Reproductive System Flashcards
Number of eggs at birth
About 7 million
Number of eggs ovulated in a lifetime
About 400
Neurohypophysis
Posterior pituitary
Adrenohypophysis
Anterior pituitary
Sperm produced per second per testis
1500
4 water soluble hormones
GnRH
LH
FSH
Oxytocin
3 lipid soluble hormone classes
Androgens
Oestrogens
Progestagens
2 androgens
Testosterone
5 alpha dihydrotestosterone
3 oestrogens
Oestradiol
Oestriol
Oestrone
The main progestagen
Progesterone
Describe how hormones are released from the posterior pituitary
Neurosecretory neurons are aggregated into nuclei and possess long axons that pass into the posterior pituitary
Neurosecretory peptide hormones are synthesised in the hypothalamus and travel bound to carrier proteins down the axon terminals to be stored in secretory vesicles
Nerve impulses travel down the axon to trigger exocytosis of the secretory vesicles releasing the peptide hormones
Describe how hormones are released from the anterior pituitary
Neurosecretory neurons synthesise releasing and inhibiting hormones which travel to the axon terminus
Neurosecretory peptide hormones are secreted in response to nerve impulses into linking hypophyseal portal vessels
Hormones act on specific anterior pituitary secretory cells arranged in clumps at the termini of the portal blood vessel
Pulsatile release
Hypothalamic secretions released in discrete bursts separated by periods of stasis
Prevents receptor desensitisation and downregulation
Vagina
Elastic muscular 7.5-9.0 cm tbue extending from cervix to external environment
Passageway for menstrual fluid elimination
Penis receiver
Sperm holder
Uterus
Small pear shaped organ hat weighs 30 - 40 g
Pathway for sperm transport
Provides mechanical protection, nutritional support and waste removal for embryo
Source of menstrual flow
Normally antiflex (90 degrees to vagina) but can be retroflex (not 90 degrees)
Stratum functionalis
Contains most of the uterine glands
During menstruation, expands, vascularises and sloughs off
Stratum basalis
Attaches endometrium to myometrium
Responsive to oxytocin by contracting
Uterine tubes
Fertilisation occurs in the ampulla
Provides a rich, nutritive environment containing lipids and glycogen for sperm, egg and embryo
Epithelial lining is ciliated and non-ciliated secretory columnar cells
Mucosa surrounded by concentric layers of smooth muscle
Fimbriae
Cilia like structures that partially cover the ovary and dray the oocyte into the uterine tube
Ovaries
Oval structures that weight 5 - 10 g
Comprised of cortex, medulla and hilum
Outer ovarian cortex
Contains developing ovarian folllicles