General Anatomy/Reproductive System

The reproductive system includes the primary organs necessary for reproduction - ovaries and the testes, but there are accessory organs as well. For the female, there is the uterus, oviduct, breasts, and vagina. The male has the penis and scrotum for accessory organs.

Female Reproductive
The female reproductive system undergoes changes every month from the menstrual system, which is caused by a variety of hormones that fluctuate over the average of 28 days. The hormones involved include luteinizing hormone and follicle-stimulating hormone from the anterior pituitary. Prolactin will also play a role in increasing the size and production of the mammary glands during and after pregnancy.

The eggs that start in a female were made when she was an embryo as primordial. From then, there will develop to become primary follicles. Secondary follicles build as the surrounding theca tissue builds creating a granular layer.

The journey of the egg starts from the ovary where it is released from the building of fluid pressure in the antrum. The secondary follicle will travel from the ovary to the oviduct where it is grabbed by cilia and then is moved from the oviduct's various regions - isthmus and ampulla. If fertilization is to occur, it will occur in the oviduct. From there it will enter the uterus and attach to the uterine lining formed by the endometrium's stratum basale.

Male Reproductive
The male reproductive system starts with the sperm being produced at the seminiferous tubules of the testes. The seminiferous tubules are surrounded by supporting cells called Sertoli cells and Leydig cells. From the seminiferous tubules, sperm will travel to the epididymis to the vas defens. At the vas deferens, accessory glands like the bulbourethral glands and the seminal vessicles will contribute additional fluids and nutrients to help maintain the life of the sperm.

The penis has two main regions - the corpora spongiosum and the corpus cavernousum. These flank the urethra. Recall that the male urethra has three regions, the prostatic, membranous, and the spongy.

At the tip of the penis is the glans, which may or may not be covered by the prepuce (also known as the foreskin).