which of the following is true of skeletal muscle

HESI A2

HESI A2 Anatomy and Physiology Practice Exam

1. 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.

2. The cheekbones are positioned ___________ to the nose.

A. anterior
B. proximal
C. deep
D. lateral

Correct answer: D

Rationale: The term 'lateral' refers to the direction away from the midline of the body. In this case, the cheekbones are situated to the sides of the nose, making them lateral to the nose. Therefore, 'lateral' correctly describes the position of the cheekbones in relation to the nose. Choices A, B, and C are incorrect: A. 'Anterior' means situated at or towards the front, which is not the correct description of the cheekbones in relation to the nose. B. 'Proximal' means situated nearer to the center of the body, which is not the correct description of the cheekbones' position in relation to the nose. C. 'Deep' refers to being situated further away from the surface, which is not the appropriate term to describe the cheekbones' position in relation to the nose.

3. What is the primary role of the stomach in the digestive system?

A. To absorb nutrients
B. To break down food
C. To secrete digestive enzymes
D. To store glucose

Correct answer: B

Rationale: The primary role of the stomach in the digestive system is to break down food. It accomplishes this through the action of gastric acid and digestive enzymes, which work together to break down food into a semi-liquid mixture known as chyme. Option B, 'To break down food,' is the correct answer. Option A, 'To absorb nutrients,' is incorrect because absorption mainly occurs in the small intestine. Option C, 'To secrete digestive enzymes,' is partially correct as the stomach does secrete digestive enzymes, but its primary function is to break down food. Option D, 'To store glucose,' is incorrect as glucose storage primarily occurs in the liver and muscles, not the stomach.

4. How might vitamin D deficiency present?

A. As bleeding gums
B. As swollen extremities
C. As red patches
D. As crooked bones

Correct answer: D

Rationale: Vitamin D deficiency can present as crooked bones in children due to a condition called rickets. This is because vitamin D plays a crucial role in calcium absorption and bone health. Inadequate levels of vitamin D can lead to soft and weak bones, resulting in skeletal deformities such as bow legs or knock knees. Choices A, B, and C are incorrect as bleeding gums are more commonly associated with vitamin C deficiency (scurvy), swollen extremities could be a sign of various conditions like edema, and red patches are not typically a direct manifestation of vitamin D deficiency.

5. What structure links the nasopharynx to the middle ear?

A. Larynx
B. Pharyngeal muscles
C. Eustachian tube
D. Bronchus

Correct answer: C

Rationale: The Eustachian tube is the structure that connects the nasopharynx to the middle ear. It functions to equalize pressure between the middle ear and the atmosphere, protecting the eardrum from damage and aiding in the drainage of fluid from the middle ear. This connection is essential for maintaining proper ear function and health. The larynx (Choice A) is not the correct structure that links the nasopharynx to the middle ear. Pharyngeal muscles (Choice B) are involved in swallowing and do not directly link the nasopharynx to the middle ear. The bronchus (Choice D) is part of the respiratory system and is not connected to the middle ear.