Flash cards on the Estrous Cycle

Estrous Cycle

The reproductive cycle in female mammals, excluding primates, characterized by recurring physiological and hormonal changes.

Purpose of Estrous Cycle

Facilitates reproductive readiness and synchronizes mating behaviors with ovulation.

Proestrus Phase

The initial phase of the estrous cycle with rising estrogen levels and follicular development.

Estrus (Heat) Phase

The phase in which the female is receptive to mating and ovulation occurs, lasting 1-9 days.

Metestrus (or Diestrus) Phase

The phase lasting about 1-2 months dominated by progesterone where the uterine lining thickens.

Anestrus Phase

A long resting phase with low reproductive hormone levels, featuring no reproductive activity.

GnRH

Gonadotropin-Releasing Hormone released by the hypothalamus to regulate the estrous cycle.

FSH

Follicle-Stimulating Hormone released by the pituitary gland that stimulates follicular growth.

LH

Luteinizing Hormone that triggers ovulation and corpus luteum formation after GnRH stimulation.

Differences from Menstrual Cycle

The estrous cycle has distinct phases of receptivity, while the menstrual cycle involves regular shedding of the uterine lining.