FACTS The corpus luteum originates from the ovulatory follicle After ovulation Theca interna and granulosa cells undergo a dramatic transformation Transformation is governed by Luteinizing hormone Corpus Luteum >>>>> Luteinizing hormone

Cells of the corpus luteum Cells of Theca and granulosa become luteal cells Theca cells >>> small luteal cells Granulosa cells >>> large luteal cells Both luteal cells can make progesterone But Large luteal cells make the majority of progesterone

Chief Hormone for luteolysis is LUTE = luteal tissue LYSIS = break down , decomposition Chief Hormone for luteolysis is Prostaglandin F2a But without uterus luteolysis cannot take place !!

Luteal oxytocin stimulates PGF2 synthesis

Endocrinology of the Male Inhibin (Sertoli) Testosterone (Leydig) LH & FSH

Interstitial Leydig cells Androgen Binding Protein LH >>>>>> theca interna cells >>>>>> Androgen Interstitial Leydig cells Testosterone Sertoli cells FSH >>>>> granulosal cells >>>>> Estradiol Inhibin Androgen Binding Protein Other factors Sertoli cells

I I Sertoli LH T T Leydig T FSH E2 E2 T = testosterone E2= Estradiol I = Inhibin Sertoli I FSH I LH E2 T E2 T Leydig T

All chromosomes duplicate Develops at the onset of Puberty Bovine Spermatogenesis Takes 43 Days 21 Days Mitotic Division Spermatocytogenesis Initial cells -provides base cell to start cell divisions All chromosomes duplicate Reduction Division 20 Days Meiosis I 2 Days Meiosis II Morphological change in Shape Second Phase 17 Days Total 60-63 Days

Spermiogenesis Cont. Four Phases of Spermiogenesis 1) Golgi phase 2) Cap phase 3) Acrosomal phase 4) Maturation phase

2 Cap phase = acrosomic vesicle spreading over nucleus INNER and OUTER acrosomic membrane Distal centriole from the Flagellum "axoneme"

Cervix Uterine Body & oviduct Capacitation factors

Capacitating factors Hyper active Sperms

Fig 12-9

Nucleus

(biochemical changes of ZP) Cortical reaction Acrosome reaction and release of enzymes ZP ZONA BLOCKING (biochemical changes of ZP)

Post Hatching events Development of extra-embryonic Membranes Massive growth of the conceptus Cow: from 3 mm to 250 mm in 4 days Development of : - Yolk sac = Site of primordial germ cells - Chorion = Give rise to Placenta - Amnion = protective sac - Allantios = waste house

Development of the Yolk sac Figure 13-3 Development of the Yolk sac Fusion of the trophoblast with endoderm and development of chorion Regression of the Yolk sac and expansion of allantois Fusion of chorion membrane, development of Amnion sac, development of placental membrane

Fetus Signals "Trophoblastic Protein" between d 13 to d 21 Glycoprotein "interferon-tau (IFN )" IFN  binds with endometrium receptors Blockage of oxytocin receptors

 Pregnancy Cattle and Sheep "interferon-tau (IFN )" between d 13 to d 21 IFN  binds with endometrium receptors Blockage of oxytocin receptors (no oxytocin action!) No increase in PGF2 secretion  Pregnancy No CL regression (progesterone stays high!)

Figure 13-6

MARE The conceptus migrate within the uterus between 12 to 14 times per day Conceptus touches receptors in the endometrium and initiates the signaling Maintenance of CL Inhibition of PGF2 secretion

Placenta classification Fig 14-1 Placenta classification Based on Chorionic villi 1. Diffuse 2. Cotyledonary 3. Zonary 4. Discord

Placenta classification Based on Placental Layers Epitheliochorial Endothelio chorial Hemo chorial Hemo endothelial

Fig 14-11

Fig 14-11