KEY
Note Taking Guide 3
Topic # 3025
Introduction to Biology of Reproduction
Created by: Tracey Hoffman
Source: Animal Science Biology & Technology
I.
Anatomy of Reproductive Tracts
A. Female
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Ovary: Primary reproductive organ
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meiosis takes place
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fertile eggs develop
Follicle: Developing egg that has not yet been released
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produce estrogen
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mature follicle is ruptured and the egg is released
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release of egg causes estrogen levels to fall
Corpus hemorhagicum (CH)
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Bloody body
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where follicle was released
Corpus luteum (CL)
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Yellow body
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produces progesterone = sustains pregnancy
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prevents new follicle development
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Estrous cycle
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Proestrous: when follicle is developing
- Estrus: when egg is released
* when female is receptive to the male
* “standing heat”
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Metestrus: CL is actively producing progesterone
*if pregnant = CL remains active
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Infundibulum
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Funnel shape
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where egg is release into
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moves egg to oviduct
Oviduct
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Diestrus: CL recedes and a new follicle begins to develop
where fertilization takes place
Uterus
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womb
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Attaches and develops until birth
Cervix
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Path from uterus to the outside of the animal
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Sperm deposited here in some species
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Seals off during pregnancy
Vagina
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Site of insemination in some species
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Vulva
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B.
Visible part of the female reproductive tract
Male
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Testis
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Seminiferous tubules
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Surround seminiferous tubules
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Produce testosterone
Rete testis
Where immature sperm collect
Efferent ducts
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Meiosis takes place here
Lydig cells
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Primary male reproductive organ
Bigger storage area
Epididymis
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Final sperm collection site
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3 parts of epididymis
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head
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body
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tail
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During ejaculation
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Sperm travel from epididymis, through vas deferens, to the uretha
and penis before being deposited in the female
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Several glands add fluid to the sperm
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II.
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II.
Semen: sperm cells and fluid
The Reproduction Cycle
A. A. Fertilization
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Capacitation
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Fluids from female “wash” sperm so make it capable of
fertilization
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Zona pellucida
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barrier surrounding egg
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Must be penetrated by sperm
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Once a sperm has penetrated, no more are allowed to enter
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“Vitelline Block”
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Zygote
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Diploid fertilized egg
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Travels remaining distance to the uterus
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Becomes an embryo
fetus
B. B. Pregnacy
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No new follicle develop
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Cervix develops a thick mucus plug to keep out bacteria
C. C. Parturition
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Fetus starts to secrete a hormone
prostaglandin
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causes mother to release
ruptures CL
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hormones released by mother
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relaxin
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oxytocin
D. D. Lactation
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Milk let-down is controlled by oxytocin
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Milk formation is controlled by prolactin
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Colostrum
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Thick and rich milk
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Contains antibodies
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Newborns need colostrum with 24 hours
end of pregnancy