Lecture 24 3/18/24 Flashcards
What is the main function of the testes?
spermatogenesis
How do FSH and LH act on the testes?
-FSH stimulates Sertoli cells
-LH stimulates testosterone production
What is the tunica vaginalis?
layer outside of the tunica albuginea that surrounds the entire testicle
What is the specific site of spermatogenesis?
seminiferous tubules
What is the tunica?
-dense fibrous connective tissue capsule surrounding each testis
-extends inward to form a central septum
How do the seminiferous tubules appear?
-highly coiled within the lobules
-converge into straight tubules leading to the rete testis
What are the characteristics of the tissue layers within the seminiferous tubules?
-each tubule is surrounded by 1-4 layers of flattened smooth muscle
-smooth muscle supports the spermatogenic cells and Sertoli cells
In which seminiferous tubule cells does spermatogenesis occur?
the most mature cells, closest to the lumen
What are the characteristics of spermatogonia?
-most immature spermatogenic cells
-small, round cells with dark, round nuclei
-adjacent to basement membrane
-undergo meiotic division to produce primary spermatocytes
What are the characteristics of spermatocytes?
-larger and more luminal than spermatogonia
-divided into primary and secondary spermatocytes
How do primary and secondary spermatocytes differ?
-primary are in 1st meiotic division
-secondary are in 2nd meiotic division
What are the characteristics of spermatids?
-formed after spermatocytes complete second meiotic division
-initially round with pale nuclei
-eventually become small and oval/elongated with dark heads and long, faint tails
What are the characteristics of spermatozoa?
-divided into head, neck, and tail
-actively mobile
-head = nucleus covered by acrosome
What are Sertoli cells?
nurse cells that provide mechanical and nutritive support for spermatogenic cells
What are the characteristics of Sertoli cells?
-irregularly columnar
-extend from basal lamina to lumen
-indistinct boundaries
-numerous invaginations in cell membranes