Reproductive System Flashcards
Cell division that produces basic reproductive cells; ova, spermatozoa
Meiosis
Coiled masses of DNA in the nuclei of cells
Chromosones
What does diploid chromosome number refer to?
Sexually reproducing organisms have two sets of chromosomes; one from each parent
What does haploid chromosome number refer to?
The reduced number of chromosomes in the gamete; results from meiosis - ensures that fertilized ovum from union of ova and spermatozoa has the diploid number
What is mitosis?
The process by which a cell replicates its chromosomes and then segregates them, producing two identical nuclei in preparation for cell division
What is meiosis?
Random half of total chromosomes go to each daughter cell
What is spermatogenesis?
The process where spermatozoa are produced in large numbers in the seminiferous tubules of the testes
What is oogenesis?
The process where ova are produced (a few at a time) in the follicles of the ovaries
Where are male reproductive cells formed?
Testes (male gonads)
What are the functions of the testes?
Spermatogenesis, hormone production
What hormones are produced in the testes and where?
Androgens, specifically testosterone; produced in the interstitial cells of the seminiferous tubules
What are the 3 main parts of spermatozoa?
Head, midpiece, tail
Where do the testes begin developing?
In the abdomen near the kidneys before birth; gradually pulled caudally and ventrally passing through the inguinal rings down into the scrotum
What is the band of connective tissue that attaches the testes to the scrotum?
Gubernaculum
What does the scrotum help regulate?
Temperature of testes - must be kept cooler than body temperature
What muscle passes down through the inguinal ring and attaches to the scrotum?
Cremaster muscle - adjusts position of testes depending on temperature
What structures does the spermatic cord contain?
Blood vessels, nerves, lymphatic vessels, vas deferens
What is the heat exchange mechanism in the spermatic cord?
Pampiniform plexus
What are the two layers of tunics?
Visceral vaginal tunic = proper vaginal tunic
Parietal vaginal tunic = common vaginal tunic
What is the tunic albuginea?
Lies beneath the tunics - forms a fibrous connective tissue capsule that encloses each testis
What divides the testis into tiny lobules that contain seminiferous tubules?
Septa
What happens in the seminiferous tubules?
Spermatogenesis in u-shaped tube = rete testis
The interstitial endocrine cells in the seminiferous tubules produce what?
Androgens
These cells support developing spermatids and shield from the body’s immune system?
Sertoli cells
Where is spermatozoa stored?
Epididymis - flat ribbon-like structure that lies along the surface of the testis
What does the vas deferens do?
Moves sperm from the epididymis up the urethra when ejaculation occurs
Spermatozoa mixed with secretions from accessory glands is what?
Semen
What are the functions and portions of the male urethra?
Urinary, reproductive (ejaculation); pelvic portion, penile portion
Where do the ducts of the accessory reproductive glands enter?
Pelvic portion of the urethra
What do the accessory reproductive glands produce?
Alkaline fluid to help counteract acidity of the female reproductive tract that helps sperm survive to reach the ovum - electrolytes, fructose, prostaglandins
What are the 3 accessory reproductive glands?
Seminal vesicles
Prostate gland
Bulbourethral gland
What does the bulbourethral gland do?
Secretes fluid to help clear out the urethra before ejaculation
What species are missing the seminal vesicles?
Cats & dogs
What is the only accessory gland that the dog has?
Prostate gland
What are the 3 main parts of the penis?
The roots - 2 bands of crura attach penis to brim of pelvis
The body - 2 bundles of erectile tissue (corpus cavernosum urethrae, corpus cavernosum penis)
The glans - distal end with numerous sensory nerves, prepuce
What does the bulb of the glans do?
Remains swollen after ejaculation to tie
What is the distal glans on the horse that flares?
Corona glandis
In horses, the urethral process extends from the central depression called what?
Fossa glandis
What causes erection of the penis and what pulls the penis back to non-erect state?
Sigmoid flexure, retractor penis muscle
What structures makes up the female reproductive system?
Ligaments, ovaries, oviducts, uterus, cervix, vagina, vulva
What are the 3 broad ligaments in the female reproductive tract?
Mesovarium - supports the ovary
Mesosalpinx - supports the oviduct
Mesometrium - supports the uterus
What is the name of the ovarian end of the mesovarium broad ligament?
Suspensory ligament of the ovary
What ligament is attached to the tip of the uterine horn located caudally to the inguinal ring?
Round ligament of the uterus
What is oogenesis?
Production of gametes in follicles
What hormones are produced in the ovaries?
Estrogen, progestins, relaxin
What is uniparous?
Species that produce one mature ovum per cycle - horses, cattle, humans
What is multiparous?
Species that produce multiple ova per cycle - cats, dogs, sows
The ovarian cycle is under the influence of what hormones?
FSH, LH
What is a primary follicle?
Immature oocyte surrounded by a single layer of flattened follicular cells - follicular activation occurs
What happens during the growing follicle stage?
Oocyte starts to grow in size
Glycoprotein zona pellucida layer forms
Granulosa cells multiply
Antrum is formed
What happens during the mature follicle stage?
Oocyte sits in mound of cumulus oophorus
Zona pellucida is surrounded by corona radiata
What follicular stage is estrogen at its peak?
Mature follicle stage
What happens during the ovulation stage?
Mature follicle ruptures
Gamete released into oviduct - now called ovum
Corpus hemorrhagicum
What is Corpus hemorrhagicum?
When the empty follicle fills with blood during ovulation
How is the corpus luteum formed?
From cells lining the corpus hemorrhagicum
What produces the progestins needed to maintain pregnancy?
Corpus luteum
What is follicular atresia?
Not all follicles activated in a single ovarian cycle will fully develop and ovulate
What are two other terms for oviducts?
Fallopian tubes
Uterine tubes
What is the purpose of the oviducts?
Guide ova from ovary to uterus
Serve as site for fertilization
Oviducts contain _______________ that catch the ova in the __________________
Fimbriae, infundibulum
What are the 3 layers of the uterus?
Endometrium
Myometrium
Perimetrium
What is the smooth muscle sphincter between the body of the uterus and the vagina and when is it open?
The cervix - estrus, parturition
What structures does the vulva contain?
Vestibule
Clitoris
Labia
The definite period in each reproductive cycle when breeding can take place - from the beginning of one heat period to the beginning of the next
Estrous cycle
What are the different intervals of the estrous cycle?
Polyestrous - cattle swine
Seasonally polyestrous - horses, sheep, cats
Diestrous - dogs
Monoestrous - foxes, minks
What are the stages of the estrous cycle?
Proestrus - follicular development in the ovary
Estrus - heat
Metestrus - after ovulation when corpus luteum develops
Diestrus - active luteal stage when corpus luteum has reached max size and exerts max effect - pseudocyesis or pseudopregnancy can happen here
Anestrus - temporary ovarian inactivity
