第一节卵巢功能的解剖组织学

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1 卵巢功能的解剖组织学

2 Anatomy of Female Reproduction Components of the female reproductive organs The internal genital organs : ovaries, oviducts, uterus, cervix, vagina external genitalia:vestibule 前庭, Labia 阴唇 Majora and Labia Minora, Clitoris 阴蒂

3 Cow reproductive tract University of Kentucky; AgriPedia

4 直肠生殖道陷凹阴道穹窿尿道下憩室肉阜尿道骨盆

5 Sow reproductive tract

6 卵巢系膜输卵管系膜子宫系膜漏斗穹窿

8 Function Produce & maintain female sex cells Transport egg cells (ova) to site of fertilization Provide favorable environment for development of offspring Move offspring to outside Produce female sex hormones

9 THE OVARY Primary sex organs The ovary, remains in the abdominal cavity. It performs both exocrine (egg release) and endocrine (steroidogenesis) functions. Produce ova ( female sex cells) Female sex hormones progesterone, estrogen

10 Cow Ovaries Normal with small follicles Normal with corpus luteum Abnormal with large cystic follicle

11 Components the cortex : the predominate tissue of the ovary The primordial germ cells 原生殖细胞 : several million oocytes arise extragonadally and migrate through the yolk sac 卵黄囊 mesentery 隔膜 to the genital ridges 生殖脊. During fetal development, the oogonia are produced by mitotic multiplication.

12 粒层卵丘

14 Medulla Cortex Hilus Tunica Albuginia The Ovary

16 Prior to birth, oogonia divide mitotically to produce primary oocyte. At birth, Pri. Oocytes are arrested at this stage until puberty is reached. Older female ovulates older oocytes. At puberty, every month one primary oocyte in a Graafian follicle gets enlarged and undergoes meiosis to produce a secondary oocyte and a 1 st polar body(much smaller) which disintegrates During ovulation, sec. oocyte is released. If fertilized, it completes division to produce ovum and a 2 nd polar body which disintegrates

17 Difference between Oogenesis & spermatogenesis Primary oocytes are already formed at birth(2 million). Pri. Spermatocytes keep forming once puberty is reached. Single sec. Oocyte is formed as opposed to 4 spermatozoa from a primary oocyte Sperms older than a month are destroyed. Pri. Oocytes are as old as a female

18 Oogenesis Figure 28.15

24 The Ovarian Cycle Figure 28.16

25 Subsequent atresia reduces the number of oocytes at the time of birth, a further reduction occurs at puberty, and only a few hundred are present during reproductive senescence At birth, a layer of follicular cells surrounds the primary oocytes to form the primordial follicles. The shape and size of the ovary vary both with the species and the stage of the estrous cycle

26 Corpus Luteum develops after the collapse of the follicle at ovulation. The inner wall of the follicle develops into macroscopic and microscopic folds that penetrate the central cavtty. These folds consist of a central core of stromal tissue and large blood vessels. They regress quickly, and within 24 hours after ovulation all remaining thecal cells are in an advanced stage of degeneration. Hypertrophy 增生肥大 and luteinization of the granulosa cells commence 开始 after ovulation.

27 The vascular pattern of the ovary changes with different hormonal states. Variations in the architecture of the vessels allow adaptation of the blood supply to the needs of the organ. The intraovarian distribution of blood undergoes remarkable changes during the preovulatory period.

28 Blood flow to the bovine ovary is highest during the luteal phase, decreases with luteal regression, and reaches a nadir just before ovulation. Ovarian blood flow increases with the newly developing CL. The decline in blood flow seems to follow the abrupt decline at the time of regression of the CL.

29 Function: Progesterone is secreted by the luteal cells In the ewe, this process appears to be maximal at day 10 of the cycle and begins to taper off 逐渐停止 noticeably at day 12.The secretory activity declines gradually until day 14 In aged animals, the functions of the CL decline as a result of an inability of follicular cells (granulosa and theca interna) to respond fully to hormonal stimuli, changes in the quantity and/or quality of hormone secretion, and a reduced stimulus for hormone secretion.

30 卵巢具有产生卵子和分泌性腺激素的双重功能位于腹腔内, 左右各一, 由卵巢系膜 mesovarium 悬挂在腰部两侧大多呈卵圆形, 后端以卵巢固有韧带与子宫角相连, 前端接输卵管伞, 血管和神经沿卵巢系膜出入于卵巢附着缘, 该缘称作卵巢门 hilum of ovary; hilus ovarii 卵巢结构因动物种类年龄和发情周期不同而异, 一般分为外部的皮质 (cortex) 和内部的髓质 (medulla)

31 卵巢表面覆盖有一层由腹膜延续而来的单层立方上皮 simple cuboidal epithelium 表面, 上皮下面是结缔组织构成的白膜 albuginea ovarii 白膜含有 5 7 层成纤维细胞, 其间分布有大量的胶原纤维皮质占卵巢大部分, 系卵巢功能结构之所在, 其中分布有许多不同发育阶段的卵泡和闭锁卵泡, 有时还有黄体或白体皮质基质由疏松结缔组织构成, 在啮齿类犬和猫, 其中含有间质腺髓质为疏松结缔组织, 与卵巢门相连系, 内含神经大血管淋巴管和平滑肌在反刍动物和肉食动物, 还可见退化的卵巢网残迹, 它是一些不规则的立方上皮管或实心的细胞束马卵巢的皮质在内髓质在外, 仅在排卵凹处可以排卵

32 一卵泡 ( 一 ) 卵泡的群体发育 astogeny 卵泡的生长发育是一个独特的生理现象出生时, 初级卵泡 primary follicle 组成的卵泡库卵泡的直径到排卵前增加 400~600 倍, 每个发情周期中有个卵泡生长发育, 但绝大多数卵泡在其发育的不同阶段发生闭锁而退化, 结果只有一个或几个在发情周期中发育起来的卵泡能排卵

33 在某些动物还需要交配的诱导才能发生排卵出生前后和初情期之前是卵泡闭锁的两个高峰期, 到了绝情期卵巢上就没有可发育的卵泡了卵泡的发育过程比较漫长, 卵泡体积的增长发育速度却越来越快卵泡在快速生长发育阶段也可能发生闭锁, 特别是相对集中在卵泡发育的后期因此, 卵巢中往往存在处于不同发育阶段的闭锁卵泡 (astretic follicle)

34 某个卵泡何时开始发育可能是一个随机现象卵泡在开始发育的阶段完全不依赖促性腺激素, 即使在切除垂体后卵泡也会发育到一定阶段此后, 卵泡必须依赖于促性腺激素才能继续生长发育

35 一组获得对促性腺激素发生反应能力的卵泡, 在相对集中的时间内同步生长, 形成一个生长卵泡群体, 称之为一个卵泡波 (follicular wave) 生长卵泡持续发育 2~3d, 通过生理选择后, 只有优势卵泡 (dominant follicle) 可以继续发育, 其余卵泡则发生退化和闭锁在发情周期中, 只有在黄体溶解时存在的那个优势卵泡才能成为该发情周期中的排卵卵泡

36 优势卵泡的命运有两个, 或者闭锁 ( 不排卵优势卵泡 ), 或者排卵, 其决定因素是该优势卵泡的生长期是否与黄体溶解相一致动物的排卵数量具有其种属特异性, 决定排卵数量的基本生理过程有两个, 卵泡的补充过程导致一批卵泡发育, 卵泡的选择过程产生一定数量的优势卵泡

37 在一个卵泡波中, 优势卵泡的数量一般与排卵卵泡的数量相当根据卵巢上优势卵泡的发育情况, 可将优势卵泡的发育分为两种类型, 一种是仅在卵泡期卵巢上才有的大卵泡, 灵长类猪和大鼠的卵泡发育属于这类 ; 另一种是在发情周期内大部分时间卵巢上都有的大卵泡, 反刍类和马的卵泡发育就属于这类

38 ( 二 ) 卵泡的个体发育处于不同发育阶段的卵泡可分为原始卵泡初级卵泡次级卵泡三级卵泡和成熟卵泡五种类型初级次级和三级卵泡又统称为生长卵泡 (growing follicle)

39 1. 原始卵泡 (primordial follicle) 原始卵泡成群 ( 肉食动物和反刍动物 ) 或分散 ( 猪 ) 地存在于卵巢的皮质外区中央是一个大的初级卵母细胞 (priimary oocyte), 四周包围着一层由卵巢上皮向内生长发育而成的扁平的卵泡细胞 (follicular cell) 两种细胞表面平滑, 互相贴近, 有桥粒相连, 卵泡细胞之间也有桥粒, 还有裂隙连接一周龄以内新生仔猪的卵细胞为卵原细胞

40 2. 初级卵泡 (primary follicle) 初级卵泡卵泡细胞变大, 成为单层立方以至柱状细胞, 细胞表面出现微绒毛 ; 卵母细胞也增大, 在卵母细胞与卵泡细胞之间出现透明带 (zona pellucida) 当初级卵泡开始出现透明带的时候, 直接包围卵泡四周的皮质基质分化为卵泡膜

41 3. 次级卵泡 (Secondary follicle) 次级卵泡中初级卵母细胞继续生长变大, 卵泡细胞分裂增殖形成复层, 最靠近卵母细胞的卵泡细胞伸出微绒毛, 微绒毛穿过透明带与卵母细胞的微绒毛或质膜接触, 其间有桥粒微绒毛随卵泡生长而增多, 最外层卵泡细胞外有明显的基膜, 卵泡细胞附着于基膜上, 透明带增厚卵泡膜逐渐分化为卵泡内膜和卵泡外膜, 细胞膜上出现 FSH 受体和 LH 受体

42 4. 三级卵泡 (tertiary follicle) 三级卵泡出现卵泡腔和卵泡液, 卵泡腔由小变大, 将迅速生长的卵母细胞及其周围的卵泡细胞挤压到一侧, 形成卵丘 (cumulus oophoms), 紧靠透明带的一层卵泡细胞体积增大, 变成高柱状并呈放射状排列, 称为放射冠 (corona radiata); 其余的卵泡细胞在卵泡壁上排列成数层, 形成颗粒层 (stratum granulosum) 卵泡内膜和卵泡外膜分化明显

43 5. 成熟卵泡 (mature follicle) 成熟卵泡卵泡液急剧增加, 卵泡腔增至最大, 卵泡壁变得最薄, 颗粒细胞层仅有 2-3 层细胞这时卵泡内膜细胞上的 LH 受体进一步增多, 颗粒细胞不再分裂增生 ; 卵母细胞基本不再生长, 放射冠细胞与卵丘细胞之间开始出现裂隙, 彼此的联系松动牛排卵前的卵泡直径为 15-20mm, 马为 50~70mm, 绵羊山羊和猪约 10mm, 犬和猫约 2mm

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女性生殖器官介紹/月經和排卵的關係 (I) (II) (III) 女性生殖器官介紹 / 月經和排卵的關係 (I) (II) (III) By: 李碧雪 (October 4, 11, 18 & 25, 2010) 女性生殖器官 : 1. 卵巢 2. 內生殖器官 : 輸卵管, 子宮, 陰道 3. 外生殖器官 : 大陰唇, 小陰唇, 陰蒂 4. 乳腺輸卵管 (uterine tubes)

第一节 卵巢功能的解剖组织学

第一节卵巢功能的解剖组织学