HESI A2 Anatomy and Physiology Practice Exam

Correct Answer: A

Rationale: The correct answer is A: The endocrine system. The endocrine system produces hormones such as cortisol and adrenaline, which play a crucial role in the body's stress response. These hormones help regulate heart rate, metabolism, and other physiological responses to stress. The digestive system (B), lymphatic system (C), and respiratory system (D) do not have primary roles in controlling stress. The digestive system is responsible for breaking down food, the lymphatic system helps with immunity, and the respiratory system is involved in breathing.

Correct Answer: D

Rationale: The correct answer is D, Achilles tendon, as it is a posterior feature of the human leg. The Achilles tendon is located at the back of the ankle, connecting the calf muscles to the heel bone. This tendon is crucial for various movements like walking, running, and jumping. Rationale: 1. The Achilles tendon is a well-known structure located at the posterior aspect of the leg. 2. It plays a vital role in the functioning of the lower leg muscles. 3. The other choices (A: Patella, B: Quadriceps sartorius, C: Triceps brachii) are not located at the posterior aspect of the leg and are not directly related to the function of the lower leg muscles.

Correct Answer: C

Rationale: The correct answer is C because the vertebrae of the spine protect the spinal cord, which is a crucial component of the nervous system. The spinal cord carries electrical signals between the brain and the rest of the body, allowing for communication and coordination of movement and sensation. It is essential for the skeletal system to provide protection to vital nervous system structures. A, B, and D are incorrect: A: While bones do provide support for body position, they do not transmit signals to the brain directly. B: While pain nerves within bones can notify the brain of injuries, this is not the primary way the skeletal system works with the nervous system. D: Bone marrow is responsible for producing blood cells, not nerve cells.

Correct Answer: C

Rationale: The correct answer is C: frontal. The coronal plane divides the body into front and back portions. The term "frontal" refers to the front of the body, making it the most appropriate descriptor for this plane. The other choices are incorrect because: A: Sagittal plane divides the body into left and right portions. B: Median plane is another term for the sagittal plane. D: Axial plane is not a commonly used term in anatomical terminology.

Correct Answer: B

Rationale: The correct answer is B because skeletal muscle attaches to bones by tendons, allowing for movement of the body. Tendons are tough connective tissues that anchor muscles to bones. This attachment enables the contraction of skeletal muscles to produce movement at the joints. Choices A, C, and D are incorrect. Skeletal muscle typically makes up around 40-50% of the body's weight, muscle contraction plays a role in temperature regulation through shivering, and skeletal muscles can contract even at rest due to maintaining posture or supporting the body.