Important Hormones and The Menstrual Cycle PDF

# IMPORTANT HORMONES Hormones are chemical messengers of the body. They are important to maintain homeostasis. ## Hormones and their structure - **Estrogen** - **Progesterone** - **Testosterone** : $C_{19}H_{28}O_2$ ## The Pituitary Gland - **Optic Chiasm** - **Hypothalamus** - **Infundibulum**...

# IMPORTANT HORMONES Hormones are chemical messengers of the body. They are important to maintain homeostasis. ## Hormones and their structure - **Estrogen** - **Progesterone** - **Testosterone** : $C_{19}H_{28}O_2$ ## The Pituitary Gland - **Optic Chiasm** - **Hypothalamus** - **Infundibulum** - **Sella Turcica** (Spenoid bone) - **Anterior Pituitary** - **Posterior Pituitary** ## The Pituitary Gland and its Hormones - **GH:** Tissue Growth - **TSH**: Thyroid Hormones - **ACTH**: Cortical Hormones - **FSH & LH:** Testis, Testosterone, Sperm, Ova, Estrogen - **PFL:** Ovary, Progesterone - **ADH**: Kidney Water Reabsorption - **Oxytocin**: Uterine Contraction, Lactation - **Adrenal Gland** ## Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH) - Male - **FSH:** Signals sperm production. - **LH:** Stimulates production of testosterone. ## Testosterone - Most important male hormone. - Responsible for: - Regulating sex differentiation. - Male sex characteristics. - Spermatogenesis. - Fertility. ## Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH) - Female - **FSH:** Signals development of egg cells (oogenesis). - **LH:** Plays a role in the development of ova, and stimulation of estradiol and progesterone production. ## Estrogen - Instrumental in: - Breast development. - Fat distribution in the hips, legs, and breasts. - Development of reproductive organs. - Secreted by ovaries **PRIOR** to ovulation. ## The Menstrual Cycle: - **Positive Feedback?** - **Negative Feedback?** ## The Menstrual Cycle: Phases - **Follicular Phase:** This is when several eggs mature inside small cysts or follicles. - **Ovulation:** This is when an egg is released from the biggest follicles and travels through the fallopian tube, where it can be fertilized. If it is not fertilized, it dissolves in about 24-48 hours. - **Luteal Phase:** This is when the endometrium (the lining of the uterus) is thick and prepared to support a pregnancy or be released in a period. - **Menstruation:** This is the "period" when the endometrium or lining of the uterus sheds over 3-7 days if there is no pregnancy. ### https://tampax.com/en-us/period-health/menstrual-cycle-phases/ ## Important Terms - **Menstruation:** The process in which blood and other tissues are shed from the uterus and leave the body through the vagina. - **Menarche:** Onset of menstruation, normally occurs between ages 11-15. - **Menopause:** Normally occurs between the ages 45 and 55. **REMEMBER:** The ovary releases an egg every 28 days. ## Menstrual Cycle: ~28 days ### **1. Flow / Menstruation Phase (Days 1-5)** - Endometrium is shed. - Follicle growth in ovary. - Estrogen and progesterone levels are low. ### **2. Follicular Phase (Days 6-13):** - Follicles grow and mature. - Secrete Estrogen. - Endometrium thickens. - Stimulates LH. ### **3. Ovulation (Day 14):** - LH peaks causing secondary oocyte to burst from the follicle in the ovary into oviduct. ### **4. Luteal Phase (Day 15-28)** - LH causes corpus luteum to develop from follicle. - Corpus luteum secretes E&P. - Endometrium thickens and is maintained (progesterone prevents contractions). - Inhibits LH & FSH.