Oestrus Cycle Flashcards
(15 cards)
Describe the oestrus cycle.
The period of fertility and sexual receptivity in animals, indicating when they are receptive to mating.
What is the role of hormonal control in the oestrus cycle?
Hormonal control regulates the cycle, with hormones that influence fertility and sexual receptivity such as oestrogen and FSH.
How does the hypothalamus influence the oestrus cycle?
Regulates the cycle through controlling the release of hormones that influence the pituitary gland and ovaries. Releases GnRH to stimulate the pituitary gland to produce FSH and LH.
What is the function of the pineal gland in the oestrus cycle?
Produces melatonin which regulates the circadian rhythm, influencing seasonal cycles within certain species.
Define pro-oestrus.
Stage where the pituitary gland releases FSH and LH, stimulating the growth of ovarian follicles which produce oestrogen.
Oestrogen production causes uterine lining to form.
What changes occur during oestrus?
Ovarian follicles grow and mature, leading to increased oestrogen production and a surge in LH, resulting in ovulation.
What happens during met-oestrus?
Follicles become the corpus luteum, which produce progesterone and inhibits FSH and LH production.
Explain the process that occurs in dioestrus.
If there is no pregnancy, the corpus luteum degenerates, leading to a decrease in progesterone and increase in FSH and LH.
What is anoestrous?
Period where the cycle pauses, characterised by low levels of oestrogen, LH and FSH.
How do some species experience the oestrus cycle during breeding seasons?
Some species have multiple oestrus cycles during a breeding season, followed by extended periods of an-oestrus.
Describe what occurs during fertilisation.
Occurs when an ovum is released and sperm releases digestive enzymes to penetrate the ovum membrane.
What happens during implantation?
Progesterone causes the uterine lining to thicken, allowing the zygote to implant into the uterine wall for embryonic growth.
Describe the development of the zygote after implantation.
Zygote grows and cells develop into a blastocyst, implanting into the uterine wall.
What is gestation?
The period of growth where the blastocyst becomes the embryo and later the foetus, allowing for development.
What is parturition?
The process of giving birth, initiated by the decreases in progesterone and increase in oxytocin.
