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Eggs in _____ are located around the _____ of the ovary.
- primordial follicles
- periphery
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Most eggs in primordial follicles _____.
atrophy
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Eggs and follicles begin to mature after _____.
Puberty.
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Mature follicle (graafian follicle) bulges outward on ovary surfce and ruptures when?
at ovulation discharging egg into coelom.
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What is the corpus luteum?
cells that remain in the follicle after ovulation that harden into a yellowish secretory.
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Describe non-mammailian ovaries.
- Generally larger
- Often are hollow with thin walls, and usually have no corpora lutea formed.
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Describe the ovaries of amphibians.
- Represent the primitive condition of ovaries.
- Long oviduct extends most of the length of the body, anterior end opens into the coelom through the ostium.
- Hormonal stimulation of coelomic cilia insures ovulated eggs get swept from the ovary to the ostium.
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Describe the ovaries of elasmobranchs.
- united oviducts with a single ostium.
- expanded caudal portion of the oviduct forms the uterus.
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Describe the ovaries of bony fishes.
- oviducts united caudally and open near the anus through a henital papilla.
- ovary is large and hollow.
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Describe the ovaries of reptiles and birds.
- Oviducts paired, long, convoluted in reptiles, right side reduced or lost in birds. (only left ovary and oviduct are functional)
- Birds have a very large ostium, fertilization occurs in upper regions of oviduct and tertiary shell membranes are secreted around the egg as it is passed down the oviduct.
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Describe the ovaries of monotreme mammals.
Uterine tube = fallopian tube is expanded to form the uterus, each uterus independently enters a urogenital sinus (other mammals join to the common vagina)
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Describe the ovaries of marsupial mammals.
- Caudal end of oviduct specialized as the vagina.
- Urogenital sinus opens directly to outside rather than passing through cloaca.
- Anterior ends of the vaginae (marsupials have 2, one for each oviduct) united to form a vaginal sinus and each uterus opens into the vaginal sinus through a neck called a cervix.
- Due to the arrangement, this is called a duplex uterus.
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Males have a _____ to accomodate the 2 vaginae.
Bifurcated
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Describe the ovaries of Eutherian mammals.
- Vaginal portions united to form a single structure.
- Uteri may take on several forms (depending on species) from simplex to duplex, depending on the degree of fusion of the uteri.
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