Introduction cont. (Chapwanya) Flashcards
What part of a mature oocyte must be extruded for normal chromosome numbers to develop?
The polar body
In embryonology what is the most totipotent cell?
Zygote
Which part of the immature embryo will differentiate primarily to the gonads, uterus, and accessory sex glands? Which part will differentiate primarily into the vagina, vestibule, penis, clitoris and mammary glands?
Mesoderm- gonads, uterus, and accessory sex glands
Ectoderm- vagina, vestibule, penis, clitoris and mammary glands
Which 2 parts of the developing embryo must link up properly for a functional reproductive system?
Mesoderm and Ectoderm
What part of a developing embryo becomes the placenta?
Blastocoel
During development, the ______ is closest to the embryo while the _____ is closest to the uterus.
a. Chorion, Amnion
b. Amnion, Chorion
b. Amnion, Chorion
During development, the AMNION is closest to the embryo while the CHORION is closest to the uterus.
Why does the brain develop early during the course of embryology?
It is required to coordinate further development of the embryo/fetus
Match the gestation length to the species:
Dog
Pig
Sheep
Cow
285 days
147 days
62 days
114 days
Dog: 62 days
Pig: 114 days
Sheep: 147 days
Cow: 285 days
What is a system that determines the sexual characteristics of an organim which generally consists of genetic or hormonal parameters?
Sex determination
What is the process whereby a group of unspecialized cells develop into a functional, recognizable group of cells that have a common function?
Differentiation
(e.g. Sex differentiation- male vs female repro tract)
What is the chromosomal complement of an organism?
Karyotype
What is the term that describes the alleles genetic constitution of an individual?
Genotype
A _____ is produced by the fusion of 2 different zygotes in a single embryo. A _____ is an individual with 2 different cell lines that originated from that same individual.
Chimera
Mosaic
A CHIMERA is produced by the fusion of 2 different zygotes in a single embryo. A MOSAIC is an individual with 2 different cell lines that originated from that same individual.
When is the chromosomal sex (i.e. the karyotype) of an individual determined?
At fertilization (determined by sperm contribution)
What sex will an individual be if the Sry gene is present?
Male
Sry gene induces testes formation
Which ducts regress in females and form the epididymis and ductus deference? Which ducts regress in males and form the uterus, oviducts, and cranial vagina?
Mesonephric ducts (Wolffian ducts) -> present in males
Paramesonephric ducts (Muellerian ducts)->present in females
What are the 3 developmental stages of the kidney?
Pronephros -> Mesonephros -> Metanephros
What hormone does the Sry gene cause the development of?
Testosterone
Which hormone induces the degeneration of the paramesonephric duct? In which sex does this occur?
Anti-Muellerian hormone (AMH)
Males
Which highly active and effective hormone must penetrate the brain of a developing embryo in order for the penis, scrotum and accessory sex glands to develop?
Dihydrotestosterone (DHT)
______ (Male/Female) development is the default.
Female
Before testicular descent occurs, where do the testes lie and how are they attached?
Retro-peritoneal position
Attached caudally ot the ligametous gubernaculum
What controls the transabdominal phase of testicular descent?
Insulin like growth factor 3 (Insl 3)
And its receptor (Lgr8)
What is responsible for the mechanical movement of the testes into the inguinal canal during the inguinal-scrotal phase of testicular descent? What is the chemical factor involved?
Rapid growth of the gubernaculum in the scrotal region followed by shrinkage which pulls the testes deeper into the scrotum
Androgens
Where is sperm with the potential for fertilization located (i.e. the sperm that is ejaculated)?
Tail of the epididymus
Which accessory sex glands do the camelid and the cat have?
Prostate
Bulboureteral
What type of penis and which accessory sex gland(s) does the dog have?
Musculovascular penis (with os penis)
Only prostate
Which accessory sex glands does the boar have? What type of penis does he have?
Bulbourethral
Prostate
Vesicular gland
No ampulla
Fibroelastic penis
Which of the 4 accessory sex glands does the bull not have?
Bulbourethral
Which species ejaculated the most semen when mating?
Porcine (the boar)
Warm _______ (arterial/venous) blood is cooled on its way to the testis so that a 6 degree (C) temperature gradient exists between the body and the testes.
Arterial
Where is the warmest temperature region of the testicles? Where is the coolest region?
Spermatic cords (37C)
Ventral scrotum (31C)
What happens if there are frequent sequential ejaculates within one day?
The sperm reserves in the distal epididymal tail is depleted
In which part of the epididymus are sperm non-motile, non-fertile and have low disulfide crosslinking?
Head of the epididymus
When sperm reach which location are they able to bind to oocytes?
Body of the epididymus
Which accessory glands of the stallion are most commonly affected by infection?
Vesicular glands
Which 2 species have the ability for rapid ejaculation and erection?
Felines
Bovine
The penis of which species have a sigmoid flexure?
Equine
Bovine
Porcine