Week 13: Sexual Organs and Reproductive Function Flashcards
(242 cards)
What is the Scrotum?
Skin-covered, muscular sac located behind the penis that houses the testes.
When is sperm production most efficient?
Sperm production is most efficient 2–4°C below core body temperature.
What happens when the muscle contract, the scrotum shrinks, and the testes move closer to the body?
Sperm get too cold, need to be warmer
What happens when the muscle relax, the scrotum expands, and the testes move farther from the body?
Sperm get too hot, need to be cooler
What is the Raphae?
A raised medial ridge on the scrotal surface.
What are the Testes?
Produce sperm & androgens (e.g., testosterone) and housed in the scrotum.
What is the Cryptorchidism?
Failure of one or both testes to descend before birth.
When do the testes descend in fetal months?
Occurs in the 7th fetal month
What are Seminiferous tubules?
They are the location of sperm production.
What is the pathway of sperm through the testes?
Seminiferous tubules → Straight tubules → Rete testes → Efferent ductules (exit testes).
What are Sertoli Cells (Sustentacular Cells)?
Support & nourish developing sperm cells; they secrete signaling molecules that regulate sperm production & germ cell survival
What are Spermatogonia?
Stem cells lining the basement membrane that can divide and differentiate throughout adulthood
What are Blood-Testis Barrier (BTB)?
Formed by tight junctions between Sertoli cells, they protect germ cells from harmful bloodborne substances; Prevents immune system from attacking sperm-specific antigens
What is Spermatogenesis?
Creation of sperm
Where does Spermatogenesis occur?
Occurs in the seminiferous tubules of the testes.
When does Spermatogenesis begin?
Begins at puberty and continues throughout life.
How long is a Spermatogenesis cycle?
~64 days per sperm production cycle with a new cycle starting every 16 days.
When does sperm count decline?
Sperm count declines after age 35
How might smoking impact Sperm production?
It may reduce sperm count
What are the 4 BASIC stages of Spermatogenesis?
- Spermatogonium → Primary spermatocytes (2n)
- Primary spermatocytes → Secondary spermatocytes (1n, haploids)
- Secondary spermatocytes → Spermatids (1n, haploids)
- Spermatids → Mature sperm
Describe how sperm cells split and multiply
- Mitosis of spermatogonia
- Meiosis I (Primary spermatocyte → Secondary spermatocytes)
- Meiosis II (Secondary spermatocytes → Spermatids)
- Spermiogenesis (Spermatids → Spermatozoa)
- Spermatozoa formation & transport
T or F: Sperm are 85,000 times smaller than the female gamete
True
How many sperm are produced every day?
100–300 million sperm are produced daily
What are the 4 structures of the sperm cell?
- Head
- Mid-piece
- Tail
- End piece