Repro Exam 1: Folliculogenesis and Oogenesis

What is a

Oocyte

What is b

Antrum

what is c

Cumulus Granulosa

What is d

Basement membrane

What are the cells surrounding the basement membrane called

Mural Granulosa

how long does it take to grow a graafian follicle in sheep

61-72 days

Follicular Steroid Genesis

2-cell, 2-gonadotropin model for estrogen synthesis

1. FSH and LH induce LH receptors

2. large antral follicle becomes LH-dependent

3. FSH increases free IGF-1 in the largest follicle, allowing the largest follicle to become dominant

4. Inhibin produced by the dominant follicle prevents the development of smaller follicles

5. If progesterone low, E2 stimulates an increase in LH, furthering the development of the dominant follicle is

Oogenesis Process

1. Multiplication: Oogonia undergo mitosis to produce millions of Oogonia

2. Growth: Oogonia differentiate and grow into diploid primary oocytes, starting meiosis 1 but pausing in prophase 1, remaining inactive until puberty

3. Maturation: Puberty to menopause

   1. Meiosis 1: Oocyte completes meiosis 1, forming one large haploid secondary oocyte and a small polar body

   2. Meiosis 2: The secondary oocyte begins meiosis II but arrests in metaphase II, and is ovulated

   3. Fertilization: If fertilization occurs, Completion of Meiosis II, complete a mature ovum