Histology Flashcards
What are the three regions of the epithelium?
Basal- the bottom
Apical- the side that will face the outside/lumen
Lateral- the sides that communicate with each other
What are microvilli?
Cytoplasmic projections that have an actin core. They are generally used in absorption and seen in the gastrointestinal system
What is stereocilia?
They are microvilli that are longer in length. Appear to be hair like projections with an actin core. They are generally restricted to the epididymis and the inner ear
What are cilia?
There are longer hair like projections that have a microtubule core. They have three main functions- motility(movement) primary(chemoreception) and nodal(axis for embryo)
What are flagella?
They are modified motile cilia used mostly in sperm cells
What is an occluding junction?
It is a cellular junction that decreases the permeability of the cell layer. They are generally lateral but more towards the apical surface and use occluding/claudins as molecules.
What is an anchoring junction?
They are lateral adhesions that link into the cytoskeleton of the adjacent cell- Two types zonula and macula
what is the difference between the zonula and macula anchoring junctions?
The zonula work with the actin filaments while the macula(also known as desmosome) will be intermediate filament, more specifically the Catherine’s
What is a Gap junction?
They allow communication between cells by providing a fluid filled channel that use connexin aggregates
What are focal adhesions?
Uses actin filaments using integrins to attach cells to the basement membrane
What are hemidesmosomes?
Anchor intermediate filaments using integrins to the basement membrane
What is a simple squamous epithelial layer?
A cell type that lines blood vessels, serous membranes and avola- they function in fluid exchange of material, act as a barrier and lubrication
What is simple cuboidal epithelial tissue?
Located in the kidney tubules, glands/ducts, covering ovary- they function in absorption, barrier and secretion
What is simple columnar epithelial tissue?
They are located in the auditory tubes, uterus, oviducts, stomach and gall bladder- they function in absorption and secretion
What is pseudostratified columnar ciliated epithelial tissue?
Line the nasal cavity, pharynx, trachea and bronchi- they have cilia projections on the top- function in absorption/secretion and will help clear debris/particulate movement
What is urothelium epithelial tissue?
These cells are domed located in the urinary bladder, uterus and uretha- they function in barrier and have distensible properties
What are non keratinized stratified squamous cells?
Located in the oral cavity, esophagus, anus and vagina they function as a barrier or protection from the outside. The most apical cells have a nucleus
What are keratinized stratified squamous cells?
They are located in the epidermis of the skin and function as a barrier- these most apical cells do not have a nucleus and they are covered by a layer of keratin
What is stratified cuboidal cells?
They are located in the sweat glands, ovarian follicles and function as a passage way or barrier
What is a mucous membrane?
A specialized epithelial tissue that secretes mucous in places like the respiratory tract and body cavities
What is a serous membrane?
A specialized membrane that secretes fluid to allow tissues to slide against eachother- found in places like the heart
What is a merocine gland?
The secretion is delivered to the apical surface by a vesicle then undergoes exocytosis
What is a holocrine gland?
These cells will accumulate product in cell then undergo apoptosis, releasing the product as it degrades
What is an apocrine gland?
The product, typically lipid based, is budded off into a membrane at the apical surface of the cell then leaves duct
