TEAS 7 Science Practice Test

Correct Answer: A

Rationale: The correct answer is A: epiglottis. The epiglottis is the cartilaginous flap that protects the larynx during swallowing by covering the glottis, preventing food or water from entering the trachea. This allows air to flow into the respiratory system while diverting food and liquids to the esophagus. B: Bronchioles are small air passages in the lungs and do not play a role in protecting the larynx during swallowing. C: Epithelium is a tissue that lines various organs, including the respiratory tract, but it does not specifically protect the larynx. D: The tongue is a muscular organ in the mouth that aids in chewing and swallowing but does not serve as a cartilaginous flap to protect the larynx.

Correct Answer: D

Rationale: The correct answer is D: conducting and respiratory. The conducting zone consists of structures that conduct air to the respiratory zone where gas exchange occurs. The respiratory zone includes the alveoli where oxygen is absorbed and carbon dioxide is released. Choices A, B, and C do not accurately represent the major zones of the respiratory system. The left and right bronchi are part of the conducting zone, not major zones. The nose and mouth are entry points but not major zones. The larynx and pharynx are part of the upper respiratory tract, not major zones.

Correct Answer: B

Rationale: The correct answer is B: sinoatrial node. The sinoatrial node is a cluster of specialized cells in the right atrium responsible for initiating the electrical impulses that regulate the heartbeat. It acts as the heart's natural pacemaker by setting the pace for the heart's contractions. The other choices are incorrect because: A: Sinus venosus is an embryonic structure in the heart, not the natural pacemaker. C: Atrioventricular node is responsible for conducting the electrical signal from the atria to the ventricles, not for generating the initial signal. D: Tricuspid valve is a heart valve that prevents backflow of blood from the right ventricle to the right atrium, not involved in generating electrical signals.

Correct Answer: C

Rationale: The primary function of the large intestine is to absorb water and compact material into solid waste. This process helps in forming feces for elimination. Absorbing digested material into the blood (Choice A) is mainly done in the small intestine. Nutrient processing and metabolizing (Choice B) occur in various organs like the liver and kidneys, not primarily in the large intestine. Bile production and storage (Choice D) are functions of the liver and gallbladder, not the large intestine.

Correct Answer: D

Rationale: The correct answer is D: insulin production and blood sugar regulation. The liver is not responsible for insulin production; it is produced by the pancreas. The liver does play a role in blood sugar regulation by storing and releasing glucose, but it is not the primary organ for insulin production. The other choices (A, B, C) are functions of the liver: A) nutrient processing involves metabolizing and storing nutrients, B) blood filtration and detoxification involves removing toxins from the blood, and C) cholesterol and lipoprotein production involves synthesizing cholesterol and lipoproteins.