Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
Basal Lamina:
A layer of extracellular material between the ... surface of all epithelial cells and the underlying ... Dense layer of material (20-100 nm thick) which is only visible by ... Composed mainly of type ... collagen, laminin and heparin sulfate, a proteoglycan. |
basal
connective tissue electron microscopy IV |
|
|
... fibrils of type 7 collagen attach from basal lamina (type 4 collagen) to the connective tissue below
Basal laminae are also present around other tissue types which are in contact with connective tissue. |
Anchoring
|
|
|
Basal lamina is also found between adjacent epithelial cells where the basal laminae from each adjacent epithelial cell fuse to form a thicker basal lamina.
fused basal lamina = ... |
basement membrane
|
|
|
Components of the basal lamina are secreted by epithelial, muscle, adipose or Schwann cells.*
... fibers (type 3 very thin collagen fibers with some associated protein) secreted by connective tissue cells (... lamina) may be closely associated with the basal lamina. |
Reticular
reticular |
|
|
what are the 2 functions of basal lamina?
|
1) provides a barrier regulating the exchange of macromolecules
2) involved in cell-to-cell interactions |
|
|
The basement membrane is a thicker structure visible by ... which is composed of either:
1) ... or 2) ... Line beneath an epithelium is usually a basement membrane Basement membrane is very important in the kidney (the filtering system) |
light microscopy
1) two fused basal laminae 2) a basal lamina and a reticular lamina |
|
|
The basal lamina has 2 parts:
-the clear layer is called the ... -the deeper, denser layer is called ... |
lamina lucida
lamina densa |
|
|
... - Membrane-associated structures contributing to adhesion or communication between adjacent cells.
|
intercellular junctions
|
|
|
Intercellular junctions:
Some of these specialized structures act to adhere epithelial cells to the basal lamina (...) * or adjacent cells to each other (zonula ... and ...). |
hemidesmosomes
adherens desmosomes |
|
|
Zonula adherens (mainly actin): microfilaments, terminal web
Macula adherens, attachment plaques, cytokeratin ... is an adherens that goes all away around the cell (think of a belt that holds the cells together) ... is called a macula adherens (a belt adhesion at “spots”). Spot connections between cells Cytokeratins are intermediate filaments Desmosomes contain cytokeratin (important for development of skin) |
Zonula adherens
Desmosome |
|
|
intercellular juctions:
Some act as impermeable barriers between cells (impermeable junctions or a fusion of the 2 membranes) = ... tight junctions |
zonula occludens
|
|
|
intercellular junctions:
They act in intercellular communication (communicating junctions: ...). ... are made up of 6 proteins called ... |
gap junctions
connexons connexins |
|
|
zonula occludens = ... junction
zonula adherens = ... junction gap junction = ... junction |
occluding
adhering communicating |
|
|
The zonulae adherens, hemidesmosomes and desmosomes are called ... junctions.*
|
adherent
|
|
|
A ... is a combination of
intercellular junctions consisting of (beginning from the most apical region of the intercellular plasma membranes) a:* zonula occludens, * zonula adherens and* a desmosome. not extremely common |
junctional complex
|
|
|
what is this?
Formed by epithelial cells that secrete a fluid of different composition than blood or intercellular fluid. Secreted substances can be ions, secretory polypeptides or proteins, lipids or glycoproteins. |
glandular epithelia
|
|
|
Glandular epithelia is classified by modes of secretion:
...: secretory granules leave by exocytosis with no loss of cytoplasm. ...: whole cell is secreted into lumen of gland. (sebacious glands; hair) ...: secretory product and a portion of the apical cytoplasm of the gland cells are secreted. (ex. during the production of milk) |
Merocrine
Holocrine Apocrine |
|
|
Types of glandular epithelia:
1.Unicellular: ex. = ...(an exocrine gland that is unicellular) 2.Multicellular: a.Endocrine glands: lose their connection (...) to the surface from which they originated. Products (...) are secreted into the blood stream. * -associated with blood vessels -there are also some unicellular endocrine glands too b. Exocrine glands: retain their connection (...) to the surface. Secretion products (produced by the secretory portion of the gland) are transported to the surface via ... ducts. Several types. |
goblet cells
ductless hormones duct epithelial cell-lined |
|
|
Glandular Epithelia
Exocrine glands : 1. ...: one unbranched duct. Secretory portion may be tubular, coiled tubular, branched tubular, or acinar (looks like grapes on a vine). 2. ...: more than one duct that branches repeatably. Secretory portion may be tubular, acinar, or tubuloacinar. |
Simple glands
Compound glands |
|
|
Exocrine Glands:
Secretory activity of glands controlled by ... and ... systems involving chemical messengers, neurotransmitters or hormones. These factors interact with ... either located in the gland cells plasma membrane or within the gland cells cytoplasm. In the first case, binding to a surface receptor often results in the activation of a ... system (e.g., adenylate cyclase and cAMP) while; binding to cytoplasmic (or nuclear) receptors results in an activation of specific ... |
nervous
endocrine receptors second messenger genes |
|
|
Chemical-messenger-producing cells
Three types: A) ...: chemical messenger is released at an intercellular space between adjacent cells. (when the cell releases a substance that affects the cell next to it. Ex. Neuron) B. ...: chemical messenger is released into extracellular fluid and diffuses at some distance to nearby cells. (something that’s released locally and causes a response in that area) C. ...: chemical messenger (hormone) is released into the blood, which is then transported to target cells. (released into the blood system. Ex. Thyroid gland) Hormones can be: derivatives of cholesterol (steroids); proteins; polypeptides; or biologically active amines. |
Neurocrine
Paracrine Endocrine |
|
|
Serous cells:
Cells that secrete serous products have a particular morphology; usually ... in shape a serous secretion = a thin water secretion made up of ... basal regions of cells are ... due to ... (stains a purple color) apical areas are ... due to ... (stains a pink color) Found in pancreas, parotid gland, and submandibular gland |
triangular
proteins basophilic rER acidophilic secretory granules |
|
|
Mucus-Secreting Cells:
Secrete a thick, viscous material. Also contains ... Most is filled with ..., which (does?/does not?) stain very well. Small amount of rough ER at the ... of the cell. ... is flattened at the base of the cell. The rest of it is filled with mucinigen. |
water
mucin does not base Nucleus |
|
|
Direction of Transport Across Epithelia:
1) direction of secretion - ? 2) direction of absorption - ? |
1) from basal part of the cell to the lumen
2) from apical surface of the cell to the connective tissue below |
|
|
Ion-Transporting Epithelia:
A. Definition: epithelial cells which are involved in the transport of certain ions ... a concentration and/or potential (charge) gradient. B. Requires energy, usually in the form of ATP ---> ADP + Pi; catalyzed by ... enzymes, e.g., Na, K-ATPase. |
against
ATPase |
|
|
Ion-transporting epithelia:
In the proximal tubule cells of the kidney, ... freely enters the apical cytoplasm of the cell but is ... transported across the ... against a charge and concentration gradient. To accomplish this tranlocation of ..., ion-transporting epithelia, contain numerous ... of their ... plasma membrane. |
Na+
actively basal plasma membrane Na+ infoldings basolateral |
|
|
Ion-transporting epithelia
Na, ... enzyme has been identified in the plasma membrane infoldings. Located between the basal infolding are found a great number of vertically oriented ... (source of ATP). The basal infoldings can often be visualized as "..." by light microscopy. |
K-ATPase
mitochondria basal striations |
|
|
what is this?
endocrine epithelial cells which are involved in the synthesis and secretion of steroid hormones (steroids). |
steroid hormone-producing epithelia
|
|
|
Steroid hormone-producing epithelia
Morphology: ... or rounded ... cell with a central nucleus. (Not a lot of rough ER found. Function is to produce steroid hormones.) Frequently the cytoplasm contains rich deposits of ... (stain with ...). |
Polyhedral
acidophilic lipid droplets osmic acid |
|
|
steroid hormone-producing epithelia:
Contains abundance of ... endoplasmic reticulum and ... that usually contains ... rather than ... cristae. |
smooth
mitochondria tubular lamellar |
