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Flashcards in Endocrine Deck (67)
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1

Name the four types of hormone and give an example of each.

  1. Peptide and protein - insulin, prolactin, ACTH, ADH, oxytocin
  2. Steroids - glucocorticoids, oetrogens, androgens
  3. Amino acid derivatives - catecholamines, thyroid
  4. Fatty acid derived - prostaglandins , leukotrienes

2

What is the difference between regulated and constitutive secretion of peptide/ protein hormones?

Regulated - hormones are stored in secretory granules and released when stimulated 

Constitutive - hormones are not stored in cells but secreted as they are synthesized (particularly as protein/ peptide hormones have short half lives)

3

How are steroid hormones excreted from the body?

Via the urine/ bile

4

How does the half life of thyroid and catecholamine hormones differ?

Thyroid > catecholamines

5

From which amino acid are thyroid and catecholamines derived?

Tyrosine

6

What effects can hormones have on target cells?

  1. Activation of enzymes or other dynamic molecule (second messenger systems)
  2. Modulation of gene expression 

 

7

Which types of hormones are able to activate cell surface receptors?

Proteins, peptides, catecholamines, fatty acid derivatives

Used in second messenger systems

8

Which types of hormones are able to activate intracellular receptors?

Steroids and thyroid hormones - these alter transcriptional gene expression

9

Endocrinopathies can be caused by which mechanisms?

  • Primary or secondary hypofunction of the gland
  • Primary or secondary hyperfunction of the gland
  • Hypersecretion of hormones from non-endocrine neoplasms
  • Dysfunction of the target cell
  • Disease of other organs due to endocrine hyperactivity
  • Iatrogenic syndromes of hormonal excess

 

10

Which hormones are released from the adenhypophysis?

FLAT PiG

11

Which hormones are produced in the hypothalamus?

ADH

Oxytocin

Hypophyseotropic releasing hormones

12

Acidophilic and basophilic cells of the adenohypophysis cause release of which hormones?

Acidophilic - growth hormone, prolactin

Basophilic - LH, FSH, TSH, ACTH

13

Diabetes incipidus is caused by deficiency in which hormone?

Outline the difference between central and nephrogenic diabetes insipidus.

ADH

Central - impaired hypothalamic production, transport, storage and pituitary release

Nephrogenic - ADH receptor defect in the collecting duct and DCT

14

Rathke's cysts

Pituitary cysts - can cause dyspnoea if grow too large

15

Hypoplasia or aplasia of the hypothalamo-adenohypophyseal system can cause what conditions in calves?

Cyclopia

Arhynencephaly

16

Pituitary dwarfism is caused by a deficiency in which hormone?

Somatotropin hormone - causes decreased growth hormone and failure to differenciate of rathkes pouch

17

An acidophilic adenoma can cause which conditions in an animal?

Excessive GH and growth

Overgrowth of connective tissue

Diabetes mellitus - GH inhibits insulin receptors

18

Which regressive changes can be seen in the HPA axis with age? 

Atrophy - horse and dog

Pituitary inflammation - abscess formation - due to viral infection

Nodular hyperplasia

Adenoma

19

Pituitary inflammation can be caused by which viral agents?

Borna disease

Classical swine fever

Infectious anaemia

20

Describe the lesion

The pituitary shows marked increase in size.

Focal grey oval lesion - filled with thick grey - yellow fluid

3x4 cm

 

21

Why can adenomas of the adenohypophysis cause cushings in dogs and horses?

Most frequently cause hypersecretion of ACTH

22

Describe the lesion

The adenohypophysis of the pituitary is affected. 

The gland shows a focal lesion which is red and shows multifocal-coelescing dark red pigmentation.

The round nodule is firm to touch and is approximately 3-4cm in diameter

MD - Pituitary adenoma

23

In the dog cushings disease is associated with which clinical signs?

  • PU/ PD
  • Polyphagia
  • Obesity
  • Skeletal muscle atrophy
  • Bilateral and symmetrical alopecia
  • Epidermal atrophy
  • Osteopenia
  • Secondary DM

24

Describe the associated lesions here.

Which condition is associated with these?

Pituitary - normal tissue has been destroyed and replaced with a round, diffusely reddened nodular, firm mass which is 2x3cm in size

Adrenal gland - the cortex of the adrenal glands show diffuse symmetrical and bilateral thickening (hyperplasia) due to increased stimulation by ACTH released by the tumour

Cushings

25

Equine Cushings is associated with which pathological mechanism?

What clinical presentation would be expected?

ACTH-producing adenohypophysis tumours

Space-occupying lesion - hypertichosis, hyperhydrosis, intermittent fever (impedes on neurohypophysis and hypothalamus)

ACTH production - PU/PD, polyphagia, hyperglycaemia, glucosuria, immunosupression

26

Outline four primary causes of hypothyroidism.

  1. Loss of parenchyma - aplasia, atrophy, neoplasia etc
  2. Deficiency of hormone components - iodine
  3. Chemical blockage of hormone production
  4. Resection of the gland

 

27

Outline the clinical presentation of primary hypothyroidism.

  • Increased body weight
  • Skin: thin coat, bilateral alopecia, hyperkeratosis, hyperpigmentation
  • Repro: abnormal cyclic, reduced sperm count
  • Goitre
  • Myxoedema: oedema of subcutis and mucosa
  • Cretinism: disproportionate dwarfism

28

Outline a cause of hyperthyroidism in the cat.

What clinical presentation would be expected?

Thyroid multinodular hyperplasia/ adenoma.

  • Increased basal metabolic rate
  • Weight loss
  • Hepatic lipidosis & necrosis (glycogen deficiency)
  • Left ventricular hypertrophy

29

How would TRH and TSH levels be expected to change with hyperthyroidism?

They are decreased to negative feedback from increased T3 and T4.

Atrophy of the thyroid gland

30

Chronic lymphocytic thyroiditis is caused by what?

Autoimmune disorder (Ab against thyroglobin)