what happens during expiration

ATI TEAS 7

ATI TEAS Science Practice Test

1. What happens during expiration?

A. The diaphragm contracts and the thoracic cavity expands.
B. The diaphragm relaxes and the thoracic cavity contracts.
C. The thoracic cavity expands, increasing pressure.
D. The diaphragm relaxes and moves upward.

Correct answer: B

Rationale: The correct answer is B. During expiration, the diaphragm relaxes, causing the thoracic cavity to contract. As the thoracic cavity decreases in size, the pressure inside the lungs increases, leading to air flowing out of the lungs. This process helps to expel carbon dioxide-rich air from the body. Choices A, C, and D are incorrect. In choice A, the diaphragm contracting and the thoracic cavity expanding describes inspiration, not expiration. Choice C is incorrect because during expiration, the thoracic cavity actually decreases in size. Choice D is incorrect as the diaphragm moving upward is not a typical movement associated with expiration.

2. Which of the following describes a responsibility of the integumentary system?

A. Distributing vital substances, such as nutrients, throughout the body.
B. Blocking pathogens that cause disease.
C. Sending leaked fluids from the cardiovascular system back to the blood vessels.
D. Storing bodily hormones that influence gender traits.

Correct answer: B

Rationale: The correct responsibility of the integumentary system is to act as a barrier that blocks pathogens from entering the body, thus helping to prevent diseases and infections. This function serves as the first line of defense for the body against external threats. Choices A, C, and D are incorrect. Choice A is a function of the circulatory system, not the integumentary system. Choice C relates to the lymphatic system, not the integumentary system. Choice D involves the endocrine system, not the integumentary system.

3. Which of the following reagents can be used to convert a primary alcohol to an alkyl halide?

A. HI
B. H2O
C. NaOH
D. SOCl2

Correct answer: D

Rationale: SOCl2 (thionyl chloride) is commonly used to convert primary alcohols to alkyl halides through an SN2 mechanism. Thionyl chloride reacts with the alcohol to form an alkyl chloride. HI (hydroiodic acid) is typically used to convert alcohols to alkyl iodides specifically, not alkyl halides in general. H2O (water) and NaOH (sodium hydroxide) are not reagents used for converting alcohols to alkyl halides. Therefore, the correct answer is SOCl2 as it facilitates the conversion of primary alcohols to alkyl halides, unlike the other options provided.

4. What is the term for the process of a liquid changing into a gas?

A. Evaporation
B. Boiling
C. Condensation
D. Sublimation

Correct answer: A

Rationale: The correct answer is 'Evaporation.' Evaporation is the process by which a liquid changes into a gas at any temperature, while boiling specifically refers to the rapid vaporization of a liquid only at its boiling point. Condensation is the opposite process of gas turning into a liquid, and sublimation is the direct transition from solid to gas without passing through the liquid phase.

5. Which organ in the body is responsible for maintaining electrolyte balance and filtering waste from the blood?

A. Liver
B. Kidneys
C. Heart
D. Lungs

Correct answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are responsible for filtering waste from the blood and maintaining electrolyte balance. They help regulate the body's fluid levels and produce urine as a means of waste elimination. The liver primarily plays a role in detoxification and metabolism, not in maintaining electrolyte balance or filtering waste from the blood. The heart is responsible for pumping blood, not for electrolyte balance or waste filtration. The lungs are primarily involved in gas exchange, not in maintaining electrolyte balance or filtering waste from the blood.