2.4 lab - epithelia Flashcards
T/F the basal end of an epithelial cell membrane is part of the basal lamina
false - the basal lamina is the connective tissue layer that the basal end of an epithelial cell attaches to – it is not the same as the basal cell membrane
what 3.5 criteria do you use to name an epithelial cell layer?
1) # of layers (simple, stratified, pseudostratified)
2) shape of Top Layer cells (squamous, cuboidal, columnar)
2. 5) keratinized vs non-keratinized (if squamous)
3) location of epithelium (epithelium, endothelium, mesothelium)
what are 2 special types of epithelia that demand a name other than “epithelium” ?
- endothelium (blood vessels)
- mesothelium (serosa)
what are 3 modifications to the usual options for classifying epithelia? (usual = 2 kinds of layers and 3 types of shapes)
- pseudostratified
- transitioinal
- karatinized (or non-keratinized)
this kind of epithelium is common in the GI system
simple columnar - absorptive & secretory functions
where are you likely to find simple columnar epithelium?
absorptive / secretory locations – e.g. the GI system
this kind of epithelium is found in areas exposed to abrasive forces
stratified squamous epithelia
where are you are likely to find stratified squamous keratinized epithelia? name an example
areas exposed to abrasive forces but also wet:
- oral cavity
- vagina
where are you are likely to find stratified squamous nonkeratinized epithelia? name an example
skin
T/F every free or lumenal surface in the body is lined by an epithelium
true - this is a “golden rule” … although there are a few exceptions that you are unlikely to encounter in this class
blood and lymphatic vessels are always lined with what kind of epithelium
simple squamous ENDOthelium
give an example of the function of the luminal surface of endothelial cells
selectively grab leukocytes and transport across epithelium
give an example of the function of the basal surface of endothelial cells
initiate clotting if exposed to platelets
where are endothelia found
lining blood & lymphatic vessels
T/F endothelia are always simple squamous
true - i think
what are two names for …monovacuolar cells containing one large lipid droplet surrounded by a thin layer of cytoplasm with the nucleus is flattened on the periphery
unilocular adipocytes or white fat cells
the appearance of a white fat cell
a monovacuolar cell (unilocular adipocyte) containing one large lipid droplet surrounded by a thin layer of cytoplasm with the nucleus flattened on the periphery
another name for a white fat cell
unilocular adipocyte
another name for a unilocular adipocyte
white fat cell
this cell type is polygonal in shape with considerable cytoplasm and lipid droplets scattered throughout with a high concentration of mitochondria. eccentrically located nucleus but not squished on periphery
multilocular adipocytes or brown fat cells
the appearance of a brown fat cell
polygonal in shape with considerable cytoplasm and lipid droplets scattered throughout with a high concentration of mitochondria. eccentrically located nucleus but not squished on periphery
the appearance of a multilocular adipocyte
polygonal in shape with considerable cytoplasm and lipid droplets scattered throughout with a high concentration of mitochondria. eccentrically located nucleus but not squished on periphery
another name for brown fat cell
multilocular adipocyte
another name for multilocular adipocyte
brown fat cell
how can you tell apart a white fat cell and a similarly sized blood vessel?
blood vessel will likely display:
- multiple endothelial nuclei - fat cell will only have one
- a basal membrane (deeper staining adjacent connective tissue)
- a more round appearance
T/F all simple squamous epithelia endothelia
false - mesothelium are also simple squamous
where can mesothelia be found
lining inner and outer surfaces of 3 spaces:
- gut (peritoneal cavity / peritoneum)
- heart (pericardial cavity / pericardium)
- lungs (pleural cavity / pleura)
what is the mesentery
a connective tissue structure suspending the jejunum and ileum in the peritoneal cavity
what is the omentum
a connective tissue structure suspending the duodenum in the peritoneal cavity
T/F you will never have a mesothelium adjacent to a lumen
true - mesothelium is always an outer, serosal, layer
does mesothelium outline the mesentery or only the circumferential layers of the small intestine?
mesothelium outlines the mesentery too
what do tangential sections of squamous cells look like?
pancakes with blueberry nuclei
what is the form and function of epithelial cells in the gallbladder
- form: simple cuboidal epithelium
- function: absorb water from the bile
on EM, the junctional complex is called…
the junctional complex
on LM, the junctional complex is called…
the terminal bar
how to tell gallbladder epithelium from intestinal epithelium
- gallbladder has only one type-simple columnar
- intestines may have a different type or multiple types
inclusions in simple columnar epithelial cells of the gallbladder may consist of…
absorbed material (water)
what do microvilli look like on LM?
a dark, sometimes fuzzy line at apical epithelia (only about 1 micron in length and barely resolvable by LM)
transverse section of apical end of simple columnar cells will appear…
more cuboidal and anucleated
transverse section of basal end of simple columnar cells will appear…
more cuboidal and nucleated
the epithelium of the duodenum consists of…
simple columnar epithelium composed of
- enterocytes (absorptive)
- goblet cells (secretory)
“entero” signifies __
intestine
“enterocyte” = intestinal cell
the most apical layer of this epithelial type is composed not of intact cells but of densely packed sheets of proteins
stratified squamous keratinized epithelium
this type of epithelium should always be further classified as keratinized or nonkeratinized
stratified squamous epithelium
the epithelium of the rectum is…
simple columnar epithelium composed primarily of goblet cells
between the small intestine and the rectum, which epithelia is primarily enterocytes and which is primarily goblet cells?
small intestine - enterocytes with some goblet
rectum - goblet with some enterocytes
the epithelium of the anal canal is…
stratified squamous nonkeratinized SSNK
how can you tell SSNK from SSK?
SSNK - nuclei exist in adluminal cells
SSK - no nuclei in adluminal layer
the epithelium of the perianal skin is…
stratified squamous keratinized SSK
T/F any dry skin in the adult is expected to be keratinized
true
what is the name for the point of transition from simple columnar epithelium in the rectum to stratified squamous nonkeratinized epithelium in the anal canal?
the pectinate line
what is the pectinate line
the point of transition from simple columnar epithelium in the rectum to stratified squamous nonkeratinized epithelium in the anal canal
