Folliculogenesis Flashcards
What are the 4 things required for reproduction?
β Differentiation into male or female
β Sexual maturation
β Production, storage and release sufficient supply of eggs and sperm
β correct number of chromosomes in eggs and sperm
β egg and sperm have to meet
What are cells that will become egg or sperm called?
β Primordial germ cells
When are PGCs first identifiable?
β in the yolk sac 3 weeks after conception
What happens to the PGCs?
β the cells undergo many cycles of mitosis
β They migrate to the genital ridge
What does the genital ridge become?
β The gonad
What does further differentiation of the PGCs depend on?
β The development of the gonad
What do germ cells become when in the ovary?
β oogonia
What are oogonia?
β Egg precursors
When oogonia enter meiosis what are they known as?
β Primary oocytes
What phase do primary oocytes remain in and until when?
β They remain in the first phase of meiosis until it ovulates or dies
Describe mitosis briefly?
β Spindle is formed
β The chromatids are lined up one behind the other
β They then separate to opposite poles of the cell
β The cytoplasm divides and there are two identical cells
Describe meiosis
β Duplication of the chromatids
β They line up adjacent to each other
β Chromosome 1 lines up with chromosome 1 from the other parent
β allows crossing over and biological variation
β homologous chromosomes separate into two haploid cells
β separate again to form gametes
βoocytes are arrested in meiosis 1 until LH surge
where are primary oocytes packed?
β Outer layer of the ovary : cortex
What do the cells around the oocyte become in the fetal ovary?
β Condense around the oocyte and differentiate into granulosa cells
What do granulosa cells secrete?
β Acellullar layer called the basal lamina