Repro 1.1 Flashcards
Approximately how long are ova viable?
36 hours
What does the female internal genitalia accommodate?
travel (ova and sperm) fertilisation implantation development of the embryo delivery of the foetus
When do secondary sexual characteristics develop?
Puberty
WHat are the principle female secondary sexual characteristics?
Breast enlargement
Growth of body hair
Widening of hips
More subcutaneous fat (buttocks, hips and thighs)
What are the male secondary sexual characteristics?
Body and facial hair
Enlargement of larynx and deepening of the voice
Increased muscle mass and stature
Broadening of shoulders
What do reproductive hormones influence?
Production of gametes
Mechanism of gestation and parturition
Where are reproductive hormones produced?
Hypothalamus
Posterior pituitary (oxytocin through neural control from hypothalamus)
Anterior pituitary gland
Gonads
Placenta
What hormones are produced in the hypothalamus?
Peptide releasing factors:
GnRH - gonadotrophin releasing hormone
PRH - prolactin releasing hormone
PIH - prolactin inhibiting hormone
What is produced in the anterior pituitary gland?
Gonadotrophins:
FSH
LH
Prolactin
What hormones are produced in the male gonads?
androgens eg testosterone (leydig interstitial cells)
What hormones are produced in the female gonads?
Oestrogen (mainly oestrodiol but also oestrogen and oestriol)
Progesterone (less)
Inhibin
What is the urogenital ridge?
A region of mesoderm giving rise to both the embryonic kidney and gonad. Gonad derived from intermediate mesoderm and primordial germ cells (migrate into mesoderm)
From where do the germ cells arise?
Epithelium of the yolk sac near the base of the allantois
To where do the germ cells migrate and at what stage?
Primordial gonad, 6 weeks post conception
Where do the primordial gonads lie?
superficial and medial to the mesonephric tissue
What does the mesonephros form?
Primitive medullary cords
What does the coelomic epithelium form?
Sex cords
What happens to the sex cords if the germ cells are male?
Vigorous growth of the sex cords into the medullary region of the gonad to meet the mesonephric cords and form the definitive testis cords (precursors to rate testes)
How do the seminiferous tubules arise?
Germ cells enter the definitive testis cords
What type of cells do mesodermal cells give rise to in males?
Sertoli cells