A N AT O M Y & P H Y S I O LO GY

THE REPRODUCTIVE SYSTEM

THE REPRODUCTIVE SYSTEM

• functions to produce human offspring with the

- male providing sperm (produced within testes)

- female providing the ovum (produced within ovaries)

IMPORTANT TERMS

Mitosis part of cell cycle which leads to two identical cells with same number of chromosomes in each

Meiosis specialized cell division which reduces the chromosome number in half

Reproductive cells gametes

MEIOSIS

• Only occurs in the testes of males during sperm production

• Only occurs in ovaries of female during egg production

• cells go from 46 chromosomes (diploid) 23 chromosomes (haploid)

MEIOSIS IN ADULTS

• Fertilization= fusion of gametes

• Zygote= sperm+ egg

https://www.youtube.com/watch?v=BFrVmDgh4v4https://www.youtube.com/watch?v=uXsCngh89fI

THE MALE REPRODUCTIVE SYSTEM

Primary Sex Organs• Testis (held within the scrotum)

Produce the sperm

Produce male sex hormones (androgens)

Lie outside of male abdominal cavity

Testis divided into lobules; each lobule contains seminiferous tubules

SPERMATOGENESIS

THE MALE REPRODUCTIVE SYSTEM-ACCESSORY ORGANS

• Epididymus -ducts where sperm mature and some sperm stored• Vas deferens – (contained within spermatic cord); transport

and store sperm• Seminal vesicles – contribute nutrients and fluid to

semen; produce prostaglandins and fructose• Ejaculatory duct –transport sperm• Prostate gland – contributes basic fluid to semen • Urethra –transport sperm• Bulbourethral glands – produce mucoid fluid that

neutralizes urine

https://www.youtube.com/watch?v=icSZrxu0hDI

https://www.youtube.com/watch?v=N66sAZH1VA8

MALE ACCESSORY SEX ORGANS

ANATOMY OF A SPERM

MORE ABOUT SPERM- Takes 74 days or about

10 weeks for sperm to be produced and fully mature for ejaculation

- Sperm mature in epididymus

- Sperm can be stored in male body for approximately 3 weeks after they are matured

VASECTOMY• Surgical procedure for male

sterilization

• Vas deferens are cut and sealed/tied off to prevent sperm from traveling which eventually prevents fertilization

• ~30 minute procedure

• Vasectomy is different than castration (where testicles are removed)

FEMALE REPRODUCTIVE SYSTEM

THE EGG- During fetal

development-6 million to 7 million eggs.

- At birth, there are approximately 1 million eggs

- by puberty, only about 300,000 remain. -only 300 to 400 will be ovulated during a woman's reproductive lifetime.

THE EGG- Egg matures due to

LH (Luteinizing Hormone) surge from increased Estrogen

- Day 14 of cycle is when ovulation occurs

- Ovulation is when egg is released from ovary

FEMALE REPRODUCTIVE SYSTEM• Corpus luteum produces

progesterone and helps thicken lining of uterus for implantation

• Corpus luteum survives 12-14 days unless begins receiving HcG from developing embryo

• If egg not fertilized, then corpus luteum dies off

• Corpus luteum deficiency corpus luteum doesn’t develop enough progesterone which leads to

WHEN THE SPERM MEETS THE EGG1. Sperm approaches egg2. Sperm acrosomal

enzymes digest the eggs jelly coat

3. Proteins in sperm bind with receptors of egg

4. Plasma membranes fuse5. Sperm nucleus enters

eggs cytoplasm6. Fertilization membrane

forms7. Nuclei fuse

https://www.youtube.com/watch?v=7G2rL5Cutd4https://www.youtube.com/watch?

v=_5OvgQW6FG4

FEMALE REPRODUCTIVE SYSTEM• Fertilization takes place in

fallopian tubes

• Uterus houses developing fetus

• Cervix contains the opening to the uterus

• Vagina serves as birth canal; exit for menstrual flow; receives penis during sexual intercourse

D I S S E C T I O N N O T E S

IN THE LAB

Adapted from Whitman College

IN THE LAB DISSECTION OF FETAL PIG

MORE ANATOMICAL LOCATION

DETERMINING THE SEX OF YOUR PIG

Male Female

In males urogenital tract opens near umbilical region