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WorksheetsChapter 10: Reproductive Hormones Introduction
Total questions: 30
Worksheet time: 15mins
Refer to the diagram of the male reproductive endocrine axis. Which statement best describes the initiating control and primary functions of this system as outlined?
Initiated by the pituitary; functions are estrogen (E2) synthesis and oogenesis
Initiated by the hypothalamus; functions include testosterone (T2) production and spermatogenesis
Initiated by the testes; functions are LH and FSH secretion only
Initiated by the adrenal cortex; functions include inhibin and progesterone release
Based on the female reproductive system overview in the figure, which pairing correctly matches a hormone with a listed physiological role?
Progesterone (P4) — stimulates spermatogenesis
Estrogen (E2) — supports oogenesis, estrus, and ovulation
Follicle-stimulating hormone (FSH) — initiates lactation without ovarian involvement
Luteinizing hormone (LH) — maintains gestation independent of progesterone
Using the estrus cycle summary and graph, during which phase does an LH surge coincide with peak estrogen (E2) and lead to ovulation?
Proestrus
Estrus
Metestrus
Diestrus
According to the diagram of steroid hormone response, what is the immediate cellular consequence after the steroid-receptor complex binds DNA in the nucleus?
Activation of a signal transduction cascade at the cell membrane
Opening of voltage-gated ion channels
Initiation of mRNA transcription leading to protein synthesis
Release of stored calcium from the endoplasmic reticulum
In the depicted peptide hormone response pathway, which event occurs first upon hormone binding to the receptor?
Translocation of the hormone–receptor complex into the nucleus
Direct binding of the complex to DNA response elements
Membrane-localized receptor activation that triggers a signal transduction cascade
Immediate synthesis of structural proteins without intermediates
Which statement best distinguishes steroid hormone action from peptide hormone action as illustrated?
Steroid hormones act by activating membrane receptors to trigger second messengers, while peptides directly regulate gene transcription.
Steroid hormones directly regulate gene transcription via intracellular receptors; peptides act through membrane receptors and cascades.
Both steroid and peptide hormones must enter the nucleus before any cellular response occurs.
Peptide hormones primarily alter DNA methylation, whereas steroids only change membrane potentials.
Which clinical indication aligns with GnRH use based on the material?
Treatment of hypothyroidism by increasing TSH secretion
Induction of ovulation and medical castration
Enhancement of insulin release in type 2 diabetes
Immediate reversal of GnRH receptor desensitization
Prolonged exposure to GnRH can lead to which side effect mentioned in the material?
Up-regulation of GnRH receptors resulting in hypersensitivity
Desensitization and down-regulation of GnRH receptors
Permanent destruction of pituitary tissue
Autoimmune attack on hypothalamic nuclei
Refer to the diagram showing the natural cycle versus the hormonal cycle with GnRH analogue. Which statement best explains why FSH and LH secretion becomes suppressed after continued GnRH analogue administration?
GnRH analogues permanently destroy pituitary cells that produce FSH and LH
Down-regulation of GnRH receptors reduces pituitary responsiveness, lowering FSH/LH release
Analogues convert FSH and LH into inactive metabolites within the ovary
GnRH analogues block hypothalamic synthesis of native GnRH
FSH and LH are diluted by increased blood volume during treatment
A farm implements an Ovsynch protocol starting with a GnRH injection, followed by PGF2α seven days later, then another GnRH two days after PGF2α. What physiological events are intended between the first GnRH and the timed artificial insemination (TAI)?
Follicular cyst formation and persistent CL
Ovulation/luteinization of the dominant follicle, luteolysis, and ovulation of a new dominant follicle
Immediate medical castration and permanent anestrus
Suppression of GnRH receptors preventing LH surge
Compared with gonadorelin, which characteristic is most accurate for buserelin?
Less potent and slower to induce LH surge
More potent and induces an LH surge within hours
Equivalent potency with prolonged duration only
Acts primarily as a GnRH antagonist in rabbits
Which dosing guideline aligns with the material for using buserelin across species?
Cattle 100–200 µg; horses 40 µg; pigs 10 µg/head
Cattle 10–20 µg; horses 40 µg; pigs 10 µg/head
Dogs 4.7 or 9.4 µg/dog; ferrets 10 µg/head
Cattle 5 µg; horses 10 µg; pigs 1 µg/head
What adverse effects and monitoring considerations are associated with deslorelin according to the material?
Severe systemic anaphylaxis is common; no monitoring required
Local inflammation and decreased libido; allergy is rare but requires monitoring
Renal failure and hypertension; routine ECG only
Profound hypoglycemia; continuous glucose monitoring mandatory
Which product form is specifically shown for deslorelin and what is its typical dose in small carnivores?
Injectable solution; dogs/ferrets 100–200 µg
Oral tablet; dogs/ferrets 1 mg/kg
Implant; dogs/ferrets 4.7 or 9.4 µg/dog
Transdermal patch; pigs 10 µg/head
Which synthetic GnRH agonist is commonly used for estrus synchronization programs across ruminants due to its ability to activate FSH receptors and drive folliculogenesis?
Gonadorelin
Buserelin
Deslorelin
Equine chorionic gonadotropin (eCG/PMSG)
Gonadorelin’s primary indication in veterinary practice is best described as which of the following?
Treatment of follicular cysts via LH surge induction
Long-term contraception through downregulation of GnRH receptors
Superovulation program with precise recombinant dosing
Postpartum anestrus treatment using chorionic gonadotropin
Deslorelin implants are most appropriately indicated for which scenario in veterinary reproduction?
Synchronizing estrus in ruminants during breeding season
Inducing ovulation and managing reproductive timing in species such as horses or companion animals
Treating postpartum anestrus in dairy cattle
Replacing FSH in superovulation protocols for goats
Which potential side effect can occur due to administering cross‑species protein hCG?
Anti‑hCG antibody formation
Hyperthyroidism
Severe hypoglycemia
Anaphylactic shock unique to r-FSH
Which statement best describes the pharmacologic role of human chorionic gonadotropin (hCG) in reproductive therapy?
It acts as a follicle-stimulating hormone (FSH) analog to promote follicular growth.
It functions as a luteinizing hormone (LH) analog to trigger ovulation and luteinization.
It mimics prolactin to enhance milk letdown during lactation.
It primarily inhibits GnRH release to suppress estrus.
A clinician aims to induce rhythmic uterine contractions during labor while avoiding contraindicated scenarios. Which situation is a clear contraindication to oxytocin administration?
Post-term pregnancy with intact membranes and cephalic presentation
Uterine atony after delivery of the placenta
Known cephalopelvic disproportion or obstructed labor
Elective induction at term with favorable cervix
Carbetocin is often discussed alongside oxytocin. Which statement best distinguishes carbetocin from oxytocin in clinical use?
Carbetocin is a long-acting oxytocin analog used to sustain uterine tone postpartum
Carbetocin is a dopamine antagonist that suppresses prolactin
Carbetocin is a prostaglandin analog that causes luteolysis
Carbetocin is a glucocorticoid that promotes fetal lung maturity
Which statement best describes dopamine’s role in regulating prolactin in lactogenesis?
Dopamine stimulates prolactin secretion from the anterior pituitary
Dopamine inhibits prolactin release, thereby reducing lactogenesis
Dopamine converts prolactin to progesterone in the mammary gland
Dopamine has no interaction with prolactin during lactation
In an animal with agalactia due to inadequate prolactin activity, which intervention aligns with the mechanism of action of bromocriptine/cabergoline?
Avoid dopamine agonists because they reduce prolactin needed for milk production
Use dopamine agonists to enhance prolactin signaling in the mammary gland
Block progesterone synthesis to increase prolactin release
Administer PGF2α to stimulate lactogenesis via uterine contractions
During the luteal phase of the estrous cycle, which statement best describes the primary physiological role of Prostaglandin F2α (PGF2α)?
Stimulates granulosa cell proliferation to promote follicular dominance
Induces luteolysis by causing regression of the corpus luteum
Enhances endometrial proliferation through positive feedback on LH
Maintains progesterone secretion from the corpus luteum
Which potential effect should be considered when using pharmacological preparations of PGF2α for reproductive management?
Risk of maintaining the corpus luteum and delaying estrus
Possible systemic side effects associated with prostaglandins such as smooth muscle contraction and transient discomfort
Enhanced estrogen synthesis leading to persistent positive feedback on LH
Development of bone marrow aplasia similar to historical concerns with certain estrogen analogs
According to the material, which adverse effect is specifically noted in dogs following estradiol administration?
Aplastic anemia
Hypoglycemia
Hepatic lipidosis
Pulmonary edema
Estrus induction and ovulation with estrogen depend on feedback that increases luteinizing hormone (LH). Which preparation aligns with this mechanism as an estrogen used in practice?
Estradiol benzoate
Medroxyprogesterone acetate
CIDR intravaginal implant
Diethylstilbestrol is a progestin
Recall/Skill: Which clinical use is linked to estrogen preparations in reproductive management protocols?
Induction of abortion through luteolysis support
Treatment of urinary incontinence due to urethral sphincter mechanism incompetence
First-line therapy for pyometra in intact bitches
Stimulating lactation by upregulating prolactin receptors
Which application aligns with a pharmacological preparation of progesterone (P4) in reproductive management?
Emergency treatment of uterine inertia by increasing contractions
Contraception by suppressing estrus through GnRH inhibition
Induction of parturition by stimulating oxytocin receptors
Enhancement of spermatogenesis via FSH activation
When using P4 analogs for estrus control, which consequence should be anticipated due to endocrine feedback?
Increased GnRH secretion leading to hyperfertility
Suppressed GnRH secretion that decreases LH/FSH availability
No change in hypothalamic activity but elevated uterine tone
Direct destruction of ovarian follicles without hormonal change
