Flashcards in Epithelium Deck (124)
Rough Endoplasmic Reticulum is responsible for
Protein assembly, secretory granules, ribosomes
packages molecules to vesicles
formed from centrioles with cylindrical microtubules
break down long chain FAs and H2O2
What are microfilaments made of?
What are microtubules made of?
What do chief cells release?
What do parietal cells release?
Gastric acid to change pepsinogen to pepsin
What color do parietal cells stain?
Pink with a dark nucleus (fried egg)
What color do chief cells stain?
Dark and located next to parietal cells
Are pale staining nuclei more or less active than dark staining nuclei?
What organelle stains pink?
What effect does mucus have on the nucleus?
It displaces the nucleus to the edge of the cell and creates a pyramidal cell
What is a defining characteristic of the plasma cell?
The golgi apparatus does not stain and contrasts the nucleus
Why do plasma cells stain blue?
The production of antibodies by ribosomes
What type of microfilaments are in microvilli
How do you determine microvilli under a microscope
It is a shiny brush border
What are cilia made of?
What surface modification is a basal body?
Which is a more active nucleus? Round or elongated?
If a nucleus stains dark, what is it composed of?
Heterochromatic (compressed DNA)
What color does euchromatic nuclei stain?
Lighter than heterochromatic
What are cell inclusions?
Temporary structures that accumulate inside the cell
Name types of cell inclusions
Lipids, crystals, pigment
What causes vacuoles in stains?
Lipids and glycogen don't stain and leave empty spaces
What color does melanin stain?
DNA is jumbled and not separaed
Chromosome are lined along the center
Chromosomes are beginning to separate to opposite sides
Cleavage furrow appears
What are artifacts?
Human made or method-dependent results that appear part of the cell but are not
Name possible artifacts
Shrinkage, knife marks, folds and tears, separation of cells, dissolution of lipids (inclusion)
Where is endoderm located?
Digestive tract, glands, and respiratory tissue
Where is mesoderm located?
Muscle and connective tissues, genitourinary and circulatory system
Where is ectoderm located?
Nervous tissue, epithelium of the skin and epidermis, connective tissue of the head
What is the purpose of epithelium?
To line and cover the surface of all organs
What are the surface modifications?
Microvilli, cilia, stereocilia
Where is the basolateral membrane?
Just above the basement membrane
Where are surface modifications located?
On the apical side of the cell
Name a non-polarized cell
What is the purpose of the basement membrane?
Divides the epithelium and connective tissue
Where are stromal cells located?
Between tubular cells
List epithelium types
Cuboidal, simple columnar, simple columnar ciliated, pseudostratified columnar ciliated, simple squamous, stratified squamous, stratified cuboidal transitional
What is a terminal bar?
A junctional complex located on the lateral surface (basal modification)
What is a constant feature of junctional complexes?
Describe adhesion belts
Actin filaments and cadherins enable binding between cells. Adhesion is Ca+ dependent
Describe tight junctions
The fusion of adjacent cell membranes to make a barrier to prevent diffusion of molecules and ions
Desmosomes are anchored by intermediate filaments and bound with E-Caherin
Half desmosomes that bind only the basal cell surface to the basement membrane
Describe gap junctions
Gap junctions allow selective molecules t cross between adjacent membranes. Gap junctions can span 2 membranes
What is an important role of tight junction?
Preventing the spread of cancer cells
What do basal infoldings do?
Engulf fluid, bacteria and ions for transport
What are caveolae?
Invaginations for endocytosis.
What are pinocytotic vesicles?
Endocytosed particles from the caveolae that travel to the endosome for digestion
How are cilia structured?
9 doublet microtubules with 2 in the middle. The basal body contains 9 sets of triplet microtubules
Describe simple squamous epithelium
A single layer of flat cells with bulging nuclei and no cytoplasm
What is the epithelium of the blood vessel called?
Describe simple cuboidal cells
Equidimensional cells with a central nucleus
Describe simple columnar cells
Basal cells with elongated nucleus
Describe pseudostratified epithelium
Generally columnar, appeas stratified but is not. Seen with cilia, goblet cells, basal cells, and columnar cells.
Describe stratified squamous cells
Many layers, with the outermost layer being squamous in appearance. Cells move up and change from cuboidal to squamous and slough off at the top
What cells can be keratinized
Stratified squamous. Non-keratinized stratified squamous cells have nuclei on the top layer
What is the stratum corneum
Soft keratin located on top of the epithelium
What is the stratum lucidum
A band of dead and flattened keratinocytes (inconstant)
What is the stratum granulosum
Thin line of lamellar granules and keratohyalin granules that act as a water barrier
What is the stratum spinosum
Main layer of squamous cells attached by desmosomes
What is the stratum basale
Bottom layer of epithelium, next to basement membrane and produces stem cells for epithelium
Where is transitional epithelium found
What is an exocrine gland
Connected to the surface through ducts
What is an endocrine gland
No surface connection, secretes to blood
What is the secretory end piece of a gland
What are adenomeres made of
simple cuboidal, columnar or pyramidal cells
What type of cells do sebaceous glands have
Stratified cuboidal epithelia (very rare and found only in ducts)
What are unicellular glands
One single secretory cell in an epithelial layer (Goblet cell)
What are simple glands
Unbranched duct system, usually part of another organ
What are compound glands
Intricate duct system
Types of secretory units in glands
Tubular (straight, coiled) or alveolar/acinar (grape-like)
Glands with both tubular and alveolar units are called
Name the gland secretions
Mucus or Serous, or a mixture of both
How is serous different from mucus
Serous stains darker than mucus due to ribosomes. Mucous glands contain glycoprotein and stain light
What is the most common method of gland secretion
Merocrine; excretes through exocytosis
part of the cell is pinched off and secreted (rare, found in sweat and mammary)
Entire cell sloughs off, very rare (sebaceous)
What are negatively charged cell components?
DNA, RNA, ribosomes
What are positively charged cell components?
Mitochondria, proteins, collagens
Name peptides secreted by the heart
Atrial Natriuretic Petide, Brain natriuretic peptide
What is the effect of BNP
What is the effect of ANP
What is an intercalated duct?
The portion of an exocrine gland leading directly from the acinus to a striated duct
What is a striated duct?
A duct that connects the intercalated duct to a interlobular duct
What is a serous demilune?
A serous cell that is squished by mucus in a mixed production gland
Describe transitional epithelium
Columnar on the bottom and cuboidal on top when relaxed
What type of sweat gland is associated with hair?
What type of sweat gland is associated with no hair?
Where can you find stratified cuboidal epithelium
Sweat gland duct
Where can you find loose connective tissue?
Eye, lamina propria
Where can mesothelium be found?
Where can you find simple cuboidal epithelium?
Where can you find simple columnar epithelium?
Where can you find a goblet cell?
Where can you find pseudostratified columnar epithelium?
Where can you find stratified squamous?
What is pyknosis?
Cells are degenerating and breaking up
What type of gland is a goblet cell?
What type of gland is sebaceous?
Where would you find a simple tubular gland?
Where can you find a serous demilune?
Esophagous, salivary gland
What is an example of a compound gland?
Parotid (salivary) gland
What type of gland is the pancreas?
Where is mesenchymal tissue found?
What is the first stage of connective tissue development?
Mesenchyme develops some collagen fibers, "Wharton's jelly"
Loose connective tissue is also known as
Where can you find loose connective tissue
Mononuclear phagocyte system
Macrophage, Kupffer cells, osteaclasts
What cells are differentiated from B lymphocytes?
What is the main connective tissue in the dermis
Where is pigmented connective tissue found?
Describe a white fat cell
Unilocular, only 1 fat droplet
Where is dense regular CT found
Tendons, Ligaments, Aponeuroses
Where is dense elastin tissue found?
Nuchal ligament, aorta
What is the parenchyma
FUnctional part of solid organs (glands)