Exam 3 Flashcards
True or False: In almost all species studied including humans, there is a marked increase in physical activity around the time of ovulation
True
True or False: The bull and ram and dog are short copulators while the boar, tom cat, and camelids are sustained copulators
False
True or False: Prenatal exposure of a female fetus to a large dose of estradiol results in decreased estrous behavior and an increase in male-like behavior
True
True or False: Sexual preparation in the bull, increases sperm numbers in the ejaculate through oxytocin release from the posterior pituitary which stimulates contractions of the distal tail of the epididymis and ductus deferens
True
True or False: When collecting see from a bull with an artificial vagina, both temperature and pressure are important to stimulate ejaculation, while only an optimal temperature is required for the boar
False
True or False: Viagra causes a prolonged erection because it inhibits the conversion of cGMP to GMP thus prolonging vasodilation
True
True or False: Following AI in cows, less sperm are lost by retrograde flow if they are deposited in the mid-cervix than if they are deposited in the uterus
False
True or False: Superfecundation in dog is a result of their long duration of estrus and the prolonged interval after the onset of estrus when fertilization can occur
True
True or False: During the acrosome reaction fusion of sperm plasma membrane and outer acrosomal membrane leads to vesiculation and loss of the acrosomal enzymes
True
True or False: Acrosin, an enzyme released during the acrosome reaction allows the sperm to penetrate the vitelline membrane
False
True or False: Zona protein 3 (ZP3) is a glycoprotein receptor which only allows sperm of the same species to bind to the zone pellucid
True
True or False: In most mammalian species sperm capacitation occurs in the male accessory sex glands prior to ejaculation
False
True or False: During cervical transport, viable sperm that encounter high viscosity sialomucin swim through the cervix with ease, while sperm encountering the low viscosity sialomucin are flushed out of the tract
False
True or False: Loss of sperm from the female tract occurs mainly through the process of phagocytosis and retrograde flow
True
True or False: The primary oocyte undergoes the first meiotic division at ovulation in cattle, sheep, and pigs, while the second meiotic division occurs at the time of fertilization
True
True or False: Each blastomere (embryonic cell) of an 4 cell pig embryo and an 8 cell cow embryo are totipotent
True
True or False: A morula is a solid ball of blastomeres, while a blastocyst contains inner cell mass cells surrounded by trophectoderm cells and a fluid filled cavity called the blastocoele
True
True or False: The trophectoderm cells surrounding the blastocyst develop gap junctions between them to allow a free exchange of information, while the inner cell mass cells develop tight junctions to hold the inner cell mass together
False
True or False: The collection of embryos from the uterus of donor cows and their transfer into recipient females should only be done after hatching of the blastocysts from the zona pellucida
False
True or False: If inner cell mass cells from a goat blastocyst are collected and injected into the blastocyst of a sheep embryo containing its own inner cell mass, and the injected embryo placed into the uterus of a goat, it will give birth to a deep (cross between sheep and goat)
False
urethralis muscle
propels sperm + seminal plasma (semen) through the pelvic urethra
Bulbospongiosus muscle
pumps semen from the pelvic urethra through the penile urethra
ischiocavernousus muscle
clamps off venous return from the penis resulting in penile extension
Yolk sac
- develops the first blood vessels in the conceptus and is called the primitive gut
- splanchnic mesoderm + endoderm
Allantois
- -thrust out from the hind gut of the embryo, and expands to vascularize the chorion
- splanchnic mesoderm + endoderm
Chorion
- not vascularized and acts as a protective outer covering of the conceptus
- somatic mesoderm + trophectoderm
Amnion
- a high pressure bubble which surrounds the embryo to prevent it from being crushed by uterine contractions
- somatic mesoderm + trophectoderm
necrotic tips form at each end of an elongating pig embryo when these parts of the placenta fail to fuse together
- Allantois
- Chorion
this part regresses at implantation when the choir-allantonic membrane forms and attaches to the uterine wall to begin to take up nutrients directly from the maternal blood
Yolk Sak
the umbilical cord forms at the sight where this part of the placenta grew out of the embryo
Allantois
goat
- signal that maintains luteal function in specie during maternal recognition of preg.
- CL indep. or dep.
- interferon??
- Cl dependent specie
women
- signal that maintains luteal function in specie during maternal recognition of preg.
- CL indep. or dep.
- hCG
- CL independent specie