the average life expectancy at birth in the united states at the beginning of the 21st century was about 75 years the average life expectancy at birth

ATI TEAS 7

Science TEAS Practice Test

1. The average life expectancy at birth in the United States at the beginning of the 21st century was about 75 years. The average life expectancy at birth in the middle of the 19th century was only about 40 years. Which of the following factors are likely to have contributed to the longer life expectancy in the 21st century? (Select the one that does not apply)

A. The human body has evolved to become more resilient to its environment.
B. There have been numerous advances in medical technology and treatments.
C. Higher standards of basic cleanliness have helped people avoid illness.
D. The creation of vaccines has nearly eliminated certain diseases that were once deadly.

Correct answer: A

Rationale: Medical advances, higher standards of cleanliness, and the creation of vaccines have all significantly contributed to the increase in life expectancy over time. While human evolution plays a role in adaptation to the environment over millennia, it is not a primary factor that has led to the substantial increase in life expectancy within a few centuries. The human body's evolution is a slow process that occurs over generations, while the advancements in medical technology, cleanliness, and vaccines have had a more immediate and direct impact on improving life expectancy.

2. What is the primary function of the placenta during pregnancy?

A. Produce insulin
B. Facilitate gas exchange between mother and fetus
C. Excrete waste products from the fetus
D. All of the above

Correct answer: B

Rationale: The primary function of the placenta during pregnancy is to facilitate the exchange of oxygen and carbon dioxide between the mother and the fetus. This ensures that the fetus receives oxygen and eliminates carbon dioxide, supporting its growth and development. While the placenta also allows for the transfer of nutrients and waste products between the mother and the fetus, its main role is to ensure proper gas exchange. Therefore, choices A, C, and D are incorrect as the primary role of the placenta is not to produce insulin or excrete waste products from the fetus. Selecting the correct answer, choice B, highlights the crucial role of the placenta in providing oxygen to the fetus and removing carbon dioxide, which are essential for fetal well-being and development.

3. What is the primary function of the lymphatic system?

A. Transporting oxygen and nutrients to cells
B. Carrying waste products away from tissues
C. Regulating body temperature
D. Producing red blood cells

Correct answer: B

Rationale: The primary function of the lymphatic system is to carry waste products away from tissues. Lymphatic vessels collect excess fluid, waste materials, and toxins from the body's tissues and transport them to the bloodstream for elimination. Choice A is incorrect because transporting oxygen and nutrients to cells is mainly the function of the circulatory system. Choice C is incorrect as regulating body temperature is primarily done by the body's thermoregulatory mechanisms. Choice D is incorrect because the production of red blood cells occurs in the bone marrow, not in the lymphatic system.

4. Which of the following areas of the body has the most sweat glands?

A. Upper back
B. Arms
C. Feet
D. Palms

Correct answer: D

Rationale: The correct answer is D: Palms. The palms of the hands have the highest concentration of sweat glands compared to other areas of the body. This is why sweating is commonly noticed on the palms during times of stress or physical exertion. Choices A, B, and C are incorrect. While these areas do have sweat glands, they are not as densely distributed as in the palms. The upper back, arms, and feet do contribute to overall body sweat, but the palms have a significantly higher density of sweat glands, making them the area with the most sweat glands.

5. If a doctor diagnoses a patient with an impaired posterior pituitary gland, which of the following symptoms related to kidney function does the patient display?

A. Thirst
B. Tiredness
C. Weight gain
D. Concentrated urine

Correct answer: D

Rationale: When the posterior pituitary gland is impaired, there is decreased secretion of antidiuretic hormone (ADH). ADH plays a crucial role in regulating water reabsorption by the kidneys. A deficiency of ADH leads to the inability of the kidneys to concentrate urine, resulting in the production of dilute urine. Therefore, 'Concentrated urine' is the correct symptom associated with impaired posterior pituitary gland. Choices A, B, and C are incorrect. Thirst is more commonly associated with diabetes insipidus, tiredness could be a general symptom but not specifically related to kidney function, and weight gain is not a typical symptom of impaired posterior pituitary gland affecting kidney function.