Flashcards in Reproductive System + Pregnancy Deck (182):
Describe the reproductive system
Non-essential for survival of individual, however a sensual, for survival of species. Evolution of sexual behavior reflects importance of reproduction.
What do the differences in gender roles affect
Behavior, anatomy, physiology between sexes
What are the purpose of the reproductive system
Produce and transport gametes to females which is the site of embryonic development. Produce hormones that cause sexual maturation, gamete production, stimulate ovulation, Gestation, lactation. Nourish developing offspring.
Describe chromosomes in relation to the reproductive system
Animals have diploid number of chromosomes in their somatic cells. 2N. Diploid cells have homologous pairs of chromosomes one for mother and one from father. Chromosome pairs are genetically different but code for the same genes.
How many chromosomes do cats have
How Many chromosomes to humans have
How many chromosomes do dogs have
What are sex chromosomes
Pair of chromosomes that determine the gender
Who is the Homogametic sex
What is the name for a sex cell
Are gametes diploid or haploid
How are gametes formed
Formed by the process of meiosis. 2N to N
What do sex cells contain
Half the genetic material of somatic cells
What is spermatogenesis
The formation of spermatozoa
What is oogenesis
The formation of ova
Why are gametes genetically different from each other
Due to independent assortment and crossing over
When does independent assortment occur
When does the crossing over occur
What is spermatogenesis
The formation of spermatozoa
Where does spermatogenesis occur
In the seminiferous tubule's
Each spermatogonium produces how many sperm
What is oogenesis
The formation of ova
Where does oogenesis occur
In the follicles of the ovaries
at what point does Oogenesis stop until estrus
How many ova does each oogonium produce
How do the polar bodies form for the ovum
What are the three male reproductive system functions
Make male sex hormones called androgens. Make spermatozoa. Deliver spermatozoa to female
Describe the testes
Paired oval structures located in external caudal sacs called the scrotum in the inguinal region
Describe the skin of the scrotum
Scrotum is thin and lacks subcutaneous fat. Has sweat glands. Alopecic but not at all species
What does the cremaster muscle do and what is it in response to
It pulls the testicles cranially. It is in response to temperature
Where did the testicles develop. And when do they decend
The testicles develop in the cranial abdominal cavity and descend into the scrotal sac prior to birth.
What is the gubernaculum
Embryonic structure of connective tissue that pulls testes through the inguinal canal into the scrotum. May be confused with testes in cryptorchid NeoNates.
What is the scrotal ligament or gubernaculum testes
Secure testes to caudle end of scrotum which restricts the movement in the sac.
Can be unilateral or bilateral. Neutering recommended. Often hereditary thus not suitable to use as breeders. Prone to testicular torsion and cancer.
If you have a bilaterally cryptorchid Kat what is the potential
The potential is for torsion of the spermatic cord which is the blood vessels and vas deferens in abdomen.
Can testicular torsion occur in normally descended males. And what does the patient presents with.
Yes it can occur but it is rare. Present with extreme abdominal pain. Tissue death of testes if restricted bloodflow. Can be fatal
What do the Leydig cells produce
What do the seminiferous tubule's produce
What are the leydig cells influenced by
What are the functions of Sertoli cells
Have FSH receptors which control spermatogenesis and make some estrogen. Also support meiotic cells physically And nutritionally as they develop into spermatozoa. Protect sperm from immune system
Describe Sertoli cell tumors
Form of testicular cancer. More common in older dogs and cats. Affects only intact males and more common in cryptorchid than those with decended testes
What are the clinical signs of Sertoli cell tumors
Feminization of animal due to increased estrogen production, alopecia. Mammary gland growth, atrophy of penis, pendulous prepuce, attraction of other males,squatting to urinate
What is the treatment for Sertoli cell tumors
Castration and chemotherapy if it metastasized
What are testicular tumors do too
Neoplasia of Laidig or Sertoli cells
Describe Laidig cell tumors
Rare. Remain benign. No obvious symptoms other than testicular tumor.
What is the protective testicular capsule of dense regular connective tissue
What divides the testes into lobes of seminiferous tubule's
Describe the epididymis
Long convoluted tubule connecting efferent ducts of testes to the ductus deferens which is the site of storage and maturation of spermatozoa.
What is the ductus deferens
Part of the spermatic cord. Paired tubes composed of smooth muscle and columnar epithelium (simple or ciliated pseudostratified). Propels sperm out through the uterus.
What is the ampulla
Enlargement of vas deferens prior to joining the urethra. Not present in all species. Glandular in some. Contributes to semen.
describe the spermatic cord
Compose the vas deferens, lymphatic and blood vessels, nerves, muscles. Sheathed in connective tissue. Countercurrent heat exchange mechanism between network of veins and the testicular artery. Reduces heat loss from body core to keep testicles cooler.
What are the vaginal tunics
Two layers of connective tissue surrounding each testy. Derived from peritoneum during development.
What is the visceral vaginal tunic
Thin, transparent, covers testes. Derived from visceral peritoneum which is Serous tissue covering testes when they're developing in the abdominal cavity.
What is the parietal vaginal tunic
Fibers soccer around testes and cord. Derived from parietal peritoneum
What are considered the male accessory reproductive glands
Seminal vesicles, prostate gland, bulbourethral gland
What is the purpose of the accessory reproductive glands in males
Contribute fluid and substances to the sperm to form semen.
Alkaline substances to neutralize acidity of the female reproductive track,
fructose, electrolytes for energy and metabolic processes,
prostaglandins to stimulate contractions of female reproductive tract.
What is benign prostatic hyperplasia
Very common in uncastrated dogs 60% at five years old, 95% at nine years old. Hormonal problem due to androgen and estrogen ratio.
What are the clinical signs of benign prostatic hyperplasia
Difficulty in defecation, urination, hematuria
How do you treat benign prostatic hyperplasia
What are the functions of the urethra
Dual function. Carry urine and semen. During ejaculation sphincter closes off urine from the bladder
What tissue type is the urethra composed of
Transitional and stratified squamous epithelium
What are the two portions of their urethra
Pelvic urethra. Penile urethra
Describe the penis
Urethra passes through to deliver urine and semen
Describe the route of the penis
The base, connected to pelvis by connective tissue and muscle.
Describe the body of the penis
Composed of erectile connective tissue that fills with blood
Describe the glans of the penis
The tip of the penis, highly sensitive, shape varies among species.
What is the skin that covers the tip of the nonerect penis
Describe the erectile tissue in the body of the penis
Sinuses with fibrous connective tissue filled with blood upon stimulation. Blood flow in is greater than blood flow out equals direction. Veins are compressed
What is the os penis
Bone in the body of the penis dorsal to urethra
What are the bulbourethral glands
Become slowly enlarged during erection and tie the pair together even after ejaculation for several minutes
What is the sigmoid flexure in ruminants
S shaped curvature of non-erect penis. Held in Fletcher by retractor penis muscle. During erection penis straightens rather than enlarges
Why do we collect semen
For purpose of artificial insemination, for evaluating sperm quality witches shape motility and density.
How do we collect semen
Manual expression, artificial vagina, electroejaculation
What are the functions of the female reproductive system
Make female sex hormones, make ova, receive sperm from male, nurtured developing embryos, care for offspring after birth
How are the reproductive structures held in place
Peritoneal sheets of mesentery suspend the reproductive structures. Called broad ligaments
What is the suspensatory ligament
Suspends ovaries from body wall
What is the round ligament
Connects uterine horn to inguinal ring
What is the ovarian ligament
Canex the ovary to the uterus and horn
What do you have to ligate during the ovariohysterectomy before cutting the ligaments and removing the organs
The ovarian pedicle
Describe the ovaries
Paired organs in the abdominal cavity near kidneys. Size and shape varies among species. Site of oogenesis
Where is estrogen made. What is its purpose
Estrogen is made by the developing follicle cells of Oocytes. Prepares female for breeding
Where is progesterone made. What is it for
Purge estrone is made by the corpus luteum. Prepares uterine lining for implementation and maintains uterine lining if implanted.
What do the oviducts consist of
The fallopian tubes and the uterine tubes
Describe the Oviducts
Paired, convoluted tubes extending cranially from uterus to ovaries. Not attached to ovaries.
What is the infundibulum
Funnel shaped opening at distal end of uterus
What do the fimbrae do
Catch ovum after ovulation
What are the oviducts composed of
Smooth muscle, ciliated columnar pseudostratified epithelium
What is the function of the oviduct
Transport egg to uterus. Site of fertilization
Describe the uterus
Muscular, thick walled Organ that's Y shaped and many uterine horns. Site of embryonic development. Forms part of the placenta along with the embryo
Describe the cervix
Thick muscular sphincter that separates uterus body from vagina. Normally closed except during estrus and parturition.
What are the three layers of the uterus
Perimetrium: visceral peritoneum serous tissue.
Myometrium: layers of smooth muscle. Endometrium: similar columnar epithelium with simple tubular glands, blood vessels.
What is the function of the uterus
Secrete mucus, nutrients for developing embryo
What is pyometra
Infection in the uterus
Describe the vagina
Mucosal lined elastic tube of smooth muscle which receives penis and sperm and extends from cervix to Volvo
Describe the Vulva
External opening to female reproductive tract
What is the vestibule
Entrance into the vagina
What is the labia
External lips, folds of skin
What is the clitoris
Sensitive tissue homologous to penis, on floor of vestibule.
What is the vesicular bulbs
Erectile tissue and mares and bitches
What is a prolapse of the vagina or uterus
Protrusion. Dropping of pelvic organs
What controls the ovarian cycle
Hormonally controlled cyclic cycles of ova development.
When does the ovarian cycle begin
Begins at sexual maturity and continues until death
What are the processes of the ovarian cycle
Ova development, ovulation, colitis, fertilization, implantation
List the ovarian cycle from start to finish
Several primary follicles containing primary oocyte begin to develop. One or more will develop into the graafian follicle containing the secondary Oocyte. Follicles rupture causing ovulation. Ruptured follicle's develop into corpus luteum.
List the six steps of follicle development
Secondary follicle – late to secondary follicle.
Mature Vesicular follicle.
Corpus luteum forms
Where is the GNRH hormone released from, why is it released and what are the target cells
It is released from the hypothalamus in response to environmental cues. Target cells are the anterior pituitary gland
Where does the FSH hormone come from and what does it do
Comes from the anterior pituitary gland and stimulates follicle development
Who produces estrogen and what does it do
The follicle cells produce estrogen. It stimulates secretion of luteinizing hormone from anterior pituitary gland. Causes negative feedback on follicle-stimulating hormone.
What hormone released triggers ovulation
What produce progesterone
The corpus luteum
What does progesterone do
Stimulates female mating behaviour.
Prepares endometrium for implantation.
What happens with progesterone if no fertilization occurs
Corpus luteum breaks down and GNRH is no longer inhibited.
What happens to the endometrium if there's no progesterone
What hormones does the uterus produce
What do prostaglandins do to the corpus luteum
It's deteriorates thus decreases progesterone levels
What does the embryo do with the prostaglandins
Blocks release of prostaglandins from uterus thus allowing CL to continue to release progesterone and maintain endometrium until a placenta is formed
Common in dogs not cats. Corpus luteum remains for 6-7 weeks after ovulation. High progesterone levels stimulate pregnancy changes (eg. Mammary gland development, maternal behaviour). High progesterone levels affect some dogs more than others.
What is estrus
Time when females will be most receptive to males. Time when she is most likely to get pregnant
What is polyesteous
Cycle continuously throughout year if no pregnancy (cattle, swine)
What animals are seasonally polyesteous
Horses, sheep, cats
What is diestrous
2 cycles per year (dogs)
What is monoestrus
1 cycle per year (foxes and minks)
What is seasonally polyesteous animals affected by
Cycle affected by length of day (pineal gland, melatonin)
What do short day breeders do
Cycle during fall/winter (Sheeps, goats)
What are long day breeders
Cycle during spring/summer (horses,cats, hamsters, ferrets)
Describe the monoestrus cycle
Describe the polyesteous cycle:
What is the length of time spent in each stage dependant on
Species and type of estrus cycle
What is Anestrus
Period of ovarian inactivity, seen in seasonally polyestrous, diestrous and monoestrus females. Polyesteous females don't have Anestrus
What is proestrus
Period of follicular development (due to FSH secretion), increasing estrogen production, physical changes to reproductive tract lining (thickening of uterine lining, start of keratinization of vaginal epithelium)
Period of sexual activity
Reproductive tract in under influence of estrogen
What is estrus
Period when female is most receptive to male; high estrogen stimulates behavioural changes (vocalizations, flagging tail)
Describe the changes that estrus causes
Decreasing FSH levels
Vaginal epithelium is cornified
Ovulation usually occurs in end of period
Some species are induced ovulators and will remain in estrus if no coitus (cats, mink, ferrets)
What is monoestrus
Period after ovulation, development of corpus luteum, Progesterone production.
What changes come from monoestrus
Reproductive tract is under influence of progesterone
Females no longer interested in males
Endometrium is thick and juicy
Declining cornification of vaginal epithelium
What is special about monoestrus
Sometimes called diestrous and lumped in with next phase in cats and horses
What is diestrus
Luteal phase; corpus luteum has reached maximum size
What changes happen in diestrus
How do you determine what stage of estrus a female is in
Vulva swelling + discharge
Thickness of vagina + uterine wall
In a vaginal cytology what can you see
Wbc, rbc, bacteria.
Changes in squamous epithelial cells: cytoplasmic ratio, size of cells
Which cells are cornification
Anucleur and superficial
What color are cornified cells
What cells are non cornified
Intermediate and parabasal.
What color are non cornified cells
How do you remember the cornification
Pisa (non cornified to cornified)
Describe the transport of sperm
Copulation(coitus) ➡️ ejaculation. The sperm is deposited in cranial portion of vagina. Except for horse and pig.
What is transport aided by
Sperm motility (flagella powered by ATP)
Uterine contractions (due to oxytocin)
When is female the most receptive for sperm
Female is most receptive just prior to ovulation so sperm should should be in oviducts and ready to fertilize by the time of egg release
What is capacitation
Series of changes occurring in sperm to allow fertilization
What changes happen in sperm
Increase in sugar metabolism, ATP made.
Sheds proteins and fats that cover it
Release enzyme from acrosome which will allow sperm to digest through layers surrounding ovum
How many sperm can fertiliZe an egg
What happens in the zone pellucida
Hardens once 1st sperm binds to ovum receptors, prevents other sperm from entering
Where does fertilization occur
In the oviduct
What do male and female haploid pronuclei join to form
A diploid ️nucleus
What is a zygote
Single diploid cell
What is cleavage
Embryonic cell division: mitosis of zygote
Increased in cell # but not size: rapid division and hardened zona pellucida prevents expansion of cells
What is a morula
Solid ball of cells
What is a blastocyst
Hollow ball of cells
Describe implantation in multiparous
Blastocytes distribute themselves equally between uterine horns
What happens to blastocytes in zona pellucida
Break out of hardened zona pullicida invade hypertrophied endometrium using digestive enzymes.
When does incubation happen in dogs
14-20 days in bitches
When does incubation happen in cats
When does incubation happen
9 days in humans
What does the placenta do
Nourishes the developing embryo
Describe the inner cell mass (future embryo)
Forms 3 germ layers by process of gastrulation
Germ layers form embryo and some of extra embryonic membranes
What is a trophoblast (future placenta)
Develops into some of the extra embryonic membrane.
In mammals these membranes become the placenta and the umbilical cord
What do germ layers (embryonic tissue) form
All tissues/organs of animal
What is an ectoderm
Outer layer of cells. Forms nervous system and epidermis.
What is neurolation
Formation of nervous system
What is mesoderm
Middle layer of cells.form most organs (dermis, heart, bones and muscle)
What is endoderm
Inner layer of cells that forms the lining of digestive, respiratory and urogenital tract
What are extra embryonic layer membranes
Tissues that don't form the embryo but are important to its development
What is the placenta
Formed from chorion (extra embryonic membrane)
Attached to uterine wall
Site of exchange of gas, nutrients waste between fetal and maternal capillary bed.
What does umbilical cord form from
Yolk sac and allantois.
How many umbilical arteries carry deO2 blood away from fetus
How many umbillical veins carry O2 blood to fetus
What is a diffuse placental attachment
Easy to shed and detaches easily (horses and pigs) from uterus
What is cotyledonary placental attachment
Many attachments (placentomes) difficult to shed and retained placenta (ruminants)
What is zonary placental attachment
Band of attached tissue that is easily shed (cats, dogs)
What is the discoid placental attachment
Disk attachment site (primates and rodents)
What is pregnancy
Gestational period, time between implantation and parturition. Divided into trimesters.
What is the first trimester called