3. Introduction/General
Info
Endocrine glands- secrete hormones.
Exocrine glands- produce secretions
that are released via ducts.
Hormones- chemical messengers carried
by plasma.
Regulates the activity of the target
organ.
Not all hormones are secreted by
endocrine glands, some are produced in
tissue from another organ.
Like EPO – produced by kidney
6. Pituitary Gland
Divided into 2 lobes, each of which
acts as a separate gland.
Anterior
Posterior
Mainly influenced by the
Hypothalamus.
7. Anterior Pituitary Gland
“Master Endocrine Gland”
Develops from glandular tissue.
Hormones-
1. Growth Hormone (GH)-
Promotes body growth
Regulates metabolism
Encourages protein synthesis
8. Anterior Pituitary
Gland…
2. Prolactin (PRL)-
Triggers and maintains
lactation.
3. Thyroid-stimulating Hormone
(TSH)-
Stimulates the growth and
development of the thyroid
gland.
4. Adrenocorticotropic Hormone
9. Anterior Pituitary
Gland…
5. Follicle-stimulating Hormone
(FSH)-
Stimulates the growth &
development of the ovarian
follicles.
Stimulates the follicle lining to
produce & secrete ESTROGEN.
Stimulates spermatogenesis.
10. Anterior Pituitary
Gland…
6. Luteinizing Hormone (LH)-
Completes the follicle development
process.
Can cause OVULATION.
Can cause the development of the
CORPUS LUTEUM-
Which produces PROGESTERONE,
which maintains pregnancy.
Can stimulate the testes to develop &
produce TESTOSTERONE.
11. Posterior Pituitary Gland
Develops from the nervous system.
Does not produce any hormones.
Stores ADH & Oxytocin
12. Posterior Pituitary
Gland…
1. Antidiuretic Hormone (ADH)-
Prevents diuresis-
Conserves water
Urine is more concentrated
The release of ADH is inhibited
by alcohol and caffeine.
13. Posterior Pituitary
Gland…
2. Oxytocin-
Has 2 targets-
The uterus & mammary glands
Can cause uterine contractions
to:
Aid in the transport of sperm
to the oviducts.
Aid in the delivery of the fetus.
15. The Thyroid Gland
Produces:
Thyroid hormones
T3- has 3 iodine atoms
T4- has 4 iodine atoms
Calcitonin
16. Parathyroid Glands
Produces parathyroid hormone
(PTH)
Works opposite to calcitonin to
maintain blood calcium levels.
Mobilizes calcium from bones to
the bloodstream.
Negative feedback loop.
19. The Adrenal Glands…
Adrenal Cortex-
Develops from glandular tissue.
Under the influence of ACTH, it
produces steroids:
Glucocorticoids
Mineralocorticoids
Sex hormones
Chemicals derived from
cholesterol.
20. The Adrenal Glands…
Adrenal Cortex…
1. Glucocorticoids-
Cortisone, Cortisol, & Corticosterone
a. Cortisol- aka hydrocortisone, influences
the metabolism of sugars and has a
anti-inflammatory effect.
b. Cortisone- similar to Cortisol, and can
be prepared synthetically. Useful in
treating inflammatory conditions.
Causes a hyperglycemic effect.
Causes blood glucose levels to rise.
21. The Adrenal Glands…
Adrenal Cortex…
2. Mineralocorticoids-
Regulates electrolyte levels.
The primary one is ALDOSTERONE.
Reabsorbs sodium, excretes
potassium.
3. Sex Hormones-
Androgens- male
Estrogens- female
Maintain secondary sex
characteristics (beard & breast
development)
These hormones are also produced in
22. The Adrenal Glands…
Adrenal Medulla-
Develops from nervous tissue.
Produces (catecholamines):
Epinepherine
Norepinepherine
Chemicals derived from amino
acids
Along with the sympathetic nervous
system, these catecholamines
stimulate the “Fight or Flight”
23. The Adrenal Glands…
Adrenal Medulla…
1. Epinepherine-
heart rate, dilates
bronchioles, and stimulates the
production of glucose for
energy.
1. Norepinepherine-
Constricts blood vessels and
raises blood pressure.
27. Hyperthyroidism
The most commonly seen
endocrine disorder in cats.
Very rare in dogs except as a
result of neoplasia.
Bilateral thyroid gland
enlargement occurs in 70% of
cases.
28. Hyperthyroidism…
Signs include:
Weight loss
Polyphagia
Vomiting
Increased appetite
Tachycardia (with or without
murmurs)
30. Hypothyroidism
Commonly seen in the dog.
Clinical signs include:
Weight gain with no change in
diet.
Bilateral symmetric alopecia &
loss of hair on the tail (“rat
tail”).
66-75% of dogs will have an
increased cholesterol level.
31. Parathyroid
Hyperparathyroidism-
production of parathormone.
Causes hypercalcemia.
Etiology is often a parathyroid tumor.
Hypoparathyroidism-
production of parathormone.
Causes hypocalcemia.
This leads to a condition called
tetany-
Constant muscle contraction.
32. Adrenal Cortex
Hyperadrenocorticoidism-
“Cushing’s Disease”
Produced by excess cortisol from
the adrenal cortex.
Hypoadrenocorticoidism-
“Addison’s Disease”
Hypofunctioning of the adrenal
cortex.
33. Pancreas
Hyperinsulinism-
Excess secretion of insulin
causing hypoglycemia.
A problem of ferrets.
Etiology may be a pancreatic
tumor or an overdose of insulin.
34. Pancreas
Diabetes mellitus-
Lack of insulin secretion or
resistance of insulin to promote
sugar, starch, and fat metabolism
in cells.
Symptoms include: PU/PD,
glucosuria, and +/- ketoacidosis.
Ketoacidosis- fats are improperly
burned leading to an
accumulation of ketones in the
35. Pancreas
Type I Diabetes-
Insulin-dependant diabetes mellitus (IDDM)
Onset is usually in young animals.
A complete deficiency of insulin.
Patients require injections of insulin for
treatment.
Type II Diabetes-
Non-insulin-dependant diabetes mellitus
(NIDDM)
A separate disease from type I.
Still has a deficiency of insulin.
Usually in older, obese animals.
Treatment is with diet and oral medications.
