Human Reproductive System Male Reproductive System Sperm Formation

Human Reproductive System

Male Reproductive System

Sperm Formation • • • MEIOSIS forms sperm in gametes Sperm forms in testes Scrotum keeps cooler than rest Semen is sperm plus protecting fluid Semen leaves testes through the vas deferens (sperm ducts) to the urethra before it exits.

Secondary Sexual Characteristics - Male • Produced by testosterone – Deeper voice – Chest and facial hair – Lengthen bones – Increased size of testes for sperm production

Female Reproductive System Mrs. Degl

Ovum Formation • MEIOSIS forms the eggs (ova) • Eggs are formed before birth • 1 egg per month is matured and released from ovaries, most of the time • Eggs travel through the fallopian tube where they may become fertilized

Secondary Sexual Characteristics - Female • Induced by increased LH, FSH, estrogen, and progesterone hormone levels – Pubic hair – Widen pelvis – Enlarge mammary tissue (breasts) – Begin menstrual cycles

Fertilization • • Occurs in upper 1/3 of Fallopian tube Only 1 sperm can fertilize an egg Fertilized egg = zygote An average woman is pregnant (gestational period) for 9 whole months. That is 40 weeks. Babies can survive if they are born earlier, but they may have complications due to being premature.

Implantation • Fertilized eggs are implanted into thick walls of uterus • Chorion membranes dig into uterus to form placenta • Zygote grows into an embryo • Embryo gets air and nutrients through the umbilical cord • Once pregnant, progesterone levels stay high in mom • Mom’s uterus grows with the baby

1 st Trimester = 1 st 12 weeks • Heart develops first • Neural tube develops • All body systems appear by Week 8 – Now a Fetus

2 nd Trimester = up to 24 weeks • Most growth • Looks more like a baby • Some preemies survive at this stage l

3 rd Trimester = Up to 40 weeks • • • More growth Kicking, rolling, stretching Eyes open – Week 32 Lungs mature Rotates to head-down position, unless baby is breech

Birth • Labor – Uterine contractions begin – Cervix dilates to 10 cm. • Birth – Uterus pushes baby through vaginal canal – Placenta delivered after baby – Cesarean Section (c-section) is a surgery that cuts through the uterus to deliver the baby if it cannot be born vaginally