Which of the following blood pressure readings falls within the normal range?

Correct Answer: A

Rationale: The correct answer is A: 9/75. In blood pressure readings, the first number represents systolic pressure while the second number represents diastolic pressure. The normal range for blood pressure is typically around 120/80 mmHg. In this case, 9/75 falls within a safe range, with the systolic pressure of 9 being low but not alarming, and the diastolic pressure of 75 being within the normal range. Choices B, C, and D all have either extremely low or high readings for both systolic and diastolic pressure, indicating abnormal blood pressure levels.

Correct Answer: A

Rationale: The correct answer is A: Occult. Occult blood refers to hidden blood that is not visible to the naked eye and can only be detected through microscopic or chemical testing. This term is commonly used in medical contexts to describe blood in stool that may indicate gastrointestinal issues or bleeding. Choice B, Hemoccult, is a specific brand name for a fecal occult blood test, so it is not a general term for hidden blood in stool. Choice C, Toxic, and choice D, Pathogenic, are unrelated to the presence of hidden blood in stool and do not describe this specific medical condition.

Correct Answer: D

Rationale: The correct answer is D because contact of the mouth with the genitals can directly transmit sexually transmitted infections (STIs) through mucous membranes. Mouth-to-mouth kissing (A) and holding hands (C) do not involve direct contact with genitalia, making transmission of STIs unlikely. Contact of hands with the breasts (B) also does not typically transmit STIs as they are not mucous membranes. Therefore, D is the correct choice for STI transmission via sexual contact.

Correct Answer: C

Rationale: The correct answer is C: Plasma. Plasma constitutes about 55% of blood volume and is a fluid component that carries various substances such as nutrients, hormones, and waste products. Erythrocytes (A) are red blood cells and make up about 40-45% of blood volume. Leukocytes (B) are white blood cells and only account for a small percentage of blood volume. Platelets (D) are cell fragments involved in blood clotting and make up a very small percentage of blood volume. Plasma is the correct answer because it is the largest component of blood by volume and carries out essential functions in the body.

Correct Answer: A

Rationale: The correct answer is A because normal age-related changes in the musculoskeletal system typically involve muscles weakening and losing tone. This is due to factors such as decreased physical activity, hormonal changes, and reduced muscle mass. Choice B is incorrect because while bones do require calcium for strength and density, age-related changes typically involve bone loss rather than gain. Choice C is incorrect as muscle mass tends to decrease with age, not increase. Choice D is incorrect as age-related changes in the musculoskeletal system do not directly cause weight gain, although decreased muscle mass and physical activity can contribute to weight gain.