Midterm 2 - Lecture 17 Flashcards
What are the 5 components of the semen manufacturing complex?
- Manufacturing Center = testes
- Finishing stop = forward excurrent ducts
- Warehouse Shipping = hind excurrent ducts
- Final Alteration and Shipping = accessory sex glands
- Delivery System = penis
What are the 4 goals of spermatogenesis?
- provide a male with continual supply of gametes
- provide billions of sperm each day to maximize reproductive efficiency
- provide genetic diversity
- provide an immunologically privileged site where spermatogenic cells will not be destroyed by the male’s immune system
Are males continually fertile? How?
Yes! Spermatogenesis provides the male with a continual supply of gametes
What is spermatogenesis?
sperm production
What are the 3 phases are spermatogenesis?
- proliferation
- meiosis
- differentiation (spermogenesis)
What happens during the proliferation phase of spermatogenesis?
- mitotic division (maintains diploid) of spermatogonia to form primary spermatocytes
- constant replacement of spermatogonia
What happens during the meiosis phase of spermatogenesis?
- Diploid (2N) primary spermatocytes go through meiotic division to produce Haploid (1N) spermatids
- Genetic diversity is guaranteed by processes such as homologous recombination and DNA methylation
What happens during the differentiation phase of spermatogenesis?
- spermatids develop into fully formed spermatozoa
What membrane is proliferation happening the closest to?
Basement membrane of the seminiferous tubule
What is the blood-testis barrier?
- cellular barrier that prevents immune system from affecting the developing sperm
What are the 2 cellular layers of the blood-testis barrier?
- Peritubular cells - surrounding the seminiferous tubules
- Junctional complexes - tight connections btw the sertoli cells within the seminiferous tubules
What are the 2 distinct compartments that the junction complexes divide the seminiferous lumen into?
- basal compartment - spermatogonia
- adluminal compartment - spermatocytes, spermatids, spermatozoa
Duration of spermatogenesis
- relatively long process
- spermatogonia to spermatid (~10 days)
- spermatid to spermatozoa (~50 days)
Spermatozoa
- sperm are simple cells the basic elements necessary to get DNA from the male tract into the female tract
What are 6 key features of spermatozoa?
- nucleus + genetic material
- little cytoplasm
- no endoplasmic reticulum
- numerous mitochondria (for energy)
- a tail
- plasma membrane + acrosome (w/ enzymes to penetrate oocyte)