PHSL 3051 Lecture Notes - Lecture 26: Y Chromosome, Meiosis, Erythropoietin
Document Summary
Sex is genetically determined (xx vs xy) Sry gene responsible for testes and testosterone production. Important in family genetics (in females use mitochondrial dna) Expresses for a time in fetal development and then goes dormant. Suspended outside abdominal cavity to keep cooler - temperature specific. When too warm sperm production is not healthy. Testicular artery and testicular vein that are close enough together that they can exchange heat. Warmer in artery - heat transfers to the vein and goes back into the body, keeping testes cooler. Provide sperm with growth factors/nutrients for development. All stages of spermatogenesis are surrounded by these support cells. Form tight junctions with each other (blood testes barrier) Secrete proteins: inhibin (hormone to inhibit fsh), activin, and androgen binding protein. Scrotum protects the testes and regulates temperature. Vas deferens - ligated for a vasectomy. Testosterone levels and levels of sperm production are regulated by negative feedback pathways.
