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Histology The microanatomy of cells, tissues, and organs of the human body correlating

structure w/ fxn.

Feulgen reaction Stains DNA red.

SEM(3D) used in dentistry to view cracks and surface structures (amalgam) sample is

coated with Au.

Microtome Tool used to cut samples very thin.

Immunocytochemistry The use of fluorescently labeled antigens to stain isolated cells

(void of any extracellular matrix).

Inclusions Nonfunctioning units of cytoplasm.

F ixation First step of tissue preparation. Preserves in vivo structure.

F luoroscein Most common fluorescent dye.

TEM Use of extremely thin samples (diamond cut). Cu mesh used in place of glass slides.Electrons used to control laser beam.

Apical Cell side farthest from the basement membrane.

B asal Cell side closest to the basement membrane.

Formalin Fixative that cross links amino acids w/o altering 3D protein structure.

H istochemistry The use of chemical stains to distinguish body tissues based on chemical

composition.

Gap Junction Communicative junction between adjacent cells via protein tubes called

connexons.

Nucleus Organelle that contains DNA (control center of cell).

Infiltration (1) wash out fixative w/ H20 (2) dehydrate w/ alcohol (3) xylol clears alcohol (4)

embed tissue w/ paraffin

R esolution The clarity of a sample being observed. (RP: distance two objects must be

separated to be distinguished as two objects)

Desmosomes Anchoring junction that allows communication between adjacent cells

(attachment plaques and fibular network).

C ytoplasm Cellular material outside the nucleus and inside the cell membrane.

Embedding Media Material used to add rigidity to a fixed sample (paraffin,

methylmethacrylate).

M agnification Expanding an image in apparent size.

T ight Junction Impermeable junction in the apical region of the proximal contact of cells.

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Plasma membrane Phospholipid bilayer membrane surrounding the cell that facilitates

communication and protection. Also contains proteins, cholesterol, and glycoproteins.

Paraffin Wax embedding agent used to prepare microscopy samples.

Resolving Power Distance two objects must be separated to be distinguished as two

objects).

M icrovilli Fingerlike projections of the plasma membrane which increase the surface area

to enhance absoroption.

U nit membrane Phospholipid bilayer with intercalating proteins.

Chromatin The combination of DNA and protein (histones) that comprise the chromosome.

H ematoxylin Stains ribosomes/DNA blue.

M ethylmethacrylate Plastic used in place of paraffin wax to add rigidity to embedded

sample.

B right field microscope Requires staining and fixation. Simplest light microscopy.

Eosin Stains fibers (collagen) red.

C onfocal microscope Converts 2D 3D. Light microscope.

Microfilament Smallest type of cytoskeleton comprised of actin subunits.

Cytoskeleton Internal framework/network of protein structures extending throughout the

cytoplasm.

N uclear pore Allows exchange of material between nucleus and cytoplasm.

Nuclear envelope Phospholipid bilayer separating nucleus from cytoplasm.

E rgastoplasm (ER) Fluid filled tubules for carrying substances.

O smium tetroxide Fixative used for electron microscopy in place of formalin. Stains

phospholipids black.

P olarizing microscope Light. Commonly used in dentistry. Used for repetitive structures

such as collagen and actin (periodicity).

Microtubule Largest type of cytoskeleton comprised of tubulin subunits.

Actin Protein subunit of microfilamentsand thin filaments.

T ubulin Protein subunit of microtubules.

Ribosome Site of proteins synthesis found free in the cytoplasm and attached to RER

(made of protein and DNA).

Mesenchyme Common embryonic precursor of connective tissue.

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Periodic Acid Schiff Rxn Staining method used to distinguish/view carbohydrate

containing structures.

F lagellum Tail-like projection involved in cellular locomotion. (Longer than cilia)

C ilia Fine projections found in eukaryotes that move materials across the cell surface.

A tomic Force Microscopy Uses a laser, views at atomic level to reveal structural

composition.

Four basic tissue types Epithelial, Connective, Muscle, Nervous

C haracteristics of epithelium Avascular, tightly packed cells that always has one free

surface (apical surface) and one basement surface (basal surface) and regenerate easily

with nourishment from connective tissue.

C lassification of types of epithelium Layers: Simple (single layer), Stratified (multi-

layered), Pseudostratified (all cells touch basement membrane, false impression of more

than one layer).

Shapes: Squamous (x>y), Cuboidal (x=y), Columnar (x

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Basal bodies

uranyl acetate

E xocrine glands Secretes enzymes through ducts to epithelial surface (eg. Sweat and oil

glands).

E ndocrine glands Secrete hormones directly into blood vessels.

Acinar cells Exocrine glandular units that comprise an acinus.

D ucts

C lassification of exocrine glands

glycocalyx

T erminal web Intracellular fibers located under microvilli near apical surface to add rigidity

to cell surface. Stain darker.

Holocrine gland

merocrine gland

C opper grid Used in place of glass slide when viewing samples under TEM.

C ryostat A microtome in a freezer used to make ultrathin samples.

E xocytosis Exporting material from cell via membranous vesicle.

Endoctytosis Engulfing extracellular material via membranous vesicle.

P hagocytosis Solid endocytosis.

P inocytosis Liquid endocytosis.

E uchromatin Lightly packed chromatin.

H eterochromatin Tightly packed chromatin.

* Terminal bars Intensely stained tight junctions.

A mphipathic Molecule with both hydrophilic and hydrophobic regions.

A pocrine gland Exocrine sweat gland.

Reticular fibers Type III collagen (smaller than type I) thin and highly branched, higher

carbohydrate content, stained preferentially by silver stain.

E lastic fibers Complements inelastic strength on extracellular matrix, composed of

microfibrils and elastin.

F ibrilin Glycoprotein subunit of elastic fibers.

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E lastin Subunit of elastic fibers that is made of desmosine and isodesmosine.

Isodesmosine Lysine derivative found in elastin

D esmosine Responsible for rubber quality of elastin

Hydroxyproline Major proteinous component of collagen.

H ydroxylysine Major proteinous component of collagen.

T ropocollagen Subunit of collagen fibrils.

C ollagen synthesis

1) Preprocollagen (single chain) formed on RER.

2) Proline hydroxylated and hydroxylysine is glycoxylated.

3) Procollagen (triple helix of modified preprocollagen) sent to and modified in Golgi.

4) Exocytosis of procollagen.

5) Telopeptides cleaved from procollagen to yield tropocollagen.

6) Tropocollagen self-assembles to form collagen fibrils.

Types of body tissues Epithelial, Connective, Nervous, Muscle

Loose connective tissue Greater proportion of cells than fibers. (Cellular)

D ense connective tissue Greater proportion of fibers than cells. (Fibrous)

A rgyrophylic Silver loving (eg. reticular fibers).

O rcein Dye extracted from lichen (eg. Litmus).

*R esorcin-fuchsin

Basement membrane Stained by PAS (collagen), carbs, basement structural support.

Epithelial/connective contribute to basement membrane.