Melanocytes give rise to the pigment melanin, which is responsible for skin color. Where can the melanocytes be found?
Loose connective tissue
Epidermis
Dermis
Superficial fascia
The Correct Answer is B
A. Loose connective tissue:
Melanocytes are not typically found in loose connective tissue. Their primary location is within the epidermis, specifically in the basal layer, where they interact with keratinocytes to produce melanin and contribute to skin color. Loose connective tissue contains collagen and elastin fibers, as well as fibroblasts, but it does not house melanocytes.
B. Epidermis:
This is the correct answer. Melanocytes are primarily located in the basal layer of the epidermis, which is the deepest layer of the epidermis. These cells produce melanin, a pigment that helps protect the skin from UV radiation and determines skin color. Melanocytes are interspersed among keratinocytes in the epidermis and transfer melanin to keratinocytes to provide skin pigmentation.
C. Dermis:
The dermis is the layer of skin beneath the epidermis and consists of connective tissue, blood vessels, nerves, hair follicles, and sweat glands. While the dermis plays a crucial role in supporting and nourishing the epidermis, melanocytes are not primarily located in the dermis. They are confined to the basal layer of the epidermis.
D. Superficial fascia:
The superficial fascia, also known as the subcutaneous tissue or hypodermis, lies beneath the dermis and consists of adipose (fat) tissue and connective tissue. It provides insulation, energy storage, and cushioning for underlying structures. However, melanocytes are not typically found in the superficial fascia. They are restricted to the epidermis, specifically the basal layer, where they carry out their function of melanin production.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
A. Body mass index (BMI) of 19:
A BMI of 19 falls within the normal weight range. While obesity (high BMI) is a known risk factor for surgical complications, including SSIs, having a lower BMI (underweight) like 19 may not directly increase the risk of SSIs. However, extreme malnutrition or low BMI due to underlying health conditions could potentially impact wound healing and immune function, indirectly contributing to infection risk.
B. History of deep vein thrombosis (DVT):
A history of deep vein thrombosis is a risk factor for surgical complications, including SSIs. Patients with a history of DVT may have impaired circulation or underlying vascular issues, which can affect tissue perfusion, wound healing, and increase the risk of infections.
C. Aged 55 years old:
Age is a risk factor for surgical complications, including SSIs. Older adults, typically defined as those aged 65 and above, may have reduced immune function, slower wound healing, and underlying health conditions that contribute to infection risk. While 55 years old is not considered advanced age in terms of surgical risk, older age in general is associated with a higher risk of complications.
D. Type 2 diabetes mellitus:
Type 2 diabetes mellitus is a significant risk factor for SSIs. Diabetes can impair immune function, delay wound healing, and increase susceptibility to infections. Poorly controlled blood sugar levels in diabetic patients can further exacerbate the risk of SSIs post-surgery.
Correct Answer is D
Explanation
A. Diabetic ketoacidosis (DKA) in a person with emphysema:
In DKA, there is typically metabolic acidosis due to the accumulation of ketones in the blood, leading to a decrease in pH. However, the respiratory compensation mechanism in DKA usually results in a decreased PaCO2 (respiratory alkalosis) rather than an elevated PaCO2 as seen in the blood gas values provided. Additionally, emphysema is associated with chronic respiratory acidosis, not respiratory alkalosis as indicated by the elevated PaCO2.
B. Diarrhea for 36 hours in an older, frail woman:
Prolonged diarrhea can lead to metabolic acidosis due to the loss of bicarbonate through the gastrointestinal tract. The pH of 7.12 and the decreased HCO3- (22 mEq/L) suggest metabolic acidosis. However, the elevated PaCO2 (respiratory acidosis) is not consistent with pure metabolic acidosis caused by diarrhea. Respiratory acidosis typically occurs due to hypoventilation or respiratory dysfunction.
C. Anxiety-induced hyperventilation in an adolescent:
Anxiety-induced hyperventilation can lead to respiratory alkalosis due to excessive blowing off of CO2, resulting in a decrease in PaCO2. The pH of 7.12 is consistent with acidosis, but the elevated PaCO2 contradicts respiratory alkalosis. Anxiety-induced hyperventilation would typically result in a higher pH and lower PaCO2.
D. Bronchial obstruction related to aspiration of a hot dog:
A bronchial obstruction causing inadequate ventilation can lead to respiratory acidosis due to CO2 retention. The pH of 7.12 and the elevated PaCO2 (65 mm Hg) indicate respiratory acidosis. This situation is consistent with the blood gas values provided.
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