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Ma. Chiela M. Cremen, M.Sc.Department of Biological Sciences

College of ScienceUniversity of Santo Tomas

1st Semester SY: 2010-2011

HistologyHistology study of microstructure of tissuesTissue

group or aggregation of cells display common functional or morphological properties

CELLS TISSUES ORGANS

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TissuesEpithelial

ConnectiveMuscleNerve

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Epithelial TissuesCovers external surfaces of the body or lines cavities

Lacks vascular supply but are nourished by diffusionfrom capillary beds in the underlying CT

For protection; secretion, absorption, lubrication &sensory perception

Shape:1. Squamous

2. Cuboidal3. Columnar

Number of Cell Layers:1. Simple

2. Stratified3. Pseudostratified4. Transitional

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BasementMembrane(extracellularmatrix)

Free surface of epithelium

Under

lyingtissue Cellnuclei

D. STRATIFIED SQUAMOUS EPITHELIUM(lining the esophagus)

A. SIMPLE SQUAMOUS EPITHELIUM(lining the air sacs of the lung)

B. SIMPLE CUBOIDAL EPITHELIUM(forming a tube in the kidney)

C. SIMPLE COLUMNAR EPITHELIUM(lining the intestine)

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Epithelial TissuesSimple Squamous Epithelium(inner lining of cheek)

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Epithelial TissueSimple Cuboidal Epithelium(Kidney tubules)

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Epithelial Tissues

Simple Columnar Epithelium(stomach / small intestine)

highly absorptive surfaces

small intestinesecretory surfaces stomachmay be specialized forsecretion goblet cells inthe small intestine

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Epithelial TissuesSimple Columnar Epithelium(Stomach / Small Intestine)

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Epithelial TissuesStratified Squamous Epithelium(Skin)

2 or more layers of cellsBasal cells udergoes

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Epithelial TissuesPseudostratified Ciliated Columnar Epithelium (Trachea)

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Epithelial TissuesTransitional Epithelium (urinary bladder)

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Connective TissueBind, anchor, and support body parts Abundant cellular matrix2 Types:

1. onnec ve ssue roper or n ng organs2. Specialized Connective Tissues binding & other

specific functionsFibers:1. Collagen thick, un-branched; appear wavy 2. Elastic thin, branched; less wavy 3. Reticular fine, delicate, branched extensively

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There are six major types of connective tissue

Cell

A. LOOSE CONNECTIVE TISSUE(under the skin)

Collagenfiber

Otherfibers

Fatdroplets

B. FIBROUS CONNECTIVE TISSUE(forming a ligament)

Cellnucleus

Collagenfibers

Connective Tissue Proper

C. ADIPOSE TISSUE

Cellnucleus

D. BLOOD

White bloodcells

Red bloodcells

Plasma

F. CARTILAGE(at the end of a bone)

Matrix

E. BONE

CentralcanalMatrix

Cells

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Connective Tissue Proper:Loose or Areolar ConnectiveTissue

Large amount of tissue fluid, many cells, few fibers

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Connective Tissue Proper:Dense Connective Tissue(Tendon)

More fibers, less ground substance & cells

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Specialized Connective Tissue:1. Adipose Tissue

Adipocytes fat cellsFats triglycerides

tores nutr ents, prov esinsulation, & acts as cushions;fills crevices in organsNucleus signet (ringconfiguration)

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Specialized Connective Tissue:2. Cartilage

Chondrocytes cartilagecells

3 Types of Cartilage based onMatrices:1. Hyaline Cartilage2. Elastic Cartilage3. Fibrocartilage

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Specialized Connective Tissue:a. Hyaline Cartilage

(trachea)Clear homogenous matrix

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er c on r um enseconnective tissue found at theperiphery; supplied withblood vesselsSpindle-shaped lacunaehouses the chondrocytes

Specialized Connective Tissue:b. Elastic Cartilage

(Epiglottis & External Ear)Contains collagenous fibers,& a network of elastic fibers

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Specialized Connective Tissue:c. Fibrocartilage

resembles connective tissueproper

collagenous fibersRound or oval lacunaehouses the chondrocytes

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Specialized Connective Tissue: 3. Bone

For support, protection,movement, forming bloodcells; reservoir of calciumLamellae matrixHaversian canalOsteocytes bone cellsLacunae small spaces

Canaliculi minute canalsradiating from the lacunaeHaversian System / Osteone Volkmanns canal - canals

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Specialized Connective Tissue:4. Blood

Transport mediumPlasma fluid medium

a. ry rocy es or e oo e s carr es emog o nb. Leucocytes or White Blood Cells

Granular WBC multi-lobulated nucleus connected by chromatin strands

Agranular WBC

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Specialized Connective Tissue:Human Red Blood Cells Frogs Red Blood Cells

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Specialized Connective Tissue:Granular WBC Agranular WBC

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Muscle TissueCells are specialized for contractionMuscle cells are elongated, thus they are calledmuscle fibers 3 Types:1. Skeletal muscle voluntary; striated2. Smooth muscle involuntary; non-striated

3. Cardiac muscle involuntary; striated

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Unit of musclecontraction

Musclefiber

Nucleus

Musclefiber

Nucleus

Junction betweentwo cells

Muscle Tissue

A. SKELETAL MUSCLE

B. CARDIAC MUSCLE

C. SMOOTH MUSCLE

Muscle fiberNucleus

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Muscle TissueSkeletal Muscle - skeleton Smooth Muscle walls of

viscera

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Muscle TissueCardiac Muscle wall of the heart

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Nervous Tissue:specialized to receive stimuli from the environment orfrom various organs of the body transmit impulses to the nerve centers in the brain &sp na corComposed of 2 Types of Cells:1. Neurons2. Neurologia

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Nervous TissueNeurons:

Nerve Processes:1. Dendrite short &

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body; conveys impulsestowards the cell body

2. Axon thinner but muchlonger; conveys impulsesaway from the cell body

Nervous TissueTeased Nerve

myelin sheath

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Nervous TissueNerve Bundle (x-s nerve trunk)

Fascicle single bundle of nerve fibers & connective tissueE ineurium connective tissuethat binds several fasciclesPerineurium denseconnective tissue that coverseach fascicle

Endoneurium connectivetissue that covers individualnerve fibers

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