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Flashcards in 510-4 Deck (23):
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Epithelia

one or more layers of closely adhering cells with a BASAL SURFACE and a FREE SURFACE. innervated but not vascular. connected to the lamina propria through a basement membrane.

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Basement membrane

anchors epithelia to underlying lamina propria. composed of BASAL LAMINA annd RETICULAR LAMINA.

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Basal Lamina

mixture of cells produced by the epithelia and fibroblasts. composed of LAMINA LUCIDA and LAMINA DENSA.

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Lamina Lucida

translucent layer directly below epithelia. contains cells adhesion moleules like LAMININ that binds to type 4 collagen fibers of the lamina densa.

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Lamina Densa

contains type 4 collagen fibers that are the site of anchoring for the RETICULAR LAMINA

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Reticular Lamina

collagen and reticular fibers that anchor type 4 collagen fibers of LAMINA DENSA to LAMINA PROPRIA

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3 components of a mucous membrane

1.) epithelia capable of producing mucous
2.) lamina propria
3.) muscalaris mucosae (smooth muscle)

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Transitional epithelia

pseudostratified layer of epithelia that appear rounded (domed) and are found in the bladder (stretch when full)

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5 types of intercellular junctions

1.) tight junction (zonula occludens)
2.) adhesive junction (zonula adherens)
3.) desmosome (macula adherens)
4.) gap junctinos
5.) hemidesmosomes

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tight junction

transmembrane proteins (JAM, claudin, occludin) tighly join cells together at the apical region to prevent leakage (quilted pattern)

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adhesive junction

actin filaments of neighboring cells joined together by cell adhesive molecules (cadherin) and are calcium dependent

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desmosome

join intermediate filaments of adjacent cells through thr formation of desmosome plaques and cadherin adhesion molecules. holds cells together under mechanical stress (very strong)

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gap junction

allow for the passage of small, water soluble molecules between cells. CONNEXINS form pores called CONNEXONS.

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hemidesmosome

anchors intermediate filaments to basal lamina

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exocrine gland

secretory epethelial gland that empties secretion into ducts

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endocrine gland

secretory epithelial gland that empties secretion into blood or intracellular fluid

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2 types of exocrine glands

simple- unbranched ducts
compound- branched ducts

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3 types of exocrine gland shapes

1.) tubular- secretory glands line the tube of duct
2.) acinar- secretory glands in bulbous ACINAR
3.) tubuloacinar- secretory glands found in tubes and acinar

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4 types of glandular secretions

1.) serous- waters
2.) mucous- contains glycoprotein mucin
3.) mixed- both serous and mucous cells
4.) cytogenic- whole cells released into ducts

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3 mechanisms of glandular secretion

1.) merocrine
2.) apocrine
3.) holocrine

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merocrine secretion

most common type of secretory mechanism. granules exist in vesicles that fuse to the plasma membrane and are released into the duct without a loss of plasma membrane

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apocrine secretion

usually hormonal after puberty is reached. granules are pinched off with plasma membrane and secreted into duct.

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holocrine

cell plasma membrane disintegrates and whole content of cell is released into the ducts