Histology Chapter 4: Epithelial Tissue

A. desmosomes

A 42-year-old woman of Mediterranean descent presents with multiple oral blisters and a few cutaneous blisters on her back and buttocks. The superficial bullae are fragile, some have unroofed to form ulcerated lesions, and there is a positive Nikolsky sign. Blood tests reveal antibodies to a subfamily of cadherins and immunohistochemical staining of a biopsy from the oral mucosa shows distribution of the antigen throughout the epithelium. In what structures is the defect that is causing this patient's condition? a. Desmosomes b. Tight junctions c. Hemidesmosomes d. Gap junctions e. Reticular lamina

A. microvilli

An 11-month-old girl is referred to a pediatric gastroenterology clinic due to a history of generalized weakness, slow growth, and refractory diarrhea. For the past month she has been hospitalized regularly to receive parenteral nutrition. Examination of the epithelium lining her small intestine confirms that the failure to absorb nutrients is most likely due to a significant decrease in which of the following? a. Microvilli b. Gap junctions c. Cilia d. Cell layers e. Basement membrane thickness

A. a material crossing the epithelium between the cells (paracellular movement)

An individual genetically unable to synthesize normal occludin is likely to have epithelia with defective regulation in which of the following? A. material crossing the epithelium between the cells (paracellular movement) B.. Communication between the cells C. Attachment to the basement membrane D. Strong attachment to neighboring cells E. Movement of membrane proteins in the apical domains of cells

E. keratin

An intermediate filament protein found in cytoplasm of most epithelial cells is which of the following? a. Actin b. Vimentin c. Laminin d. Myosin e. Keratin

B. connective

Except in the brain and spinal cord, the stroma is always? A. epithelial B. connective C. muscle D. nervous

C. mucous gland

Exocrine glands in which the acini all produce a secretion of heavily glycosylated, hydrophilic proteins are an example of which type of gland? a. Serous gland b. Mixed gland c. Mucous gland d. Tubuloacinar gland e. Simple gland

B. molecular filtering

Functions of the basement membrane include which of the following? A. contractility B. molecular filtering C. active ion transport D. excitability E. modification of secreted proteins

brush or striated border

In cells such as those lining the small intestine, densely packed microvilli are visible as ________ projecting into the lumen

lamina propria

The connective tissue that underlies the epithelia lining the organs of the digestive, respiratory, and urinary systems is called?

type 3 , type 7

The more diffuse meshwork of the reticular lamina contains type _____ collagen and is bound to the basal lamina by anchoring fibrils of type _______ collagen, both of which are produced by cells of connective tissue.

C. apocrine

The release of lipid droplets from cells is which type of secretion? a. Merocrine b. Serous c. Apocrine d. Mucous e. Holocrine

helicobacter pylori (gastric ulcers)

This bacteria binds the extracellular domains of tight-junction proteins in cells of the stomach and inserts a protein into these cells, which targets ZO-1 and disrupts signaling from the junction.

B. false- cilia contain internal arrays of microtubules

True or False: Cilia are long, highly motile apical structures, larger than microvilli, containing internal arrays of microfilaments. A. true B. false

B. false Small blood capillaries normally never enter epithelia.

True or False: Nerve fibers and small blood capillaries normally penetrate the basement membrane of epithelia. A. true B. false

integrins

Unlike desmosomes, in hemidesmosomes, the clustered transmembrane proteins that indirectly link to cytokeratin intermediate filaments are ___ rather than cadherins.

C. gap junctions

Using immunohistochemistry a population of cells is shown to be positive for the protein connexin. From this we can infer that the cells are connected by what type of junction? A. tight (occluding) junctions B. zonula adherens C. gap junctions D. hemidesmosomes E. desmosomes (macula adherens)

clostridium perfringens (food poisoning)

Which bacteria binds claudin molecules of intestinal cells, prevents insertion of these proteins during maintenance of tight junctions, and causes the loss of tissue fluid into the intestinal lumen via the paracellular pathway?

B. number of cell layers

Which of the following cellular features is used in naming types of epithelia? a. Shape of cells in the basal layer b. Number of cell layers c. Presence of a basal lamina d. Size of the nuclei e. Nature of the cell junctions that are present

B. cilia

With a 5-year history of chronic respiratory infections, a 23-year-old, non-smoking man is referred to an otolaryngologist. A bronchial biopsy indicates altered structures in the epithelial cells. Which of the following, if altered to reduce function, is most likely involved in this patient's condition? a. Hemidesmosomes b. Cilia c. Basolateral cell membrane folds d. Microvilli e. Tight junctions

various blistering (bullous) diseases such as Pemphigus Vulgaris

abnormal desmosome function caused by autoimmune reactions against specific desmogleins that reduce cell-to cell adhesions causes this

apocrine secretion (used by exocrine) -lipid droplets are secreted in mammary glands in this manner

accumulates at the cell's apical ends, portions of which are then extended to release the product together w/ small amount of cytoplasm and cell membrane

epithelial tissue

aggreagted polyhedral cells -lining of surface or body cavities; glandular secretion

gap junction (Nexus)

allows direct transfer of small molecules and ions from one cell to another (communication)

hemidesmosome

anchors cytoskeleton to basal lamina

holocrine secretion (used by exocrine) best seen in sebacreous glands producing lipid-rich material in skin

cells accumulate product continuously as they enlarge & undergo terminal differentiation, culminating in complete cell disruption which releases the product & cell debris into the gland's lumen

celiac disease (gluten-sensitive enteropathy) (sprue)

disorder of small intestine in which one of the 1st pathologic changes is loss of microvilli brush border of the absorptive cells immune reaction against gluten during digestion which produces diffuse enteritis (intestinal inflammation)

nervous tissue

elongated cells with extremely fine processes -transmission of nerve impulses

muscle tissue

elongated contractile cells -strong contraction; body movements

Simple Squamous

facilitates the movement of the viscera, active transport by pinocytosis, secretion of biologically active molecules -lining of vessels and cavities

stratified cuboidal

function as protection, secretion -sweat glands, developing ovarian follicles

Simple cuboidal

functions as covering, secretion -covering the ovary, thyroid , renal collecting tubule

stratified columnar

functions as protection -conjunctiva

stratified transitional

functions as protection, distensibility -bladder, ureters, renal calyces

Simple columnar

functions as protection, lubrication, absorption, secretion -lining of intestine, gallbladder

stratified squamous keratinized

functions as protection, prevents water loss (dry) -epidermis

stratified squamous nonkeratinized

functions as protection, secretion, prevents water loss (moist) -mouth, esophagus, larynx, vagina, anal canal

laminin

large glycoproteins that attach to transmembrane proteins called integrins at the cells' basal surface and project through the network of type IV collagen

Merocrine secretion (used by exocrine)

most common method of protein or glycoprotein secretion & involves typical exocytosis from membrane-bound vesicles or secretory granules

chronic bronchitis

number of goblet cells in lining or airways in the lungs are increased greatly leads to excessive mucus production in areas where there are too few ciliated cells for its rapid removal & contributes to obstruction of the airways

pseudostratified

protection, secretion, cilia-mediated transport of particles trapped in mucus out of air passages -lining of trachea, bronchi, nasal cavity

adherent junction (Zonula Adherens)

provides points linking the cytoskeleton of adjacent cells -strengthens and stabilizes nearby tight junctions

desmosome (macula adherens)

provides points of strong intermediate filament coupling between adjacent cells -strengthens the tissue

tight junction (Zonula occludens)

seals adjacent cells to one another, controlling passage of molecules between them -separates apical & basolateral membrane domains

connecfive tissue

several types of fixed and wandering cells very abundant ECM -support & protection of tissues/organs

immotile cilia syndrome (Karteagener syndrome)

symptoms are chronic respiratory infections caused by the lack of the cleansing action of cilia in the respiratory tract and immotile spermatozoa, causing male infertility

papillae

the area of contact between the two tissues may be increased by small envaginations called ____ projecting from the connective tissue to epithelium

endocrine glands

what glands lose the connection to their original epithelium and therefore lack ducts

Exocrine Glands

what glands remain connected with the surface epithelium, the connection forming the tubular ducts lined with epitheium which deliver the secreted material where it is used