MDS PREP
What is the osmolarity of the tubular fluid leaving the early distal tubule?
1) Isotonic to plasma
2) Hypertonic
3) Hypotonic
4) Variable
The osmolarity of the tubular fluid leaving the early distal tubule is hypotonic, as it has lost solutes while retaining water.
What are the main characteristics of type I (slow twitch) muscle fibers?
1) High myoglobin content and oxidative metabolism
2) Low myoglobin content and oxidative metabolism
3) High actin and myosin content for rapid contraction
4) Large diameter and high glycolytic enzyme activity
Type I fibers are also called slow-twitch fibers due to their high myoglobin content, which supports aerobic metabolism and allows for sustained contractions over time.
Which of the following statements is true about the regulation of the sympathetic nervous system?
1) The sympathetic nervous system is primarily regulated by the parasympathetic nervous system.
2) The sympathetic nervous system is mainly controlled by the hypothalamus.
3) The sympathetic nervous system is regulated by the spinal cord through the sympathetic chain ganglia.
4) The sympathetic nervous system is primarily regulated by the sympathetic chain ganglia.
Answer: 3) The sympathetic nervous system is regulated by the spinal cord through the sympathetic chain ganglia, which receive input from the hypothalamus and other higher centers.
In which part of the male reproductive system does spermatogenesis occur?
1) Seminal vesicles
2) Epididymis
3) Prostate gland
4) Seminiferous tubules
Physiology
Answer: 4
Spermatogenesis is the process of sperm cell development. It takes place in the seminiferous tubules within the testes. These tubules are lined with spermatogonia, which mature into primary spermatocytes, then secondary spermatocytes, and finally into spermatids, which mature into spermatozoa.