which is the first step in pulmonary circulation

HESI A2

HESI A2 Anatomy and Physiology Practice Exam

1. What is the first step in pulmonary circulation?

A. Blood moves toward the heart through the pulmonary veins.
B. The pulmonary artery carries blood from the heart to the lungs.
C. Carbon dioxide is exchanged for oxygen.
D. Oxygenated blood moves through the aorta.

Correct answer: B

Rationale: The correct answer is B: The pulmonary artery carries blood from the heart to the lungs. The first step in pulmonary circulation involves the right ventricle of the heart pumping deoxygenated blood into the pulmonary artery. The pulmonary artery then carries this deoxygenated blood from the heart to the lungs for oxygenation. This step is crucial for the exchange of carbon dioxide for oxygen to occur in the lungs, facilitating the oxygenation of blood. Choices A, C, and D are incorrect because they do not represent the initial step in pulmonary circulation. Option A refers to blood moving away from the heart, option C describes the gas exchange process that occurs in the lungs but not as the first step, and option D mentions oxygenated blood moving through the aorta, which happens after oxygenation in the lungs.

2. How do the digestive system and urinary system work together?

A. The digestive system controls the function of the ureter.
B. The urinary system removes toxins from the products of digestion.
C. The digestive system manufactures hormones that influence urination.
D. The urinary system eliminates some waste products of digestion.

Correct answer: D

Rationale: The correct answer is D because the urinary system eliminates some waste products of digestion. After digestion in the digestive system, nutrients are absorbed into the bloodstream, and waste products are transported to the kidneys via the urinary system to be excreted as urine. This process helps eliminate waste products generated during digestion, illustrating the coordination between the digestive and urinary systems. Choices A, B, and C are incorrect. Choice A is incorrect as the ureter is part of the urinary system, not controlled by the digestive system. Choice B is incorrect as the urinary system primarily removes metabolic waste, not toxins from digestion. Choice C is incorrect because the digestive system mainly aids in digestion and nutrient absorption, not hormone production affecting urination.

3. 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.

4. The lateral side of the right knee would be ___________.

A. the kneecap
B. closest to the left knee
C. farthest from the left knee
D. on the underside of the knee

Correct answer: C

Rationale: The lateral side of the right knee is the side that is farthest from the left knee when looking at the knee joint from the front. The term 'lateral' refers to the side of the body that is farther away from the midline or center of the body. In this case, the lateral side of the right knee is on the outer side of the knee joint, away from the other knee. Choice A is incorrect as the kneecap is located at the front of the knee. Choice B is incorrect as it describes the medial side, not the lateral side. Choice D is incorrect as it refers to the underside, which is not related to the lateral aspect of the knee.

5. Which cellular structure is responsible for protein synthesis?

A. Nucleus
B. Ribosome
C. Endoplasmic reticulum
D. Golgi apparatus

Correct answer: B

Rationale: The correct answer is B: Ribosome. Ribosomes, the cellular structures located in the cytoplasm or on the endoplasmic reticulum, are responsible for protein synthesis in the cell. They are the sites where mRNA is translated into proteins, making them essential for the synthesis of proteins in all living cells. The other choices, such as the nucleus (choice A), endoplasmic reticulum (choice C), and Golgi apparatus (choice D), are not directly involved in protein synthesis. The nucleus contains DNA and is responsible for housing the genetic material, the endoplasmic reticulum is involved in protein folding and transport, and the Golgi apparatus is responsible for modifying, sorting, and packaging proteins.