Chapter 13 - Exam 4 Flashcards
Apposition of male and female pronuclei
Syngamy
An organism in the early stages of development and can’t be distinguished as a member of a specific species
Zygote becomes embryo
A potential offspring that is still within the uterus, but is generally recognizable as a member of a given species
Fetus
More advanced form of an embryo
Fetus
The product of conception
Conceptus
Conceptus includes the embryo during the
Early embryonic stage
Conceptus includes the embryo and extra embryonic membranes during the
Preimplantation stage
Conceptus includes the fetus and placenta during the
Post-attachment phase
4 steps must be achieved for embryo to attach to uterus
Development with confines of zona pellucida
Hatching of blastocyst from zona pellucida
Formation of extraembryonic membranes
Maternal recognition of pregnancy
Stage of embryo development when the male and female pronuclei can be observed
Newly fertilized oocyte
Ootid
One of the largest single cells in body
High cytoplasm:nucleus ratio
Ootid
Embryo undergoes a series of mitotic divisions
Cleavage divisions
First cleavage generates a
2-cell embryo
Each cell of the 2-cell embryo is called a
Blastomere
Each cell of the 2-cell embryo is of proportionate side and represents almost exactly ____ of a single celled zygote
Half
Each blastomere undergoes subsequent divisions, yielding a ____, _____, _____ celled embryo
4
8
16
Early on in development, each blastomere has ability to develop into
Separate healthy offspring
Blastomeres from the 2-,4-,8-,16-celled embryos and even further into development are
Totipotent
When a single cell (blastomere) gives rise to a complete, fully formed individual
Totipotency
As cleavage divisions proceed, the cells become progressively _______ with no net _____ in the size of the embryo
Smaller
Increase
Why as cell cleavage divisions proceed do the cells become progressively smaller with no net increase in the size of the embryo?
Because you started with a fixed volume
When a solid ball of cells is formed and you can no longer count how many blastomeres are present
Morula stage
Cells in center of the morula become more ________ than those cells in the outer region
Compacted
Develop gap junctions
Inner cells
Allow for intracellular communication and may allow cells to remain in a defined cluster
Gap junctions
Develop tight junctions
Outer cells
Cell to cell adhesions
Alter the permeability characteristics of the outer cells
Tight junctions
After tight junctions are formed, _____ accumulates inside the embryo
Fluid
Brought about by an active sodium pump in outer cells which pump into center portion of morula
Fluid accumulation
Fluid-filled cavity
Blastocoele
When a distinct cavity (blastocoele) is recognizable
Blastocyst
2 cellular populations
Inner cell mass
Trophoblast
Becomes fetus proper
Inner cell mass
Becomes chorion - fetal portion of placenta
Trophoblast
Trophoblastic cells produce
Proteolytic enzymes
Weaken zona pellucida so it easily ruptures upon increased growth of blastocyst
Proteolytic enzymes
Blastocyst contracts and relaxes producing
Intermittent pressure pulses
3 forces governing hatching of blastocyst
Growth and fluid accumulation within blastocyst
Production of enzymes by trophoblastic cells
Contraction of blastocyst
Free-floating embryo without the zona pellucida
Squeezes out of the opening of the development of the small crack in the zona pellucida
Hatched blastocyst
Cow: the embryo increases from ___ mm to ____ mm in __ days and is long and looks like a _________ ______
3mm
250mm
4 days
Filamentous thread
Cow: on day 18, blastocyst occupies both
Uterine horns
Pig: embryo increases from ___ mm to ____ mm in __ days
2mm
200mm
2 days
Pig: hatched blastocyst grows at a rate of ___ to _____ mm per hour
4 to 8
Pig: by day 16, hatched blastocyst has reached ____ to ______ mm in length
800 to 1000 mm
________ _______ formation is essential for embryo to attach to uterus of ram
Extraembryonic membrane
There are 4 membranes which originate from the ________, the ________ ______ and the _______
Trophectoderm
Primitive endoderm
Embryo
Extraembryonic membranes of preattachment embryo consists of
Yolk sac
Chorion
Amnion
Allantois
Eventually attaches to uterus
Chorion
Fluid-filled protective sac for fetus
Amnion
Chorion and amnion develop from
Trophyblast
Primitive endoderm
Yolk sac develops from
Primitive endoderm
Contributes primordial germ cells which migrate to genital ridge
Yolk sac
Filled with fluid
Serves to protect embryo from mechanical perturbations
Acts as an anti-adhesion material to prevent tissues in embryo from adhering to each other
Amniotic cavity (sac)
Fluid filled sac that collects liquid from embryo
Allantoic cavity
_________ ____ continues to expand until pressed against _____ and eventually fuses with it
Allantoic cavity
Chorion
Allantoic cavity fused with the chorion
Fetal contribution to placenta and provides surface for attachments to endometrium to uterus
Chorioallantoic membrane
Series of events by which conceptus initially signals it’s presence to the dam and enables pregnancy to continue
Maternal recognition of pregnancy
What of ruminants releases oxytocin
CL
What stimulates uterine endometrial cells to synthesize PGF2alpha
Oxytocin
Production of PGF2alpha is dependent on threshold number of ________ ________ synthesized by endometrial cells during critical time in estrous cycle
Oxytocin receptors
In what species does the blastocyst block synthesis of endometrial oxytocin receptors
Cow
Ewe
In the cow and the ewe, the blastocyst produces specific proteins that provide signal for prevention of
Luteolysis
Special proteins
Produced by leukocytes, fibroblasts, lymphocytes and trophoblastic cells
Interferons
Types of interferons
Ovine interferon tau
Bovine interferon tau
Interferons have _______ action and alter the function of ______ _____
Antiviral
Target cells
Small protein
Produced by trophoblastic cells of blastocyst
Promotes protein synthesis
Inhibits oxytocin receptor synthesis
Ovine interferon tau
Pig blastocyst produces ______ which serves as signal for _______ ______ of pregnancy
Estradiol
Maternal recognition
In what species is PGF2alpha produced in significant quantities and is rerouted into uterine lumen
Sow
Pig embryo produces estradiol between day ___ and ___ after ovulation
11 and 12
In pigs, PGF2alpha has little access to ______ and can’t cause _______
Vasculature
Luteolysis
In the pig, at least __ conceptuses myst be present in each uterine horn for pregnancy to be maintained
2
In the mare, presence of ______ causes prevention of luteolysis
Conceptus
In mares, what must migrate within uterus from one horn to the other
Conceptus
Equine conceptus does not _______which means less contact between ______ and ______ _______
Elongate
Conceptus
Uterine endometrium
The net effect of successful pregnancy recognition is maintenance of
High blood progesterone concentrations
Extraembryonic membranes form an attachment with uterine endometrium to provide semi—permanent link between day and fetus
Placenta
What animal has no vagina, but retains a urogential sinus
Nine-banded armadillo
The nine-banded armadillo gives birth to
Identical quadruplets
True implantation does not occur in
Domestic animals
In rodents, a successful pregnancy can be terminated if an alien male shows up and hangs out with the pregnant female
The Bruce Effect
A pair of Indian pythons have been observed copulating for ____ days
180
After copulation, the male garter snake plugs the female’s cloaca with a material made from
Renal secretions
Cantharidin has been illegal since the
1800s
What insects were believed to increase penile turgidity and prevent ejaculation
Dragonflies
Silkworms
Scale insects and stink bugs were considered by the Chinese as
Aphrodisiacs
The word aphrodisiac is derived from the name of the Greek goddess of love ______
Aphrodite
When and by who was the book “The Male Generative Organs-Health and Disease from Infancy to Old Age” created
1848
Frederick Holland
What was the punishment for several male sex offenders in 12th century BC
Castration
What was likely the first survivable surgery in humans
Castration
Who thought that the function of the testis was only as a weight to keep the kinks out of the ductus deferens
Aristotle
What animal begin their life as males, but then most change into a female with a slight twist
Peppermint shrimp
On average, the bilaterally castrated man lives ___ years longer than intact men
12
In cephalopods, the male deposits a special sperm package called a ______ in the female body cavity by the way of an artificial penis
spermatophore
What is the name of the artificial penis in cephalopods that is also a specially modified tentacle
Hectocotylus
Spiders have an artificial penis that is a leg that doubles as a penis and is known scientifically as a
Maxillary palp