Nokea
Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________.
- A. peptide hormones always enter the cell membrane and elicit a response without assistance from other messengers
- B. hormones alter cellular operations through stimulation of a gene directly
- C. G protein acts as the link between first and second messengers
- D. the hormone receptor complex moves into the cytoplasm as a unit
Correct Answer: C
Rationale: The correct answer is C: G protein acts as the link between first and second messengers.
Rationale:
1. Peptide hormones cannot enter the cell membrane due to their large size.
2. Hormones do not directly stimulate genes; they act through signaling pathways.
3. G proteins are key in transmitting signals from hormone receptors to second messengers, facilitating cellular responses.
4. The hormone receptor complex typically stays on the cell membrane to initiate signaling cascades.
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A nurse working in an outpatient clinic plans a screening program for diabetes. What recommendations for screening should be included?
- A. OGTT for all minority populations every year
- B. FPG for all individuals at age 45 and then every 3 years
- C. Testing people under the age of 21 for islet cell antibodies
- D. Testing for type 2 diabetes in all overweight or obese individuals
Correct Answer: B
Rationale: Fasting plasma glucose (FPG) should be tested for all individuals at age 45 and every 3 years thereafter.
What is meant by the term biodiversity?
- A. an increase in the number of different species that live in an area
- B. how organisms and their environment interact
- C. the number of different animals that live in an area
- D. the number of different species that live in an area
Correct Answer: D
Rationale: The correct answer is D because biodiversity refers to the variety of living organisms in an ecosystem, specifically the number of different species present. This term encompasses all forms of life, from bacteria to plants to animals. Choice A is incorrect as it only focuses on the increase in the number of species, not the overall diversity. Choice B is incorrect as it describes the interaction between organisms and their environment, not the diversity of species. Choice C is incorrect as it limits biodiversity to only animals, neglecting the importance of other living organisms in an ecosystem.
Which of the following is an alpha-blocker used in the treatment of hypertension:
- A. Tyramine
- B. Prazosin
- C. Ergometrine
- D. Ergotamine
Correct Answer: B
Rationale: Step 1: Understand the question is about an alpha-blocker for hypertension.
Step 2: Identify Prazosin as an alpha-blocker used for hypertension by blocking alpha-1 receptors.
Step 3: Explain how Prazosin works to dilate blood vessels and lower blood pressure.
Step 4: Summarize why other choices are incorrect:
- A: Tyramine is not an alpha-blocker, it is found in certain foods.
- C: Ergometrine is an ergot alkaloid used for uterine contractions, not hypertension.
- D: Ergotamine is also an ergot alkaloid used for migraines, not hypertension.
The diabetic patient has all of these assessment findings. Which will you instruct the LPN/LVN to report immediately?
- A. Fingerstick glucose of 185 mg/dL
- B. Numbness and tingling in both feet
- C. Profuse perspiration
- D. Bunion on left great toe
Correct Answer: B
Rationale: Numbness and tingling in both feet are signs of diabetic neuropathy and could be indicative of a worsening condition that requires immediate reporting.
With respect to calcium metabolism / bone formation:
- A. osteoclasts secrete alkaline phosphatase
- B. osteoblasts are haemopoietic derivatives of monocyte lineage
- C. 1,25(OH)2 ???D3 and PTH stimulate both osteoblasts and osteoclasts
- D. oestrogens are thought to be protective of osteoporosis as their main effect is osteoblasts stimulation
Correct Answer: C
Rationale: Rationale for Correct Answer (C):
1,25(OH)2 D3 and PTH stimulate both osteoblasts and osteoclasts. 1,25(OH)2 D3 enhances calcium absorption in the gut, promotes bone resorption, and stimulates osteoclast activity. PTH increases calcium levels in the blood by enhancing calcium reabsorption in the kidney and stimulating osteoclast activity. Both hormones indirectly stimulate osteoblasts by increasing calcium availability for bone formation.
Summary of Incorrect Choices:
A: Osteoclasts actually secrete acid, not alkaline phosphatase.
B: Osteoblasts are derived from mesenchymal stem cells, not monocytes.
D: Estrogens have a dual effect, inhibiting bone resorption by osteoclasts and stimulating bone formation by osteoblasts; their main effect is inhibiting osteoclast activity, not solely stimulating osteoblasts.