Which of the following is not an example of a negative homeostatic mechanism in the human body?
Increasing heart rate and force of contraction when blood pressure falls.
Secreting insulin after a meal to return blood sugar concentration to normal.
Retention of fluid leads to retention of more fluid.
Shivering when body temperature falls below normal.
The Correct Answer is C
This is because it is an example of a positive feedback loop, which amplifies the change and moves the system away from its normal state.
A negative feedback loop is a mechanism that reverses a deviation from the set point and maintains homeostasis.
Choice A is wrong because increasing heart rate and force of contraction when blood pressure falls is a negative feedback loop that restores blood pressure to normal.
Choice B is wrong because secreting insulin after a meal to return blood sugar concentration toward normal is a negative feedback loop that regulates glucose levels.
Choice D is wrong because shivering when body temperature falls below normal is a negative feedback loop that increases heat production and raises body temperature.
Normal ranges for blood pressure are 90/60 mmHg to 120/80 mmHg, for blood glucose, are 70 mg/dL to 140 mg/dL, and for body temperature are 36.5°C to 37.5°C or 97.7°F to 99.5°F.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
Calcitonin is a hormone that protects against excessive blood calcium levels by inhibiting bone turnover and decreasing reabsorption.
It is produced by the thyroid gland and acts on both osteoclasts and osteoblasts.
Choice B is wrong because parathyroid hormone (PTH) stimulates both resorption and formation of bone, and controls the level of calcium in the blood.
Choice C is wrong because thyroxine is a thyroid hormone that is required for skeletal maturation and influences adult bone maintenance but does not directly affect calcium deposition into bone.
Choice D is wrong because insulin is a hormone that regulates both bone formation and bone resorption but does not specifically stimulate calcium deposition into bone.
Correct Answer is B
Explanation
The aorta is the largest artery in the human body, as well as the main artery in the circulatory system.
It originates from the left ventricle of the heart and extends down to the abdomen, where it splits into two smaller arteries (the common iliac arteries).
The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.
Choice A. Carotid is wrong because the carotid artery is not the largest artery in the body, but one of the main arteries that pumps blood from the heart to the brain and the rest of the head.
It has a diameter of 4.3 mm-7.7 mm and a blood flow of 350-550 milliliters per minute.
Choice C. Celiac is wrong because the celiac artery is not the largest artery in the body, but a major branch of the abdominal aorta that supplies oxygenated blood to the liver, stomach, spleen, pancreas, and duodenum.
Choice D. Femoral is wrong because the femoral artery is not the largest artery in the body, but the largest artery found in the leg region.
It runs down the inner thigh and carries out the important role of supplying blood to the lower body.
It has a diameter of 6.6 mm and a blood flow of 284 milliliters per minute.
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