Tissues, Glands and Tissues, Glands and MembranesMembranes

A A tissuetissue is a group of cells that have is a group of cells that have a similar structure and functiona similar structure and function

The microscopic study of tissues is The microscopic study of tissues is called called histologyhistology

Epithelial Epithelial ConnectiveConnective MuscleMuscle Nervous Nervous

Four Types of TissueFour Types of Tissue

Epithelial TissueEpithelial Tissue

Epitihelial – “ Covering Lining”Epitihelial – “ Covering Lining”

Covers internal and external surfaces Covers internal and external surfaces throughout the body throughout the body

Three parts: free surfaceThree parts: free surface

basement membranebasement membrane

very little extracellular very little extracellular spacespace

Functions of the epithelial cellFunctions of the epithelial cell

Protects the underlying structures- for Protects the underlying structures- for

example the skinexample the skin Acts as a barrier to certain substance- for Acts as a barrier to certain substance- for

example water, toxic molecules, and example water, toxic molecules, and microorganismsmicroorganisms

Also allows the passage of certain Also allows the passage of certain substances – for example oxygen and substances – for example oxygen and carbon dioxidecarbon dioxide

Secretes substance – for example Secretes substance – for example secretions from sweat glandssecretions from sweat glands

Absorbs substances – for example Absorbs substances – for example vitamins, mineralsvitamins, minerals

Classified according to the number of layers Classified according to the number of layers and the cell shapeand the cell shape

#of layers Cell shape#of layers Cell shape Simple (one layer) SquamousSimple (one layer) Squamous CuboidalCuboidal ColumnarColumnar

Pseudo stratified ColumnarPseudo stratified Columnar Stratified SquamousStratified Squamous Keratinized Keratinized Non KeratinizedNon Keratinized

Transitional Roughly cuboidal to Transitional Roughly cuboidal to columnar columnar

when not when not stretched,squamousstretched,squamous

when stretchedwhen stretched

The structure relates to the functionThe structure relates to the function

Simple epithelium- found in movement Simple epithelium- found in movement epitheliumepithelium

- gasses across wall of alveoli- gasses across wall of alveoli - filtration of fluid across kidneys - filtration of fluid across kidneys - secretion of glands - secretion of glands - nutrient absorption- nutrient absorption

Sratified epitheliumSratified epithelium well adapted for its protective well adapted for its protective

functionfunction as outer layers are damaged , they as outer layers are damaged , they

are replaced by deeper cell layersare replaced by deeper cell layers Found where abrasions may occur, Found where abrasions may occur,

such as skin, anal canal and vaginal such as skin, anal canal and vaginal canalcanal

Differences also reflected in the cell shapeDifferences also reflected in the cell shape Flat and thin cells – for diffusion in lungs and Flat and thin cells – for diffusion in lungs and

filtration in kidneysfiltration in kidneys Cuboidal or columnar cells are cells with Cuboidal or columnar cells are cells with

major functions of secretion or absorption. major functions of secretion or absorption. They are larger because they contain more They are larger because they contain more organelles for all the functions they must organelles for all the functions they must perform e.g. columnar cells of the stomach perform e.g. columnar cells of the stomach lining have secretory vesicles that secrete lining have secretory vesicles that secrete mucus. mucus.

Free Surface of the cellFree Surface of the cell

Cell ConnectionsCell Connections

Cell Connections Tight Junctions

Desmosoes Hemidesmosomes

Gap junctions

GlandsGlands

Glands- A gland is a multicellular Glands- A gland is a multicellular structure that secretes substances structure that secretes substances on to a surface, into a cavity or into on to a surface, into a cavity or into the blood the blood

Most are made of epithelial cells Most are made of epithelial cells

Types of GlandsTypes of Glands

Exocrine- glands that have ducts Exocrine- glands that have ducts - simple- no branches- simple- no branches -compound- branches-compound- branches ends- 1-tubular ends- 1-tubular straight tubularstraight tubular coiled tubularcoiled tubular 2- acinar/ alvoelar or saclike2- acinar/ alvoelar or saclike 3- both tubuloacinar3- both tubuloacinar

Types of Exocrine GlandsTypes of Exocrine Glands

Endocrine-have no ducts and empty Endocrine-have no ducts and empty their secretions directly into the their secretions directly into the bloodblood

Secretions are called hormones and Secretions are called hormones and these hormones are carried to other these hormones are carried to other parts of the body by the blood parts of the body by the blood

Endocrine Glands Endocrine Glands

Connective TissueConnective Tissue

Connective TissueConnective Tissue Connective Tissue structure – large Connective Tissue structure – large

amounts of extracellular materials that amounts of extracellular materials that separate cells from one another separate cells from one another

This extracellular matrix is divided into This extracellular matrix is divided into three parts:three parts:

-protein fibers-protein fibers

- ground substance consisting of non - ground substance consisting of non fibrous protein and other molecules fibrous protein and other molecules

- fluid- fluid

Connective Tissue MatrixConnective Tissue Matrix

Protein FibersProtein Fibers

- Collagen Fibers- resemble microscopic ropes, - Collagen Fibers- resemble microscopic ropes, flexible but resist bendingflexible but resist bending

- Reticular Fibers- very fine short collagen - Reticular Fibers- very fine short collagen fibers that branch to form the supporting networkfibers that branch to form the supporting network

- Elastic Fibers- structure similar to coiled - Elastic Fibers- structure similar to coiled

metal bed springsmetal bed springs but after being stretched , elastic fibers recoil to but after being stretched , elastic fibers recoil to

their original shapetheir original shape

Connective Tissue MatrixConnective Tissue Matrix

Ground Substance Ground Substance

Ground Substance is the shapeless Ground Substance is the shapeless background against which cells and background against which cells and collagen fibers are seen in the light collagen fibers are seen in the light microscopemicroscope

Made up of highly structured Made up of highly structured moleculesmolecules

Consists of Proteoglycans (proteins Consists of Proteoglycans (proteins and carbohydrates that trap water)and carbohydrates that trap water)

Connective Tissue MatrixConnective Tissue Matrix

Cells of the matrixCells of the matrix

How Do We Name Connective Tissue ?How Do We Name Connective Tissue ?

According to Their FunctionsAccording to Their Functions examples:examples:

Blast- produces the matrixBlast- produces the matrix Cyte – maintains the matrixCyte – maintains the matrix Clast-break down the matrix forClast-break down the matrix for remodelingremodeling

Macrophage Macrophage Mast CellMast Cell

Functions of the Connective Functions of the Connective TissueTissue

Encloses and SeparatesEncloses and Separates Connecting tissue to one anotherConnecting tissue to one another Supporting and MovingSupporting and Moving StoringStoring Cushioning and insulatingCushioning and insulating TransportingTransporting ProtectingProtecting

Classification of Connective Classification of Connective TissueTissue Loose (areolar)Loose (areolar)

AdiposeAdipose Dense Connective TissueDense Connective Tissue - Dense collagenous connective- Dense collagenous connective A) Collagen arranged in same directionA) Collagen arranged in same direction B) Collagen arranged in many directionsB) Collagen arranged in many directions Dense elastic connective tissueDense elastic connective tissue A)Elastic arranged in many directionsA)Elastic arranged in many directions b) Elastic fibers arranged in same directionb) Elastic fibers arranged in same directionCartilageCartilage HyalineHyaline FIbrocartilageFIbrocartilage Elastic CartilageElastic Cartilage BoneBone BloodBlood

Loose Areolar Tissue Loose Areolar Tissue -mostly collagen, few elastic -mostly collagen, few elastic and widely separated from and widely separated from

each othereach otherProduced by the fibroblastProduced by the fibroblast

This is the tissue that fills in This is the tissue that fills in the spacesthe spaces

Loose Connective TISSUELoose Connective TISSUE

Adipose TissueAdipose Tissue

Has very little collagen and elastic Has very little collagen and elastic fibersfibers

Large cells filled with lipidsLarge cells filled with lipids Pads of protection and thermal Pads of protection and thermal

insulationinsulation

Dense Connective TissueDense Connective Tissue

Densely packed fibers that produced by the Densely packed fibers that produced by the fibroblast fibroblast

Dense Collagenous- mostly collagenDense Collagenous- mostly collagen tendons, ligaments, capsules tendons, ligaments, capsules

around organsaround organs same direction in tendons, same direction in tendons,

different in organsdifferent in organs Dense Elastic Tissue- abundant elastic Dense Elastic Tissue- abundant elastic

fibers among collagen fibers fibers among collagen fibers vocal cords, walls of large arteries vocal cords, walls of large arteries

Dense Elastic Dense Elastic

Cartilage Cartilage

Composed of cartilage cells or Composed of cartilage cells or ChondrocytesChondrocytes

Located in the matrix along with collagenLocated in the matrix along with collagen Amongst the extracellular matrixAmongst the extracellular matrix It gives the matrix resilienceIt gives the matrix resilience HyalineHyaline FibroFibro ElasticElastic

Hyaline CartilageHyaline Cartilage

The most abundant type of cartilage The most abundant type of cartilage Ends of bones where they come Ends of bones where they come

together to form joints. It is the together to form joints. It is the smooth and resilientsmooth and resilient

Surfaces that withstand repeated Surfaces that withstand repeated compressioncompression

Costal , respiratory, and nasal Costal , respiratory, and nasal cartilgescartilges

FibrocartilageFibrocartilage

Has more fibrous tissue than does Has more fibrous tissue than does hyaline cartilagehyaline cartilage

, bundles of collagen, bundles of collagen Resists pulling or tearing Resists pulling or tearing Found in the disks between Found in the disks between

vertebrae and in some joints vertebrae and in some joints

Elastic CartilageElastic Cartilage

Has elastic fibers, collagen Has elastic fibers, collagen proteoglycansproteoglycans

Coiled fibers amongst bundles of Coiled fibers amongst bundles of collagen fiberscollagen fibers

Can recoil to its original shape when Can recoil to its original shape when bentbent

External ear, epiglottis, auditory tube External ear, epiglottis, auditory tube

Bone Bone

Is hard connective tissue that consists Is hard connective tissue that consists of cells and a mineralized matrixof cells and a mineralized matrix

Osteoblasts secrete the matrix called Osteoblasts secrete the matrix called lamellaelamellae

osteocytes are located in lacuneosteocytes are located in lacune The Osteon ( Haversion system) The Osteon ( Haversion system)

consist of central canal with blood consist of central canal with blood vessels, osteocytes and lamellaevessels, osteocytes and lamellae

Haversion System/OsteonHaversion System/Osteon

Blood Blood

Here the matrix is a liquid which Here the matrix is a liquid which enables the blood to move through enables the blood to move through the vessels to carry nutrients and the vessels to carry nutrients and other materials other materials

Muscle TissueMuscle Tissue

Main Characteristic is its ability to Main Characteristic is its ability to contract , making movement contract , making movement possible possible

Contractile proteins in the muscle Contractile proteins in the muscle cells themselves, called actin and cells themselves, called actin and myosinmyosin

Muscle cells are called muscle fibers Muscle cells are called muscle fibers because they resemble tiny threadsbecause they resemble tiny threads

Three Types of Muscle Three Types of Muscle Tissue Tissue

Skeletal MuscleSkeletal Muscle

Cardiac MuscleCardiac Muscle

Smooth MuscleSmooth Muscle

Skeletal MuscleSkeletal Muscle

Normally thought of as “muscle”Normally thought of as “muscle” Meat of animals, 40% of persons body weightMeat of animals, 40% of persons body weight Attaches to the skeletal system and enables body Attaches to the skeletal system and enables body

movementmovement

Long and cylindrical cells with several nuclei per cell Long and cylindrical cells with several nuclei per cell Some cells are the entire length of the muscleSome cells are the entire length of the muscle

Striated, Striated, VountaryVountary

Smooth MuscleSmooth Muscle

Forms the hollow walls of the organs Forms the hollow walls of the organs and is also in the skin and eyesand is also in the skin and eyes

Movement of food and emptying of Movement of food and emptying of the Urinary Bladderthe Urinary Bladder

InvoluntaryInvoluntary Tapered at each end , have a single Tapered at each end , have a single

nucleus and are not striatednucleus and are not striated

Cardiac MuscleCardiac Muscle

Muscle of the heart and is Muscle of the heart and is responsible for responsible for

Involuntary controlInvoluntary control Cylinder in shape and shorter than Cylinder in shape and shorter than

skeletalskeletal Striated and one nucleusStriated and one nucleus Connected by intercalated disksConnected by intercalated disks

Classification of MusclesClassification of Muscles

Skeletal Smooth CardiacSkeletal Smooth Cardiac Voluntary involuntary Voluntary involuntary

involuntaryinvoluntary Striated not striated striatedStriated not striated striated >1nuclei 1 nuclei 1 nuclei>1nuclei 1 nuclei 1 nuclei

Nervous TissuesNervous Tissues

Forms the brain, spinal cord and nerves Forms the brain, spinal cord and nerves Coordinates and controls many body Coordinates and controls many body

activitiesactivities Conscious and unconsciousConscious and unconscious Awareness, emotion, reasoningAwareness, emotion, reasoning Communicate through action potentialsCommunicate through action potentials Cell= neuron or nerve cell responsible for Cell= neuron or nerve cell responsible for

conduction of action potentialsconduction of action potentials Neuron – cell body , dendrites and axons Neuron – cell body , dendrites and axons Neuroglia surrounding support cellsNeuroglia surrounding support cells

Neurons and Glial cellsNeurons and Glial cells

MembranesMembranes

Serous Membranes Serous Membranes simple squamous epithelium simple squamous epithelium

resting on delicate layers of loose resting on delicate layers of loose connective tissueconnective tissue

cavities and cover the organs cavities and cover the organs inside these cavitiesinside these cavities

secretes serous fluid which lines secretes serous fluid which lines the cavititesthe cavitites

prevents trauma and damageprevents trauma and damage

MembranesMembranes

Pleural- lungs - PleuritisPleural- lungs - Pleuritis Pericardium- heart - PericarditisPericardium- heart - Pericarditis Peritoneal other - PeritonitisPeritoneal other - Peritonitis

Other MembranesOther Membranes

CutaneousCutaneous SynovialSynovial PeriostealPeriosteal