Endocrine #1 Flashcards
What is your best definition for an endocrine gland?
A ductless gland that secretes its products (hormones) into the blood stream
What are the only “types” of hormones released from the pituitary gland?
Proteins & polypeptides
What are other examples of organs or areas in the body where protein or polypeptide type hormones are released or secreted?
C-cells of the thyroid gland
Islet of langerhans of the pancreas
Parathyroid gland
- What are two organs that secrete amino acid derived hormones?
- What are the hormones their secreting?
- Adrenal medulla & Thyroid
- Thyroxine (thyroid) & Epinephrine/norepinephrine (adrenal medulla)
What is the mechanism of action of protein and polypeptide hormones?
Bind to target cell surface receptors
What is the mechanism of action of a steroidal hormone?
Binds target cell cytoplasmic receptors
- What is the best example of an endocrine organ that secretes steroidal hormones?
- What hormones is that secreting?
- Adrenal cortex
- Aldosterone, cortisol, estrogens, androgens
True or False:
- Steroidal hormones are lipid soluble, which mean they can get through the cell membrane and act quickly!
- Steroidal hormones have to get into the nucleus to exert their activity.
- FALSE : although steroidal hormones ARE lipid soluble and ARE able to pass through the cell membrane, they do have a DELAYED REACTION
- TRUE : steroidal hormones do have to get into the nucelus to exert their activity, which is actually the main reason for their delayed activity
Which type of endocrine lesion results in an increase in size OR magnitude of a gland?
Productive lesions
What are 2 examples of productive lesions in an endocrine gland?
- Hyperplasia
- Neoplasia
What are some examples of a destructive lesion of an endocrine gland?
- Hypoplasia
- Atrophy
- Inflammation
- Neoplasia
- Amyloidosis
- Necrosis
- Surgical misadventure
- Which type of endocrine glands are known for accumulating amyloid?
- Give an example of one of these organs or specific cell types.
- Those that produce protein or polypeptide type hormones
- Islet of langerhans, parathyroid gland, c-cells of the thyroid, pituitary gland
More commonly are beign and malignant tumors functional or non-functional?
Benign = functional
Malignant = non-functional
What are the general causes of hyperfunction of an endocrine organ?
- Increased production of hormone
- Primary = uncontrolled production
- Secondary = increased trophic stimulus
- Decreased breakdown
- Production of hormone like molecules
- Latrogenic/exogenous intake
The following scenerio is an example of which type of hyperfunction of an endorcine gland:
Parathyroid adenoma: producing PTH uncontrollably so the animal becomes hypercalcemic as a result
Primary hyperfunction
(Uncontrollable production)
The following scenerio is an example of which type of hyerfunction OR hypofunction of an endrocrine gland:
The thyroid gland is making thyroxine at its normal level, however, the half-like of the hormone is prolonged.
Hyperfunction due to decreased breakdown
The following scenerio is an example of which type of hyerfunction or hypofunction of an endocrine gland:
Tumor of the pituitary gland is making ACTH uncontrollably and is causing an increase in cortisol levels.
Secondary hyperfunction
(Increased production due to increased trophic stimulus)
The following is an example of what “type” of hypofunction of an endocrine gland?
An autoimmune disease is attacking the thyroid gland, killing off the follicular cells. This is decreasing the production of thyroid hormone.
Primary hypofunction
(Decreased produciton due to destruction of a gland)
With an endocrine disease, what type of lesions might you find in other tissues/with what clinical signs might the animal present?
Epidermal atrophy
Bilaterally symmetrical alopecia
Hepatic lipidosis
Soft tissue mineralization
Arthrosclerosis
Cataracts
PU/PD
Muscle atrophy
- What specific type of endocrinopathy is most often associated with epidermal atrophy?
- Which hormone caues this manifestation?
- Hypothyroidism
- Increased cortisol levels
When it comes to alopecia, what is its hallmark feature when associated with an endocrine disease?
Bilaterally symmetrical
What about endocrine disease causes bilateral alopecia?
There is a lack of the appropriate stimulation to a hair follicle
|–> Hair follicles become atrophied
|–> Hair is rubbed off
|–> And hair is NOT replaced
What are the manifestations of hepatic lipidosis?
Enlarged liver
Increased lipid content in the liver
Which hormone is particular stimulates the breakdown of muscle in some endocrinopathies?
Cortisol
In which endocrinopathy would you most likely see cataracts clinically?
Diabetes mellitus
- From what is the adenohypophysis derived?
- From what is the neurohypophysis derived?
- Adenohypophysis = oral ectoderm
- Neurohypophysis = neuroectoderm (down growth from the hypothalamus)
Pituitary and brainstem, normal dog.
What is labeled?
A.
B.
C.
A. Optic chiasm
B. Pars distalis (of the anterior pituitary)
C. Pars nervosa (of the posterior pituitary)
Pituitary and brainstem, normal dog.
What is labeled?
A.
B.
A. Hypothyalamus
B. Pars intermedia (of the anterior pituitary)
From this pituitary gland, label the following parts:
A.
B.
C.
A. Pars nervosa (posterior pituitary)
B. Pars intermedius (anterior pituitary)
C. Pars distalis (anterior pituitary)
What is the area circled in red?
The 3rd ventricle
This is from the Pars Distalis of the anterior pituitary.
What cells should be present?
Basophils (dark cells)
Acidophils (red cells)
Chromophobes (all other cells)
Again, this is a slide from the pars distalis. Recognize the rich capillary network.
What is the significance of the close association these cells have with the capillaries?
This close associated allows hormones to be released quickly!