Tissues + Epithelia + Glands

Ectoderm

(Outer layer), epidermis, brain, spinal cord, nerves

Mesoderm:

(Middle layer) structure, circulatory, muscles, bones, cartilage, blood, heart, kidenys, and gonads

Endoderm

(Innermost) Epithelial, lungs, liver, pancreas, thyroid, urinary bladder

Cellularity:

Epithelial tissue is composed almost entirely of cells

Polarity:

Establishes distinct top (apical) and bottom (basolateral) domains of epithelial sheets

Apical surface

Faces lumen or the outside enviorment

Basal surface

Attaches to underlying basement membrane, while lateral domains connect to neighboring cells

Avascularity

Lacking of blood vessels (all epithelial tissues)

Innervation

Having nerves

Basement tissue

a thin, dense, specialized layer of extracellular matrix that lies beneath epithelial and endothelial cell sheets and surrounds individual muscle, fat, and nerve cells

Membranous Epi Tissue

Covers exposed body surfaces — lines insides and outsides of hollow organs

Glandular epithelium

Relating to, or involving a gland — specialized type of epithelial tissue that produces and releases substances such as sweat, saliva, mucus, enzymes, and hormones

a type of gland that releases its secretions through ducts onto an epithelial surface

Basal lamina

a thin, gel-like layer of extracellular matrix that sits directly beneath epithelial and endothelial cells, separating them from the underlying connective tissue — Part of the basment membrane

Recticular laminate

A thin layer of extracellular matrix located deep to the basal lamina that anchors epithelial tissue to underlying connective tissue — Collagen fibers — part of the basment membrane

Simple epithelium

a single layer of cells that rests on a basement membrane

Stratified Epithelium

a body tissue composed of two or more layers of cells stacked on top of each other,

Pseudostratified epithelium

a single layer of irregularly shaped cells that appears multi-layered because their nuclei sit at different heights

Squamous cells

thin, flat cells that look like fish scales and form the outer surface of the skin (epidermis) as well as the linings of hollow organs, the digestive tract, and the respiratory tract

Protective shield prote ting delicate tissues, physical damage, germs, and fluid loss, intake of gasses

Cubodial cells

cube-shaped epithelial cells that are roughly equal in height and width, featuring a single, round, centrally located nucleus

Secreation, absorption, and active transport.

Columnar cell

tall, rectangular, or column-shaped epithelial cell found lining various organs and tracts throughout the body

Absorption, secreation, protection

Traditional cells

Cells that rapidly change shape and size based on how stretched the epithelium becomes

Goblet cells

specialized, wineglass-shaped, unicellular exocrine glands found scattered within the simple columnar epithelial lining of the body's mucous membranes

Exocrine glands

specialized groups of cells that release chemical substances through ducts onto body surfaces or into internal cavities

Cilia

microscopic, hair-like membrane protrusions that extend from the surface of many eukaryotic cells

Endocrine Glands

specialized organs that produce and release chemical messengers called hormones directly into your bloodstream to regulate bodily functions like metabolism, growth, and stress response

Glands

specialized cell or organ in the body that produces and secretes specific substances used by the organism or eliminated as waste

Tight junctions

Limits the flow of substances between cells from the external enviorment