Epithelial lined structures that produce a chemical that is secreted extracellularly.
Glands can be ______ or ______.
endocrine (secrete into bloodstream) or exocrine (secrete into duct)
3 mechanisms for glandular secretions.
1. Merocrine- exocytosis of secretory vesicles to the lumen of the gland.
2. Holocrine- death of an entire cell within a gland releases content into the lumen of the gland.
3. Apocrine- release of budding vesicles off the epithelial cells into the lumen of the gland (an actual piece of the cell blebs off, unlike merocrine, which releases vacuoles from the cytoplasm)
Sweat glands are _____.
Sebaceous glands are _____.
Cell surface modifications which increase surface area of a cell, while keeping the size of the cell relatively small.
Microvilli are seen in organs where _________ is a primary function, such as ______ and _______.
absorption of molecules; small intestine; kidneys
Modifications of epithelium that are projections and type of organelle that are seen on the apical surface of epithelial cells, beat in a coordinated fashion, and assist in the movement of material over the epithelial surface.
Cilia are always found on the _______ of epithelial cells.
Tight junctions ________, and hen present in a sheet, they allow ______________ [functions].
hold cells together; epithelium to form a barrier between two compartments
Tight junctions are aka ______.
Gap junctions serve as a _____________, and they allow _________ [functions].
connection between cells which joins their cytoplasms; the passage of molecules freely between the cells
Desmosomes join _______ to ________.
cells to other cells.
Hemidesmosomes join ________ to _________.
cells to the basement membrane
Desmosomes and hemidesmosomes bind __________ across cells and are anchored by __________ within a cell.
cell surface proteins; filaments
Single layer of flat cells that can be continuous or discontinuous and is permeable to the passage of molecules.
simple squamous epithelium
Simple squamous epithelium is particularly important inside of ______.
The outer membrane that covers internal organs.
The serosa and cells forming it.
The most inner wall of the blood vessels.
The endothelium is _____, ______ epithelium.
Simple squamous epithelium that has small openings; common in the liver.
Simple squamous epithelium that has large spaces.
A single layer of cuboidal epithelium lining a basement membrane.
simple cuboidal epithelium
Simple cuboidal epithelium provide ______ and ______ functions.
Epithelium in which the length if greater than the width and the nuclei are located at the base of the cell; often has a modification (cilia or microvilli).
simple columnar epithelium
A single layer of cells similar to columnar epithelium, except the nuclei are arranged at different levels and every cell is attached to the underlying basement membrane.
pseudostratified columnar epithelium
Pseudostratified columnar epithelium have _______ and ________ functions.
absorptive and secretory
Pseudostratified columnar epithelium is common in the _____.
Epithelium arranged in layers; superficial cells are flat, but deeper layers may be cuboidal.
Stratified squamous epithelium
Stratified squamous epithelium is common in regions where ___________ is necessary.
protection against abrasions
Stratified squamous epithelium is common in _______.
Layers of this type of epithelium can be shed and regrown.
stratified squamous epithelium
Intracellular filament which provides structure to cells.
A tough waterproof barrier is formed through cornification (keritinization), which is...
cells int he uppermost layer of stratified squamous epithelium lose their nuclei and organelles, leaving behind a dead cell with keratin and other inert structural elements
Unique type of stratified epithelium in which the cells can change shape in response to stretching of the organ.
urothelium (transitional epithelium)
All types of connective tissue are composed of... (2)
cells and extracellular matrix
__________ is the primary structural component of connective tissue.
Material formed from glycoproteins and glycosaminoglycans in connective tissue; holds water and acts as a space filler.
ground substance (extrafibrillar matrix)
The fiber component of extracellular matrix can be... (3)
collagen, reticular fibers, or elastic fibers (elastin)
Describe the structure of collagen.
AA sequence--> triple helix (tropocollagen) --> fibrils --> fibers
Fibrils are cross-linked with each other in collagen to form ________.
Type I collagen
most abundant; tendons, dermis, arterial walls
Type II collagen
Type III collagen
reticulin fibers, granulation tissue
Type IV collagen
basil lamina, ocular membranes, basement membrane of glomerular capillaries
Type V collagen
interstitial connective tissue (fine/in between cells)
New vascular tissue in granular form on an ulcer or the healing surface of a wound.
subtype of collagen that are delicate and unorganized and easily identified by silver staining.
Reticulin fibers are present in...
lymphatic organs and bone marrow
Provide connective tissue with the ability to stretch.