Hormonal Regulation of the Reproductive System (Section 14.3) Today: Male and Female Hormones and feedback controls Spermatogenesis/Oogenesis Terminology TOMORROW: Quiz – Reproductive Systems – Structure/Function and Hormone Function Hormonal Regulation of the Menstrual Cycle

Male Hormones and Sperm Production

HORMONES - MALE

Regulation of Male Hormones

Spermatogenesis pg 480 and 569 Sperm are created from spermatogonia, which are specialized sperm producing cells Spermatogonia have a full set of chromosomes (human = 46) Spermatogonia undergo mitosis thus creating spermatocytes, (some of which will undergo meiosis to produce cells which have 23 chromosomes) After 9 – 10 weeks, spermatocytes develop into spermatids, which mature into sperm in the epididymis, and are stored for about 4 – 5 days

Spermatogenesis

The Structure of Sperm Sperm are continuously being produced in the testes Sperm have three basic sections: The Head Contains the nucleus Has little cytoplasm Contains enzymes to break down the ovum wall to allow for fertilization, stored in the acrosome The Midsection Contains lots of mitochondrion to provide movement for the tail The Tail Also called the flagella Provides motility for the sperm Because they lack a lot of cytoplasm, sperm are provided with energy by Sertoli cells

Female Hormones and Egg Production

HORMONES - FEMALE

Regulation of Female Hormones In the presence of FSH, estrogen levels will increase If estrogen levels are too high, estrogen will inhibit FSH In the presence of LH, progesterone levels will increase Elevated levels of progesterone will inhibit FSH and LH Recall FSH and LH are released from the pituitary gland, where as estrogen and progesterone are released from the corpus luteum

OOGENESIS Oogenesis is the process of meiosis in the female organism from an oogonium (mitosis) to a primary oocyte (meiosis) to a secondary oocyte and then to an ovum

Oogenesis

The Structure of Eggs (Ova/Ovum) Largest human cell Provides the nutrients for initial growth of zygote (cytoplasm)

Comparison of Sperm and Egg Criterion for Comparison Sperm Cell Egg Cell Size Head ~ 5 μm long Middle ~ 5 μm long Tail ~ 40 μm long Cell ~ 100 μm in diameter Energy reserves Before ejaculation – process fat for energy After ejaculation – process fructose for energy *can live for 3-5 days inside woman* Can live for ~ 1 day if no F! If F! will implant in endometrium, which serves as energy source Mitochondria Middle piece contains , which supply ATP for movement Cytoplasm of egg cell contains ~ Numbers produced Produced continuously ~ million each day At puberty, each ovary contains ~ follicles Usually one egg is released each month Motility Sperm are motile (flagellum allows it to “swim”) Eggs are not motile Outer structures Sperm head has a cap called an acrosome which contains enzymes that help the sperm enter the egg Egg is covered by a specialized outer coating, which can be penetrated by only ONE SPERM of the same species