Histo Ch 4 Epithelial Tissue

Stratified cuboidal epithelium

Function: protection Location: Largest ducts of sweat glands, mammary glands, and salivary glands.

Perlecan

Proteoglycan which links the laminin and type IV networks of the basal lamina

Type IV collagen

basement membrane

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

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

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

A

Nidogen

A component of the ECM that connects laminins and collagens together.

Axoneme

A structure found in eukaryotic cilia and flagella and responsible for their motion; composed of two central microtubules surrounded by nine doublet microtubules (9 + 2 arrangement).

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

B

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

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

B

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

C

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

C

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)

C

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

E

Kartagener's syndrome

Immotile cilia due to a dynein arm defect. Results in male and female infertility (sperm immotile), bronchiectasis, and recurrent sinusitis (bacteria and particles not pushed out); associated w/ situs inversus.

myoepithelial cells

Squeeze apocrine gland secretions onto skin surface In response to hormonal or nervous signal

Cilia

The hairlike projections on the outside of cells that move in a wavelike manner Microtubules Microvilli contain microfilaments

Cadherins

calcium-dependent glycoproteins that hold similar cells together

Lamina propria

connective tissue that underlies the epithelia lining the organs of the digestive, respiratory, and urinary systems

Stratified squamous keratinized epithelium

found mainly in the epidermis of skin, where it helps prevent dehydration from the tissue

Laminin

key basement membrane glycoprotein

Stereocilia

line the male reproductive system

Stratified squamous nonkeratinized epithelium

lines moist internal cavities (eg, mouth, esophagus, and vagina) where water loss is not a problem.

pseudostratified columnar epithelium

linings of respiratory passages

Apocrine glands

secretion involves loss of membrane-enclosed apical cytoplasm, usually containing one or more lipid droplets. Apocrine secretion, along with merocrine secretion, is seen in mammary glands.

Holocrine glands

secretion is produced by the disintegration of the secretory cells themselves as they complete their terminal differentiation, which involves becoming filled with product. Sebaceous glands of hair follicles are the best examples of holocrine glands.

merocrine glands

secretion releases products, usually containing proteins, by means of exocytosis at the apical end of the secretory cells. Most exocrine glands are merocrine.

urothelium

transitional epithelium in the wall of the bladder