which muscle is responsible for the extension of the elbow

HESI A2

HESI A2 Anatomy and Physiology Practice Test 2023

1. Which muscle is responsible for the extension of the elbow?

A. Biceps brachii
B. Triceps brachii
C. Deltoid
D. Pectoralis major

Correct answer: B

Rationale: The correct answer is B: Triceps brachii. The triceps brachii muscle is responsible for extending the elbow joint. It is located on the back of the upper arm and acts in opposition to the biceps brachii, which is responsible for elbow flexion. The deltoid muscle is primarily responsible for shoulder abduction, not elbow extension. The pectoralis major muscle is involved in movements of the shoulder joint, not the elbow.

2. A stye is an infection of the ___________.

A. eyelid
B. eardrum
C. nostril
D. scalp

Correct answer: A

Rationale: A stye is an infection that occurs at the base of an eyelash or on the eyelid. It is typically caused by a bacterial infection, leading to redness, swelling, and sometimes discomfort in the affected area. Choices B, C, and D are incorrect because a stye specifically refers to an infection of the eyelid area, not the eardrum, nostril, or scalp.

3. Which statement would not be inferred by the reader in the passage about Super Foods?

A. Instant oatmeal can be part of a healthful breakfast.
B. Blueberries are an especially healthful food.
C. Certain grains and dairy products are super foods.
D. Super foods are more expensive than processed foods.

Correct answer: D

Rationale: The passage does not imply or provide information regarding the cost of superfoods compared to processed foods. Therefore, D is the correct answer, as it identifies a statement that cannot be inferred from the passage.

4. A 3-volt flashlight uses a bulb with 60-ohm resistance. What current flows through the flashlight?

A. o.05 amp
B. o.5 amp
C. 1.8 amp
D. 18 amp

Correct answer: A

Rationale: : Using Ohm's Law, I = V / R: I = 3 / 60 = 0.05 amp. So, the correct current is 0.05 amp.

5. A scientist needs 12 mL of a solution. They have a bottle with 12L in it. Do they have enough?

A. Yes, they have exactly what they need
B. Yes, they have more than what they need
C. No, they do not have enough
D. None of the above

Correct answer: B

Rationale: 1 liter has 1000 milliliters. To convert from milliliters to liters, the decimal point moves three places to the left. So, the bottle has 12000 mL of solution, which is a lot more than the required 12 mL. Therefore, the scientist has more than what they need. Choice A is incorrect as the bottle has more than the required amount. Choice C is incorrect as the bottle contains significantly more solution than needed. Choice D is incorrect as the scientist does have more than enough solution.