Chap 1 Part 1 Flashcards
What are the 3 general function of epithelium?
absorption, secretion and providing a barrier
What are the 3 specialized functions of epithelium?
transport molecules across epi, selective permeability, and sensory
T/F: epithelial cells being adjacent to each other is a characteristic shared among all types of epithelium.
True
What are the two types of basement membranes that epithelial cells are associated with?
either complete or partial basement membranes
What are the parts of a complete basement membrane?
basal lamina and reticular lamina
What are the parts of a partial basement membrane?
basal lamina only
What produces the basal lamina?
epithelial cells
What produces the reticular lamina?
fibroblasts in connective tissue
What are the 3 main functions of a basement membrane?
provides a surface for epithelial cell attachment, molecular filter, and limits stretch
T/F: collagen I fibers can stretch.
false; this how basement membranes limit stretch
T/F: epithelium is directly supplied by blood vessels.
False; epithelium is avascular and cells obtain nutrition by diffusion
What are the 2 functions of CT?
provides nutrition and source of defensive cells
What are epithelial cells held together by?
cell junctions
What are the 4 types of cell junctions?
Zonula Occludens, Zonula Adherens, Macula Adherens, and Gap Junctions
Which type of cell junction is considered a tight junction?
Zonula Occludens
Which type of cell junction involves sharing of intrinsic membrane proteins between adjacent cells?
Zonula Occludens
What are the two functions of the Zonula Occludens?
Provide strong attachment and prevent passage of material between cells
Which type of cell junction can be considered and adhesion belt?
Zonula Adherens
Which type of cell junction consists of cadherins and marginal bands?
Zonula Adherens
What are cadherins?
Linkage proteins between cells
What are marginal bands?
microfilaments which attach the cytoskeleton to the cell membrane
What are the two functions of the Zonula Adherens?
strong attachment function and provide cell structural stability
Which cell junction is essentialy just desmosomes?
Macula Adherens
What is the function of the macula adherens?>
strong attachment
Which type of cell junction consists of six connexins arranged in a cylinder?
Gap junctions
What are connexins?
proteins; a complete structure
What are the 2 functions of Gap Junctions?
strong attachment, and transport materials
Which types of cell junctions function is providing a strong attachment?
All 4
What is the Junctional Complex?
Zona Occludens, Zona Adherens, and Macula Adherens
Hemidesmosomes and focal point contacts are junctions that do what?
hold the epithelium to the basement membrane and the CT below
What are hemidesmosomes?
Essentially, half of a desmosome; help to connect epithelial cells to the basal lamina
What are focal point contacts?
The area where Integrin (a transmembrane protein of the cell membrane) binds to structural CT glycoproteins and also connects to cytoskeleton
What is Bullous pemphigold?
an autoimmune skin disease causing large blistering lesions that burst, but do heal
What causes Bullous pemphigold?
antibodies bind to some proteins in hemidesmosomes
What is simple epithelium?
epithelium that is a single cell thick
What are the 4 different types of simple epithelium?
Simple Squamous, Simple Cuboidal, Simple Columnar, and ciliated pseudostratified columnar (respiratory epithelium)
Where is simple squamous found?
lung, parietal layer of the Bowman’s capsule in the kidney, and serosa on the outside of organs
What kind of simple epithelium can be described as a single layer of flattened cells?
simple squamous
What are the 2 functions of simple squamous?
provide a barrier and provide a living filter
What kind of simple epithelium can be found in exocrine ducts, thyroid follicular cells, and kidney tubules?
Simple Cuboidal
Which type of simple epithelium can be described as a single layer of cube shaped cells where the nucleus occupies much of the cell cytoplasm and typically looks like a square when sectioned for a slide?
simple cuboidal
What are the 3 main functions of simple cuboidal?
provides a barrier, secretion, and absorption
What types of simple epithelium function in both secretion and absorption?
simple cuboidal and simple columnar
Which types of simple epithelium function in providing a barrier?
simple squamous, simple cuboidal, and simple columnar
Which type of simple epithelium can be found in the gallbladder and larger exocrine ducts.
Simple columnar; can also be found in stomach and SI
Which type of simple endothelium typically looks rectangular when sectioned for a slide?
simple columnar
What are the 3 functions of simple columnar epithelium?
barrier, secretion, and absorption
Which type of simple epithelium can be found in the trachea, nasal cavity and bronchi?
ciliated pseudostratified columnar epithelium
Why does ciliated pseudostratified columnar epithelium sometimes appear stratified?
it has 3 cell types of various heights
What are the 3 types of ciliated pseudostratified columnar epithelium?
goblet cells, ciliated columnar cells, and basal cells
Which type of ciliated pseudostratified columnar epithelium is a modified columnar cell, produces mucus, and is an important part of respiration?
Goblet cells
Which type of psudostratified columnar epithelium contains cilia anchored to athe apex by basal bodies?
Ciliated Columnar cells
What is the function of ciliated columnar cells?
to move mucus over the surface
What type of cell functions as the stem cell for ciliated pseudostratified columnar epithelium, is shaped like a short pyramid and does not reach the surface?
Basal Cells
What are microvilli?
finger-like projections at the apical surface on some epithelial cells; also called a brush border or a striated border
What is the function of microvilli?
to increase surface area thus increasing absorption
Where are microvilli located?
kidney tubule cells and small intestine
What are stereocilia?
extremely long microvilli; not related to true cilia
where can stereocilia be found?
epididymis and cochlear hair cells
What is the term for thin apical hair-like extensions of the cytoskeleton that function to move something over the surface?
cilia
T/F: cells with cilia have very few mitochondria.
False; they have many
Can cells with cilia secrete or absorb things? why or why not?
No, the basal bodies block the free surface
Where can cells with cilia be found?
trachea and fallopian tube
What is glycocalyx?
surface layer of glycoproteins and carbohydrates that covers some epithelium
What produces glycocalyx?
epithelial cells
What are the functions of the glycocalyx?
protection and cell recognition
Where can you find glycocalyx?
stomach and SI
