Tissues - PowerPoint Presentation

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TissuesSlide2

Tissues

Groups of cells that have specialized structural and functional roles

Four major types

EpithelialConnectiveMuscleNervousSlide3

Epithelial

Covers organs

Forms the inner lining of body cavities

Lines hollow organsAlways has a free surface, one that is exposed to the outside or to an open space internallyBasement Membrane: nonliving layer of connective tissue that anchors the tissueSlide4

Epithelial Tissue

Lack blood vessels

Nutrients diffuse from underlying connective tissues

Cell readily divideInjuries heal rapidlySkin cells, stomach and intestine lining are continually damaged and replaced

Tightly Packed with little intercellular material

Effective barriers: skin and mouth

Secretion, absorption, excretion, and sensory receptionSlide5

Simple Epithelium

Simple Squamous Epithelium

Single thin layer of flattened cells

Nuclei are broad and thinCommon site of diffusion and filtrationLine air sacs, capillaries, blood and lymph vessels

Easily damagedSlide6

Simple Epithelium

Simple Cuboidal Epithelium

Single layer of cubed shaped cells

Centrally located spherical nucleiCover the ovaries and lines most kidney tubules Kidney functions in secretion and absorption

Glands of certain ducts: thyroid, pancreas, and liver

Secretes glandular productsSlide7

Simple Epithelium

Simple Columnar Epithelium

Elongated

Think tissue  protects underlying tissueSingle layer of cellsNuclei located near the basement membrane

Line the uterus and most digestive organs

Stomach and small intestines

Secrete digestive fluids and absorb nutrients

Microvilli: cylindrical projections from cell membrane

Increase surface area

 for increased absorptionSlide8

Simple Columnar EpitheliumSlide9

Pseudostratified Columnar Epithelium

Appear stratified or layered, but are not

Possess cilia, which move constantly

Goblet cells scattered throughout secrete mucusCilia sweeps awayLine passage of respiratory system

Mucus cover linings trap dust and microorganisms

Cilia move the mucus and its captured particles upward and outSlide10

Stratified Squamous Epithelium

Layered cells

 thick tissue

Cells divide in deep layers and newer cells push older one outward, where they flattenOuter skin layer, epidermis

As they age, accumulate the protein keratin, then harden and die

tough, hard, waterproof covering

Blocks foreign invaders

Line the mouth, throat, vagina, and anal canal

Not keratinizedSlide11

Stratified Squamous EpitheliumSlide12

Stratified Cuboidal Epithelium

Two to three layers of cuboidal cells that form lining of lumen

More protection than single layer

Lines the larger ducts of mammary glands, sweat glands, salivary glands, and pancreasLining of developing ovary follicles and seminiferous tubules female and male respectivelySlide13

Stratified Columnar Epithelium

Several layers of cells

Superficial cells are elongated

Basal layer are cubed shapedMale urethraParts of the pharynxSlide14

Transitional Epithelium

Specialized to change in response to tension

Inner lining of urinary bladder

Lines the ureters and part of the urethraProvides an expandable liningSlide15

Glandular Epithelium

Specialized to produce and secrete substances into ducts or into body fluids

Found in glands

Exocrine glands: glands that secrete their products into ducts that open onto some internal or external surface

Merocrine Glands: watery, protein rich fluid

Apocrine Glands: lose small portions of their glandular cell bodies during secretion

Holocrine Glands: the entire cell lyses during secretion

Endocrine: secrete products into tissue fluid or bloodSlide16

Glandular EpitheliumSlide17

Types of TissueSlide18

Connective TissueSlide19

Functions of Connective Tissue

Binds structures

Provides support and protection

Serves as a frameworkFills spacesStore fatProduce blood cells

Protect against infection

Help repair tissue damageSlide20

General Characteristics

Farther apart than epithelial

Have an abundance of intercellular material between them, matrix

Fibers and ground substanceCan usually divideVarying degrees of vascularityEspecially bone and cartilage

Some are flexible

AdiposeSlide21

Major Cell Types

Fixed: present in stable numbers

Fibroblasts: most common type

Large star shaped Produce fibers by secreting proteins into the matrixMast cells: large widely distributed

Near blood vessels

Release heparin, prevent blood clotting

Release histamine: promotes some reaction of inflammation and allergiesSlide22

Major Cell Types

Wandering: temporarily appear in tissue

Macrophages: originate as white blood cells

Specialized for phagocytosisFunction as scavengers and defensive cells that clears tissues of foreign particlesSlide23

Connective Tissue Fibers

Produced by fibroblasts

Collagenous Fibers: thick threads of protein collagen

Grouped in long, parallel bundlesSlightly elastic and flexible Great tensile strength

Components of:

Ligaments: bone to bone

Tendons: muscle to bone

White FibersSlide24

Connective Tissue Fibers

Elastic Fibers: elastin protein

Branch, forming complex networks

Weaker than collagenous fibersStretch easier and resume original shape

Common In: Vocal Cords

Yellow Fibers

Reticular Fibers

Very thin collagenous fibers

Highly branched and form delicate supporting networksSlide25

Loose Connective Tissue

Areolar Tissues: forms delicate, thin membranes

Cells located some distance apart and separated by a gel-like matrix containing collagenous and elastic fibers

Binds the skin to the underlying organs and fills space between musclesBeneath most epitheliumSlide26

Adipose Tissue

Fat

Specialized form of connective tissue that develops when certain cells store fat in droplets within the cytoplasm and enlarge

Cushions joints and some organsInsulates for heatStores energy

beneath the skin between muscles

around kidneys behind eyeballs

abdominal membrane surface of the heart

around certain jointsSlide27

Adipose TissueSlide28

Dense Connective Tissue

Many closely packed, thick, collagenous fibers

Fine network of elastic fibers

Relatively few cells, mostly fibroblastsVery strongPoor blood supply  slow repair

Part of tendons and ligaments

Protective white layer of eyeball

Deeper skin layersSlide29

Cartilage

Chondrocytes: cartilage cells

Perichondrium: protective tissue enclosing cartilaginous structures

Supplies nutrientsLack of direct blood supply  slow healing

Rigid connective tissue

Support, framework and attachments

Protects underlying tissues

Structural models for developing bonesSlide30

Types of Cartilage

Hyaline Cartilage: most common

Very fine

collagenous fibers in a matrixWhite glassEnds of bones in joints, soft part of nose, supporting rings of respiratory passageSlide31

Types of Cartilage

Elastic Cartilage: dense network of elastic fibers

More elastic and flexible

Ears & larynx

Fibrocartilage

very tough tissue, many collagenous fibers

Shock absorber: knees and pelvic girdle

Pads of intervertebral disks between vertebraeSlide32

Bone

Most rigid connective tissue

Hardness: mineral salts between cells

calcium phosphate and calcium carbonate Great amount of collagenSupports body structuresProtects cranial and thoracic cavities

Attachment for muscle

Contain red marrow

forms WBC

Stores and releases inorganic chemicals, Ca and PSlide33

More about Bones

Osteocytes: bone cells

Located in the lacuanae

Forms concentric circlesOsteon: layers of osteocytes around the osteonic canalContains blood vesselsMaterial can move rapidly between blood vessels and bone cells

Heals faster than cartilageSlide34

Blood

Transports materials between interior body cells and the external environment

Helps maintain homeostasis

Composed of formed elements suspended in a fluid matrixFluid Matrix: blood plasmaFormed Elements: RBC, WBC, platelets

Forms in red marrow in long bonesSlide35

Muscle and Nervous TissuesSlide36

Muscle Tissue

Contractile

Muscle Fibers: elongated cells that can shorten

Move body partsAs they contract, fibers pull at their attached ends3 TypesSkeletal Muscle TissueSmooth Muscle Tissue Cardiac Muscle TissueSlide37

Skeletal Muscle Tissue

Muscle is attached to bone

Voluntary: consciously controlled

Contract when stimulated by nervous impulse then relaxMoves head, trunk, and limbsFacial Expressions, write, talk, sing, chew, swallow, and breatheSlide38

Skeletal Muscle Tissue

Appearance

Long thread like fibers

Striations: alternating light and dark cross-markingsEach cell has many nuclei just beneath the cell membraneSlide39

Smooth Muscle Tissue

Smooth

 cells lack striations

Shorter than skeletal cellsSpindle-shapedSingle, centrally located nucleus

Comprises the walls of hollow internal organs

Stomach, intestines, urinary bladder, uterus, and blood vesselsSlide40

Smooth Muscle Tissue

Involuntary: cannot be consciously stimulated

Moves food through digestive tract

Constricts blood vesselsEmpties urinary bladderSlide41

Cardiac Muscle Tissue

Only in the heart

Bulk of the heart

Pumps blood through the heart chambers into blood vesselsCells: striated and joined end to endMuscle fibers are branched Connected in complex networksSingle nuclei

Intercalated disk: where it touches another cell

Specialized intercellular junction

Controlled involuntarilySlide42

Cardiac Muscle TissueSlide43

Nervous Tissue

Brain, spinal cord, and peripheral nerves

Neurons: basic cells

Send nerve impulses along cytoplasmic extensions, or nerve fibers Single to: neutrons, muscles, or glandsCoordinated, regulate, and integrate many body functionsSlide44

Nervous Tissue

Neuroglial

Cells

Support and bind the components of nervous tissueCarry on phagocytosisSupply nutrients to neurons  connecting with blood vesselsSlide45

Neuroglial Cells