Reproductive System Study Guide

The Human Reproductive System

It is a set of organs and structures that work together to ensure the survival of the species by producing offspring.

Functions of Reproductive System

1.) To produce gametes (Eggs and Sperm Cells)
2.) To store and transport these reproductive cells
3.) To nurture offspring as it develops
4.) To produce hormones

Prostate

Produces a fluid that mixes with sperm to form semen, nourishing and protecting sperm.

Testes

Produce male sex hormones

Seminiferous Tubules

Where sperm are produced

Interstitial Cells

Produces male sex hormones

Epididymis

Where sperm matures and moves to the ductus deferens

Ductus Deferens (Vas Deferens)

Carries sperm to ejaculatory duct

Seminal Vesicle

Creates alkaline fluid to neutralize acidic seminal fluid and help sperm motility.

Bulbourethral Gland

Creates mucus that lubricates end of penis and alkaline substances to neutralize acidity.

Scrotum

Encloses and protects testes

Penis

Conveys urine and semen to outside of the body. Organ for sexual intercourse

Fallopian Tube

Passageway for eggs from the ovaries to the uterus and provides the site for fertilization by the sperm.

Uterus

Where a fertilized egg implants and grows into a fetus during pregnancy.

Cervix

Allows menstrual blood to flow from the uterus and is a pathway for sperm to enter the uterus.

Ovary

Produces egg and female sex hormones (Estrogen and Progesterone)

Vagina

Receives the penis during sexual reproduction, allows the menstrual blood to exit the body, and lets the baby pass through during childbirth.

Journey of the Sperm Cell

1.) Testes
2.) Epididymis
3.) Vas Deferens
4.) Urethra
Ejaculation
5.) Vagina
6.) Cervix
7.) Uterus
8.) Fallopian Tubes
Fertilization

Menstrual Cycle

It is a natural, recurring process in the female reproductive system that lasts about an average of 28 days.

*Preparation for potential pregnancy

Menstruation

Lining of the uterus is shed which results in the release of blood and tissue from the body through the vagina

Follicular Phase

The pituitary gland releases hormones that stimulate the growth and development of ovarian follicles.

Ovulation Phase

When a mature egg is released from the ovary and is ready for potential fertilization.

Luteal Phase

Empty ovarian follicle becomes the corpus luteum, producing hormones that prepare the uterus for possible embryo implantation.

Easy Menstrual Cycle Summary

“Many Lovely Flowers Open”

M → Menstruation (uterine lining sheds)

L → Luteal Phase (corpus luteum forms, preps uterus)

F → Follicular Phase (follicles grow, hormones rise)

O → Ovulation (egg is released)

Purpose of Menstrual Cycle

Prepares the body for possible pregnancy by releasing an egg and preparing the uterus for pregnancy.

If no pregnancy happens, the uterus sheds its lining during menstruation.

Stages of Pregnancy (Weeks 1–40)

Month 1 (Weeks 1–4)

• Fertilized egg travels, implants in uterus

• Embryo forms (cluster of cells)

• Placenta begins forming; connection to mother’s blood

Month 2 (Weeks 5–8)

• Basic features appear; spinal cord & umbilical cord develop

• Placenta grows; nutrient & oxygen exchange begins

Month 3 (Weeks 9–13)

• Organ systems & facial features form

• Muscles develop for movement

• Continued internal development

Month 4 (Weeks 14–17)

• Organs function; bones harden

• Starts sucking/swallowing

• Mother may begin to feel movement

Month 5 (Weeks 18–22)

• Growth spurt; red blood cells formed

• Hearing develops; skin protected by vernix

• Increased body strain

Month 6 (Weeks 23–27)

• Proportions improve; breathing practice

• Eyelids/eyebrows develop

• Fetal movement felt clearly

Month 7 (Weeks 28–31)

• Brain & nervous system mature

• Vigorous movement; body positioning

• More noticeable movements

Month 8 (Weeks 32–35)

• Weight gain; organs mature

• Head moves into pelvis

• Less fetal movement (tight space)

Month 9 (Weeks 36–40)

• Final growth; full development

• Head engaged, ready for birth

• Labor may begin soon

Stages of Pregnancy by Trimester

First Trimester (Weeks 1–12)

• Fertilization & implantation in the uterus

• Embryo develops into fetus

• Basic organs & features begin forming (spinal cord, umbilical cord, eyes, limbs)

• Placenta forms and starts nutrient/oxygen exchange

• Mother may experience fatigue, nausea, and hormonal changes

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Second Trimester (Weeks 13–26)

• Organs function more fully

• Bones harden, muscles develop

• Hearing, facial features, and red blood cells form

• Baby starts moving, and skin is protected by vernix

• Mother feels baby’s movement and gains weight

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Third Trimester (Weeks 27–40)

• Brain and nervous system mature

• Rapid weight gain and growth

• Lungs develop, movements become limited

• Head shifts into pelvis, preparing for birth

• Mother may feel pressure, discomfort, and signs of early labor