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ANSC4045 - quiz [2]
for exam 2: cyclicity, phases, estrous control, male endo, sperm + semen
| Term | Definition |
|---|---|
| mare cycle classification | • long-day breeder |
| mare estrus duration | • 7 days |
| sow cycle classification | • polyestrus |
| sow estrus duration | • 50 hours |
| ewe cycle classification | • short-day breeder |
| ewe estrus duration | • 30 hours |
| cow cycle classification | • 15 hours |
| cow estrus duration | • 15 hours |
| During proestrus, there is a significant rise in [1] produced by maturing follicles. When [1] reaches certain levels, the female becomes [2] followed by [3]. | 1. estradiol 2. sexually receptive 3. ovulates |
| During metestrus, there is a rise in [1] as a result of luteinization of follicle cells. Sustained secretion of [1] makes the female [2]. | 1. progesterone 2. sexually unreceptive |
| The menstrual cycle is characterized by endometrial sloughing after luteolysis, initiated by [1]. In the menstrual cycle, [1] inhibits GnRH and has [2] on sexual receptivity. | 1. uterine PGF2a 2. no influence |
| With increasing age, females having menstrual cycles experience follicular depletion, which causes the ovary to stop producing hormones. This is known as: | • menopause |
| definition of anestrus | • a period in which reproductive cyclicity stops |
| definition of estrus | • a period of sexual receptivity |
| definition of estrous cycle | • a series of reproductive events, starting with sexual receptivity and ending with the subsequent period of sexual receptivity |
| In the menstrual cycle, inhibin produced by the corpus luteum has the following role: | • suppress FSH and LH during the luteal phase |
| T / F : In seasonal breeders, increasing light periods causes pineal gland to secrete less melatonin. Low melatonin --> high RFRP3 --> stimulation of kisspeptin neurons in short-day breeders --> GnRH starts reproductive cyclicity | • false; this applies to long-day breeders |
| T / F : Ovulation marks the beginning of both the estrous and menstrual cycles. | • false; estrous cycle begins with estrus and menstrual cycle begins with menstruation |
| The preovulatory LH surge also causes increase in enzyme [1] in the preovulatory follicle, which degrades the basement membrane separating granulosa and theca interna cells. After luteinization, granulosa cells become [2] and theca interna cells [3]. | 1. collagenase 2. large luteal cells 3. small luteal cells |
| The uterus is not necessary for luteolysis in sub-primate mammals. The luteolytic agent [1] is directed through a countercurrent system from the [2] into the [3]. | 1. PGF2a 2. utero-ovarian vein 3. ovarian artery |
| In the first follicular wave, follicles that were recruited and selected do not become dominant due to [1]. In the second, one follicle becomes dominant, causing the others to become [2]. | 1. high progesterone 2. atretic |
| The dominant follicle produces [1] which has positive feedback on the hypothalamus, resulting in increased GnRH pulse frequency. Thus, the [2] occurs, then [3] occurs. | 1. estradiol 2. LH surge 3. ovulation |
| hormonal dynamics during follicular recruitment | • low estradiol • low FSH • high LH pulse frequency |
| hormonal dynamics during follicular selection | • low inhibin • low FSH • moderate LH pulse frequency |
| hormonal dynamics during follicular dominance | • high inhibin • low FSH • high LH pulse frequency |
| effect of total hysterectomy on CL lifespan | • CL lifespan is comparable to normal gestation length |
| effect of partial hysterectomy (ipsilateral to CL) on CL lifespan | • CL lifespan is longer than normal cycle length |
| effect of partial hysterectomy (contralateral to CL) on CL lifespan | • CL lifespan is comparable to in a normal cycle |
| Species that ovulate a single oocyte per cycle are referred to as: | • monotocous |
| Two steps of the 2-cell, 2-gonadotropin model for estradiol synthesis | 1. LH binds to receptor on theca interna cell, stimulates enzymatic transformation of cholesterol --> testosterone 2. testosterone enters the granulosa cell; when stimulated by FSH, aromatase converts testosterone --> estradiol |
| Timeline for fixed time AI protocol: | 1. D0: GnRH 1st 2. D0 - D5: CIDR 3. D5 - D6: PGF2a 4. D8: GnRH 2nd 5. 16h + AI |
| The hypothalamus in the male lacks a surge center. Therefore, [1] is released in short regular pulses + stimulates gonadotropin secretion. LH binds to receptors on [2] + stimulates synthesis + release of [3]. | 1. GnRH 2. Leydig cells 3. testosterone |
| In [1], testosterone is converted into [2] or estradiol. Estradiol + testosterone have [3] feedback on GnRH neurons. | 1. Sertoli cells 2. dihydrotestosterone 3. negative |
| structures in the mature sperm cell: arranged in helical pattern, provide energy for motility | • mitochondria |
| structures in the mature sperm cell: contains hydrolytic enzymes that are vital to fertilization | • acrosome |
| Effect of single dose of PGF2a on bovine cycle length when cow is in metestrus (D0 - D5): | • no effect on CL • no response to treatment |
| Effect of single dose of PGF2a on bovine cycle length when cow is in proestrus: | • no effect on CL • estrus in 2 - 4 days |
| Effect of single dose of PGF2a on bovine cycle length when cow is in diestrus (D6 - D17): | • CL regression • estrus in 2 - 3 days |
| The release of spermatozoa from Sertoli cells into lumen of seminiferous tubules is known as: | • spermiation |
| T / F : The estrus synchronization protocol consisting of two PGF2a injections is advantageous because it yields consistently high conception rates + can induce estrus in non-cycling females. | • false; it does yield consistently high conception rates but cannot induce estrus in non-cycling females |
| Which two species require pressure applied through the artificial vagina for ejaculation? | 1. ram 2. boar |
| Which two species do not require pressure applied through the artificial vagina for ejaculation? | 1. bull 2. stallion |
| bull ejaculate volume | • 5 - 6 mL |
| ram ejaculate volume | • 0.75 - 1.2 mL |
| boar ejaculate volume | • 150 - 300 mL |
| stallion ejaculate volume | • 75 - 100 mL |
| bull ejaculate concentration | • 1,000 - 1,500 million sperm per mL |
| ram ejaculate concentration | • 1,500 - 3,000 million sperm per mL |
| boar ejaculate concentration | • 100 - 150 million sperm per mL |
| stallion ejaculate concentration | • 100 - 150 million sperm per mL |
| bull matings per ejaculate | • 350 |
| ram matings per ejaculate | • 20 - 25 |
| boar matings per ejaculate | • 20 |
| stallion matings per ejaculate | • 40 - 60 |
| beef bull semen collection method | • electro-ejaculation |
| stallion semen collection method | • artificial vagina |
| boar semen collection method | • gloved-hand technique |
| What are the main semen extender requirements? | 1. protect from cold shock 2. buffer pH 3. nutrients for sperm metabolism 4. cryoprotection 5. isotonic to semen |
| What are some benefits of artificial insemination? | 1. helps prevent disease spread 2. maximizes number of offspring per ejaculate |
| T / F : Electro-ejaculation yields both larger volumes + higher sperm concentrations vs. collection with an artificial vagina. | • false; through electro-ejaculation, semen volume increases while concentration decreases. |
| What slows sperm metabolic rate to allow for indefinite storage? | • cryopreservation |
| What is the most common assessment of sperm viability? | • motility |
| What is the percentage of sperm moving in a forward pattern? | • progressive motility |
| What is used to determine the number of breeding doses after semen collection? | • concentration |
Created by:
junoreg
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