Reproductive Systems Chapter 16

Male Reproductive System bladder seminal vesicle vas deferens prostate gland bulbourethral gland urethra epididymis scrotum testis penis

Semen = Sperm + Secretions Secretions from epididymis aid sperm maturation Seminal vesicle secretes fructose and prostaglandins Prostate-gland secretions buffer pH in the acidic vagina Bulbourethral gland secretes mucus

Prostate Cancer Second leading cause of death in American men Detection Digital rectal exam by physician Blood tests for prostate-specific antigen (PSA), a tumor marker

Testicular Cancer About 5,000 U.S. cases per year Can be detected by self exam Men should check testes monthly Check for hardening, lumps Changes should be reported to physician

Spermatogenesis Spermatogonium (2n) divides by mitosis to form primary spermatocyte (2n) Meiosis produces haploid spermatids Spermatids mature to become sperm

Other Testicular Cells Sertoli cells Line the seminiferous tubules Nourish the developing sperm Leydig cells Lie between the seminiferous tubules Secrete testosterone

Male Hormonal Control Hypothalamus GnRH Inhibin Anterior Pituitary FSH Leydig cells Sertoli cells Testes Testosterone Formation and Development of Sperm

Female Reproductive Organs ovary ovary oviduct uterus uterus oviduct vagina clitoris vagina

Menstrual Cycle The fertile period for a human female occurs on a cyclic basis Menstrual cycle lasts about 28 days Follicular phase and luteal phase

Oocytes Arrested in Meiosis I Girl is born with primary oocytes already in ovaries Each oocyte has entered meiosis I and stopped Meiosis resumes, one oocyte at a time, with the first menstrual cycle

Menarche to Menopause First menstruation, or menarche, usually occurs between ages 10-16 Menstrual cycles continue until menopause, in a woman’s late 40s or early 50s

Ovarian Cycle Follicle grows and matures Ovulation occurs secondary oocyte Ovarian Cycle first polar body Follicle grows and matures Ovulation occurs Corpus luteum forms antrum corpus luteum primordial follicle

Female Hormonal Control Hypothalamus GnRH Rising estrogen stimulates surge in LH Anterior Pituitary Progesterone, estrogens LH FSH Ovary Follicle growth, oocyte maturation Estrogen Corpus luteum forms

hypothalamus GnRH Cycle Overview anterior pituitary FSH LH FSH LH GnRH secretion affects LH and FSH secretion by pituitary LH and FSH affect follicle maturation Estrogen and progesterone from ovary affect uterus FSH LH LH ovulation estrogens estrogens progesterone estrogens menstruation FOLLICULAR PHASE LUTEAL PHASE

Ejaculation Involuntary contractions in smooth muscle of male reproductive tract force sperm from epididymides and contents of seminal vesicles and prostate gland out through urethra Sphincter closes off the neck of the bladder to prevent escape of urine

Prevent fertilization Birth Control Options Prevent fertilization Prevent ovulation Block implantation

Reproductive Options Artificial insemination In vitro fertilization (IVF) Intra-cytoplasmic sperm injection GIFT (gamete intrafallopian transfer) ZIFT (zygote intrafallopian transfer)

Abortion Removal of blastocyst, embryo, or fetus First trimester abortions are painless, and relatively complication free Later abortions are more difficult and more controversial