Test 3: endocrine Flashcards
(126 cards)
1
Q
pituitary will secrete ACTH which will cause the release of — from the adrenal glands which causes
A
cortisol
inhibitory to secretion of ACTH
feedback inhibition
2
Q
give example of feedback inhibition
A
ACTH and cortisol
primary product will cause secondary organ to secrete a hormone which will turn off pathway
2
Q
give example of feedback inhibition
A
ACTH and cortisol
primary product will cause secondary organ to secrete a hormone which will turn off pathway
3
Q
A
4
Q
anterior lobe of the pituitary is called
A
adenohypophysis
5
Q
posterior lobe of the pituitary
A
neurohypohysis
6
Q
three type of cells in the pars distalis
A
acidophils
basophils
chromophobes
7
Q
acidophils secrete
A
somatotrophs→growth hormones
luteotrophs→ LTH and prolactine
8
Q
basophils secrete
A
thyrotrophs- TSH
gonadotrophs- LH and FSH
9
Q
chromophobes secrete
A
ACTH
melanocyte secreting hormone (MSH)
10
Q
the posterior pituitary is made from — cells
A
modified glial cells (pituicytes) and axonal processess
11
Q
cells in the posterior pituitary extend from the
A
supraoptic and paraventricular nuclei down the pituitary stalk to the posterior lobe (neurohypophysis)
12
Q
posterior pituitary secretes
A
ADH and oxytocin
13
Q
— cause contraction of smooth muscle in
uterus and myoepithelial cells surrounding
mammary gland ducts
A
oxytocin
14
Q
corticotroph adenoma will cause
A
bilateral hyperplasia of the adrenal glands
and/or
CNS damage
15
Q
pars distalis adenoma is most common in
A
dogs
16
Q
pars intermedia adenoma are most common in
A
horses
less common in dogs
17
Q
A
Equine Pituitary Pars Intermedia Dysfunction
unique form of cushings
caused by mass on pars intermedia
increased production of POMC peptides
loss of normal inhibitory control
18
Q
what causes equine pituitary pars intermedia dysfuction
A
tumor in pars intermedia
decrease in dopamine
causes increased production of POMC peptides
from loss of inhibitory control
19
Q
what controls the pars intermedia
A
dopamine
20
Q
PPID is caused by a decrease in — which leads to —
A
dopamine → normally
inhibits cells (melanotrophs) in the pars
intermedia
loss of inhibition leading to hypertrophy and hyperplasia = mass
Equine Pituitary Pars Intermedia Dysfunction
21
Q
POMC is turned into — in the pars distalis
A
ACTH, β-endorphin, β-
lipotropin
22
Q
POMC is turned into — in the pars intermedia
A
ACTH → α-MSH,
corticotrophin-like intermediate lobe peptide (CLIP), β-MSH, β-endorphin
23
Q
Plasma cortisol inhibits ACTH secretion by the — but has little effect on the —
A
pars distalis
pars intermedia
24
clinical signs of equine with mass in pars intermedia
PPID→ Equine Pituitary Pars Intermedia Dysfunction
fever, sweating, hypertrichosis/hirsutism
increased POMC
weight loss, muscle weakness
poor wound healing
PU/PD, increased appetite
25
hyperhidrosis
generalized sweating
26
hypertrichosis
hirsutism- too much hair- failure of seasonal shedding
27
what do acidophils produce
somatotrophs- growth hormones
luteotrophs- LTH and prolactin
28
acidophilic adenoma are seen in ---
middle-aged to older, often male, cats
rare in dogs
29
acidophilic adenoma cause
acromegaly from too much growth hormone
cardiomegaly, enlargement of other organs
bone growth- broad facial structures
increased weight due to increased size of bone, muscle and organs
30
feline acromegaly can cause severe---- due to GH induced insulin resistance
insulin-resistant, diabetes mellitus
31
three causes of hypofunction of the pituitary glands
Compressive disease
Trauma
Congenital defects
32
pituitary carcinomas are usually nonfunctional, --- and ---
compressive and infiltrative
can expand and destroy the remaining pituitary and hypothalamus
33
ADH is released by the ---
neurohypophysis (posterior lobe)
travels to the kidney and causes fluid retention
34
diabetes insipidus is a problem with ---
ADH receptors
can be congenital- lack adenylate cyclase in the cytoplasm
can be secondary to a pyometra
35
what type of diabetes insipidus would improve with ADH supplement
hypophyseal form- brain form
nephrogenic form is issue with ADH receptor in the kidney
36
Hypofunction: Juvenile Panhypopituitarism (pituitary dwarfism)
due to lack of anterior pituitary - adenohypophysis
autosomal recessive trait in german shepherds
37
Panhypopituitarism clinical signs is due to
growth hormone
deficiency; +/- hypothyroidism and
hypoadrenocorticism
dwarfism
38
what part of the adrenal gland is NOT controlled by the pituitary?
Zona glomerulosa- makes mineralocorticoids (aldosterone)
39
what parts of the adrenal gland is controlled by the pituitary
Zona fasciculata- makes glucocorticoids
Zona reticularis- makes sex hormones
40
Mineralocorticoids (aldosterone) are produced where in the adrenal gland
zona glomerulosa
41
Glucocorticoids (principally cortisol) which are synthesized in the
zona fasiculata
42
Sex steroids are made where in the adrenal gland
zona reticularis
43
normal cortex:medulla ratio for most species
examined is approximately
1:1
44
Adrenal medulla is composed of chromaffin cells, which synthesize and secrete ---
catecholamines-
mainly epinephrine
NOT controlled by the pituitary gland
45
Bilateral cortical hyperplasia of the adrenal gland
46
what makes this a carcinoma
invades the vena cava
47
primary adrenal hyperfunction is caused by
Adrenocortical adenoma/carcinoma
48
secondary adrenal hyperfunction is caused by
Corticotroph adenoma in Pituitary- aka “PDH”
49
What is the name given to syndrome of
adrenocortical hyperfunction?
cushings
50
What causes hyperfunction of the medulla of the adrenal gland?
Pheochromocytoma
too much epi or norepinephrine
51
cushings disease is caused by ---
too much cortisol
52
cushing disease presents with
↑ALP
Pendulous abdomen “pot-belly”
PU/PD (dogs)
Increased appetite
Hepatomegaly
Panting!
53
primary pituitary tumor will cause what to happen to the adrenal gland
bilateral hyperplasia
high ACTH and high cortisol
54
one big adrenal gland with a tumor. is i functional?
yes
other adrenal gland has atrophied
high cortisol, low ACTH
55
addisons disease does what to the adrenal gland
bilateral adrenal cortical atrophy
immune mediated
caused by atrophy of all 3 cortical zones
leads to decreased cortisol and increased ACTH
56
what happens to ACTH and cortisol
high and high
57
low ACTH
high cortisol
58
non functional tumor
no change in ACTH and cortisol
59
pheochromocytoma
60
calcinosis cutis is ---
mineralization of collagen of the dermis
can be caused by long term use of steroids
61
how to treat cushings
trilostane
enzyme blocker in the steroidogenesis pathway
block cortisol production in the adrenal gland
62
cats have what weird clinical sign with cushings
fragile skin
63
what happens when you remove the adrenal glands?
death
high Potassium
low sodium
volume of extracellular fluid and blood decrease
the heart begins to function poorly, cardiac output declines and shock ensues
need to supplement with salt and mineralocorticoids
64
primary hypoadrenocorticisim is also called
addison's disease
65
addisons disease does what to the adrenal galnd
Idiopathic loss/atrophy of all 3 cortical zones
body can't produce cortisol
66
clinical signs of addisons
Weakness/lethargy or collapse
Weak femoral pulse
Dehydration, bradycardia
Hypothermia
Abdominal pain, GI signs (e.g., diarrhea)
Hyponatremia and hyperkalemia with unconcentrated
urine. (low sodium, high potassium)
67
low aldosterone will cause
high potassium
hypovolemia, hypotension, reduced cardiac output;
hyperkalemia leads to decreased myocardial
excitability, increased refractory period, slowing of conduction.
68
low cortisol will cause what clinical signs
GI signs of
anorexia, vomiting, abdominal pain (unknown
mechanism); weight loss; diminished energy
metabolism; impaired tolerance of stress
69
secondary hypoadrenocorticism is caused by
long term steroid use
leads to decreased ACTH secretion, cause cortisol stops ACTH
70
how can treatment for cushings lead to addisons
treatment attacks cells that produce cortisol can eventually kill and atrophy area to cause addisons (too low cortisol and too low aldosterone)
71
What can cause hyperfunction of the adrenal medulla?
Tumor of medullary chromaffin cells.
pheochromocytoma
72
what kind of animals get pheochromocytoma
horse and dogs
horses- benign but functional
dogs- nonfunctional but malignant
not cats
73
clinical symptoms of pheochromocytoma
paroxysmal tachycardia, hypertension, hyperglycemia, vasoconstriction and diffuse sweating
74
what does pheochromocytoma do to ACTH and cortisol
nothing
75
active thyroid cells are ---
cuboidal to columnarr
76
inactive thyroid cells are ---
flattened and more colloid
77
C cells make
calcitonin
counters parathyroid hormone effects
78
iodine binds to --- in the lumen to form thyroxine
(---) and triiodothyronine (---) via thyroid peroxidase
thyroglobulin
T4
T3
79
T3 and T4 are bound to ---
plasma proteins
will form in the lumen then released into the blood stream
80
increased levels of T3 and T4 in the blood will cause
inhibition of TRH from the hypothalamus and TSH from the pituitary
81
hyperthyroidism is common in ---
cats
82
hypothyroidism is common in ---
dogs
83
---thyroidism
hypo
84
hyperthyroidism will do what to the thyroid?
will atrophy
small tumor (adenomatous hyperplasia) cause increased t4 and T3 will decreased TSH
85
what forms with feline hyperthyroidism
adenomatous hyperplasia
mass on thyroid that makes T3 and T4, normal thyroid gland will atrophy
86
clinical findings with hyperthyroidism in cats
Weight loss with
*Ravenous appetite*
Nervousness,
tachycardia
Heat intolerance,
weakness
Cardiomegaly →
arrythmias, saddle
thromboemboli and
death
87
two causes of hypothyroidism in dogs
Lymphocytic thyroiditis
Idiopathic atrophy
88
in lymphocytic thyroiditis the thyroid gland is invaded by ---
lymphocytes, plasma cells
and macrophages
immune mediated canine hypothyroidism
89
when do you see signs of lymphocytic thyroiditis
75% of gland destroyed
genetic - beagles
dog hypothyroidism
90
what happens during idiopathic atrophy of the thyroid gland in a dog
Gland may be 1/10 size, replaced by adipose tissue
and fibrous connective tissue, may be end-stage of lymphocytic thryoiditis
hypothyroidism in a dog
91
clinical manifestation of hypothyroidism
slow metabolism
lethargic
exercise intolerance
**Heat seeking**, mental dullness, weight gain,
slow pulse
Neuromuscular and reproductive problems
**Anemia**
**Hypercholesterolemia**
dog hypothyroidism
92
what derm lesions will a dog with hypothyroidism have?
**Scaling** (bilateral alopecia- maybe but subtle), sometimes “rat” tail
**Myxedema** but only if severe → “tragic face”
Secondary infections →otitis, pyoderma
93
what is wrong?
hypothyroidism
| myxedema →tragic face
scaling on tail
94
what blood test for hypothyroidism and what will it show
free T4
| low T4
high TSH
95
goiters are bilateral enlargement of thyroid glands due to
--- and --- causes
nonneoplastic
noninflammatory
96
goiter will do what to thyroid
normal T4
or
hypothyroid
97
what causes goiter
Deficiency of iodine
Ingestion of goitrogenic substances
interfere with thyroid hormone synthesis
drugs, plants, Brassica
Excessive iodine- (rare)
genetic- defects in enzymes (or
thyroglobulin) for synthesis of thyroid hormones → increased TSH
98
old dogs will form what type of thyroid tumor
nonfunctional bilateral carcinoma
metastasize to the lungs
99
parathyroid gland is made of --- cells that make ---
chief cells
PTH
100
PTH does what
increases Calcium
Bone→activates bone resorption
Kidney →activates Vit D, reabsorbs calcium, gets rid of phorphorous
GI→ increases calcium absorption
101
what cell has the opposite effect of chief cells
chief cells- parathyroid- increase Calcium
C-cells in thyroid- make calcitonin that decrease Calcium
102
why is vit D needed for calcium
can get vit D from diet or the sun
turned into Vit D3 (cholecalciferol)
activated in the liver (25-
hydroxy D3) and kidney (1,25 -vitamin D3)
allows for increased absorption of Ca:P, needed for mineralization and ossification
103
What is the cause of *primary* hyperparathyroidism?
Functional parathyroid adenoma (dogs)
104
What happens to blood calcium with primary hyperparathyroidism
Does not respond to negative feedback
High
105
What clinical signs would you expect to see with hyperparathyroidism
Anorexia, muscle weakness, PU/PD, stiff gait, +/- pathologic fractures (rare), thickened mandible (rare) or loose teeth (rare)
elevated serum PTH and Ca
106
what causes secondary hyperparathyroidism?
Chronic renal disease
107
how does Chronic renal disease cause secondary hyperparathyroidism?
↓ P excretion by kidneys (hyperphosphatemia)
↓ active Vit D3 → ↓ intestinal absorption of Ca
High P lowers serum Ca → PTH secretion → Parathyroid hyperplasia → osteocyte release of calicum
108
What are the clinical signs of secondary hyperparathyroidism?
Chronic renal disease (vomiting, PU/PD, dehydration, breath
odor of ammonia) and fibrous osteodystrophy (FOD) “rubber jaw”
FOD is uncommon and usually affects young animals
109
what two tumors cause Pseudohyperparathyroidism
anal sac adenocarcinoma
Lymphosarcoma
will produce Parathyroid hormone related protein (PTHrP)
will cause high Calcium
110
blood test of animals with Pseudohyperparathyroidism will show?
high calcium
low PTH
tumors will produce Parathyroid hormone related protein (PTHrP)
111
primary hyperparathyroidism effects what animals?
dogs
112
beta cells in the pancreas make
insulin
113
alpha cells in the pancreas make
glucagon
114
delta cells in the pancreas make
somatostatin
115
F cells in the pancreas make
Pancreatic polypeptide
116
what does insulin do
increases cell uptake & storage of glucose, amino
acids, FA, secreted in response to hyperglycemia
causes protein synthesis in muscle
increases glycogen synthesis in the liver
117
What causes hyperfunction of the endocrine pancreas?
Most common cause is iatrogenic insulin
overdose (low BG)
Functional tumor of islet cells
118
what animals get beta cell tumors /insulinomas
Uncommon in dog- malignant to lymph nodes and liver
rare in cat
common in ferrets- benign
119
dog or ferret will have a malignant insulinoma?
dog- less common to have a beta cell tumor but malignant
beta cell tumor common in ferret but usually benign
120
What are clinical signs of beta cell hyperfunction?
insulinoma →low BG
incoordination, ataxia,weakness, syncope, muscle twitching, blindness, polyphagia, seizures
Ferret: weakness but seizures are uncommon
common benign in ferret
malignant uncommon in dogs
121
DM is caused by
pancreas beta cells not making insulin
or
insulin receptors not working
122
type 1 DM
skinny DM
lose beta cells that make insulin
need to be given insulin
123
type 2 DM
fat people DM
insulin resistance- receptors not working
124
clinical signs of DM
high BG
glucose in urine
PU/PD
weight loss
ketoacidosis
cataracts
fatty liver
125
what causes the fatty liver in animals with DM
lack of insulin means body breaks down lipids and muscle for energy
leads to ketoacidosis
liver will try to filter but excess fat will be stores in the liver
