Present in the newborn female, the <u>primordial</u> follicle can remain in a resting state for up to five decades.
<h3>Ovarian follicle</h3>
Ovarian follicles are small fluid-filled sacs found inside a woman's ovaries. Follicles secrete hormones, such as estrogen and progesterone, that affect the menstrual cycle.
In the body, follicles have several functions:
Feeds and protects the egg.
Releasing reproductive hormones such as estrogen and androgens.
Transforms into the corpus luteum after ovulation, which releases the hormone progesterone. This hormone functions to prepare the lining of the uterus for the process of implanting an embryo if pregnancy occurs.
Stages of ovarian follicle development
Primordial follicle: This is the earliest stage, namely the follicles that are in the ovaries of newborns.
Primary follicle: A small number of primordial follicles develop into primary follicles every day. This process begins at puberty and continues until menopause.
Secondary follicle: At this stage, the follicle develops and contains theca cells, which release hormones, such as androgens and estrogens.
Tertiary follicles or also called antral follicles: This follicle contains a fluid-filled space called the antrum. At this stage, the follicles can be seen via transvaginal ultrasound.
Graafian Follicle: This is the largest follicle, mature, and ready to ovulate. Only 1-2 tertiary follicles in each menstrual cycle eventually mature and ovulate.
Corpus luteum: The ovulated follicle develops into the corpus luteum, which releases the hormone progesterone.
Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.
Taking steps to reduce or eliminate pollution from nonpoint sources such as streets and farms will help to maintain the ecological balance. Sewage and run-off of agricultural fertilizer can cause the rapid growth of algae in lakes and streams. The growth of algae blocks sunlight and depletes the oxygen in the water.
