Nokea
The relatively constant internal environment of the body is maintained by _______.
- A. negative feedback.
- B. positive feedback.
- C. homeostasis.
- D. metabolism.
Correct Answer: C
Rationale: The correct answer is C: homeostasis. Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. It involves various physiological mechanisms to regulate temperature, pH, blood sugar levels, and more. Negative feedback (choice A) is a key component of homeostasis, where the body reverses a deviation from the set point to restore balance. Positive feedback (choice B) amplifies a response and does not contribute to maintaining stability. Metabolism (choice D) is the sum of all chemical processes in the body and is necessary for homeostasis but does not directly regulate the internal environment.
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Which one of the following hormones is secreted by neurones?
- A. Insulin
- B. Oxytocin
- C. Thyroid stimulating hormone
- D. Cortisol
Correct Answer: B
Rationale: The correct answer is B: Oxytocin. Neurones secrete oxytocin, a hormone involved in social bonding, childbirth, and lactation. Neurones release oxytocin from the hypothalamus into the bloodstream. Insulin is secreted by pancreatic cells, not neurones. Thyroid stimulating hormone is produced by the pituitary gland, and cortisol is released by the adrenal glands. Therefore, the correct answer is oxytocin as it is the hormone secreted by neurones.
For the patient with hyperthyroidism, what intervention should you delegate to the experienced certified nursing assistant?
- A. Instruct the patient to report palpitations, dyspnea, vertigo, or chest pain.
- B. Check the apical pulse, blood pressure, and temperature every 4 hours.
- C. Draw blood for thyroid-stimulating hormone, T3, and T4 levels.
- D. Explain the side effects of propylthiouracil (PTU) to the patient.
Correct Answer: B
Rationale: Checking the apical pulse, blood pressure, and temperature every 4 hours is within the scope of practice for a certified nursing assistant and helps monitor the patient's condition.
Hypocalcemic tetany:
- A. is a consequence of a deficiency of calcitonin.
- B. is caused by a lack of TSH.
- C. is caused by osteoclastic activity.
- D. develops in response to a deficiency of parathyroid activity.
Correct Answer: D
Rationale: Step-by-step rationale:
1. Hypocalcemic tetany results from low blood calcium levels.
2. Parathyroid hormone (PTH) regulates calcium levels by increasing calcium release from bones and reabsorption in the kidneys.
3. A deficiency in parathyroid activity leads to decreased calcium levels, causing tetany.
4. Choice D is correct as it directly links hypocalcemic tetany to parathyroid dysfunction.
Summary:
A: Incorrect, calcitonin lowers blood calcium levels.
B: Incorrect, TSH regulates thyroid function, not calcium levels.
C: Incorrect, osteoclasts break down bone tissue but are not directly related to hypocalcemic tetany.
The chemical break down of starch begins in?
- A. The mouth
- B. The oesophagus
- C. The small intestine
- D. The stomach
Correct Answer: A
Rationale: The correct answer is A: The mouth. Starch digestion begins in the mouth due to the enzyme amylase present in saliva. Amylase breaks down starch into maltose. This process initiates digestion before food reaches the stomach or small intestine. The other choices are incorrect because oesophagus primarily serves as a passage for food, the small intestine is where most digestion and nutrient absorption occur, and the stomach's main role is to break down proteins with the enzyme pepsin, not starch.
The secretion of this gland enhances a sympathetic response.
- A. Adrenal medulla
- B. Pancreas
- C. Adrenal cortex
- D. Parathyroid
Correct Answer: A
Rationale: The correct answer is A: Adrenal medulla. The adrenal medulla secretes adrenaline and noradrenaline, which are hormones that enhance the sympathetic response of the body. This response includes increased heart rate, dilation of airways, and increased blood flow to muscles. The other choices, B: Pancreas, C: Adrenal cortex, and D: Parathyroid, do not directly enhance sympathetic responses. The pancreas regulates blood sugar levels, the adrenal cortex produces cortisol and aldosterone, and the parathyroid regulates calcium levels. Therefore, only the adrenal medulla directly contributes to the sympathetic response, making it the correct choice.