Nervous system ppt/question, Schemes and Mind Maps of Law

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Female reproductive

system_

Dr Reem Abraham

1. Describe the biosynthesis, transport, metabolism, and physiological effect of steroid hormones.
2. Describe the process of oogenesis./Sexual reproduction
3. Summarize the hormonal changes and their physiologic effects during perimenopause and menopause.
4. Summarize the hormonal changes that occur at puberty.

At the end of this lecture, students should

be able to:

Learning

Objectives

• (^) After 6 months in utero, the number of oocytes in the

human ovary decreases by apoptosis , a type of

programmed cell death.

• (^) Degeneration of egg cells and follicles  atresia.
• (^) Per ovary, there are ~ 2 x 10^6 oocytes left at birth , and ~ 250,000 left at puberty.
• (^) The decline continues, so that 400 - 500 (200 – 250 from each ovary) will actually be ovulated in a normal reproductive lifetime (~30 – 40 reproductive years). Oogenesis

Synthesis of steroid hormones in the ovary

• (^) Two percent of the circulating estradiol is free
• (^) Remainder is bound to protein: 60% to albumin and 38% to gonadal steroid-binding globulin (GBG)
• (^) 2% of the circulating progesterone is free
• (^) 80% is bound to albumin and 18% is bound to corticosteroid-binding globulin Transport of steroid hormones

Estrogen

receptors Estrogen (steroid) binds

to its intracellular receptors ESTROGEN-RECEPTOR COMPLEX binds to specific sequences of DNA known as hormone response elements. The DNA/receptor complex then recruits other proteins (coactivators) that are responsible for the transcription of downstream DNA into mRNA and finally proteins that result in a

https://cnx.org/resources/7bf1c12f116ccfcbc2ea636193925132a35e6d7a/

Puberty and Regulation of Its Onset

Hormonal changes with the onset of puberty:

1. Increased pulsatile secretion of GnRH

2. GnRH stimulates secretion of gonadotropins (LH, FSH) from anterior pituitary
3. Increased response of gonads to LH and FSH

• (^) During the onset of puberty, decreased negative feedback

Feedback regulation of ovarian Hormones

• (^) Mild thermogenic action, which increases basal body temperature at the time of ovulation and during the luteal phase of the menstrual cycle

Ovarian reserve

• (^) The number of oocytes within a woman’s ovary declines over time.
• (^) Ovarian reserve: reservoir of eggs a woman has in her

ovaries that have the potential to produce mature

follicles for ovulation to sustain the menstrual cycle

and/or create a pregnancy.

Perimenopause

• (^) Transition to menopause
• (^) Years leading up to the final menstrual period (FMP) and the 12 months after the FMP
• (^) lasts between 2–8 years
• (^) Occasional missed cycles or irregular cycles
• (^) Hormonal changes:
  1. Decreased Anti-Mullerian hormone (AMH)
  2. Decreased estrogen
  3. Decreased progesterone
  4. Increased GnRH
  5. Increased FSH
  6. Increased LH

17 Menopause

• (^) Stoppage of menstrual cycles /amenorrhea for 12 months.
• (^) Average age in US: 51 years
• (^) Range  45 to 55 years
• (^) Associated hormonal changes that might begin at 45 years of age
• (^) Ovulation frequency decreases
• (^) Menses and fertility declines
• (^) Estrogen level DECREASES (ovarian burnout)
• (^) So, less negative feedback on GnRH, FSH, LH HIGH GnRH HIGH FSH, HIGH LH (NO LH surge)

19

• (^) Menopause creates HAVOCS because of decreased estrogen level : - H ot flashes - A trophy of the Vagina - O steoporosis (bone density decreases) - C oronary artery disease - S leep disturbances
• (^) Decreased libido in women with ovarian failure Menopause

Active learning : Think- Pair-Share Student generated questions (SGQ)

• (^) Think pair share (modified)
• (^) Write 2 multiple choice questions , with 3 options for each question, from the content discussed till now, individually
• (^) Form a pair with the person sitting next to you
• (^) Share the questions and explain why the correct option is the best option and why the other options are incorrect