which cut is considered a cross section

HESI A2

HESI A2 Anatomy and Physiology Practice Test

1. Which cut is considered a cross section?

A. A sagittal or frontal section
B. A cut along the coronal plane
C. A cut along the median plane
D. A cut through the transverse plane

Correct answer: D

Rationale: The correct answer is D: A cut through the transverse plane. A transverse plane cut, also known as a cross-section, divides the body or an organ into superior and inferior portions. This type of cut is perpendicular to the long axis of the body and is commonly used in medical imaging to display internal structures and organs in a horizontal view. Choices A, B, and C are incorrect because a sagittal or frontal section (A) divides the body into left and right portions, a cut along the coronal plane (B) separates the body into anterior and posterior parts, and a cut along the median plane (C) divides the body into equal left and right halves.

2. Which structure is responsible for carrying oxygen to the cells?

A. Hemoglobin
B. Plasma
C. Platelets
D. Red blood cells

Correct answer: A

Rationale: Hemoglobin, located in red blood cells, is responsible for binding to oxygen in the lungs and transporting it to tissues throughout the body. Red blood cells contain hemoglobin, making them the primary carrier of oxygen to cells. Hemoglobin is the correct answer because it is the protein within red blood cells that directly binds to oxygen for transport. Plasma is the liquid component of blood and does not carry oxygen. Platelets are responsible for blood clotting and have no role in oxygen transport. While red blood cells do carry oxygen, it is specifically the hemoglobin within them that performs this function.

3. Which organ is involved in the immune system?

A. Heart
B. Bronchi
C. Appendix
D. Esophagus

Correct answer: C

Rationale: The correct answer is the Appendix. The appendix is now known to play a role in the immune system by housing beneficial bacteria that aid in maintaining gut health and supporting immune responses. This organ contributes to overall immune function. Choices A, B, and D are incorrect as the heart, bronchi, and esophagus are not primarily associated with the immune system.

4. What is the function of parathyroid hormone?

A. Increasing energy levels
B. Stimulating cell reproduction
C. Speeding up metabolism
D. Activating vitamin D

Correct answer: D

Rationale: The correct answer is D. Parathyroid hormone plays a crucial role in activating vitamin D. This activation occurs in the kidneys, where parathyroid hormone stimulates the conversion of inactive vitamin D to its active form. Active vitamin D is essential for maintaining proper levels of calcium and phosphorus in the body, which are important for bone health and other physiological functions. Choices A, B, and C are incorrect because parathyroid hormone is not involved in increasing energy levels, stimulating cell reproduction, or speeding up metabolism. Its primary function is related to calcium and phosphorus homeostasis through the activation of vitamin D.

5. Which of the following is not part of the central nervous system?

A. Retina
B. Spinal cord
C. Brain
D. Heart

Correct answer: B

Rationale: The central nervous system consists of the brain and spinal cord, which are responsible for processing and coordinating information. The retina is part of the eye, while the heart is part of the circulatory system. Therefore, the correct answer is 'Spinal cord' as it is not part of the central nervous system.