ap exam 2

Testes

Produce sperm (spermatogenesis) and testosterone.

Epididymis

Stores and matures sperm.It is a coiled tube located behind the testes that helps in the maturation and storage of sperm cells after they are produced.

Vas Deferens

A muscular tube that transports sperm from the epididymis to the ejaculatory duct.

Seminal Vesicles

Glands that secrete fluid to nourish sperm and form semen.

Prostate Gland

A gland that produces prostate fluid, an essential component of semen, which helps nourish and transport sperm.

Bulbourethral (Cowper’s) Glands

Two pea-sized glands that secrete a clear fluid that lubricates the urethra and neutralizes acidity, contributing to semen. These glands are located near the base of the penis and play a crucial role in sexual function.

Penis

The male reproductive organ that delivers semen through the urethra during ejaculation and is involved in sexual intercourse.

Scrotum

Regulates temperature of testes (optimal at ~34°C).

GnRH (Hypothalamus)

 stimulates pituitary.

LH (Pituitary)

stimulates Leydig cells → testosterone production

FSH (Pituitary)

stimulates Sertoli cells → spermatogenesis.

Testosterone

 secondary sex traits, muscle mass, libido, sperm production

Spermatogonium

(diploid stem cell) → mitosis → primary spermatocyte.

Primary spermatocyte

meiosis I → secondary spermatocytes

Secondary spermatocyte

meiosis II → spermatids.

Spermatids

1. mature into spermatozoa (sperm).

2. Occurs in seminiferous tubules (~64–72 days).

Ovaries

Produce oocytes (eggs) and hormones (estrogen, progesterone)

Fallopian Tubes (Oviducts)

Transport oocyte; site of fertilization

Uterus

Houses and nourishes embryo/fetus

Cervix

Connects uterus to vagina; produces mucus for sperm passage.

Vagina

Receives sperm, serves as birth canal.

External Genitalia (Vulva)

Protects internal organs and sensory stimulation

Follicular Phase (Days 1–14)

• FSH stimulates follicle growth.

• Follicle secretes estrogen → thickens endometrium.

LH surge around day 14 → ovulation (release of oocyte).

 Luteal Phase (Days 15–28)

• Remaining follicle becomes corpus luteum → secretes progesterone.

• Progesterone maintains uterine lining.

• If no fertilization → corpus luteum degenerates → menstruation

Oogenesis

(diploid) → primary oocyte (arrests in prophase I until puberty)

1. Each month, one completes meiosis I → secondary oocyte + polar body.

2. Ovulation releases secondary oocyte.

If fertilized → completes meiosis II → ovum + polar body

Fertilization

• Occurs in ampulla of fallopian tube.

• Acrosomal reaction: sperm enzymes break through egg’s zona pellucida.

• Cortical reaction: prevents polyspermy (multiple sperm entry).

Fusion → zygote (diploid).

Zygote

Fertilized egg

Day 0

Cleavage

Rapid mitotic divisions

Days 1–3

Morula

Solid ball of 16–32 cells

~Day 3

Blastocyst

Hollow ball with inner cell mass

Days 4–6

Implantation

Blastocyst embeds in uterine wall

Days 6–10

Embryonic Layers (Gastrulation)

Germ Layer	Future Structures
Ectoderm	Skin, nervous system
Mesoderm	Muscles, bones, circulatory system
Endoderm	Digestive and respiratory linings

Placenta & Extraembryonic Membranes

Chorion	Gas exchange; develops into placenta.
Amnion	Cushions embryo in amniotic fluid.
Yolk Sac	Early blood cell formation.
Allantois	Helps form umbilical cord and bladder.

1st (Weeks 1–12) fetal del

Organogenesis; placenta forms; heartbeat detectable

2nd (Weeks 13–26)

Growth; skeletal and muscular development; movement felt.

3rd (Weeks 27–40)

Fat accumulation; brain maturation; birth preparation

Gamete Production

Spermatogenesis (testes)

Oogenesis (ovaries)

Hormones

Testosterone

Estrogen, Progesterone

Primary Function

Sperm production, delivery

Egg production, nurturing embryo

Meiotic Output

4 sperm per cell

1 ovum per cell

Gamete Lifespan

~3–5 days in tract

~12–24 hours post-ovulation

Key Hormones Summary

GnRH	Hypothalamus	Stimulates FSH & LH release.
FSH	Pituitary	Stimulates gamete development.
LH	Pituitary	Triggers ovulation / testosterone release.
Estrogen	Ovaries	Endometrial growth, secondary sex traits.
Progesterone	Corpus luteum	Maintains uterine lining.
Testosterone	Testes	Male characteristics, sperm production.
hCG	Embryo (trophoblast)	Maintains corpus luteum early in pregnancy.