1.Histology Orientation & Introduction Bsbio

*Junqueiras Basic Histology Ross Histology Text and AtlasBloom & Faucetts Concise HistologyDi Fiores Atlas of Histology

Expect a quiz every meeting3 term examinations (Prelim, Midterm, Final)Coverage of the examination may include previously discussed topics from the startStudents who are late beyond 15 minutes during examinations will not be allowed to take the exam

Immediate feedback may be done right after each examinationStudents will be informed of their scores and scores are announcedFinal examination is a comprehensive exam

Absences and tardiness 15 mins. grace Complete uniformElectronic gadgetsCell phones, camera, laptop, tablets, recorders NOT ALLOWEDPresident of class Liaison officer between me and studentsCheating in any form is NEVER TOLERATED

JOHARI M. ANCHETA, RMT, MD DOC JAO

HISTOLOGY

HistologyGreek word histo- means tissue or webBranch of morphological science that deals with the study ofMany cell types and extracellular componentsTissues arranged into organsCells tissues - organ

Microscopic Anatomy

Cytology

Study of cellsCells spontaneously shed off Cells physically removed by swabs or brushings

Tissue section

Cytology smear

StepsFixation- to avoid tissue digestionDehydration- series of increasing concentration of alcoholClearing- removal of alcohol Impregnation/Infiltration melted paraffin at 58C - 60C Embedding- paper boats, paraffinTrimming or cutting to expose the tissue for sectioningSectioning- microtomeStaining- for visualization, H& EMounting on microscopic slidesLabeling

Histological stainingH and E: universal stain(Hematoxylin and Eosin)Histochemical stainSpecial stains- Mallory stain for nucleiEnzymes- Gomori Lead method for Acid PhosphataseImmune reactions fluoroscopy Immunohistochemical stainingAnatomic Pathology Biopsy Applications

Hematoxylin and eosin (H & E)

Hematoxylin stains nucleus and other acidic structures (RNA-rich portions) blue

Eosin stains cytoplasm and collagen pink

H and E stain result

Nuclei: blue to blue blackNucleolus: dark blueCytoplasm: pinkRBC, eosinophil granules, keratin: bright orange-red

H and E stain resultBasophil cytoplasm, plasma cells, osteoblast: purplishMuscle fibers: deep pinkCollagen tissue: light pinkCartilage: light blue to dark blueCalcium, calcified bone: purplish blue

Tissue sectionHematoxylin and eosin (H & E)Hematoxylin stains nucleus and other acidic structures (RNA-rich portions) blueEosin stains cytoplasm and collagen pink

Cytology smear

Papanicolau stainGiemsa or Wright stain

Cytology smearPapanicolaus stainHematoxylinH & EWrights stain

Transverse/cross-section and Sagittal/longitudinal sectionBasophilic and eosinophilicNucleus: pyknotic and vesicularSolid organs: stroma and parenchymaHollow organs: wall(mural) or layers

Transverse/cross-section and longitudinal

Basophilic and eosinophilic

Nucleus: pyknotic and vesicular

Solid organs: stroma and parenchyma

Hollow organs: wall or layers

Bright-field microscopy- widely used; composed of mechanical and optical partsTotal Magnification(TM)- Resolving power- smallest distance between 2 particles at w/c they can be seen as separate objects

Tissue sections are irradiated w/ UV light and the emission is in the visible portion of the spectrumAcridine Orange- example of fluorescent stain

- uses a lens system that produces visible images from transparent objectsFor tissue cultures and observing living cellsDIM- produces an image w/ a more apparent 3D aspect than phase contrast

Avoids stray light and achieves greater resolution by using:(1) small point of high intensity light provided by laser and (2) a plate w/ a pinhole aperture in front of image detector

Allows the recognition of structures made of highly organized moleculesBirefringence- ability to rotate the direction of vibration of polarized light. A feature of crystalline substances

Transmission electron microscopy- permits resolution around 3mm allowing up to 400,000 times magnificationScanning electron microscopy- permits pseudo 3D images of surfaces of cells

*******************************