Histology Flashcards

Flashcards for all the histology terms in the lecture

Tissue

A group of cells with similar structure and function that have similar extracellular substances located between them.

Histology

The microscopic study of tissue structure

Epithelial Tissue

Covers external and internal surfaces, has a basement membrane, little EM, and no blood vessels.

Functions of Epithelial Tissues (PAPSA)

Protecting, Acting as a barrier, Permitting passage, Secreting, Absorbing.

Simple Epithelium

Single-layered epithelium

Stratified Epithelium

Multi-layered epithelium

Pseudostratified Columnar Epithelium

Single-layered but appears to be stratified

Transitional Epithelium

Stratified and can be greatly stretched

Squamous

Flat cells

Non-keratinized

Moist squamous cells in the deepest and outermost layers

Keratinized

Composed of dead cells containing keratin; durable, moisture-resistant, dry

Cuboidal

Cube-like cells

Columnar

Tall and thin cells

Tight Junctions

Bind adjacent cells and form permeability barriers

Desmosomes

Mechanical links that bind cells together

Hemidesmosomes

Anchor cells to the basement membrane

Gap Junctions

Allow small molecules and ions to pass

Glands

Secrete substances onto a surface

Exocrine glands

Secrete through ducts

Endocrine Glands

Release hormones that are absorbed directly into the blood.

Merocrine

Products are released but no actual cellular material is lost.

Apocrine

Secretory products are released as fragments.

Holocrine

Shedding of entire cells.

Connective Tissue

Large amounts of extracellular matrix

Functions of Connective Tissue (EC2S2PT)

Enclosing, Connecting, Supporting, Storing, Cushioning, Transporting, Protecting.

Blast (germ)

Forms the matrix (connective tissue)

Cyte (cells)

Maintains the matrix (connective tissue)

Clast (break)

Breaks down the matrix (connective tissue)

Macrophages

WBCs that move about and ingest foreign substances

Mast Cells

Play an important role in inflammation

Collagen Fibers

Microscopic ropes; flexible but resist stretching

Reticular Fibers

Fine, short fibers that branch; support network

Elastic Fibers

Coiled; can recoil back to shape

Proteoglycans

Trap large quantities of water in ground substance

Loose Connective Tissue

Few protein fibers, numerous spaces

Adipose Tissue

Consists of adipocytes (fat cells): contain large amounts of lipid (for energy storage).

Dense Connective Tissue

Large amount of protein fibers

Cartilage

Composed of chondrocytes, in spaces called lacunae; flexibility and strength; provides support

Hyaline Cartilage

Most abundant, covers the ends of bones

Fibrocartilage

More collagen, able to resist pulling or tearing; found in disks between vertebrae and some joints

Elastic Cartilage

Contains elastic fibers, able to recoil to its original shape

Osteocytes

Bone cells, are located within lacunae

Blood

Liquid matrix; carry nutrients, oxygen, waste products

Muscle Tissue

Has the ability to contract

Skeletal Muscle

Large, long, cylindrical cells, multinucleated, attached to bones

Cardiac Muscle

Cylindrical cells, branched, single nucleated, found in the heart.

Smooth Muscle

End tapered cells, single nucleated, found in hollow organs.

Action potentials

Ability of nervous tissue cells to communicate with one another by means of electric signals

Neurons

Responsible for conducting action potentials

Mucous Membranes

Consists of epithelium and loose connective tissue; line the digestive, respiratory, reproductive tracts

Serous Membranes

Simple squamous epithelium and loose connective tissue; line the trunk cavities and cover the organs within it

Synovial Membranes

Formed by connective tissue; line the inside of joint cavities

Histamine & Prostaglandins

Chemical mediators of inflammation

Regeneration

New cells are the same type as those that were destroyed

Fibrosis/Replacement

A new type of tissue develops that eventually causes scar production

Granulation Tissue

Delicate, granular appearing connective tissue that consists of fibroblasts, collagen, capillaries