NBME Histology 2 — Questions and Answers
Question 1: Which epithelial type lines the urinary bladder and can change shape with distension?
- Stratified squamous
- Pseudostratified columnar
- Transitional (urothelium) (Correct answer)
- Simple cuboidal
Correct answer: Transitional (urothelium)
Transitional epithelium (urothelium) is unique to the urinary tract and flattens as the bladder fills.
Question 2: Goblet cells secrete mucus and are scattered among which epithelial cell type in the small intestine?
- Stratified squamous cells
- Simple columnar absorptive cells (Correct answer)
- Pseudostratified ciliated cells
- Simple cuboidal cells
Correct answer: Simple columnar absorptive cells
The small intestinal lining is simple columnar epithelium interspersed with mucus-secreting goblet cells.
Question 3: Reticular fibers, which form the scaffolding of lymph nodes and the liver, are composed primarily of which collagen type?
- Type I collagen
- Type II collagen
- Type III collagen (Correct answer)
- Type IV collagen
Correct answer: Type III collagen
Reticular fibers are thin Type III collagen fibers that stain with silver and support hematopoietic and lymphoid organs.
Question 4: Which connective tissue is characterized by irregularly arranged collagen bundles and is found in the dermis of the skin?
- Dense regular connective tissue
- Dense irregular connective tissue (Correct answer)
- Loose areolar connective tissue
- Elastic connective tissue
Correct answer: Dense irregular connective tissue
Dense irregular connective tissue has randomly oriented collagen bundles that resist tension from multiple directions, as in the dermis.
Question 5: Mast cells degranulate in response to IgE-mediated stimuli, releasing which primary vasoactive mediator?
- Serotonin
- Histamine (Correct answer)
- Bradykinin
- Leukotriene B4
Correct answer: Histamine
Mast cell granules are packed with histamine, which causes vasodilation and increased vascular permeability during allergic reactions.
Question 6: The esophagus is lined by which epithelial type that protects against abrasion from food?
- Simple columnar with goblet cells
- Keratinized stratified squamous
- Non-keratinized stratified squamous (Correct answer)
- Pseudostratified columnar ciliated
Correct answer: Non-keratinized stratified squamous
The esophagus has non-keratinized stratified squamous epithelium, providing abrasion resistance without the dryness of true keratinization.
Question 7: Pseudostratified ciliated columnar epithelium with goblet cells is the hallmark lining of which anatomical region?
- Renal collecting ducts
- Trachea and primary bronchi (Correct answer)
- Gallbladder
- Ureter
Correct answer: Trachea and primary bronchi
The respiratory tract (trachea and bronchi) is lined by pseudostratified ciliated columnar epithelium that moves mucus via the mucociliary escalator.
NBME Histology 2
Which epithelial type lines the urinary bladder and can change shape with distension?