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. What type of joint is found in the elbow?

A. Ball and socket joint
B. Hinge joint
C. Pivot joint
D. Saddle joint

Correct answer: B

Rationale: The correct answer is a hinge joint. The elbow joint is a hinge joint that allows for flexion and extension movements, much like the movement of a door hinge. This type of joint permits movement in one plane, similar to the action of opening and closing a door. The other choices are incorrect: A) Ball and socket joints allow for a wide range of motion in multiple directions, such as the hip and shoulder joints. C) Pivot joints allow rotation around a single axis, like the joint at the top of the neck that allows the head to turn from side to side. D) Saddle joints are found in the thumb and have a biaxial range of motion allowing flexion, extension, adduction, abduction, and circumduction.

3. A person who has damage to their ulnar nerve will have decreased sensation in which part of the body?

A. Hand
B. Arm
C. Leg
D. Foot

Correct answer: A

Rationale: Corrected Rationale: Damage to the ulnar nerve typically results in decreased sensation in the hand, particularly affecting the little finger and half of the ring finger. The ulnar nerve innervates the hand and is responsible for providing sensation to these areas. This nerve does not extend to the leg or foot, so choices C and D are incorrect. While the ulnar nerve travels through the arm, its primary sensory impact is felt in the hand, making choice B less specific and therefore not the best answer.

4. What is the main function of the digestive system?

A. To break down food and absorb nutrients
B. To regulate body temperature
C. To transport nutrients
D. To produce hormones

Correct answer: A

Rationale: The main function of the digestive system is to break down food into nutrients through the process of digestion. Once the food is broken down, the nutrients are absorbed into the bloodstream and utilized by the body for various functions. Choice B, regulating body temperature, is incorrect as it is the function of the body's thermoregulatory system, not the digestive system. Choice C, transporting nutrients, is incorrect as the digestive system primarily focuses on breaking down and absorbing nutrients rather than transporting them. Choice D, producing hormones, is also incorrect as hormone production is mainly carried out by endocrine glands and not the digestive system.

5. Which of the following epithelial types is correctly matched with its major function?

A. Simple squamous epithelium – diffusion
B. Stratified squamous epithelium – protection
C. Stratified squamous epithelium – diffusion
D. Simple columnar epithelium – secretion or absorption

Correct answer: D

Rationale: The correct answer is D. Simple columnar epithelium is indeed primarily responsible for secretion and absorption due to its tall shape and presence of microvilli, which increase surface area for these functions. Simple squamous epithelium is mainly involved in diffusion, allowing for the exchange of gases or nutrients. Stratified squamous epithelium functions more for protection against mechanical stress and pathogens, as it forms a tough, protective barrier due to its many layers.