Reproductive Functions

NOTES: Reproductive FunctionsSpermatogenesis & OogenesisHormone ProductionMenstrual CycleMammary GlandsMake sure you have AUDIO/SOUND on (Use headphones please!)

RememberThe job of the primary sex organs is to:Make gametes (sex cells) for reproductionSecrete sex hormones

Meiosis = a special type of cell division that occurs mostly in the testes and ovariesOccurs in 2 divisions (Meiosis I and Meiosis II)Results in 4 daughter cells (gametes) with half as much DNA as other body cells

Spermatogenesisa.k.a. Production of male gametes (sperm)Begins at puberty and continues throughout lifeOccurs in the seminiferous tubulesTakes 64 to 72 days

Process ofSpermatogenesis

Diagram can be filled out using the textbook

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Male sex hormonesMain hormone produced by testes = testosteroneFunctions:Stimulates reproductive organ developmentUnderlies sex driveCauses secondary sex characteristicsDeepening of voiceIncreased hair growthEnlargement of skeletal musclesThickening of bones

Oogenesisa.k.a. Production of female gametes (ova)Females total supply of eggs are present at birthAbility to release eggs begins at puberty and ends at menopausePrimary oocytes are present at birth in a state of suspended animation through childhoodAfter puberty, a small number of these are activated each month (ovarian cycle)

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Female sex hormonesEstrogenProduced by follicle cellsCauses secondary sex characteristics (e.g. enlargement of accessory organs, development of breasts, widening of pelvis, etc.)ProgesteroneProduced in corpus luteumHelps build up endometrium wall in preparation for implantation; helps maintain pregnancy; prepares breasts for milk production

Uterine (Menstrual) CycleCyclic changes of the endometriumRegulated by cyclic production of estrogen and progesterone

Stages of the Menstrual CycleMenstrual Phase (days 1-5) = functional layer of the endometrium is shed (menstrual period)Proliferative Phase (days 6-14) = regeneration of functional layer(OVULATION OCCURS HERE around day 14)Secretory Phase (days 15-28) = endometrium increases in size and readies for implantation of a fertilized egg

Look again (notice trends)

Mammary GlandsPresent in both sexes, but only functional in femalesModified sweat glandsFunction is to produce milkStimulated by sex hormones (mostly estrogen) to increase in size

Anatomy of Mammary GlandsAreola = central pigmented areaNipple = protruding central area of areolaLobes = internal structure that radiate around the nippleAlveolar glands = clusters of milk-producing glands within the lobesLactiferous ducts = connect alveolar glands to nipple