Which of the following is a modification of the simple columnar epithelium that allows for efficient absorption along portions of the digestive tract by increasing the surface area?
fibroblasts
thin and permeable
dense microvilli
cilia
The Correct Answer is C
A. fibroblasts: Fibroblasts are connective tissue cells responsible for producing extracellular matrix and collagen. They are not part of the epithelium and do not enhance absorptive surface area.
B. thin and permeable: While simple columnar epithelium is relatively thin to allow some absorption, this characteristic alone does not significantly increase surface area for efficient nutrient uptake.
C. dense microvilli: Microvilli are finger-like projections on the apical surface of simple columnar epithelial cells. Their dense arrangement forms the brush border, greatly increasing surface area and enhancing absorption in the small intestine.
D. cilia: Cilia are hair-like structures that move substances across the epithelial surface, such as mucus in the respiratory tract. They do not increase surface area for absorption and are not a feature of absorptive digestive epithelium.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
A. basal cell carcinoma:Basal cell carcinoma is the most common type of skin cancer, typically arising from the basal cells in the epidermis. It grows slowly and rarely metastasizes, making it less deadly than other skin cancers.
B. squamous cell carcinoma:Squamous cell carcinoma originates from the keratinocytes of the epidermis. It is more aggressive than basal cell carcinoma but still has a relatively good prognosis with early treatment.
C. skin lymphoma:Skin lymphoma is a rare cancer affecting lymphocytes in the skin. While it can be serious, it is not the most deadly form of skin cancer compared to melanoma.
D. melanoma:Melanoma arises from melanocytes and is the least common type of skin cancer. It is highly aggressive and prone to metastasis, making it the most deadly form if not detected and treated early.
Correct Answer is A
Explanation
A. accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer:Keratinocytes take up melanin granules produced by melanocytes and position them above the nucleus. This arrangement shields nuclear DNA from harmful UV radiation, reducing the risk of mutations and cellular damage.
B. provide the melanocyte with nutrients necessary for melanin synthesis:Nutrients for melanocyte function are delivered through blood supply in the dermis rather than directly by keratinocytes. Keratinocytes do not supply essential substrates for melanin production.
C. maintain the appropriate pH in order for the melanocyte to synthesize melanin granules:pH balance in the skin is regulated mainly by sweat and sebaceous secretions. Keratinocytes do not directly control melanocyte pH for melanin synthesis.
D. maintain the appropriate temperature so the product of the melanocyte will not denature:Temperature regulation is largely a function of dermal blood flow and sweat glands. Keratinocytes do not control melanocyte temperature or prevent denaturation of melanin.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.