Endocrine Flashcards
(80 cards)
1
Q
primary endocrine disease- hypo
A
decreased cellular activity
2
Q
primary endocrine disease- hyper
A
increased cellular activity
3
Q
secondary endocrine disease- hypo
A
lesion of another organ leads to decreased cellular activity of the endocrine gland
4
Q
secondary endocrine disease- hyper
A
lesion of another organ leads to increased cellular activity of the endocrine gland
5
Q
increased function
A
mostly hyperplasia/neoplasia
6
Q
decreased function
A
mostly immune mediated, inflammation, necrosis/atrophy
7
Q
Primary hyperfunction
A
usually neoplasia
increased autonomous secretion of a hormone from a primary endocrine organ
8
Q
primary hypofunction
A
usually due to immune mediated destruction of primary endocrine gland
decreased secretion of a hormone from a primary endocrine organ –> CS due to decreased hormone level
9
Q
Secondary hyperfunction
A
increased secretion of hormone from primary endocrine organ due to a signal from outside the gland
10
Q
secondary hypofunction
A
the causative defect of lesion arises outside of the primary endocrine gland
often decreased secretion of trophic hormone from another endocrine organ = decrease hormone production in primary target endocrine organ –> decreased function
11
Q
Pituitary
A
in sella turcica, attached to the hypothalamus by the pituitary stalk
Anterior: requires a releasing hormone from the hypothalamus
posterior: ADH, oxytocin released from axons of neurons in hypothalamus into blood
12
Q
pars distalis
A
largest, secretes most of hormones
13
Q
pars tuberalis
A
wraps around the neural stalk
14
Q
pars intermedia
A
junction between pars distalis and pars nervosa
residual region of rathke pouch
can secrete a variety of hormones
15
Q
acidophils
A
somatotrophs secrete growth hormones
luteotrophs secrete leuteotrophic hormone
16
Q
basophils
A
thyrotrophs secrete thyroid stimulating hormone
gonadotrophs secrete LH and FSH
17
Q
chromophobes
A
adrenocorticotropic hormone
melaocyte secreting hormone
18
Q
Neurohypophysis
A
cell bodies of large neurons in hypothalamus nuclei produce: ADH, oxytocin
their axons comprise the infundibulum and pars nervosa
herring bodies: hormone storage
Pituicytes: support
19
Q
ADH
A
Antidiuretic hormone-regulares body’s retention of water
released when dehydrated -> renal CDs and distal nephron to increase water resorption from glomerular filtrate
20
Q
Oxytoxin
A
contraction of smooth muscle in uterus and myoepithelial cells surroundigng mammary glnad ducts
21
Q
adenoma
A
expansile, compressive, often functional
22
Q
carcinoma
A
usually nonfunctional, compressive and infiltrative
23
Q
Functional tumors
A
CS due to hyperfunction/hormone excess
if large may also decrease level of other hormones- hypofunction
24
Q
non functional tumors
A
CS due to compression- hypofunction/lack of hormone secretion
25
anterior pituitary neoplasia: hyperfunction
dogs: pars distalis > pars intermedia; corticotrope adenoma (ACTH)
cats: pars distalis; somatotroph adenoma (GH)
equine: pars intermedia; adenoma/hyperplasia
26
Canine corticotroph adenoma
secondary pituitary endocrin eorgan hyperfunction
corticotrophs produce ACTH -> bilateral adrenocortical hyperplasia -> inc corticol secretion
hypercortisolaemia- cushings
27
Zona glomerulosa
mineralocorticoids
stimulated by angiotensin II
aldosterone- RAAS, saves Na secretes K, restores blood v
28
Zona fasiculata
glucocorticoids
| cortisone, stimulated by ACTH
29
Zona reticularis
weak androgens
30
medulla
catecholamines (EPI, NE)
stimulated by SNS or PSNS
chromaffin cells
31
Pituitary ACTH secreting tumor in dogs
rarely cats
usually microadenomas vs macroadenomas
result in cushing disease because of excessive cortisol secretion from hyperplastic adrenal glands
32
Adrenal cortical adenoma
Could produce cushings in dogs
| zona fasiculata, can be adenoma or carcinoma
33
Hyperfunction in medulla?
pheochromocytoma
34
Cushings- predisposing factors
Middle age/old (6+); poodles, GSD, boxer, dachshunds
female>male
slowly progressive
35
Cushings cats
less common
80% PDH
fragile skin, UTI, associated with DM
36
Primary cushings
Adrenal tumor- zona fasiculata (unilateral atrophy)
adrenal dependent hyperadrenocorticism (ADH)
50% adenoma, 50% carcinoma, 10% bilateral
not always productive
37
Secondary cushings
adrenal cortical hyperplasia -> ACTH secreting pituitary tumor
pituitary dependent hyperadrenocorticism (PDH)
most of cases (85%)
majority are <1cm adenoma,
pars distalis
productive
38
Cushings CS
```
PU/PD/PP
pot bellies, panting, muscle weakness
ligamanet weakness, alopecia (bilaterally symmetrical)
calcinosis cutis
cutaneous hyperpigmentation
```
39
cushings path
increase ACTH
increased stimulation of adrenal glands
bilateral adrenal cortical hyperplasia
increased cortisol production
40
Cushings lesions
nodular cortical hyperplasia vs diffuse cortical hyperplasia (PDH)
cortical adenoma vs cortical carcinoma (ADH)
41
Cushings effects
PU/PD = ADH interference
protein catabolism = muscle atrophy, poor wound healing,
hepatomegaly = inc cortisol, impaired gluconeogenesis, lipid metabolsim
hypertension 2ndary to inc adrenocorticoids
immunosuppression = dec CKs = dec WBCs
42
Cushings can be caused by
ACTH producing tumor of anterior pituitary
Cortisol producing tumor of adrenal cortex
Dosing with high prolonged levels of glucocorticoids
43
Feline acromegaly
Somatotroph (acidophil) adenoma
pars distalis adenoma -> inc GH -> inc insulin resistance -> DM
middle/older male cats
44
Feline acromegaly- signs
```
organomegaly (heart, liver kidney)
new bone formation (wide face)
inc weight due to inc muscle, organ, bone mass
thick mm so resp stridor
severe insulin resistance DM
```
45
Pituitary Pars Intermedia Dysfunction (PPID)
equine cushings (adenoma hyperplasia- pars intermedia)
non productive pituitary adenoma
tumor extends out of sella turcica -> hypothalamus and optic n compression
=compression, deranged hypothalamic fnc
inc proopiomelanocortin molecule = exc variety of hormones
POMC from intermedias does not inhibit ACTH secretion
46
PPID CS
hirsutism, hyperhidrosis, laminitis, WL, muscle weakness, atrophy, poor wound healing, pU/PD/PP, insulin resistance
47
hirustism
curly coat- not shed
48
hypofunction of pituitary gland
compressive dz- from enlarging tumors, may be functional
loss of ADH secretion = most common manifestation
PDDM
pu/pD
trauma/infection
congenitial defects
49
Diabetes insipidus- hypophyseal form
ADH released from neurohypophysis is transported to kidney -> receptors in distal nephron and CS -> increases reabosrption of H2O
inadequate ADH produced results from compression and destruction of neurohypophysis
compression = dec ADH
PU/PD
dec action on distal nephrons and CDs = dec aquaporitns activation and reabsorption of water
50
Diabetes insipidus- nephrogenic form
distal tubules and collecting ducts cant respond to ADH (dec/no receptors)
aka kidney issue
51
Pituitary dwarfism
congenital juvenile panhypopituitarism
Cyst in sella tursica = no adenohypophysis
autosomal recessive in GSD
hormones deceased (GH, TSH, ACTH)
CS: normal at birth, slow growth, small stature, keep pup coat, delayed teeth eruptio, infantile genitalia, sterile
hypothyroids/hypoadrenocorticism
52
Conn's syndrom
in cats- inc aldosterone
zona glomerulosa
CS- hypertension, polymyopathy
inc Na, dec K
53
Ferret adrenal neoplasm
Adult, female,
zona retiularis- inc estrogen
CS: vulval enlargement, hair loss, hyperplasia, pu/pd, anemia, normal cortisol
path: animals gonadectomized at early stage= chronic stimulation of zona reticularis by LH
54
Pheochromocytoma
neoplasia of medullary chromaffin cells
benign > malignant (will metastasize widly via vena cava)
CS: in epi/NE
tachycardia, hypertension, hyperglycemia, vasoconstriction, hyperhidrosis
most are incidental findings at necropsy
55
Addisons-hypoadrenocorticism- primary
immune mediated lymphocytic adrenalitis
typical: glomerulosa/fasiculata = dec mineralcorticoids/glucocorticoids
atypical: iatrogenic- long term steroid use, no weaning off period, zona fasiculata atrophy
anorexia, vomiting, abdominal pain, WL, low energy, weakness
56
Thyroid follicles
cuboidal lining cells- produce thyroglobulin
Lumen: stored as colloid with iodine, thyroglobulin + iodine, mono or di iodotyrosin
T3 and T4
lining cells stimulated: colloid -> active thyroxine, fT3 and fT4,
57
hypothalamus
secretes TRH -> pituitary basophils secretes TSH -> thyroid follicular cells secrete T3 and T4
T3 and T4 enter blood stream
inc t4= hyperfunction
no t4 = hypofunction
58
Feline hyperthyroidism
Most common endocrine disorder in cats
old cats, PP and urinating outside litter box, acts like a kitten
functional adenoma/hyperplasia
inc T4 -> inc metabolic rate (inc glycolysis, liposlysis, gluconeogenesis)
cardiovascular consequences
hypertension, cardiac hypertrophy
59
Feline hyperthyroidism- CS
WL, thin BCS, palpable thyroid, hyperactivity, PP tachycardia
60
K9 primary hypothyroidism
Middle aged, CS with 75% destruction of gland
slow metabolism= inc weigh without appetite change, hair loss, lazy, heat seeking, anemia, inc chol
alopecia, bilateral, rate tail
61
K9 primary hypothyroidism- lymphocytic thyroiditis
immune mediated
thyroid gland infiltrated by lymphocytes, plasma cells and macros
CS when 75% destoryed, genetic component in beagles,
thyroid gland damage -> Ag released into circulation
can have circulating autoantibodies
62
K9 primary hypothyroidism- idiopathic atrophy
fat or fibrous CT replace gland tissue
| possible end stage lymphocytic thyroiditis
63
Goiter
Thyroid hypofunction
bilateral enlargement- non neoplastic, non inflammatory
impaired synthesis of thyroid hormone= euthyroid/hypothyroid
dec thyroid hormone -> inc TSH -> thyroid hyperplasia
BC: diet (dec iodine, ingestion of goitrogenic substances, excessive iodine) or hereditary
64
Thyroid neoplasia
Dogs: non productive malignant- thyroid carcinoma
30% metastasize before dx, histology confirm
Cats- productive benign
65
Parathyroid
2 glands per thryroid
tightly packed chief cells- secrete parathormon, inc osteoclast activity, inc renal resorption and inc intestinal uptake
inc Ca
66
Primary hyperparathyroidism
parathyroid adenoma dogs>cats (may compress remaining PT gland and even thyroid)
hormones: inc PTH, inc Ca, Dec P
anorexia, PU/PD, muscle weakness, stiff gait, pathological fractres
can mimic/cause CRF
67
Secondary hyperparathyroidism
renal dz (high P, reduced vit D)
nutritional (highP/lowCa, low vit D)
renal CRF -> high P -> low vit D -> dec Ca
fibrous osteodystrophy in growing animals
nutritional- hypovit D
extensive bon resorption with prolif od fibrough tissue, poorly mineralized immature bone
rare in sheep/cattle
68
Pseudohyperparathyroidism
PTHrP-secreting neoplasm- hypercalcemia of malignancy
anal sac adenocarcinoma
lymphoma
PTH dec- PT normal to small
69
hypoparathyroidism
rare
Iatrogenic: removal of PT glands during thyroidectomy in cats
Idiopathic hypoparathyroidism
rare in dogs,
lymphocytic parathyroidisis
no PTH -> low Ca -> nervousness, ataxia, tremors -> tetany, seizures
70
Endocrine Pancrease
```
Ilets of langerhans
a- glucagon, CCK, GIP
B- insulin
D-somatostatin
hyper=neoplasia
hypo=DM (dogs =1 no insulin, cats =2 insulin resistance)
```
71
Insulinoma
Dogs- malignant
ferrets- benign
productive- lots of insulin
small tumor, liver metastasis
CS: hypoglycemia, depression, weakness, muscle fasiculations, seizures
histology confirmation- low criteria of malignancy
72
Pancreatic islet hypofunction- DM
CS of hypoinsulinemia- dec production/resistance
| PU/PD, WL, PP, cataracts (dogs), glucosuria, hyperglycemia, ketoacidosis, hepatic lipidosis
73
DM type 1
```
dogs
B cells not working
mini poodles, rotties, tibetan terriers
Insulin dependent
linked to pancreatitis and/or immune mediated autoAb agains B cells
```
74
DM type 2
cats
peipheral insulin resistance -> hyperglycemia
induced by inc glucocorticoids, progesterone
Obese, male, over 10 y, burmese
B cell vacuolar degeneration bc of inc glycogen
overstimulated B cells -> inc IAPP + insulin -> amyloid deposition -> islet cell atrophy
ocveralll dec in B cells
50-75% of cats progress to insulin dependent DM
75
Diabetic nephropathy
chronic hyperglycemia -> formation of glycosylated proteins -> deposition into capillary basement membranes -> thickened BM
76
Cataracts in dogs with DM
excessive glucose taken up by epithelium of lense (no insulin required) -> metabolized to sorbitol by aldose reductase -> sorbitol osmotically draws water into the lens -> cataract formation
77
what causes DM
B cell degeneration
B cell amyloidosis
Isletitis
Chronic pancreatitis
78
Paraganglia tumors
tumors of chemoreceptor organs that sense changes in CO2, pH, O2
aid in regulation of circulation and respiration
79
Aortic body tumors
rare- in boxers and boston terriers
| Space occupying effect -> compression of atria, vena cava -> dyspnea, ascites, hydrothroax, hydropericardium
80
Carotid body tumors
Arise near the bifurcation of the common carotid artery in the cervical area
rare tumors
