Reproductive system Flashcards
Produce sex cells called sperm
Testes (male gonads)
Produce sex cells called ova (oocytes, eggs)
Ovaries (female gonads)
Sex cells have 1 set of genetic instructions on 23 chromosomes
compared to 2 sets on 46 chromosomes in other body cells
Sex cells are produced by a special type of division called
Meiosis
*Involves synapsis: Pairing of homologous chromosomes
*Crossover occurs: Exchange of genetic material between homologous chromosomes, to produce chromosomes with genetic information from both parents
Prophase I
- Chromosome pairs line up on midline of spindle
- Alignment is random, with respect to maternal or paternal origin
Metaphase I
*Homologous chromosome pairs separate, each replicated member migrating to a different pole
*Each daughter cell receives only 1 replicated member of each chromosome pair; this reduces the chromosome number by half
Anaphase I
*Cell divides completely, forming 2 new haploid daughter cells
*Each new cell contains 23 individual chromosomes with 2 chromatids
Telophase I
What begins after telophase I
Meiosis II
What are the four stages of meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
*Chromosomes condense and reappear, still replicated
Prophase II
Replicated chromosomes attach to spindle fibers along midline
Metaphase II
Centromeres separate, and chromatids migrate to opposite poles
*Chromatids are now considered chromosomes
Anaphase II
Each of 2 cells produced in Meiosis I divides into 2 daughter cells
Telophase II
Primary sex organs (gonads) are the
2 testes
-Produce sperm cells, or spermatozoa
*Produce male sex hormones
Secondary (accessory) sex organs
*Other internal and external sex organs
*Secrete male sex hormones
*Transport sperm and secretions to outside of body
aids descent through the inguinal canal
Gubernaculum (fibrous cord)
contains the ductus deferens, blood vessels, and nerves
spermatic cord
Tough, fibrous capsule enclosing each testis
Tunica albuginea
Compartments in testis, separated by connective tissue septa
Lobules
*Highly coiled tubules inside lobules
*Lined with a special stratified epithelium containing spermatogenic cells that give rise to sperm cells
Seminiferous tubules
*Lie between seminiferous tubules
*Produce and secrete male sex hormones
Interstitial cells (cells of Leydig)
Channels that transport sperm from testis to epididymi
Rete testis
Coiled tube on surface of testis, that transports sperm from rete testis to ductus deferens
Epididymis