which part of the nephron is closest to the collecting duct

ATI RN

ATI Anatomy and Physiology

1. Which part of the nephron is closest to the collecting duct?

A. Distal convoluted tubule (DCT)
B. Bowman's Capsule
C. Afferent Arteriole
D. Proximal Convoluted Tubule (PCT)

Correct answer: A

Rationale: The correct answer is the Distal convoluted tubule (DCT). The DCT is the part of the nephron closest to the collecting duct, where the final adjustments to electrolyte and fluid balance are made. Bowman's Capsule is located at the beginning of the nephron, where filtration of blood occurs. The Afferent Arteriole brings blood to the glomerulus for filtration. The Proximal Convoluted Tubule (PCT) is situated after the Bowman's Capsule and is not the part closest to the collecting duct.

2. When does cell death first occur?

A. At age 60.
B. At age 50.
C. At puberty.
D. In the fetus.

Correct answer: D

Rationale: Cell death, also known as apoptosis, first occurs during fetal development when specific cells are programmed to die. This process is essential for shaping and organizing tissues and organs. Choices A, B, and C are incorrect because cell death begins much earlier, during fetal development, rather than later in life or at puberty. Understanding the timing of cell death in different stages of life is crucial in developmental biology.

3. Which of the following is produced by the prostate gland?

A. testosterone
B. fluid to lubricate the head of the penis
C. substance to enhance sperm mobility
D. Gonadotrophin-releasing hormone

Correct answer: B

Rationale: The correct answer is 'fluid to lubricate the head of the penis.' The prostate gland produces a milky fluid that makes up part of the seminal fluid, which helps to nourish and transport sperm. Testosterone is produced mainly by the testes, not the prostate gland. While the prostate gland does contribute to sperm mobility, its primary function is to produce the fluid that lubricates the penis during ejaculation. Gonadotrophin-releasing hormone is produced by the hypothalamus and regulates the release of hormones from the pituitary gland.

4. Which of the following types of cells is primarily responsible for the destruction of old cells and invasive micro-organisms?

A. Basophils
B. Eosinophils
C. B-cells
D. Macrophages

Correct answer: D

Rationale: Macrophages are a type of white blood cell that plays a crucial role in the immune system by engulfing and digesting cellular debris, foreign substances, microbes, cancer cells, and old or damaged cells. Basophils are primarily involved in allergic reactions and parasitic infections, eosinophils combat multicellular parasites and have a role in allergic reactions, and B-cells are responsible for producing antibodies. Therefore, the correct answer is macrophages as they are specialized in phagocytosis and removal of unwanted cells and microorganisms.

5. Does aging begin in the fetus?

A. Yes
B. No
C. Not Sure
D. None of the above

Correct answer: A

Rationale: Aging does begin in the fetus. The aging process starts even before birth due to cellular changes and the passage of time. The cells in a fetus undergo growth, division, and aging from the moment of conception. This continual process of cellular aging continues throughout life. Therefore, the statement is true. Choice B is incorrect because aging does initiate during the fetal stage. Choice C is incorrect as the process of aging commences in the fetus. Choice D is incorrect as the correct answer is 'Yes,' indicating that aging does start in the fetus.