TEAS 7 science quizlet

Correct Answer: B

Rationale: Histamine is a chemical released by the immune system during an allergic reaction. It is responsible for causing symptoms such as a runny nose, itchiness, sneezing, and watery eyes. These symptoms are commonly seen in allergies like hay fever. Fever and fatigue (option A) are not typically caused by histamine release during an allergic reaction. Muscle aches and joint pain (option C) are not common symptoms of histamine release in allergic reactions. Cough and shortness of breath (option D) are more commonly associated with asthma or respiratory allergies rather than histamine release.

Correct Answer: C

Rationale: Refraction occurs due to a change in wave speed when waves enter a new medium. As waves travel from one medium to another, their speed changes, causing them to bend. This change in speed is responsible for the bending of waves during refraction. It is not the change in wavelength or frequency that causes refraction, but rather the change in speed as waves move through different mediums. Therefore, the correct answer is the change in wave speed (Choice C). Choices A and B are incorrect as refraction is not primarily influenced by changes in wavelength or frequency, but by changes in wave speed. Choice D is also incorrect as there is a specific principle, which is the change in wave speed, behind the phenomenon of refraction.

Correct Answer: C

Rationale: The tonsils and adenoids are lymphatic tissues located in the head and neck region, specifically in the throat area. They are essential components of the immune system, acting as the first line of defense against infections that can enter through the nose and mouth. The tonsils are situated at the back of the throat, while the adenoids are positioned high in the throat behind the nose. Choices A, B, and D are incorrect as they do not correspond to the anatomical location of the tonsils and adenoids. Therefore, the correct answer is the head and neck region.

Correct Answer: C

Rationale: Endotoxins are toxic substances that are part of the outer membrane of the cell wall of gram-negative bacteria. These toxins are released when the bacteria are destroyed or during bacterial growth. Endotoxins can cause a variety of harmful effects in the host, including fever, inflammation, and septic shock. Viruses do not produce endotoxins; they are typically associated with producing viral proteins that can be toxic to host cells. Gram-positive bacteria produce exotoxins, which are different from endotoxins found in gram-negative bacteria. Parasites, though capable of causing diseases, are not typically associated with the production of endotoxins.

Correct Answer: B

Rationale: Atrophy is the correct term for the process by which muscle tissue wastes away due to disuse or lack of nutrients. It is essential to differentiate atrophy from hypertrophy, which is the increase in muscle size due to exercise or strength training. Fibrosis involves the formation of excess fibrous connective tissue, which is distinct from muscle wasting. Rigor mortis, on the other hand, is the stiffening of muscles that occurs after death and is not related to muscle wasting during life.