what is the largest organ in the human body

ATI TEAS 7

ATI TEAS Practice Test Science

1. Which of the following is the largest organ in the human body?

A. Liver
B. Brain
C. Heart
D. Skin

Correct answer: D

Rationale: The skin is the largest organ in the human body. It covers the entire body, serving as a protective barrier against pathogens, UV radiation, and physical damage. Additionally, the skin plays a crucial role in regulating body temperature and synthesizing vitamin D when exposed to sunlight. Choices A, B, and C are incorrect. The liver is the largest internal organ, the brain is the control center of the body, and the heart is a vital organ responsible for pumping blood throughout the body. However, none of these organs are the largest in terms of surface area or overall size.

2. In a single displacement reaction, one element takes the place of another element in a compound. Which of the following is an example?

A. 2H2 + O2 -> 2H2O
B. Zn + 2HCl -> ZnCl2 + H2
C. CaCO3 -> CaO + CO2
D. CH4 + 2O2 -> CO2 + 2H2O

Correct answer: B

Rationale: Option B demonstrates a single displacement reaction where zinc (Zn) displaces hydrogen (H) in hydrochloric acid (HCl) to produce zinc chloride (ZnCl2) and hydrogen gas (H2). This reaction exemplifies the concept of one element (Zn) replacing another element (H) in a compound (HCl), which is characteristic of single displacement reactions. Choices A, C, and D do not involve a single element displacing another in a compound, making them incorrect. In choice A, hydrogen and oxygen combine to form water, which is not a single displacement reaction. In choice C, calcium carbonate decomposes into calcium oxide and carbon dioxide, not involving displacement of elements. In choice D, methane reacts with oxygen to form carbon dioxide and water, which is a combustion reaction, not a single displacement reaction.

3. Which hormone is responsible for regulating blood sugar levels?

A. Thyroxine
B. Insulin
C. Adrenaline
D. Cortisol

Correct answer: B

Rationale: The correct answer is B: Insulin. Insulin, produced by the pancreas, plays a crucial role in regulating blood sugar levels by facilitating glucose uptake into cells. Thyroxine, adrenaline, and cortisol do not directly regulate blood sugar levels. Thyroxine is produced by the thyroid gland and regulates metabolism. Adrenaline and cortisol are hormones involved in stress responses and do not have a primary function in blood sugar regulation. Understanding the functions of these hormones is crucial in differentiating their roles in the body and identifying the specific hormone responsible for blood sugar regulation.

4. When referring to blood vessel walls, the term 'atherosclerosis' describes:

A. The abnormal buildup of plaque within the arterial walls.
B. The inflammation of the inner lining of blood vessels.
C. The dilation and weakening of a blood vessel wall (aneurysm).
D. The normal process of blood vessel wall thickening with age.

Correct answer: A

Rationale: The correct answer is A: 'The abnormal buildup of plaque within the arterial walls.' Atherosclerosis is the process where plaque, consisting of fat, cholesterol, calcium, and other substances, accumulates within the arteries. This buildup can lead to the hardening and narrowing of arteries, reducing blood flow and potentially causing severe health issues like heart attacks and strokes. Choice B is incorrect because inflammation of the inner lining of blood vessels is known as vasculitis, not atherosclerosis. Choice C is incorrect as it describes an aneurysm, which is a dilation and weakening of a blood vessel wall, not atherosclerosis. Choice D is incorrect as it describes arteriosclerosis, a process of blood vessel wall thickening with age, which is different from atherosclerosis.

5. Which organ in the body is responsible for filtering toxins from the blood?

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

Correct answer: B

Rationale: The liver is the organ responsible for filtering toxins from the blood. It plays a crucial role in detoxification by processing and eliminating harmful substances from the body. The kidneys primarily filter waste and excess substances from the blood to form urine, while the heart pumps blood throughout the body and the lungs facilitate gas exchange by oxygenating blood. Therefore, the correct answer is the liver as it is specifically involved in detoxifying the blood.