OvaryThe ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus. There is an ovary () found on the left and the right side of the body. The ovaries also secrete hormones that play a role in the menstrual cycle and fertility. The ovary progresses through many stages beginning in the prenatal period through menopause. It is also an endocrine gland because of the various hormones that it secretes. The ovaries are considered the female gonads.
Hyaline cartilageHyaline cartilage is the glass-like (hyaline) and translucent cartilage found on many joint surfaces. It is also most commonly found in the ribs, nose, larynx, and trachea. Hyaline cartilage is pearl-gray in color, with a firm consistency and has a considerable amount of collagen. It contains no nerves or blood vessels, and its structure is relatively simple. Hyaline cartilage is covered externally by a fibrous membrane known as the perichondrium or, when it's along articulating surfaces, the synovial membrane.
Corona radiata (embryology)The corona radiata is the innermost layer of the cells of the cumulus oophorus and is directly adjacent to the zona pellucida, the inner protective glycoprotein layer of the ovum. Cumulus oophorus are the cells surrounding corona radiata, and are the cells between corona radiata and follicular antrum. Its main purpose in many animals is to supply vital proteins to the cell. It is formed by follicle cells adhering to the oocyte before it leaves the ovarian follicle, and originates from the squamous granulosa cells present at the primordial stage of follicular development.
Embryological origins of the mouth and anusThe embryological origin of the mouth and anus is an important characteristic, and forms the morphological basis for separating bilaterian animals into two natural groupings: the protostomes and deuterostomes. In animals at least as complex as an earthworm, a dent forms in one side of the early, spheroidal embryo. This dent, the blastopore, deepens to become the archenteron, the first phase in the growth of the gut. In deuterostomes, the original dent becomes the anus, while the gut eventually tunnels through the embryo until it reaches the other side, forming an opening that becomes the mouth.
Yolk sacThe yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though yolk sac is far more widely used. In humans, the yolk sac is important in early embryonic blood supply, and much of it is incorporated into the primordial gut during the fourth week of embryonic development. The yolk sac is the first element seen within the gestational sac during pregnancy, usually at 3 days gestation.
