Histology Vocab (Definitions and Pictures)

Histology

The anatomical study of the microscopic structure of animal and plant tissue

Free Surface

Cells that line passageways (vessles, digestive system, air, etc...

Basement Membrane

Anchors epithelial tissue to the musculature... Think of the basement of a house, anchoring the house to the ground; last row of cells attach to this

Cell Connections

Bind cells together; provide permeability barrier and communication; think of a kid building blocks, cells are like the blocks, they wouldn't get knocked over if they had been connected

Desmosomes

Cell to cell connection; glycoproteins are like a natural, biological glue; filaments=protein wire

Hemidesmosomes

Cell to basement membrane cell connection

Tight Junctions

Hld cells together, act like a Zip Lock Bag - will not let out water; Consists of two parts Zonula Aderens and Zonula Occtudens

Zonula Adherens

Runs the lenth of the cell; actin protein

Zonula Occludens

Runs the lenth of the cell; HUGE thicc (not as thicc as you tho) fibers; at junction, actin tough filaments

Gap Juntions

Hold two parts, and allow molecules and ions through. Think of rivets

Glands

Lined with epithelial tissue; produce secretion

Endocrine Gland

An aggregate of cells WITHOUT a duct; relies on bloodstream and release of hormones

Exocrine Glands

Has a duct; a flask made of an aggregate of cells

Merocrine Glands

Water producing sweat glands; take materials from blood vessels like salt and water.

Apocrine Gland

Discharges fragments of the gland cells in the secretion

Holocrine Glands

Shed entire cells; entire cell becomes part of secretion

Connective Tissue

They support and suspend

Matrix

Background material; 3 parts: protein fibers, ground substance, and fluid; can be thin and watery or thick like cartilage (or your ass)

Collagen Fibers

Thicker, rope like, strong, long protein, support watery environment; ligaments/tendons

Reticular Fibers

Very fine, short, thin collogen, fibers; tendency to form an interlocking network; filler material; every basement membrane, organs (spleen, liver, kidneys)

Elastic Fibers

Contain protein elastin; its own category of protein, suspension like rubber band, found in all basement membranes

Blasts

Do bulk of work: young, active, and create matrix ex: Fibroblasts

Cytes

Put polish on; maintain the matrix mature cells ex: Fibrocytes

Ground Substance

The liquid, gelatinous or very dense substance that is the matrix minus fibers, blood vessels etc...

Squamous "Flat"

Interlock like a puzzle huge thin sheet. They transfer nutrients ex: lungs

Cuboidal "cube"

As tall as they are wide. If most appear cuboidal it is cuboidal epithelial tissue

Columnar "columns"

Taller than wide. Some have cilia. If cells are ciliated, must be columnar. Cilia sweeps away mucus.

Goblet Cells

Produce mucus. Only found in columnar cells, but not all columnar have mucus.

Simple Arrangement

Only one layer

Stratified Arragement

Two or more layers

Pseudostratified

One layer of cells, but it looks like many due to the different heights of the nuclei

Transitional Epithelial Tissue

Alter shape on circumstance; look half stratified, half cuboidal. Cytoplasm pushes up on the membrane

Urinary bladder

If empty, stratified cuboidal or columnar. If full stiatified squamous. Always look at the top 2-3 layers.