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ANSC4045 Exam 3 Questions And Answers
- Dairy bull: Ejaculate volume Ejaculate motility Ejaculate concentration
- Beef bulls: Ejaculate volume Ejaculate motility Ejaculate concentration Matings/Ejaculate
- Ram/Bucks: Ejaculate volume Ejaculate motility Ejaculate concentration Matings/Ejaculate
- Boars: Ejaculate volume Ejaculate motility Ejaculate concentration Matings/Ejaculate
- Stallions: Ejaculate volume Ejaculate motility Ejaculate concentration Matings/Ejaculate
- Environmental parameters for sperm survival
Volume: 5-6mL Motility: 50-80% Concentration: 1000-
Volume: 4-5 mL Motility: 40-70% Concentration: 1000- Matings/Ejaculate: 350
Volume: 0.75-1.2mL Motility: 60-80% Concentration: 1500- Matings/Ejaculate: 25/
Volume: 150-300mL Motility: 50-70% Concentration: 100- Matings/Ejaculate: 20
Volume: 75-100mL Motility: 40-70% Concentration: 100- Matings/Ejaculate: 40-
Temperature pH (Optimum pH: 6.9-7.5) Osmotic pressure Light Concentration Hormones Gases
- Semen extender requirements Isotonic to semen Act as a buffer to maintain pH
ANSC4045 Exam 3 Questions And Answers
- Nutrients to provide for semen extender
- What are the two main functions of extending sperm?
- Amount of extender added to se- men depends on what two pri- mary factors?
- What is the dilution of semen ex- tender in boars?
- What is the dilution of semen ex- tender in stallions?
Protect against cold shock Provide nutrients for sperm metabolism Prevent bacterial growth Provide cryoprotection Preserve fertility
Fructose or glucose
- Expand lifespan of spermatozoa
- Increase volume to breed multiple fe- males
- Sperm concentration
- Number of females to be bred
1:4 to 1:
1:1 to 1:
- What does cooling sperm do? It results in a longer lifespan of 24- hours without a decline in fertility
- What happens if sperm is cooled too quickly?
- What industry almost exclusive- ly uses frozen semen?
- Requirements for cryopreserva- tion
- What usually causes the most damage in cryopreservation?
The cool shock will kill sperm cells
Cattle industry
Cryoprotective agent (Glycerol) Cooling conditions that allow spermato- zoa to dehydrate Warming conditions that prevent ice crys- tal formation
Ice crystals
- Receptivity Copulatory behavior of females that en- sures insemination, such as lordosis
- Lordosis Immobility or "standing" response
- Describe the nervous system pathway for reproductive-spe- cific behavior
Sensory --> Hypothalamus --> Midbrain --> Medulla --> Spinal cord
- What is a pheromone? A volatile substance secreted or released from the body and perceived by the ol- factory system and/or activated by the vomeronasal organ
- Vomeronasal organ An accessory olfactory organ that de- tects pheromones
- Flehmen response Sexual behavior in the male of several species in which the male curls his upper lip and inhales
- What are some examples of pre- copulatory behavior?
- Why are bulls put in "warm up" stalls prior to semen collection?
- What completes the precopula- tory phase?
- In the bull, ram, and boar there is simultaneous relaxation of what muscle during protrusion?
- Erection of the penis requires what 5 things?
Unique vocalization or mating calls
To observe ejaculatory behavior of an- other bull to reduce stimulation time and increase sperm production
Penile erection and protrusion
The retractor penis muscles
- Elevated arterial blood inflow
- Dilation of corporal sinusoids
- Restricted venous outflow
- Elevated intrapenile pressure
- Contractions of what muscles compress the penile veins?
- There is a buildup of blood where during erection?
- What is nitric oxide and what is its purpose in the erectile process?
- Relaxation of the retractor penis mus- cle
Ischiocavernosus muscles
Corpus cavernosum
It is the principle neurotransmitter that drives the process
- How does viagra work? Acts on an enzyme in the nitric oxide pathway to initiate/maintain erection
- What releases nitric oxide? Non adrenergic noncholinergic parasym- pathetic neurons
- What two stimuli are required for ejaculation?
- Ejaculation requires the con- traction of what three muscles?
Temperature and pressure
Urethralis, bulbospongiousus, and is- chiocavernosus muscles
- What is emission? Movement of seminal fluids into pelvic urethra to mix with spermatozoa
- What is the refractory period? Occurs in all males- must occur before a second ejaculation can occur
- How can you enhance reproduc- tive behavior?
- Why is artificial vagina pre- ferred?
- Electroejaculation is preferred when?
Introducing novel stimulus Changing stimulus settings Sexual preparation
Better quality semen
With males that cannot mount and ejac- ulate
- Why is docking crucial to sperm survival?
Promotes cascade in sperm that pro- motes viability. Without docking, sperm die within 6-10 hours after insemination
- With completion of capacitation, They become hyper motile what happens to sperm?
- Sperm capacitation is initiated in the and completed in the
Uterus, oviduct
- Zona pellucida Non cellular "shell" outside the cellular membrane of the oocyte
- What are the 3 glycoproteins found in the zone pellucida?
ZP1, ZP2, and ZP
- What initiates the acrosomal re- action?
Binding
- Acrosomal reaction A fusion of the spermatozoa plasma membrane and the outer acrosomal membrane
- Vesiculation Formation of many small vesicles
- What enzyme aids in penetra- tion of the zona pellucida?
Acrosin
- Define fertilization Plasma membrane of the equatorial seg- ment of the sperm is still intact and fuses with the plasma membrane of the oocyte
- The oocyte plasma membrane and contents of the cortical granules are released where?
Perivitelline space
- It decondenses
What happens to the nucleus of the sperm after membrane fu- sion?
- Cortical reaction Enzymes prevent any other sperm from binding to the egg
- After fusion of membranes, what happens to cortical granules?
They undergo exocytosis and contents are released into the perivitelline space
- Vitelline Block that changes the polarity and/or membrane receptors of the oocyte so that no more sperm can fertilize
- Syngamy The fusion of two gametes in fertilization.
- The fertile period for sperm is short in species such as ...
- The fertile period for sperm is long in species such as ...
- In cows, how approximately how much spermatozoa is lost dur- ing AI?
- Name the type of artificial in- semination in each species: Cow Mare Sow Bitch
The cow
Dog, mare, woman
Cow: Transcervical Mare: Transcervical Sow: Intracervical Bitch: Intravaginal
- Embryo Organism in the early stages of develop- ment
- Fetus Potential offspring within the uterus
- Conceptus Product of conception
Maternal recognition of preg- nancy
The process by which the embryo signals its presence to the mother
- What does oxytocin do? Stimulates endometrial cells to synthesis PGF
- How is oxytocin related to lute- olysis?
- In the ewe and cow, how is lute- olysis prevented?
- What happens to oxytocin re- ceptors in the absence of a con- ceptus?
- What happens to oxytocin re- ceptors in the presence of a con- ceptus?
- In the non-pregnant sow, what happens to oxytocin?
- In the pregnant sow, what hap- pens to oxytocin?
- Movement must occur during what days in the mare to inhibit PGF?
CL of ruminants produce oxytocin, which stimulates endometrial cells to synthe- size PGF. If sufficient receptors are avail- able in the secretion of PGF, luteolysis occurs
Free-floating blastocyst produces specif- ic proteins that provide signal
Oxytocin receptors increase over time and oxytocin interacting with those re- ceptors stimulates pulsatile release of PGF and luteolysis
Oxytocin receptors do not increase and the secretion of PGF is prevented
Oxytocin from the corpus luteum and/or pituitary promotes PGF synthesis by endometrium which enters endometrial capillaries and enters the uterine vein and is transported to the corpus luteum resulting in luteolysis
The blastocyst produces estradiol that causes PGF to be rerouted into the uter- ine lumen where it is destroyed
12-
Maternal recognition of preg- nancy in humans
- Why does maternal recognition of pregnancy in dogs and cats not require a signal from the conceptus?
The conceptus secretes a hormone called human chorinoic gonadotropic (hCG). This is a LH-like hormone that inhibits intraovarian luteolysis
Dog: CL of pregnancy and CL of cycle have similar lengths Cat: Induced ovulation. Without mating, the CL is not formed
- Embryo transfer Embryo is collected from one female and transferred to another female to complete gestation
- Superovulation Treatment of donor animal with go- nadotropin to produce multiple ovulations
- Synchronization Matching estrous cycle of donor and re- cipient
- Why do we transfer embryos? Increase number of offspring from select- ed females Increase offspring from select males Import/Export
- Steps of embryo transfer 1. Synchronization of recipients with donor
- Superovulation of donor
- Inseminate donor with semen from ge- netically superior bull
- Recovery and identification of viable embryos
- Transfer of viable embryos into syn- chronized recipients
- In vitro embryo production com- ponents
In vitro oocyte maturation In vitro fertilization In vitro culture
- Cotyledonary placenta Occurs in ruminants. Numerous, discrete button-like structures called cotyledons
- Cotyledon Placental unit of trophoblastic origin con- sisting of abundant blood vessels and connective tissue
- Difference between cow and ewe placentomes
Cow: Convex Ewe: Concave
- Epitheliochorial placenta Maternal blood is separated by several tissues from fetal blood. Occurs in the sow and the mare. 6 layers
- Binucleate giant cells Cells originating in the chorion of the ruminant placenta that migrate toward the endometrial epithelium and produce pregnancy specific substances
- Endotheliochorial placenta Occurs in dogs and cats. Maternal cap- illaries are directly exposed to epithelial cells of the chorion. 4-5 layers
- Hemochorial placenta Maternal blood is in direct contact with chorion. Occurs in primates and rodents. 3 layers
- How are gases and water trans- ported in the placenta?
- How are glucose and metabolic materials transported in the pla- centa?
- How are pumps for sodium and potassium transported in the placenta?
- What cannot cross the placen- ta?
Simple diffuse
Facilitated diffusion
Active transport
Nutritionally based lipids and large pro- tein hormones, such as insulin
- The placenta secretes hor- mones that can:
- What does equine chorionic go- nadotropin do?
- What is the primary role of hu- man chorionic gonadotropin?
- Human chorionic gonadotropin in non-primate females can cause what?
- Is progesterone required for ear- ly embryonic development?
- What inhibits myometrial con- tractions?
Stimulate ovarian function Maintain pregnancy Influence fetal growth Stimulate mammary function Assist in parturition
Provides a stimulus for maintenance of the primary corpus luteum. It is responsi- ble for controlling the formation and main- tenance of supplemental corpora lutea
Provide luteotropic stimulus for the ovu- latory CL as it progresses to the CL of pregnancy
Ovulation
No
Progesterone block
- Placental lactogen Polypeptide hormone produced by the placenta to promote growth of the fetus and stimulation of the mammary gland
- Describe the three stages of par- turition
- What causes stage 1 of parturi- tion?
Stage 1: Initiation of myometrial contrac- tions Stage 2: Expulsion of the fetus Stage 3: Expulsion of the fetal mem- branes
Fetal stress caused by space limitations. Secretion of adrenal corticotropin
- Relaxin Glycoprotein hormone produced by the corpus luteum or the placenta that is
