Lesson 1 — The Endocrine System
The endocrine system is a network of glands that produce hormones — chemical messengers that regulate growth, metabolism, mood, reproduction, and more.
Pituitary GlandThe "master gland" — regulates other glands; controls growth hormone
ThyroidControls metabolism, energy, and body temperature
Adrenal GlandsProduce adrenaline (epinephrine) for fight-or-flight response; also cortisol
PancreasProduces insulin and glucagon to regulate blood sugar
Hormones & Puberty
During puberty, the pituitary gland signals the gonads (ovaries/testes) to produce sex hormones — estrogen, progesterone, and testosterone — triggering physical and emotional changes.
During puberty, the pituitary gland signals the gonads (ovaries/testes) to produce sex hormones — estrogen, progesterone, and testosterone — triggering physical and emotional changes.
Quick Check: What is the role of the pituitary gland in the endocrine system?
Lesson 2 — Puberty & Physical Development
Puberty is the process of physical and sexual maturation driven by hormonal changes. It typically begins between ages 8–13 for females and 9–14 for males.
- Female changes: breast development, pubic/underarm hair, menstruation, hips widening
- Male changes: testicular growth, pubic/facial hair, voice deepening, muscle development
- Both: growth spurts, acne, body odor, emotional changes
Normal Variation
The timing of puberty varies widely and is largely genetic. Early or late development is usually normal — but persistent concerns should be discussed with a healthcare provider.
The timing of puberty varies widely and is largely genetic. Early or late development is usually normal — but persistent concerns should be discussed with a healthcare provider.
Quick Check: What hormone primarily drives puberty in males? In females?
Lesson 3 — Reproductive Systems
The male and female reproductive systems have distinct structures and functions, all regulated by the endocrine system.
Female ReproductiveOvaries (produce eggs/hormones), fallopian tubes, uterus, cervix, vagina
Male ReproductiveTestes (produce sperm/testosterone), epididymis, vas deferens, penis
Menstrual Cycle~28-day cycle; prepares uterus for potential pregnancy; regulated by hormones
FertilizationSperm + egg → zygote; occurs in fallopian tube if timing aligns
Quick Check: Where does fertilization typically occur in the female reproductive system?
Lesson 4 — Reproductive Health & Care
Reproductive health involves physical, emotional, and social well-being related to the reproductive system throughout life.
- Annual gynecological exams recommended beginning in the teen years
- Testicular self-exams monthly — report unusual lumps to a provider
- Abstinence is the only 100% effective method to prevent pregnancy and STIs
- HPV vaccine is recommended for preteens — prevents several cancers
- Understanding consent is fundamental to all sexual health decisions
Quick Check: Why is the HPV vaccine recommended for teens?
Chapter Vocabulary
Endocrine systemThe system of glands that produce and release hormones into the bloodstream.
HormoneA chemical messenger produced by a gland that travels through the blood to regulate body functions.
PubertyThe period of physical and sexual maturation driven by hormonal changes.
EstrogenThe primary female sex hormone responsible for reproductive development and the menstrual cycle.
TestosteroneThe primary male sex hormone responsible for male reproductive development and muscle growth.
MenstruationThe monthly shedding of the uterine lining when pregnancy does not occur.
OvulationThe release of a mature egg from the ovary, typically mid-cycle.
FertilizationThe union of a sperm cell and an egg cell to form a zygote.
InsulinA hormone produced by the pancreas that regulates blood sugar levels.
Adrenal glandsGlands above the kidneys that produce adrenaline and cortisol for stress response.
