Note- Differentiate into sperm cells

Controlled by hormones Ovulation releasing of the egg from the ovary Ovulation Menstruation - shedding lining of uterus Menopause Honors Ovulation

Vas deferens Passageway for sperm

Glands Add secretions Prostate gland – thin fluid for nourishment Seminal vesicle – (thick fluid contains fructose) - nutrients Bulburethral gland – basic fluid to balance acid of urine in urethra and acidity of vagina Urethra Exit for semen and urine H

Glands Add secretions Prostate gland Seminal vesicle - provides fluid nourishment for sperm) Bulburethral gland Urethra Exit for semen and urine A

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1. Sperm approaches egg 2. Acrosome releases enzymes to digest jelly layer 3. Proteins on sperm head bind receptor proteins on egg (prevents other species’ sperm) 4. Cell membranes of egg & sperm fuse Nucleus Video (5min)

Connects the mother and fetus Provides oxygen and nutrients Removes CO2 and waste Provides protective antibodies Blood of mother and baby NEVER mix – (blood barrier)

Fertilization Cleavage Implantation Development Growth Parturition - Length of gestation varies depending on organism

Humans266 days Rodents21 days Dogs and cats60 days Cows270 days Giraffes420 days Elephants600 days

Month 1 Fertilization, Cleavage, implantation HCG (hormone) is produced signaling pregnancy Embryo until 8 weeks

Month 2 – ¼ inch to 1 inch (bean) Nervous system is first organ system to form Heart develops and is the first organ to begin working Called a FETUS at 8 weeks Legs and arms start to form Eyes and ears become visible Placenta begins to form Umbilical cord connects mother and embryo Every essential organ has begun to form Bones begin to form, muscles can contract

Month 3 – 1 ½ to 3 inches Baby is 1.5 inches long Organ systems continue to develop. Genitalia clearly form (not always visible in ultrasound) Eyelids close (won’t open until week 28) Teeth buds form

Month 5: 8 inches Mother can feel baby moving Nails, eyelashes and eyebrows form Skin is covered by soft hair Heartbeat of baby can be heard by doctor

Embryo Pictures

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