Nokea
Which of the following is not part of the body's secondary defense system?
- A. Macrophages
- B. Leukocytes
- C. T cells
- D. Cilia
Correct Answer: D
Rationale: Cilia are not part of the body's secondary defense system. They are hair-like structures primarily involved in movement and transporting substances across cell surfaces, such as in the respiratory tract for debris and pathogen removal. However, cilia do not play a direct role in the immune response mechanisms characteristic of the body's secondary defense system. Macrophages, leukocytes, and T cells are immune cells that actively participate in the secondary defense system by targeting and eliminating pathogens.
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What structures are likely torn in a rotator cuff tear?
- A. Tendon and possibly ligament
- B. Muscle and possibly tendon
- C. Ligament and possibly muscle
- D. Tendon only
Correct Answer: A
Rationale: In a rotator cuff tear, the most common structures torn are the tendons of the rotator cuff muscles. In severe cases, the tear may also extend to involve the surrounding ligaments. Therefore, the correct answer is A, as it accurately represents the structures that are likely to be affected in a rotator cuff tear. Choice B is incorrect as muscles are not typically torn in a rotator cuff tear. Choice C is also incorrect as ligaments are not the primary structures involved in a rotator cuff tear. Choice D is incorrect because a rotator cuff tear typically involves more than just the tendons.
What does the parathyroid hormone regulate?
- A. Magnesium
- B. Calcium
- C. Calcitonin
- D. Glucocorticoids
Correct Answer: B
Rationale: The parathyroid hormone primarily regulates calcium levels in the blood. It acts to increase calcium levels by stimulating the release of calcium from bones, enhancing calcium reabsorption in the kidneys, and promoting the conversion of vitamin D to its active form, which aids in calcium absorption from the intestines. Therefore, the correct answer is B. Choices A, C, and D are incorrect because the parathyroid hormone does not play a significant role in the regulation of magnesium (Choice A), calcitonin (Choice C), or glucocorticoids (Choice D).
Which of the following is true about skeletal muscle?
- A. Skeletal muscle makes up 40% of the body's weight.
- B. Skeletal muscle attaches to bones by tendons.
- C. Muscle contraction is not involved in temperature regulation.
- D. Skeletal muscles contract only when in use.
Correct Answer: B
Rationale: The correct statement is that skeletal muscle attaches to bones through tendons, enabling movement. Tendons connect muscles to bones and allow the force generated by muscle contraction to be transmitted to the bones, facilitating voluntary movements. Choice A is incorrect because skeletal muscle typically makes up around 40-50% of an individual's body weight, not a fixed 40%. Choice C is incorrect as muscle contraction plays a vital role in temperature regulation by generating heat. Choice D is incorrect as skeletal muscles may have constant low-level contractions even at rest, known as muscle tone.
When are gallstones most problematic?
- A. When they block a duct
- B. When they contain cholesterol
- C. When they contain bilirubin
- D. When they begin to dissolve
Correct Answer: A
Rationale: Gallstones become most problematic when they block a duct, such as the bile duct or cystic duct. This blockage can lead to various complications, including inflammation, infection, and even damage to the gallbladder or liver. In severe cases, a blocked duct can cause intense pain, jaundice, and other serious symptoms that require medical intervention. Choices B, C, and D are incorrect because the presence of cholesterol or bilirubin in gallstones or the process of dissolution do not necessarily indicate when gallstones become most problematic. The critical issue arises when the stones obstruct a duct, leading to complications.
The shoulder is _________ to the elbow.
- A. posterior
- B. proximal
- C. distal
- D. medial
Correct Answer: B
Rationale: Proximal refers to a position closer to the point of attachment or origin. In this case, the shoulder is closer to the point of attachment to the body compared to the elbow, making it proximal to the elbow. 'Posterior' refers to the back side of the body, 'distal' means farther away from the point of attachment, and 'medial' refers to the middle of the body. These terms do not accurately describe the relationship between the shoulder and the elbow in this context.