2 Ultrasound Image of Normal Ovary, Classification of COD, Pathogenesis
Transcript
Greetings! to all.
Today we are in Lesson 2, the last class, we discussed the Introduction, Hormonal regulation of Ovarian activity, Predisposing factors, Signs, and Symptoms of cystic ovarian degeneration. In this class, the objective is a discussion of Ultrasonographic images of normal Ovarian Structures, Classification of cystic ovaries, Mechanism of cyst formation, Signs and symptoms of Cystic Ovarian Degeneration. This is the picture having Ultrasonographic images of normal ovarian structures, that is normal ovary during the time of estrous, it is always having dominant follicle even though the presence of regressing CL with numerous follicles, one follicle may be dominated during estrous that may be observed during the estrous, second one is the coherence of follicles, during any stage of the estrous cycle, multiple follicles, small follicles, may be observed in proestrus, it may be developing follicle with regressing CL and during the time of estrous, that is developed follicle or matured follicle with regressed corpus luteum and late time of estrous that is corpus haemorrhagecam may be observed during this estrous cycle and after the formation of corpus luteum, that corpus luteum may be cavity corpus luteum or Non-cavity corpus luteum may be observed in either one of the ovaries.
Cavity corpus luteum sometimes contains fluids also, the central cavity comprises or there is an accumulation of fluids and the Non-cavity corpus luteum may or may not have any fluids. So the next one is Classification of cystic ovaries: How to classify? that is based on the number of cysts, the texture of the cyst, and then fluid accumulation present in the cyst. how long the cyst persists in the ovary, based on that, the cyst is classified into the Follicular cyst, Luteal cyst, and Cystic Corpora Lutea.
What is meant by a Follicular cyst? The follicle cyst is defined as one or more than one thin[1]walled anovulatory follicles and greater than 2.5 centimeters in diameter with a fluid-filled cavity, Persists for 10 or more than 10 days in the absence of a functional CL, and is accompanied by either nymphomania or frequent estrous.
In the case of Luteal cyst: it is defined as thick-walled, partially luteinized anovulatory follicles, more than 2.5. Centimeter in diameter, which persists for a prolonged period characterized by anoestrous.
In the case of Cystic Corpora Lutea: it is defined as non-pathological CL containing greater than 7-millimeter fluid filled the central cavity with a distinct ovulation papilla, which produces a sufficient concentration of progesterone, that is about 7 to 8 nanograms per ml (7-8 ng/ml) which is sufficient for maintaining pregnancy, Most of the researchers stated that 100 micrograms of progesterone P4, in the circulation, is sufficient to support the pregnancy. It is often slightly fluctuating inconsistency also, So based on that Causes and Persistence and Conception, it is Classified as the Follicular cyst, and Luteal cyst and are always considered Pathological and Cystic Carpora Lutia is considered as a Physiological cyst.
Suppose the animal is not able to conceive, what will happen in the Cystic Corpora Lutea, the regression of corpus luteum occurs within a certain period of time and then cyclicity will be initiated, that’s why it is called as Non-pathological cyst or Physiological cyst. Mechanism of cyst formation: In spite of much researchers demonstrated and done research in so many aspects, the exact mechanism of cystic ovarian degeneration is still unclear. However, the generally accepted mechanism is disruption of the Hypothalamo-Pituitary Gonadal axis, which comprises Intrinsic factors and Extrinsic factors. Mechanism of cyst formation- The first one is the Intrinsic factors; here the Hypothalamus secreting GnRH will act on the anterior pituitary and release FSH and LH, that FSH will act on the follicle, it is involved in the development of follicle, which in turn secretion of estrogen, that estrogen positive feedback is highly essential for the LH surge and then LH will act on the ovary and ovarian follicle and ovulation occur. This is a normal mechanism. But here fails to elicit or miss-timed or delayed GnRH or LH surge at the Hypothalamus pituitary level will cause the failure of ovulation by the dominant follicle. So what will happen after that one? The follicle can grow continuously, however, aberrant follicular growth also maybe there, so it will lead to alterations in receptor expression, and steroidogenesis activity will be affected, finally, it becomes a cyst. That is called Intrinsic factors involved in cystic formation.
The next one is Extrinsic factors: extrinsic factor, the similar way the Hypothalamus, GnRH, Anterior pituitary, FSH and LH, estrogen and everything will occur in normal animals, however low insulin level or insulin-like IGF1 growth factor one, concentration is very low means low proliferative follicular cells occurs. Follicle cell proliferation will be affected, which leads to low estradiol production. In the presence of low estradiol production, means that may not able to induce LH surge, so LH surge is also low, however, reduction of Gonadotropin-releasing hormone will be there, which will end up in retarded dominant follicle growth and pattern with estradiol production that will disrupt the Hypothalamo pituitary-adrenal axis, finally development of cystic follicles occurs.
The next one is the Signs and Symptoms of Cystic Ovarian Degeneration. The first symptom observed in follicle or cyst is concerned Nymphomania, what is Nymphomaniac? It is a frequent, irregular, prolonged, or continuous sign of estrous absorbed in the affected animals, those animals are affected, means those animals are having often nervous, restlessness and bellow frequently, and then it is frequently attempting to ride other cows, but refused to stand to be riden and by other cows. Affected animals always have aggravated homosexual characteristics that are called Bullers. In the Bullers and in Nymphomania cows, the uterus and cervix are always larger in size edematous, and flaccid. Uterus and Cervix are concerned, at the time of examination, you can reveal that the presence of a large edematous and flaccid uterus, the cervical canal is always dilated and relaxed, permitting one finger you can insert or a pencil may be inserted inside the cervix. The endometrium is smooth, moist, semi-transparent, and edematous. Vagina Clitoris Vulva is always swollen in condition. That is called Nymphomania.
The next one is Sterility hump: affected animals that are chronically affected animals are having excess relaxation of the pelvic ligament lead to the tipping of pelvis and elevation of the tail head, In long-standing cases of Nymphomania tipping of the pelvis is very commonly observed, that is(showing picture) this is tipping of the pelvis area. This is the tipping of the pelvis area that is sacroiliac ligaments and all the ligaments are excessively relaxed and the tail head is elevated in nature, The ligaments, even after recovery, failed to regain their tone, and even after conception animal may be maintained with that excess relaxation of the pelvic ligament and sterility hump situation itself.
The tipping of the pelvis may result in an unsteady gait and predispose to injuries. More common these injuries are absorbed in aged animals and later stage of the pregnancy in more number of calved animals. The next one is Adrenal Virilism: commonly observed in chronic follicular cyst cases, those affected animals exhibit a muscular behavior and appearance. That is, those animals always have increased levels of 17 beta keto steroids in urine from the adrenal gland. And then the appearance of the animal is masculinization of head and neck is also noticed that is called Steer like appearance. This is the region, neck region, and head region is having a masculine appearance. The animal looks like bull-like. It just looks like a Steer like appearance, that is bull[1]like appearance.
The next one is Mucometra or Hydrometra: What is meant by Micrometra? It means accumulation of mucus.
Hydrometra means an accumulation of watery-like contents, that is chronically affected cases often noticed with Mucometra, and Hydrometra. In these cases Hyperplasia of the mucosa is always noticed, Cystic dilatation of the endometrial glands is also noticed. Marked cystic dilatation develops a typical Swiss cheese appearance. This is the Swiss cheese appearance of the endometrium(showing picture).
Always in the affected cases, the uterus accumulated with 100-1000 CC of watery mucus. Affected animals may have affected the single horn or portion of the horn, if infection occurs may lead to Byometra also, that is an accumulation of pus inside the uterus.
So far we discussed Ultrasonographic images of normal ovarian structures, Classification of cystic ovaries, Mechanism of cyst formation that is Extrinsic factors and Intrinsic factors, Signs, and Symptoms of the cystic ovary, that is, Nymphomania, Sterility hump, Adrenal Virilism, Mucometra and Hydrometra, the remaining portion will be discussed in the next class.
Thank you!
