AGRISCIENCE AND NATURAL RESOURCES EDUCATION CURRICULUM
(3000) Core Area: ANIMAL SCIENCE
(3180) Unit Title: EQUINE
(3184) Sub Unit Title: ANATOMY/PHYSIOLOGY OF THE EQUINE
(3184E) Topic: ENDOCRINE SYSTEM
Topic Objectives: Upon completion of this lesson, the student will be able to:
Topic 3184E-A List the body functions controlled by the endocrine system.
Topic 3184E-B Identify the hormones produces in the endocrine system.
Topic 3184E-C Describe the functions of the hormones produced in the endocrine system.
Evaluation: Written test, quiz, work sheet, and/or application exam.
Interest Approaches:
1. Obtain the brain of a horse from a local rendering plant, dissect the brain and locate the anterior and posterior pituitary glands.
2. Discuss with the students the ethical use of growth hormone and the unethical use of epinephrine in humans.
CONTENT: ENDOCRINE SYSTEM (3184E)
1. The endocrine system exercises long-range control over the body systems.
2. The endocrine system, in combination with the nervous system, is important in maintaining internal body stability, called homeostasis.
3. DUCTLESS GLANDS
a. Produce chemical substances called hormones.
i. Hormones are transported by the circulatory system.
ii. Influence a variety of body functions.
4. FUNCTIONS CONTROLLED BY THE ENDOCRINE SYSTEM
a. Growth.
b. Reproduction.
c. Metabolism.
d. Digestion.
5. HORMONES PRODUCED BY THE ENDOCRINE SYSTEM
a. Growth Hormone (GH)
i. Produced by the anterior pituitary gland.
ii. Promotes growth of muscle and bone.
b. Thyrotropin (TSH).
i. Produced by the anterior pituitary gland.
ii. Influences the thyroid gland.
iii. Assists with the maintenance of the thyroid gland.
c. Adrenocorticotropin (ACTH).
i. Produced by the anterior pituitary gland.
ii. Influences the Adrenal cortex.
iii. Assists with the maintenance of the adrenal cortex.
d. Follicle Stimulating Hormone (FSH)
i. Produced by the anterior pituitary gland.
ii. Influences the ovary.
iii. Causes ovarian follicles to grow and produce increasing amounts of estrogen substances as they grow.
e. Luteinizing Hormone (LH).
i. Produced by the anterior pituitary gland.
ii. Influences the ovary.
iii. Causes ovulation and initiates the formation of the corpus luteum.
f. Luteotropin (LTH).
i. Produced by the anterior pituitary gland.
ii. Influences the ovary and mammary glands.
iii. Assists with maintenance of the corpus luteum, progesterone secretion, and the formation of milk in the alveoli.
g. Oxytocin.
i. Produced by the posterior pituitary gland.
ii. Stimulates muscle contractions in the uterus and mammary glands.
h. Vasopressin.
i. Produced by the posterior pituitary gland.
ii. Influences the blood vessels.
i. Insulin.
i. Produce by the pancreas.
ii. Controls sugar level in the body.
j. Thyroxine.
i. Produced by the thyroid.
ii. Controls metabolic rate.
k. Parathyroid hormone.
i. Produced by the parathyroid.
ii. Influences the kidneys and bones.
iii. Maintains calcium and phosphorus levels.
l. Corticoids.
i. Produced by the cortex adrenal gland.
ii. Controls salt, sugar, and water levels in the body.
m. Epinephrine.
i. Produced by the medulla adrenal gland.
ii. Controls blood flow and strength of muscle contractions.
n. Estrogens.
i. Produced by the follicles on the ovaries.
ii. Influences the mammary glands and the genital tract.
iii. Causes duct development and prepares ova for fertilization.
o. Progesterone.
i. Produced by the corpus luteum.
ii. Influences the mammary glands and the genital tract.
iii. Causes alveolar development and helps maintain pregnancy.
p. Androgens.
i. Produces by the testes.
ii. Influences the sex organs.
iii. Aids in sperm production, sex drive, and secondary male characteristics.
q. Pregnant Mare's Serum Gonadotrophin (PMSG).
i. Produced by the uterus.
ii. Influences the ovary and the uterus.
r. Prostaglandin (PGF2α)
i. Produced by the uterus.
ii. Influences the corpus luteum.
6. Refer to "The Horse,", Evans 1977, Pages 199-203.