A&P 2 Reproductive System Review

What is the main function of the reproductive system?

To pass genes to the next generation and develop secondary sexual characteristics.

From what do the male and female reproductive systems originate?

They originate from the same embryonic structures.

What are secondary sexual characteristics?

Physical features that appear during puberty/sexual maturity that distinguish the sexes, influence mate attraction, and signal sexual maturity.

What causes secondary sexual characteristics to develop?

Hormonal influence.

three examples of secondary sexual characteristics.

Breast development, wider pelvis, facial hair.

What are sex organs also called?

Genitals or genitalia.

What happens when an ovum and sperm fuse?

They form a diploid zygote

What are primary sex organs, and what is their function?

sex organs that produce gamates

Male Primary Sex Organ

Testes

Female Primary Sex Organ

Ovary

What are secondary sex organs, and what is their function?

sex organs do not produce gametes but are essential for reproduction.

Example of Male Secondary Sex Organs

spermatic ducts and semen producing glands

Example of Female Secondary Sex Organs

Uterine Tubes, Uterus, and Vagina

How is the male sex determined in humans?

By the parent who produces motile sperm, which requires the presence of a Y chromosome.

How is the female sex determined in humans?

By the parent who produces an immobile, nutrient-rich ovum, which requires the absence of a Y chromosome.

In mammals, what additional role does the female parent play in reproduction?

The female provides a sheltered internal environment for the developing embryo.

Function of FSH in females?

Stimulates the development of ovarian follicles.

What is the function of FSH in males?

Stimulates sperm production.

What is the function of LH in females?

Stimulates ovulation and the formation of the corpus luteum.

From where are gonadotropin hormones released?

Anterior Pituitary Gland

What is puberty in males?

The period from the onset of gonadotropin secretion until the first ejaculation of viable sperm

Age range for beginning of puberty in males

10-12 to 14

What is puberty in females?

The period from the onset of gonadotropin secretion until the first menstrual period (menarche)

What factor is required for puberty to start in females?

Sufficient body fat to stimulate GnRH production.

What is the average age range for puberty in females?

Starts around ages 8–10 and ends around 12.5.

What is adolescence?

The period from the onset of puberty until full adult height is reached.

What is the general cause of puberty?

Secretion of gonadotropins (FSH and LH).

What causes puberty in males?

Rising levels of two androgens: testosterone and dihydrotestosterone (DHT).

What are the effects of testosterone in males during puberty?

Sperm production, generalized body growth, and increased libido.

What are the effects of dihydrotestosterone (DHT) in males during puberty?

Body and facial hair growth, increased skin oil secretion, and acne.

What causes puberty in females?

Ovarian follicles producing estrogens, progesterone, and some androgens.

What are the effects of estrogen in females during puberty?

• Body fat deposition

• widening of pelvis

• generalized body growth

What hormones contribute to breast development (thelarche) in females?

Estrogen, progesterone, and prolactin.

What hormone is responsible for pubic and axillary hair growth in females?

Androgens

What is menarche?

first menstrual cycle in females.

What is the function of the ovary?

house oocytes and ovarian follicles for support and protection

What are the uterine tubes and their function?

muscular tubes that receive the oocyte from the ovary and transport the zygote to the uterus.

What is the uterus and its role in reproduction?

a muscular chamber that opens into the roof of the vagina and is where the embryo implants into the endometrium.

What is the sexual cycle?

monthly events (≈28 days) in the reproductive system when pregnancy does not occur.

What two cycles occur simultaneously in the sexual cycle?

1. Ovarian Cycle

2. Menstrual Cycle

The Ovarian Cycle includes

1. Follicular Phase

2. Luteal Phase

The Menstrual Cycle includes

1. Menstrual Phase

2. Proliferative Phase

3. Secretory Phase

4. Premenstrual Phase

What happens in the ovary during the follicular phase?

FSH stimulates follicle growth, leading to estradiol secretion by granulosa cells.

What happens hormonally during days 1–5 of the follicular phase?

Moderate estradiol levels inhibit GnRH and FSH but stimulate LH production.

What happens hormonally during days 6–14 of the follicular phase?

High estradiol levels cause a spike in GnRH, FSH, and especially LH.

What happens in the uterus during the follicular phase?

1. Menstrual Phase: shedding

2. Proliferative Phase: mitosis of endometrium and progesterone receptors

What triggers ovulation?

A spike in LH.

What occurs during ovulation?

The follicle bursts and releases the oocyte into the uterine tube; ovulation lasts only about 3 minutes.

What happens in the ovary during the luteal phase (days 15–26)?

• LH transforms the ruptured follicle into the corpus luteum.

• Corpus luteum secretes high levels of estradiol and progesterone.

• These hormones inhibit LH and FSH by negative feedback.

• Low LH leads to corpus luteum involution into corpus albicans.

What is involution

shrinkage into scar tissue

What happens in the uterus during the luteal phase?

• Secretory Phase (days 15-26): secretion of fluid and glycogen for embryo support

• Premenstrual Phase (days 27-28): degeneration and ischemia of ethe ndometrium

What happens hormonally on days 27–28 of the cycle?

• Corpus Albicans stops hormone production

• Estradiol and Progesterone levels drop

• LH and FSH secretion stimulates new follicle growth

LH Surge

Sudden rise in LH that triggers ovulatoin

Oocyte

Immature female gamete

Ovarian Follicle

Structure supporting an oocyte

Follicular Phase

First half of the ovarian cycle; follicle development occurs.

Luteal Phase

Second half of the ovarian cycle; corpus luteum activity dominates.

Menstrual Phase (Menses)

Shedding of the uterine lining.

Proliferative Phase:

endometrial regrowth under estrogen

Ovulation:

LH-triggered release of oocyte from ovary.

Secretory Phase

Progesterone-driven thickening of endometrium.

Premenstrual Phase

Endometrial degeneration from hormone withdrawal.

Corpus Luteum

Hormone-secreting structure formed after ovulation.

Corpus Albicans

• Inactive scar tissue left after corpus luteum involution.

Estradiol (estrogen)

hormone regulating follicular and uterine changes.

Progesterone

Hormone from corpus luteum supporting the secretory endometrium.

How is pregnancy divided?

into trimesters

What is a zygote?

A fertilized egg formed by the fusion of an ovum and sperm.

Where does fertilization occur?

In the ampulla of the uterine tube.

When does an embryo become a fetus?

After 8 weeks of development.

What is the placenta and its function?

organ that develops in the uterus after implantation to provide nutrition, gas exchange, waste removal, and hormone secretion.

What structure initially supports pregnancy before the placenta fully takes over?

The corpus luteum

What is human chorionic gonadotropin (HCG) and its role?

A hormone secreted by the embryo and then the placenta; it maintains the corpus luteum and is detected in pregnancy tests.

What is the role of estradiol in pregnancy? Fetus?

promote growth

What is the role of estradiol in pregnancy? Mother?

• increases size of uterus and mammary ducts

• widen pelvis for delivery

What is the role of progesterone in pregnancy?

• Promotes mammary gland development.

• With estradiol, inhibits FSH and LH to prevent new follicle development

What is human chorionic somatomammotropin (HCS) and its function?

A hormone secreted in greater amounts than other pregnancy hormones; it has growth hormone-like effects but weaker.

What digestive changes occur during pregnancy?

• Reduced intestinal motility

• pressure on the stomach from the uterus

• constipation

• heartburn.

What causes morning sickness?

HCG spikes

How does metabolism change during pregnancy?

• increases 15% in the second half of gestation

• increase in apetite

• gain ~24lbs

What nutrients are especially needed during pregnancy?

• Protein

• Calcium

• Iron

• Vitamin D

• Folic Acid

Why is iron important in late pregnancy?

to prevent anemia

Why is folic acid supplementation important before and during pregnancy?

reduces the risk of spina bifida in fetus development

Mothers blood volume rises by __ during pregnancy

30%

Mothers cardiac output increases by

30-40%

What is inhibited by pressure from growing fetus

venous return in the lower limbs

What changes occur to skin during pregnancy

• Fat deposition in hips and thighs

• stretch marks

• chloasma

What is chloasma

temporary blotchy darkening of skin on the face from increased melanocyte activity, which fades after pregnancy.

What hormone dominates the luteal phase

progesterone

If no fertilization occurs →

corpus luteum degenerates → decrease in progesterone & estrogen → menstruation begins