Nokea
Which is true of dark (red) muscle?
- A. This muscle is optimized for endurance training
- B. There is less mitochondria in this muscle
- C. This muscle contains more fast-twitch fibers
- D. This muscle contains an equal amount of fast and slow twitch fibers
Correct Answer: a
Rationale: The correct answer is A: This muscle is optimized for endurance training. Dark (red) muscle contains more myoglobin, which stores oxygen and enhances endurance performance. This muscle type is rich in mitochondria, allowing for sustained energy production. Choice B is incorrect because dark muscle actually has more mitochondria. Choice C is incorrect because dark muscle contains more slow-twitch fibers, which are fatigue-resistant and contribute to endurance. Choice D is incorrect because dark muscle predominantly consists of slow-twitch fibers, making it optimized for endurance rather than speed.
You may also like to solve these questions
A short-acting cycloplegic and mydriatic drug is:
- A. Atropine
- B. Homatropine
- C. Hyoscine
- D. Tropicamide
Correct Answer: D
Rationale: The correct answer is D: Tropicamide. Tropicamide is a short-acting cycloplegic and mydriatic drug commonly used in ophthalmology. It acts quickly, providing temporary dilation of the pupil and relaxation of the ciliary muscle for refraction assessment. Atropine (A) is a long-acting cycloplegic, not short-acting. Homatropine (B) and Hyoscine (C) are also longer-acting drugs compared to Tropicamide. Therefore, D is the correct answer for its rapid onset and short duration of action in dilating the pupil and paralyzing accommodation.
Estrogen, progesterone, and testosterone:
- A. are feminizing hormones.
- B. induce virilization.
- C. are secreted by the gonads.
- D. are secreted by the adenohypophysis.
Correct Answer: C
Rationale: Estrogen, progesterone, and testosterone are indeed secreted by the gonads. Estrogen and progesterone are primarily produced by the ovaries in females, while testosterone is mainly produced by the testes in males. These hormones play crucial roles in reproductive functions and secondary sexual characteristics. Choices A and B are incorrect because testosterone induces virilization (masculinizing effects) while estrogen and progesterone are more associated with feminizing effects. Choice D is incorrect because estrogen, progesterone, and testosterone are not secreted by the adenohypophysis, which mainly produces and releases other hormones such as growth hormone and prolactin.
The release of cortisol is stimulated by
- A. aldosterone
- B. angiotensin
- C. antidiuretic hormone (ADH)
- D. adrenocorticotropic hormone (ACTH)
Correct Answer: D
Rationale: The correct answer is D: adrenocorticotropic hormone (ACTH). ACTH is released by the pituitary gland in response to stress or low cortisol levels, stimulating the adrenal glands to release cortisol. Aldosterone (A) regulates electrolyte balance, angiotensin (B) regulates blood pressure, and antidiuretic hormone (C) regulates water balance, but they do not directly stimulate cortisol release. So, ACTH is the correct choice for stimulating cortisol production.
The correct term for the digestive tract that begins at the mouth and finishes at the anus is called?
- A. Digestive passage
- B. Elementary canal
- C. Alimentary canal
- D. Intestinal tract
Correct Answer: C
Rationale: The correct term for the digestive tract that begins at the mouth and finishes at the anus is called the alimentary canal. This term specifically refers to the entire passage through which food passes and is digested. The term "alimentary" pertains to nourishment or nutrition, making it the most accurate description of the digestive tract.
A: Digestive passage is too broad and vague, not specifying the entire route of digestion.
B: Elementary canal is not a commonly used term in anatomy to describe the digestive tract.
D: Intestinal tract specifically refers to the section of the digestive system that includes the small and large intestines, excluding the mouth, esophagus, and stomach.
Which of these hormones is released by the posterior pituitary gland?
- A. thyroid hormone
- B. antidiuretic hormone
- C. glucagon
- D. insulin
Correct Answer: B
Rationale: The correct answer is B: antidiuretic hormone (ADH). ADH is released by the posterior pituitary gland to regulate water balance in the body by controlling the reabsorption of water in the kidneys. Thyroid hormone (A) is produced by the thyroid gland, while glucagon (C) and insulin (D) are produced by the pancreas to regulate blood sugar levels. ADH is the only hormone among the choices that is released by the posterior pituitary gland, making it the correct answer.