Hormone, Endocrine, Repro Flashcards
The endocrine system is composed of ___________ that secrete chemical messengers called __________ into the blood.
ductless glands, hormones
The endocrine system is controlled by a?
Feedback mechanism
The endocrine system consists includes?
Hypothalamus, pituitary gland and other endocrine glands
Hormones are?
Chemical substances produced by cells in one part of the body and transported to another part of the body where they influence cellular activity.
Two major control systems linked together by the hypothalamus?
Nervous and endocrine
Endocrine glands
Pituitary, adrenal, thyroid, ovaries, testes, pancreas, kidneys
Hormones administered for two basic reasons
Correct a deficiency and achieve a desired effect
Administered hormones
Exogenous
Naturally produced
Endogenous
Endogenous hormones are?
Naturally produced
Exogenous hormones are?
Administered
Master gland
Pituitary
Two lobes of the pituitary
Adenohypophysis
Nerohypophysis
Hypothalamus
Exerts control over anterior pituitary lobe
Uses releasing hormones of factors
The anterior pituitary lobe releases ______ hormones into the circulation.
trophic
Anterior pituitary lobe stimulates?
target organs
Feedback loops may be either?
Positive or negative
What feedback loop is more common?
Negative
What feedback loop responds to low or high levels of hormone in the body?
Negative
What feedback look occurs when hormone levels continue to rise in response to stimuli?
Positive
What gland is controlled by hypothalamus by releasing factors?
Pituitary
Anterior pituitary lobe
Adenohypophysis
Posterior pituitary lobe
Neurohypophysis
Adenohypophysis releases _______ hormones
TSH, ACTH, LH, FSH, LTH, and GH
Adenohypophysis is _____ acting
indirect
What part of the pituitary gland causes target organ to release another hormone to cause an action?
Anterior/ Adenohypophysis
What part of the pituitary gland secretes ADH and oxytocin?
Posterior/ Neurohypophysis
Neurohypophysis is _______ acting
direct
What part of the pituitary gland produces and effect directly on an organ?
Posterior/ Neurohypophysis
TSH=
Thyroid stimulating hormone
ACTH=
Adrenocorticotropic hormone
FSH=
Follicle stimulating hormone
LH=
Luteinizing hormone
GH=
Growth hormone
TSH is used in?
Diagnosis of primary hypothyroidism
ACTH is used?
To stimulate the adrenal cortex to secrete corticosteroids in the diagnosis of adrenal cortex disease.
GH is used?
To increase growth rate and feed use efficiency in livestock and increase milk production in dairy cows.
ADH=
Anti Diuretic Hormone
ADH is used?
To treat diabetes insipidus
Diabetes insipidus is?
A disease characterized by the inability to concentrate urine due to insufficient amounts of ADH.
Oxytocin is used?
To aid in uterine contraction and induce labor labor in animals at term, expel the placenta, induce milk letdown, and as an adjunct therapy for animals with open pyometra.
What feedback loop has adequate amounts in plasma signal to decrease production?
Negative
What feedback loop has decreased amounts that increase production?
Positive
Applies to release of oxytocin
Neurohormonal Reflex
The neurohormonal reflex is initiated by?
Udder stimulation by calf or milker
Stimulation of uterus/vagina for parturition
Stimulation of cerebral cortex by sensory stimuli associated with milking or nursing
Drugs that act similarly to hormones
Gonadotropins
Gonadotropins may be prepared from?
Pituitary glands of slaughtered animals
Urine of pregnant women or horses
Gonadorelin treats?
Cystic follicles, chorionic gonadotropin, cystic follicles, male infertility and cryptorchidism.
Estrogen
Promotes female sex characteristics and stimulates and maintains the reproductive tract
Synthetic estrogen
Used in dogs to prevent implantation of fertilized ova and to correct urinary incontinence, vaginitis, and dermatitis,
Used in cattle to treat persistent corpus luteum, aid in expulsion or retained placentas and mummified feti, and to promote weight gain
Used in horses to induce estrus in the non breeding season.
Estrogen side effects.
Can cause severe anemia, may be linked to human cervical cancer, do not give during pregnancy.
Male sex hormones
Androgens
Male sex hormones are produced in…?
Testicles, ovaries, adrenal cortex
Androgens promote?
Anabolism, weight gain and RBC formation
Testosterone
Made in interstitial cells of testes
Used to treat conditions such as infertility and hypogonadism, produce estrus detectors, and for testosterone-responsive urinary incontinence in dogs.
Types of Androgens
Mibolerone and Zinc gulconate neutralized by arginine
What drug blocks the release of LH from the anterior pituitary gland (therefore the follicle does not fully develop)?
Mibolerone
What drug is used to prevent estrus in adult female dogs and the treatment of false pregnancies?
Mibolerone
Adverse side effects of Mibolerone?
Premature epiphyseal closure, vaginitis, clitoral hypertrophy, riding and increases body odor. No not use on cats- very low margin of safety.
Nonsurgical neutering drug
Zinc gulconate neutralized by arginine
Chemical sterilant approved for use in _________ male dogs
3-10 month old
Chemical sterilant approved for use in young male dogs?
Zinc gulconate neutralized by arginine
What drug is used as an intratesticular injection?
Zinc gulconate neutralized by arginine
Group of compounds similar to progesterone?
Progestins
Progestins
Increase secretions by endometrium, decreased motility of uterus and increased secretory development of the mammary glands
Can cause elevations of glucose or suppression of adrenals
Used to treat false pregnancy, suppress estrus, behavioral disorders and progestin-responsive dermatitis
What drug increases secretions by endometrium, decreased motility of uterus and increased secretory development of the mammary glands
Progestins
Progestins can cause?
elevations of glucose or suppression of adrenals
Progestins are used?
To treat false pregnancy, suppress estrus, behavioral disorders and progestin-responsive dermatitis
Common name for Megesterol acetate?
Ovaban
Megesterol acetate
Labeled for dogs but used in cats for behavioral and dermatitis (Progestins)
Side effects of Megesterol acetate (Progestins)
Hyperglycemia, adrenal suppression, endometrial hyperplasia and increased appetite.
Medroxyprogesterone acetate are used for?
Behavioral and dermatological problems (Progestins)
Common name for Medroxyprogesterone acetate?
Depo-provera (Progestins)
Altrenogest
Oral drug for equines
Used for suppression of estrus
Easily absorbed through the skin
Drug used for the suppression of estrus?
Altrenogest (Progestins)
Common drug name for Altrenogest?
Regu-mate
What drug decreases uterine activity when a female is in estrus or pregnant?
Progesterone
Progestins are used in dogs to block?
Estrus
What drug is used in cattle to synchronize breeding and birth cycles?
Progestins
How many classes of Prostaglandins are there?
6 classes: A,B,S,D,E,F
Prostaglandin F2a causes…?
Lysis of corpus luteum, which initiates a new estrus cycle
In small animals, what drug is used to treat pyometra, cause abortion and induce parturition?
Prostaglandins
Prostaglandins are used in cattle for?
Estrus synchronization and induce uterine contractions to facilitate emptying of the uterus (pus or fetus)
Prostaglandins are used in horses for?
Estrus synchronization
Most important Prostaglandin in VM?
Prostaglandin F2a
Prostaglandin F2a uses?
Lyses CL uterine contractions, cervical relaxation
Prostaglandin F2a causes?
Bronchoconstriction
Increased BP
Smooth muscle contractions
Two hormones secreted by the thyroid gland?
T4- Throxine
T3- Triiodothyronine
Hypothyroidism is characterized by?
Decrease in thyroid hormone
Signs of hypothyroidism
Coat and hair luster Weight gain Listlessness, Intolerance to cold Reproductive failure
How is hypothyroidism measured?
Serum total T4 and T3 or by a thyroid stimulation test
Hyperthyroidism is characterized by ?
Increase in thyroid hormone
Signs of hyperthyroidism
PU/PD, weight loss, increased stool production, restlessness, tachycardia
How is hyperthyroidism measured?
Total T4 and T3
How is hyperthyroidism treated?
Antithyroid drugs, radiotherapy or surgical removal
Common thyroid drug?
Methimazole (tapazole)
Two hormones of the pancreas?
Insulin and Glucagon
Insulin
Responds to a rise in blood glucose and promotes the uptake and use of glucose for energy in cells
Glucagon
Increases blood glucose levels by promoting the breakdown of glycogen into glucose
Diabetes mellitus is a disease of?
Fat, carbohydrate and protein metabolism caused by a lack of or inefficient use of insulin
Diabetes mellitus is treated by?
Diet changes and medically
Insulin is used to treat?
Diabetes mellitus by keeping blood glucose in the proper range
Sources of insulin
Pork, synthetic and recombinant forms
Type of insulin used for initial treatment of diabetic ketoacidosis and keep blood glucose stable?
Short-acting (regular,crystalline insulin, semilente))
Type of insulin used to control blood glucose in uncomplicated cases of diabetes mellitus?
Intermediate-acting (NPH and lente)
Type of insulin used to control blood glucose for longer periods of time, especially in cats?
Long-acting (Protamine zinc insulin and ultralente))
Oral hypoglycemic agents work by?
Stimulating pancreatic beta cells to secrete insulin
Some pancreatic function is needed
More successful in cats
Oral hypoglycemic agent?
Glipizide
2 hormones from Islet of Langerhans
Insulin (Beta cell)
Glucagon (Alpha cells)
Incidental hyperglycemic agents
Corticosteroids, progesterone, epinephrine
Primary agents used to treat hypersecretion of insulin from tumors?
Hyperglycemic agents
Hyperglycemic agents mode of action.
Block release of insulin
Aldosterone is a…?
Mineralocorticoid
Cortisol is a…?
Glucocorticoid
What adrenal cortex hormone regulates nutrient levels in the blood (increase blood glucose)?
Glucocorticoids
Addison’s disease is…?
Adrenocortical insufficiency. Condition associated with adrenal atrophy
Signs of Addison’s disease
Lethargy, weakness, anorexia, vomiting, diarrhea and PU/PD
Addison’s is diagnosed by?
ACTH stimulation test
Treatment of Addison’s disease?
Long-acting mineralcorticoids and corticosteroids
Cushing;s disease is…?
Hyperadrenocorticism.
How is Cushing’s disease characterized?
Excessive glucocorticoid production due to prolonged administration of adrenocortical hormones, adrenosortical tumors or pituitary disorders
Signs of Cushing’s disease
PU/PD, hair loss, peduloud abdomen
How is Cushing’s disease diagnosed?
ATCH stimulation test or low-dose desamethasone suppression test
Treatment of Cushing’s disease?
Destroying part of the adrenal cortex
Growth promoters are used primarily in?
Ruminants
Growth promoters increases…?
Water retention, protein synthesis, fat deposition and possible increased release of growth hormone.
What drug is prepared as pellets for SQ implant?
Growth promoters
Anabolic steroids produce?
Tissue building effect
Labeled for use in dogs, cats and horses for anorexia, weight loss and denilitation.
Anabolic steroids