Presentation on theme: "Reproductive Systems Female"— Presentation transcript:
1Reproductive Systems Female Ovaries – produce eggs (ova) and secrete estrogen and progesteroneOogenesis begins in embryonic developmentPrimary oocyte – Meiosis I (prophase)Puberty – begin releasing primary oocyte (now progessed through Meiosis I)During meiosis I, cytoplasm is divided unequally, one cell is polar body (very little cytoplasm)Other cell is secondary oocyte, will complete meiosis II during fertilization in fallopian tube.
6Ovulation – release of the egg from the ovary ends the follicular phase. Ova floats into fallopian tube (oviduct)
7Phase 2Luteal phaseFollicle has released the egg and changes into the corpus luteumCorpus luteum continues to secrete estrogen and now begins to produce progesteroneProgesterone increases vessels and glands in uterusAfter about days, if fertilization and implantation have NOT occurred the corpus luteum shuts down
8Phase 3MenstruationUterus reabsorbs some of the tissue created in the endometriumThe rest sheds off and is passed out of the body
10PregnancyIf pregnancy occurs, the fetus releases HGC human chorionic gonadotropinThis maintains the uterine lining
11Male Reproductive system UreterUrinary bladderSeminal vesicleProstatic urethraAmpulla ofductus deferensPubisMembranous urethraEjaculatory ductUrogenital diaphragmRectumErectile tissueof the penisProstateBulbourethral glandSpongy urethraShaft of the penisDuctus (vas) deferensEpididymisGlans penisTestisPrepuce(a)ScrotumExternal urethralorificeFigure 16.2a
12Male reproductive organs Sperm undergo meiosis I and II in the seminiferous tubules (primary to secondary spermatocyte)Mature in the epididymis (secondary spermatocyte becomes spermatazoa)Seminal vesicles produce fructose fluid for energyProstate secretes alkaline substance to neutralize vaginal fluidsFSH – stimulates sperm productionLH – stimulates interstitial cells to produce testosterone
13Development Morphogenesis – organization of human structure When an egg is fertilized it becomes the zygoteCleavage – rapid cell divisionSolid ball of cells – morulaNext stage is the blastula – cells divide and press close to each other leaving a fluid-filled cavity called a blastocoelCells migrate into the blastocoel forming the gastrulaEndoderm, mesoderm, ectoderm form
14Indeterminate and Determinate Cleavage Indeterminate – if daughter cells are separated, they can individually complete normal development.Determinate cells cannot
16Egg CytoplasmCytoplasmic material is unequally distributed in the egg, cytoplasmic material will vary in daughter cellsThis results in embryonic axesGray crescent in frog eggs – region essential in frog developmentMorphogens – proteins with asymmetrical distribution in oocyte – determines dorsal/ventral side, anterior/posterior regions of the cell, also act as transcription factors
18Embryonic InductionOrganizers are cells that exert influence over other cells during development through cell-cell communication. Regulates the expression of certain genesDorsal lip of the blastopore in a newt is an organizer – produces a notochordIn a roundworm, the anchor cell secretes an inducer molecule that binds to pm of neighboring cells, activate trans. Factors, they bind to promoter on DNA, signal the synthesis of a protein that stimulates the differentiation into a vulva cell.
19Apoptosis Programmed cell death External signal initiates a signal trans. Pathway, activating cell death genes (Ced genes in C. elegans), destroys 131 different cells.Humans have webbing during development. Activation of apoptosis of certain cells, cause fingers and toes to separate.
20Control of Gene expression Methylation of histones in chromatin, prevents expressionmicroRNAs – small segments of RNA that influence expression by blocking mRNA translationHomeotic genes – master genes that specify development. Contain homeobox, Hox genesHox genes code for transcription factors, dictate the spatial organization of fruit flys