Chapter 5, Lesson 5: Cellular Junctions, Glands, and Membranes

Flashcards from Chapter 5, Lesson 5 of McGraw Hill Anatomy and Physiology, Ninth Edition, by Kenneth S. Saladin.

Cell junctions

The connections between two cells; they are usually anchored with each other or the matrix for communication, strength, and transfer

Tight junction

A zipper-like, interlocking linkage between cells by trans membrane adhesion proteins

Desmosome

A Velcro-like patch that holds cells together and resists mechanical stress, has hook-shaped proteins with more space in between

Hemidesmosome

A half-desmosome that anchors basal cells of an epithelium to the basement membrane

Gap junction

Junction formed by orange-like connexons, these transfer substances like a bridge and are located in cardiac and smooth muscle as well as the embryo, lens, and cornea

Connexon

Six trrans membrane proteins arranged like segments around a water-filled pore

Gland

A cell or organ that secretes substances for use in the body or releases them

Secretion

Keeping a product useful to the body

Excretion

Removing a product not useful to the body (waste products)

Exocrine glands

Glands that maintain their contact with the surface of the epithelium via a duct

Endocrine glands

Glands that have no ducts or contact with the outside, they secrete hormones directly into the blood

Hormones

Chemical messengers that stimulate cells elsewhere in the body

Unicellular glands

Found in an epithelium that is predominantly non-secretory; can be endocrine or exocrine

Capsule

The connective tissue covering of the exocrine gland

Septa (trabeculae)

Extensions of a capsule that divide into compartments

Stroma

The connective tissue framework of the gland; supports and organizes glandular tissue

Parenchyma

Cells that perform both the tasks of synthesis and secretion

Classification of glands

By duct (simple and unbranched, or compound and branched) or by gland shape (tubular with narrow secretory portion, acinar with multiple secretory cells, or tubuloacinar with both characteristics)

Serous glands

Produce thin, watery secretions (perspiration, milk, tears, digestive juices)

Mucous glands

Produce glocyoprotin, mucin, to absorb water from mucous

Mixed glands

Contain both serous and mucous cell types and produces a mixture

Eccrine glands

Uses vesicles that release secretion by exocytosis, like tears, the pancreas, etc

Apocrine glands

A liquid droplet covered by the membrane and cytoplasm from the cell surface; used to make milk

Holocrine secretion

Cells accumulate a product until they disintegrate, secretes cell fragments and substances

Membranes

Only epithelial, only connective or a mix of epithelial, connective, and muscular tissues

Cutaneous membrane

The skin (the largest membrane in the body), made up of stratified squamous epithelium on connective tissue

Mucous membrane

Lines passages that open to the external environment (like the digestive tract); absorbs, secretes, and protects often with goblet cells

Serous membrane

Internal membranes of simple squamous epithelium on areolar tissue; produces serous fluid that arises from blood and lines organs and body cavities (endothelium to the heart, mesothelium on cavities)