MCQ-1
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. Keratin
What cells numerous in loose connective tissue are filled with secretory
granules and stain with metachromasia?
a. Macrophages
b. Mast cells
c. Fibrocytes
d. Active fibroblasts
e. Leukocytes
b. Mast cells
A type of connective tissue present in the tendons
Dense regular connective tissue
Classify epithelial tissue.
According to the number of layers: simple & stratified
According to the shape of the cells at the top layer into: squamous, columnar and cuboidal
2 other types: transitional - pseudostratified
Macrophages are derived from bone marrow
False
Macrophages are derived from monocytes
A male patient has very thin, slender legs and unusually long, slender fingers. The patient’s history indicates that he has been diagnosed as Marfan syndrome.The mutation that causes this syndrome affects which of the following structures?
a. tropomyosin
b. troponin
c. laminin
d. elastin
e. fibrillin
e.Fibrillin
Using immunohistochemistry some cells are 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. Gap junctions
A type of epithelium in which its main function is protection
Stratified squamous epithelium
Describe the structure of Plasma cells
LM: oval cells, rounded eccentric nucleus, basophilic cytoplasm, negative Golgi image
EM: Abundant rER, Well developed Golgi complex, numerous mitochondria
Elastic fibres are also called argyrophilic fibres because they can be stained with silver salts
False
true answer is: Reticular fibers
An elderly patient is seen by her physician for dry
mouth. It appears that her parotid glands no longer
produce saliva. Which is the correct classification of
the parotid glands?
a. apocrine
b. holocrine
c. merocrine
d. mixed
e. endocrine
c. merocrine
Which of the following connective tissue components is located in
the ECM but not in the ground substance?
a. Collagen bundles
b. Fibronectin
c. GAGs
d. Hyaluronan
e. Proteoglycans
a. Collagen bundles
A type of connective tissue fibers that are long and branch to form a network
Elastic fibers
Describe the structure of the motile cilia
Formed of microtubules in which the arrangement differ in both shaft and basal body
In the shaft: 9 peripheral doublets with 2 central microtubules
In the basal body: 9 peripheral triplets of microtubules
The simple squamous epithelial lining of serous membranes is called endothelium
False
The simple squamous epithelial lining of serous membranes is called mesothelium
A 10-year-old girl scrapes her elbow. Physical examination reveals a deep skin wound. Which of the following cellular processes aids in regeneration of her skin?
a. Wound contraction by myoepithelial cells
b. Loss of cell transmembrane integrin proteins
c. Platelet activation and intravascular coagulation
d. Proliferation of capillary endothelial cells by pericytes
e. Stimulation of fibroblasts to deposit an extracellular matrix
e. Stimulation of fibroblasts to deposit an extracellular matrix
Blood tests of a patient reveal antibodies to a subfamily of cadherins and immunohistochemical staining of a biopsy from his oral mucosa shows distribution of this antigen throughout the epithelium. In what structures is the defect ?
a. Desmosomes
b. Tight junctions
c. Hemidesmosomes
d. Gap junctions
e. Reticular lamina
a. Desmosomes
Cells of the connective tissue are responsible for production and maintenance of extracellular matrix
Fibroblasts
Describe the layers forming the basement membrane
1. Lamina lucida: Just under the basal cell membrane of epithelium. Electron lucent, formed of: Integrin & Glycoprotein(Laminin & fibronectin)
2. Lamina densa: Faces the underlying CT. Electron dense, formed of: Glycoproteins, GAGs and collagen type IV
3. Reticular lamina: A layer that separate lamina densa and CT. Formed of Collagen type I & III (reticular fibers) and anchoring fibers of type VII collagen fibers.
In mucoid connective tissue, the predominant structure is the undifferentiated mesenchymal cells
False
The predominant structure is the ground substance composed chiefly of hyaluronic acid, with sparse collagen fibers and scattered fibroblasts & mesenchymal stem cells.
An 11-month-old girl 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. Microvilli
What is the first step of collagen production that occurs after the
protein undergoes exocytosis?
a. Cross-linking of collagen fibrils with a short-linking collagen
b. Removal of the terminal nonhelical domains by peptidases
c. Hydroxylation of lysine and proline
d. Assembly of subunits to form a larger structure
e. Disulfide bond formation
b. Removal of the terminal nonhelical domains by peptidases
Structures present on the epithelial surface that are long, non motile and are specialized for absorption
Stereocilia
Describe the cross banding pattern in the collagen fibril structure
Each collagen molecule is 300 nm in length arranged in quarter-staggered overlapping pattern. Each new molecule starts 67 nm below the previous one, creating:
✔ Overlap regions
✔ Gap regions
These alternating gaps and overlaps give collagen fibrils their characteristic banded appearance under electron microscopy
In adhering junctions, the intracellular part claudins binds to the actin filaments of the terminal web
False
In adhering junctions, the intracellular part cadherins binds to the actin filaments of the terminal web