Tissues Aim: How does the tissue level impact homeostasis?

TissuesTissues

Aim: How does the tissue Aim: How does the tissue level impact homeostasis?level impact homeostasis?

TissuesTissues

Cells work together in functionally Cells work together in functionally related groups called tissuesrelated groups called tissues

How is this done?How is this done? AttachmentsAttachments communicationcommunication

Types of tissues:Types of tissues:1.1. Epithelial – lining and coveringEpithelial – lining and covering2.2. Connective – support Connective – support 3.3. Muscle – movementMuscle – movement4.4. Nervous – controlNervous – control

Lateral Surface FeaturesLateral Surface Features

Factors holding epithelial cells Factors holding epithelial cells togethertogether Adhesion proteins link plasma Adhesion proteins link plasma

membranes of adjacent cellsmembranes of adjacent cells Contours of adjacent cell membranes Contours of adjacent cell membranes Special cell junctionsSpecial cell junctions

Lateral Surface Features Lateral Surface Features – Cell Junctions– Cell Junctions

Tight junctions (zona occludens) – Tight junctions (zona occludens) – close off intercellular space close off intercellular space Found at apical region of most Found at apical region of most

epithelial typesepithelial types Some proteins in plasma membrane of Some proteins in plasma membrane of

adjacent cells are fusedadjacent cells are fused Prevent molecules from passing Prevent molecules from passing

between cells of epithelial tissuebetween cells of epithelial tissue

Tight JunctionTight Junction

Lateral Surface Features – Lateral Surface Features – Cell JunctionsCell Junctions

Adherens junctions (zonula Adherens junctions (zonula adherens) – anchoring junctionadherens) – anchoring junction Transmembrane linker proteins attach Transmembrane linker proteins attach

to actin microfilaments of the to actin microfilaments of the cytoskeleton and bind adjacent cellscytoskeleton and bind adjacent cells

Along with tight junctions, form the Along with tight junctions, form the tight junctional complex around apical tight junctional complex around apical lateral borders of epithelial tissueslateral borders of epithelial tissues

Zonula Adherens (Belt Zonula Adherens (Belt Desmosome)Desmosome)


Desmosomes (macula adherens) – Desmosomes (macula adherens) – two disc-like plaques connected two disc-like plaques connected across intercellular spaceacross intercellular space Plaques of adjoining cells are joined by Plaques of adjoining cells are joined by

proteins called cadherins proteins called cadherins Proteins interdigitate into extra-Proteins interdigitate into extra-

cellular spacecellular space Intermediate filaments insert into Intermediate filaments insert into

plaques from cytoplasmic sideplaques from cytoplasmic side

CDH1 - E-cadherin (epithelial) CDH2 - N-cadherin (neural) CDH12 - cadherin 12, type 2 (N-cadherin 2) CDH3 - P-cadherin (placental) CDH4 - R-cadherin (retinal) CDH5 - VE-cadherin (vascular endothelial) CDH6 - K-cadherin (kidney) CDH7 - cadherin 7, type 2 CDH8 - cadherin 8, type 2 CDH9 - cadherin 9, type 2 (T1-cadherin) CDH10 - cadherin 10, type 2 (T2-cadherin) CDH11 - OB-cadherin (osteoblast) CDH13 - T-cadherin - H-cadherin (heart) CDH15 - M-cadherin (myotubule) CDH16 - KSP-cadherin CDH17 - LI cadherin (liver-intestine) CDH18 - cadherin 18, type 2 CDH19 - cadherin 19, type 2 CDH20 - cadherin 20, type 2 CDH23 - cadherin 23, (neurosensory epithelium)

DesmosomeDesmosome

Figure 4.7b

Desmosome DetailDesmosome Detail


Gap junctions – passageway between Gap junctions – passageway between two adjacent cellstwo adjacent cells Let small molecules move directly Let small molecules move directly

between neighboring cellsbetween neighboring cells Cells are connected by hollow cylinders Cells are connected by hollow cylinders

of proteinof protein

Gap JunctionGap Junction

Figure 4.7c

Aim: How do epithelial Aim: How do epithelial tissues differ?tissues differ?

Epithelial Tissue – Epithelial Tissue – General Characteristics & General Characteristics &

FunctionsFunctions Covers a body surface or lines a Covers a body surface or lines a

body cavity body cavity Forms most glandsForms most glands Functions of epitheliumFunctions of epithelium

ProtectionProtection Absorption, secretion, and ion transportAbsorption, secretion, and ion transport FiltrationFiltration Forms slippery surfacesForms slippery surfaces

Special Characteristics Special Characteristics of Epitheliaof Epithelia

CellularityCellularity cells are in close contact with each other with little or no cells are in close contact with each other with little or no

intercellular space between themintercellular space between them Specialized contactsSpecialized contacts

may have junctions for both attachment and may have junctions for both attachment and communicationcommunication

PolarityPolarity epithelial tissues always have an apical and basal surfaceepithelial tissues always have an apical and basal surface

Support by connective tissue Support by connective tissue at the basal surface, both the epithelial tissue and the at the basal surface, both the epithelial tissue and the

connective tissue contribute to the basement membraneconnective tissue contribute to the basement membrane AvascularAvascular

nutrients must diffusenutrients must diffuse InnervatedInnervated Regenerative Regenerative

epithelial tissues have a high capacity for regenerationepithelial tissues have a high capacity for regeneration

Special Characteristics Special Characteristics of Epitheliaof Epithelia

First name of tissue indicates First name of tissue indicates number of layersnumber of layers Simple – one layer of cellsSimple – one layer of cells

Stratified – more than one layer of cellsStratified – more than one layer of cells

Classifications of Classifications of EpitheliaEpithelia

Classifications of Classifications of EpitheliaEpithelia

Last name of tissue describes shape Last name of tissue describes shape of cellsof cells Squamous – cells wider than Squamous – cells wider than

tall (plate or “scale” like)tall (plate or “scale” like)

Cuboidal – cells are as wide as Cuboidal – cells are as wide as tall, as in cubestall, as in cubes

Columnar – cells are taller thanColumnar – cells are taller than they are wide, like columns they are wide, like columns

Naming EpitheliaNaming Epithelia Naming the epithelia includes both the layers Naming the epithelia includes both the layers

(first) and the shape of the cells (second)(first) and the shape of the cells (second) i.e. stratified cuboidal epitheliumi.e. stratified cuboidal epithelium

The name may also include any accessory The name may also include any accessory structuresstructures Goblet cellsGoblet cells CiliaCilia KeratinKeratin

Special epithelial tissues (don’t follow naming Special epithelial tissues (don’t follow naming convention)convention) PsuedostratifiedPsuedostratified TransitionalTransitional

Simple Squamous Simple Squamous EpitheliumEpithelium

Description Description single layer of flat cells with disc-shaped single layer of flat cells with disc-shaped

nucleinuclei Special types Special types

Endothelium (inner covering) Endothelium (inner covering) slick lining of hollow organsslick lining of hollow organs

Mesothelium (middle covering) Mesothelium (middle covering) Lines peritoneal, pleural, and pericardial Lines peritoneal, pleural, and pericardial

cavities cavities Covers visceral organs of those cavitiesCovers visceral organs of those cavities


Function Function Passage of materials by passive diffusion and Passage of materials by passive diffusion and

filtrationfiltration Secretes lubricating substances in serous Secretes lubricating substances in serous

membranesmembranes

Location Location Renal corpusclesRenal corpuscles Alveoli of lungs Alveoli of lungs Lining of heart, blood and lymphatic vesselsLining of heart, blood and lymphatic vessels Lining of ventral body cavity (serosae/serous Lining of ventral body cavity (serosae/serous

memb.) memb.)


Simple squamous

lining the walls of the capillary

If it’s from a mesothelial lining

Aim: How do epithelial Aim: How do epithelial tissues differ? Day 2tissues differ? Day 2

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Classification of Classification of EpitheliaEpithelia

1 2 3

1 2 3

?

Simple Cuboidal Simple Cuboidal EpitheliumEpithelium

DescriptionDescription single layer of cube-like cells with large, single layer of cube-like cells with large,

spherical central nucleispherical central nuclei Function Function

secretion and absorptionsecretion and absorption Location Location

kidney tubules, secretory portions of small kidney tubules, secretory portions of small glands, ovary surfaceglands, ovary surface

Simple Cuboidal Simple Cuboidal EpitheliumEpithelium

Simple Columnar Simple Columnar EpitheliumEpithelium

Description Description single layer of column-shaped single layer of column-shaped

(rectangular) cells with oval nuclei(rectangular) cells with oval nuclei Some bear cilia at their apical surfaceSome bear cilia at their apical surface May contain goblet cellsMay contain goblet cells

Function Function Absorption; secretion of mucus, Absorption; secretion of mucus,

enzymes, and other substancesenzymes, and other substances Ciliated type propels mucus or Ciliated type propels mucus or

reproductive cells by ciliary actionreproductive cells by ciliary action

Simple Columnar Simple Columnar EpitheliumEpithelium

Location Location Non-ciliated form Non-ciliated form

Lines digestive tract, gallbladder, ducts of Lines digestive tract, gallbladder, ducts of some glandssome glands

Ciliated form Ciliated form Lines small bronchi, Lines small bronchi,

uterine tubes, and uterusuterine tubes, and uterus

Pseudostratified Pseudostratified Columnar EpitheliumColumnar Epithelium

DescriptionDescription All cells originate at basement membraneAll cells originate at basement membrane Only tall cells reach the apical surfaceOnly tall cells reach the apical surface May contain goblet cells and bear ciliaMay contain goblet cells and bear cilia Nuclei lie at varying heights within cellsNuclei lie at varying heights within cells

Gives false impression of stratificationGives false impression of stratification

Function Function secretion of mucus; propulsion of mucus secretion of mucus; propulsion of mucus

by ciliaby cilia

Pseudostratified Pseudostratified Columnar EpitheliumColumnar Epithelium

LocationsLocations Non-ciliated type Non-ciliated type

Ducts of male Ducts of male reproductive tubes reproductive tubes

Ducts of large Ducts of large glandsglands

Ciliated variety Ciliated variety Lines trachea and Lines trachea and

most of upper most of upper respiratory tractrespiratory tract

Aim: How do epithelial Aim: How do epithelial tissues differ? Day 3tissues differ? Day 3

Epithelial tissue has several distinctive properties. Which correctly lists these

properties?

1. Avascular and cellularity

2. Polarity and regeneration

3. Contractility and excitability

4. 1 and 2

Which of the following is NOT a characteristic of epithelial tissue?

1. It is composed entirely of cells.

2. It stores energy reserves.

3. It is avascular.

4. It is capable of regeneration.

An epithelial surface bears many microvilli. What is the probable function

of this epithelium?

1. absorption

2. secretion

3. transportation

4. sensation

What is the functional significance of gap junctions?

1. They maintain water-tight passages.

2. They resist stretching and twisting.

3. They share ions between adjacent cells

4. They attach cells to extracellular matrix.

Stratified EpitheliaStratified Epithelia

Contain two or more layers of cellsContain two or more layers of cells Regenerate from belowRegenerate from below Major role is protectionMajor role is protection Are named according to the Are named according to the shape of shape of

cells at apical layercells at apical layer

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Classification of Classification of EpitheliaEpithelia

1 2 3

1 2 3

?

Stratified Squamous Stratified Squamous EpitheliumEpithelium

DescriptionDescription Many layers of cells – squamous in Many layers of cells – squamous in

shapeshape Deeper layers of cells appear cuboidal Deeper layers of cells appear cuboidal

or columnar or columnar Thickest epithelial tissue – adapted for Thickest epithelial tissue – adapted for

protectionprotection


Specific types Specific types KeratinizedKeratinized – contain the protective protein keratin – contain the protective protein keratin

Surface cells are dead and full of keratin Surface cells are dead and full of keratin Non-keratinizedNon-keratinized – forms moist lining of body – forms moist lining of body

openingsopenings FunctionFunction

Protects underlying tissues in areas subject to Protects underlying tissues in areas subject to abrasionabrasion

Location Location Keratinized – forms epidermisKeratinized – forms epidermis Non-keratinized – forms lining of esophagus, Non-keratinized – forms lining of esophagus,

mouth, and vaginamouth, and vagina


Non-keratinized vs. Keratinized

Stratified Cuboidal Stratified Cuboidal EpitheliumEpithelium

DescriptionDescription generally two generally two

layers of cube-layers of cube-shaped cellsshaped cells

FunctionFunction protectionprotection

LocationLocation Forms largest Forms largest

ducts of sweat ducts of sweat glandsglands

Forms ducts of Forms ducts of mammary glands mammary glands and salivary glandsand salivary glands

Stratified Columnar Stratified Columnar EpitheliumEpithelium

DescriptionDescription several layers; basal several layers; basal

cells usually cells usually cuboidal; superficial cuboidal; superficial cells elongatedcells elongated

FunctionFunction protection and protection and

secretionsecretion Location Location

Rare tissue typeRare tissue type Found in male Found in male

urethra and vas urethra and vas deferens, largest deferens, largest ducts of salivary ducts of salivary glands, nasopharynxglands, nasopharynx

Transitional EpitheliumTransitional Epithelium

Description Description Basal cells usually cuboidal or columnarBasal cells usually cuboidal or columnar Superficial cells dome-shaped or squamousSuperficial cells dome-shaped or squamous

FunctionFunction stretches and permits distension of urinary stretches and permits distension of urinary

bladderbladder Location Location

Lines ureters, urinary bladder and part of Lines ureters, urinary bladder and part of urethra urethra

Transitional EpitheliumTransitional EpitheliumRelaxed state

Stretched state

Glandular EpitheliumGlandular Epithelium Ducts carry products of exocrine Ducts carry products of exocrine

glands to epithelial surfaceglands to epithelial surface Include the following diverse glands Include the following diverse glands

Mucus-secreting glands Mucus-secreting glands Sweat and oil glandsSweat and oil glands Salivary glandsSalivary glands Liver and pancreasLiver and pancreas

May be: unicellular or multicellularMay be: unicellular or multicellular

Unicellular Exocrine Unicellular Exocrine Glands Glands

(The Goblet Cell)(The Goblet Cell) Goblet cells Goblet cells

produce mucin produce mucin Mucin + water Mucin + water

mucusmucus Protects and Protects and

lubricates many lubricates many internal body internal body surfacessurfaces

Multicellular Exocrine Multicellular Exocrine GlandsGlands

Have two basic partsHave two basic parts Epithelium-walled ductEpithelium-walled duct Secretory unitSecretory unit

Classified by structure of ductClassified by structure of duct SimpleSimple CompoundCompound

Categorized by secretory unitCategorized by secretory unit TubularTubular AlveolarAlveolar TubuloalveolarTubuloalveolar

Types of Multicellular Types of Multicellular Exocrine GlandsExocrine Glands

Exocrine Vs. Endocrine Exocrine Vs. Endocrine GlandsGlands

Endocrine Gland Characteristics:Endocrine Gland Characteristics: Ductless glandsDuctless glands Secrete substances directly into Secrete substances directly into

bloodstream bloodstream Produce molecules called hormonesProduce molecules called hormones

Which is Which?

Basal Feature: The Basal Basal Feature: The Basal LaminaLamina

Noncellular supporting sheet between the Noncellular supporting sheet between the epithelium and the connective tissue deep to it epithelium and the connective tissue deep to it

Consists of proteins secreted by the epithelial cells Consists of proteins secreted by the epithelial cells Functions:Functions:

Acts as a selective filter, determining which molecules Acts as a selective filter, determining which molecules from capillaries enter the epithelium from capillaries enter the epithelium

Acts as scaffolding along which regenerating epithelial Acts as scaffolding along which regenerating epithelial cells can migrate cells can migrate

Basal lamina and reticular layers of the underlying Basal lamina and reticular layers of the underlying connective tissue form the basement membraneconnective tissue form the basement membrane

Hemidesmosomal junctions… holding it Hemidesmosomal junctions… holding it all down!all down!

Epithelial Surface Epithelial Surface FeaturesFeatures

Apical surface features Apical surface features Microvilli – finger-like extensions of Microvilli – finger-like extensions of

plasma membraneplasma membrane Abundant in epithelia of small intestine Abundant in epithelia of small intestine

and kidneyand kidney Maximize surface area across which Maximize surface area across which

small molecules enter or leavesmall molecules enter or leave Act as stiff knobs that resist abrasionAct as stiff knobs that resist abrasion

Epithelial Surface Epithelial Surface FeaturesFeatures

Apical surface featuresApical surface features Cilia – whip-like, highly motile Cilia – whip-like, highly motile

extensions of apical surface membranesextensions of apical surface membranes Contains a core of nine pairs of Contains a core of nine pairs of

microtubules encircling one middle pairmicrotubules encircling one middle pair Axoneme – a set of microtubulesAxoneme – a set of microtubules Each pair of microtubules – arranged in a Each pair of microtubules – arranged in a

doublet doublet Microtubules in cilia – arranged similarly to Microtubules in cilia – arranged similarly to

cytoplasmic organelles called centriolescytoplasmic organelles called centrioles Movement of cilia – in coordinated wavesMovement of cilia – in coordinated waves

A CiliumA Cilium

The secretory cells of sebaceous glands fill with secretions and then rupture, releasing their

contents. Which type of secretion is this?

1. acinar

2. apocrine

3. merocrine

4. holocrine

Milk production in mammary glands involves a combination of which two types

of secretion?

1. Apocrine and serous

2. Holocrine and merocrine

3. Mucous and exocrine

4. Apocrine and merocrine

Simple branched tubular glands are characteristic of which examples of glands?

1. Sweat glands and mammary glands

2. Gastric glands and mucous glands of esophagus

3. Salivary glands and pancreas

4. Bulbourethral glands and seminiferous tubules

The singular example of a unicellular exocrine gland is the ________?

1. Sweat gland

2. Intestinal gland

3. Goblet cell

4. Not found in adult

A gland has no ducts to carry the glandular secretions, and the gland’s secretions are released directly into the

extracellular fluid. Which type of gland is this?

1. exocrine gland

2. endocrine gland

3. acinar gland

4. tubular gland

Aim: How do connective Aim: How do connective tissues differ?tissues differ?

Connective TissueConnective Tissue Most diverse and abundant tissueMost diverse and abundant tissue Main classesMain classes

Connective tissue properConnective tissue proper CartilageCartilage Bone tissueBone tissue BloodBlood

Components of connective tissue:Components of connective tissue: Cells (varies according to tissue)Cells (varies according to tissue) MatrixMatrix

Fibers (varies according to tissue)Fibers (varies according to tissue) Ground substance (varies according to tissue)Ground substance (varies according to tissue)

dermatin sulfate, hyaluronic acid, keratin sulfate, dermatin sulfate, hyaluronic acid, keratin sulfate, chondroitin sulfate…chondroitin sulfate…

Common embryonic origin – Common embryonic origin – mesenchymemesenchyme

Classes of Connective Classes of Connective TissueTissue

Connective Tissue Model Connective Tissue Model Areolar connective tissueAreolar connective tissue

Underlies epithelial tissueUnderlies epithelial tissue Surrounds small nerves and blood vesselsSurrounds small nerves and blood vessels Has structures and functions shared by other Has structures and functions shared by other

connective tissues connective tissues Borders all other tissues in the body Borders all other tissues in the body

Structures within areolar connective tissue Structures within areolar connective tissue allow:allow: Support and binding of other tissuesSupport and binding of other tissues Holding body fluidsHolding body fluids Defending body against infectionDefending body against infection Storing nutrients as fatStoring nutrients as fat

Connective Tissue ProperConnective Tissue Proper Loose Connective TissueLoose Connective Tissue

AreolarAreolar ReticularReticular AdiposeAdipose

Dense Connective Dense Connective TissueTissue RegularRegular IrregularIrregular ElasticElastic

Areolar Connective Areolar Connective TissueTissue Description Description

Gel-like matrix with:Gel-like matrix with: all three fiber types (collagen, reticular, elastic) for supportall three fiber types (collagen, reticular, elastic) for support Ground substance is made up by glycoproteins also made and Ground substance is made up by glycoproteins also made and

screted by the fibroblasts.screted by the fibroblasts. Cells – fibroblasts, macrophages, mast cells, white blood Cells – fibroblasts, macrophages, mast cells, white blood

cellscells Function Function

Wraps and cushions organsWraps and cushions organs Holds and conveys tissue fluidHolds and conveys tissue fluid Important role in inflammation Main battlefield in fight Important role in inflammation Main battlefield in fight

against infectionagainst infection Defenders gather at infection sitesDefenders gather at infection sites

MacrophagesMacrophages Plasma cellsPlasma cells Mast cellsMast cells Neutrophils, lymphocytes, and eosinophilsNeutrophils, lymphocytes, and eosinophils

Areolar Connective Areolar Connective TissueTissue

Location Location Widely distributed under epitheliaWidely distributed under epithelia Packages organsPackages organs Surrounds capillariesSurrounds capillaries

Adipose TissueAdipose Tissue Description Description

Closely packed adipocytes Closely packed adipocytes Have nucleus pushed to Have nucleus pushed to

one side by fat droplet one side by fat droplet FunctionFunction

Provides reserve food fuelProvides reserve food fuel Insulates against heat Insulates against heat

lossloss Supports and protects Supports and protects

organsorgans LocationLocation

Under skin Under skin Around kidneys Around kidneys Behind eyeballs, within Behind eyeballs, within

abdomen and in breastsabdomen and in breasts

Reticular Connective Reticular Connective TissueTissue

Description – Description – network of reticular network of reticular fibers in loose ground fibers in loose ground substancesubstance

Function – form a Function – form a soft, internal skeleton soft, internal skeleton (stroma) – supports (stroma) – supports other cell typesother cell types

Location – lymphoid Location – lymphoid organs organs Lymph nodes, bone Lymph nodes, bone

marrow, and spleenmarrow, and spleen

Dense Irregular Dense Irregular Connective TissueConnective Tissue

Description Description Primarily Primarily irregularlyirregularly

arranged collagen fibersarranged collagen fibers Some elastic fibers and Some elastic fibers and

fibroblastsfibroblasts Function Function

Withstands tensionWithstands tension Provides structural Provides structural

strength strength LocationLocation

Dermis of skinDermis of skin Submucosa of digestive Submucosa of digestive

tracttract Fibrous capsules of joints Fibrous capsules of joints

and organsand organs

Dense Regular Dense Regular Connective TissueConnective Tissue DescriptionDescription

Primarily Primarily parallelparallel collagen fibers collagen fibers Fibroblasts and some elastic fibersFibroblasts and some elastic fibers Poorly vascularizedPoorly vascularized

FunctionFunction Attaches muscle to boneAttaches muscle to bone Attaches bone to boneAttaches bone to bone Withstands great stress in Withstands great stress in

one directionone direction LocationLocation

Tendons and ligamentsTendons and ligaments Aponeuroses Aponeuroses Fascia around musclesFascia around muscles

CartilageCartilage Characteristics:Characteristics:

Firm, flexible tissueFirm, flexible tissue Contains no blood vessels or nervesContains no blood vessels or nerves Matrix contains up to 80% waterMatrix contains up to 80% water Cell type – chondrocyte Cell type – chondrocyte

Types:Types: HyalineHyaline ElasticElastic FibrocartilageFibrocartilage

Hyaline CartilageHyaline Cartilage

DescriptionDescription Imperceptible collagen fibers (hyaline = Imperceptible collagen fibers (hyaline =

glassy)glassy) Chodroblasts produce matrixChodroblasts produce matrix Chondrocytes lie in lacunae Chondrocytes lie in lacunae

FunctionFunction Supports and reinforcesSupports and reinforces Resilient cushionResilient cushion Resists repetitive stressResists repetitive stress

Hyaline CartilageHyaline Cartilage

LocationLocation Fetal skeletonFetal skeleton Ends of long bonesEnds of long bones Costal cartilage of ribsCostal cartilage of ribs Cartilages of nose, Cartilages of nose,

trachea, and larynxtrachea, and larynx

Elastic CartilageElastic Cartilage DescriptionDescription

Similar to hyaline cartilageSimilar to hyaline cartilage More elastic fibers in matrixMore elastic fibers in matrix

Function Function Maintains shape of structureMaintains shape of structure Allows great flexibilityAllows great flexibility

LocationLocation Supports external earSupports external ear EpiglottisEpiglottis

FibrocartilageFibrocartilage DescriptionDescription

Matrix similar, but less firm than hyaline Matrix similar, but less firm than hyaline cartilagecartilage

Thick collagen fibers predominateThick collagen fibers predominate FunctionFunction

Tensile strength and ability Tensile strength and ability to absorb compressive to absorb compressive shockshock

LocationLocation Intervertebral discsIntervertebral discs Pubic symphysisPubic symphysis Discs of knee jointDiscs of knee joint

Bone TissueBone Tissue FunctionFunction

Supports and Supports and protects organsprotects organs

Provides levers and Provides levers and attachment site for attachment site for musclesmuscles

Stores calcium and Stores calcium and other mineralsother minerals

Stores fatStores fat Marrow is site for Marrow is site for

blood cell formationblood cell formation Location Location

BonesBones

Blood TissueBlood Tissue DescriptionDescription

red and white blood cells red and white blood cells in a fluid matrixin a fluid matrix

FunctionFunction transport of respiratory transport of respiratory

gases, nutrients, and wastesgases, nutrients, and wastes LocationLocation

within blood vesselswithin blood vessels CharacteristicsCharacteristics

An atypical connective tissueAn atypical connective tissue Develops from mesenchymeDevelops from mesenchyme Consists of cells surrounded by nonliving matrixConsists of cells surrounded by nonliving matrix

Mesenchyme connective tissue gives rise to which tissue type(s)?

1. Stratified epithelial tissues

2. Smooth and cardiac muscle tissues

3. All nervous tissue

4. All connective tissues

Lack of vitamin C in the diet interferes with the ability of fibroblasts to produce collagen. What

effect might this interference have on connective tissue?

1. Tissue is unable to phagocytize.

2. Tissue is unable to produce melanin.

3. Tissue is weak and prone to damage.

4. Tissue is unable to produce heparin.

Brown fat is functionally and structurally different from white fat in

which ways?

1. It is highly vascularized and contains numerous mitochondria

2. It does not capture energy that is released

3. It generates heat, which warms blood

4. All of the above are correct

Many allergy sufferers take antihistamines to relieve their allergy symptoms. Which type of cell

produces the molecule that this medication blocks?

1. eosinophils

2. mast cells

3. basophils

4. 2 and 3

Connective tissues share three basic components. Which of the following

lists these components?

1. Specialized cells, extracellular fibers, and ground substance

2. Mast cells, adipocytes, and mesenchymal cells

3. Macrophages, elastic fibers, and collagen fibers

4. None of these is correct

Which type of connective tissue contains primarily triglycerides?

1. areolar

2. adipose

3. reticular

4. mesenchyme

Why does cartilage heal so slowly?

1. It lacks a direct blood supply, necessary for proper healing.

2. Chondroitin sulfate prevents healing.

3. Matrix inhibits cellular regeneration.

4. Interstitial fluid, necessary for proper healing, is excluded.

If a person has a herniated intervertebral disc, which type of cartilage has been

damaged?

1. elastic cartilage

2. fibrocartilage

3. hyaline cartilage

4. areolar cartilage

Which two types of connective tissue have a fluid matrix?

1. lymph and cartilage

2. cartilage and bone

3. blood and bone

4. blood and lymph

Which types of connective tissue are classified as supporting connective

tissue and why?

1. Adipose and dense regular connective tissue/they are connective tissue proper

2. Muscle and blood/they have the highest need for oxygen

3. Bone and cartilage/form framework of body

4. 2 and 3

Covering and Lining Covering and Lining MembranesMembranes

Combine epithelial tissues and Combine epithelial tissues and connective tissuesconnective tissues

Cover broad areas within bodyCover broad areas within body Consist of epithelial sheet plus Consist of epithelial sheet plus

underlying connective tissueunderlying connective tissue

Three Types of Three Types of MembranesMembranes

Cutaneous membrane – skin Cutaneous membrane – skin Mucous membrane Mucous membrane

Lines hollow organs that open to surface of Lines hollow organs that open to surface of bodybody

An epithelial sheet underlain with layer of An epithelial sheet underlain with layer of lamina propria lamina propria

Serous membrane – slippery membranesSerous membrane – slippery membranes Simple squamous epithelium lying on Simple squamous epithelium lying on

areolar connective tissueareolar connective tissue Line closed cavitiesLine closed cavities

Pleural, peritoneal, and pericardial cavitiesPleural, peritoneal, and pericardial cavities



Muscle TissueMuscle Tissue

TypesTypes Skeletal muscle tissueSkeletal muscle tissue Cardiac muscle tissue Cardiac muscle tissue Smooth muscle tissueSmooth muscle tissue

Skeletal Muscle TissueSkeletal Muscle Tissue CharacteristicsCharacteristics

Long, cylindrical cellsLong, cylindrical cells MultinucleateMultinucleate Obvious striationsObvious striations

Function Function Voluntary movementVoluntary movement Manipulation of Manipulation of

environmentenvironment Facial expressionFacial expression

LocationLocation Skeletal muscles attached to bones Skeletal muscles attached to bones

(occasionally to skin)(occasionally to skin)

Cardiac Muscle TissueCardiac Muscle Tissue

FunctionFunction Contracts to propel blood into circulatory Contracts to propel blood into circulatory

systemsystem CharacteristicsCharacteristics

Branching cellsBranching cells UninucleateUninucleate Intercalated discsIntercalated discs

LocationLocation Occurs in walls of heartOccurs in walls of heart

Smooth Muscle TissueSmooth Muscle Tissue CharacteristicsCharacteristics

Spindle-shaped cells withSpindle-shaped cells withcentral nucleicentral nuclei

Arranged closely to form Arranged closely to form sheetssheets

No striationsNo striations FunctionFunction

Propels substances along Propels substances along internal passagewaysinternal passageways

Involuntary controlInvoluntary control LocationLocation

Mostly walls of hollow organsMostly walls of hollow organs

Nervous TissueNervous Tissue FunctionFunction

Transmit electrical signals Transmit electrical signals from sensory receptors to from sensory receptors to effectorseffectors

LocationLocation Brain, spinal cord, and nervesBrain, spinal cord, and nerves

DescriptionDescription Main components are brain, Main components are brain,

spinal cord, and nervesspinal cord, and nerves Contains two types of cellsContains two types of cells

Neurons – excitatory cellsNeurons – excitatory cells Supporting cells (neuroglial cells) Supporting cells (neuroglial cells)

Tissue Response to Tissue Response to InjuryInjury

Inflammatory response – non-Inflammatory response – non-specific, local responsespecific, local response Limits damage to injury siteLimits damage to injury site

Immune response – takes longer to Immune response – takes longer to develop and very specificdevelop and very specific Destroys particular microorganisms at Destroys particular microorganisms at

site of infectionsite of infection

The Tissues Throughout The Tissues Throughout LifeLife

At the end of second month of development:At the end of second month of development: Primary tissue types have appearedPrimary tissue types have appeared Major organs are in placeMajor organs are in place

AdulthoodAdulthood Only a few tissues regenerateOnly a few tissues regenerate Many tissues still retain populations of stem cellsMany tissues still retain populations of stem cells

With increasing age:With increasing age: Epithelia thin Epithelia thin Collagen decreasesCollagen decreases Bones, muscles, and nervous tissue begin to Bones, muscles, and nervous tissue begin to

atrophyatrophy Poor nutrition and poor circulation – poor health of Poor nutrition and poor circulation – poor health of

tissuestissues

Which cavities in the body are lined by serous membranes?

1. cranial and abdominal

2. pleural, peritoneal, and pericardial

3. synovial and fascial

4. nasal, urinary and reproductive

Serous membranes contrast mucous membranes in what way?

1. Mucous membranes line passageways that open to the exterior/serous membranes line

sealed internal subdivisions of the body cavity

2. Serous membranes line passageways that open to the exterior/mucous membranes line

sealed internal subdivisions of the body cavity

3. Serous membranes are parietal/mucous membranes are visceral

4. Serous membranes secrete mucous/mucous membranes secrete transudate

Which type of muscle tissue has small, tapering cells with single nuclei and no

obvious striations?

1. skeletal

2. cardiac

3. smooth

4. all of the above

A tissue contains irregularly shaped cells with many fibrous projections, some several

centimeters long. These are probably which type of cell?

1. neuroglia

2. neurons

3. myocytes

4. adipocytes

If skeletal muscle cells in adults are incapable of dividing, how is new skeletal muscle

formed?

1. through the enlarging and splitting of existing cells

2. through the atrophy of existing cells

3. through the addition of new striations

4. through the division and fusion of satellite cells

Tissues Aim: How does the tissue level impact homeostasis?

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