodyCell body Axon – impulses travel down axon to terminalsAxon – impulses travel down axon to terminals Synapse – space between neurons Synapse – space between neurons

Neurotransmitters – chemicals released from axon into synapseNeurotransmitters – chemicals released from axon into synapse Motor neurons – send messages to effectors (muscles and glands)Motor neurons – send messages to effectors (muscles and glands) Sensory neurons – receive sensory information from external and Sensory neurons – receive sensory information from external and

internal environmentinternal environment Interneurons – connect and integrate information from sensory neurons Interneurons – connect and integrate information from sensory neurons

to motor neuronsto motor neurons Neuroglial cells – accessory cells of nervous systemNeuroglial cells – accessory cells of nervous system

Support, bind components of nervous system together, phagocytosis, Support, bind components of nervous system together, phagocytosis, help supply nutrientshelp supply nutrients

unit 3: cells and tissues ch. 3, 5. cell basics cells are the basic unit of structure and function...

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