Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

RUSVM Clinical Pathology > Endocrine > Flashcards

Endocrine Flashcards

1
Q

T/F: no single test definitively diagnoses hypothyroidism

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ectopic thyroid tissue often localized in what areas?

A

Cervical

Mediastinum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Secretion and regulation of thyroid hormone is regulated by ?

A

TSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the biologically active form of thyroid hormone?

A

Unbound

Enters cells -> bind receptors -> initiates changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the effects of thyroid hormone?

A

CATABOLIC!

Increase metabolic rate 
Increase O2 consumption 
Stimulate erythropoiesis 
positive inotrope and chronotrope 
Catabolizes muscle and adipose tissue 
Alters lipoprotein metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 main thyroid function tests?

A 
Total thyroxine (TT4)
Free thyroxine (FT4) 
Thyroid stimulating hormone (TSH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What thyroid panel is usually run in dogs?

A 
Total thyroxine (TT4) 
Free thyroxine (FT4) 
Thyroid stimulating hormone (TSH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What thyroid panel is usually run in cats?

A

Total thyroxine (TT4) only required*

Can run free thyroxine (FT4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the gold standard for TT4?

A

Radioimmunoassay (RIA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does a radioimmunoassay function?

A

Known amountof T4 Ab is mixed with T4*(radiolabelled)

Serum is mixed with the Ab-T4*

T4 in serum will displace the Ab from T4*
T4-Ab complexes are measured for radioactivity

High radioactivity -> less serum T4
Low radioactivity -> more serum T4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What two assays measure unbound T4

A 
Equilibrium dialysis (ED)- gold standard 
Radioimmunoassya (RIA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What three assays are used to measure TSH?

A

Immunoradiometric
Chemiluminescent
ELISA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

T/F: Assays measuring TSH are efficient at detecting both high a low concentrations of TSH

A

FALSE

Cannot detect low [TSH]
-> in hyperthyroid cats, dont bother running this because values of TSH will be too low to be detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the two major disease syndromes of canine hypothyroidism ?

A

Primary - autoimmune disease

Secondary - pituitary gland neoplasia/congenital malformation/ trauma/surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Primary hypothyroidism results form???

A

Lymphocytic thyroiditis -> idiopathic thyroid atrophy

Thyroglobulin auto-antibodies (TGAA)
Lymphocytes and macrophages
Fibrous tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Clinical signs associated with hypothyroidism?

A

Fat, sleepy, lethargic, metal dullness
Weight gain

Cold intolerant

Bradycardia

Skin lesions: alopecia, increased shedding, poor hair coat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What may you see on a CBC in a dog that has hypothyroidism ?

A

Mild to moderate non-regenerative anemia

-decreased metabolic rate -> decrease O2 demand -> decreased EPO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the most common chemistry abnormality associated with canine hypothyroidism ?

A

Hypercholesterolemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

TT4 decreased
FT4 decreased
TSH incresed

A

Primary hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

TT4 decreased
FT4 decreased
TSH decreased

A

Secondary hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the DDx for a decreased TT4?

A

Hypothyroid
Euthyroid sick syndrome
Spurious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is euthyroid sick syndrome

A

Adaptive response to illness.

Absent clinical signs for hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

TT4 decreased
FT4 normal
TSH normal

A

Euthyroid sick syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the most common endocrine disorder of cats?

A

Hyperthyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the pathogenesis of feline hyperthyroidism?
Functional adenoma (hyperplasia) Over production of thyroid hormone
26
Clinical signs associated with hyperthyroidism
``` Palpable thyroid slip Tachycardia Polyphagia Hyperactivity Diarrhea ```
27
What may you expect to see on a CBC of a hyperthyroid patient?
Polycythemia - increased metabolic rate -> increase O2 demand -> increased EPO - T4 directly stimulates BM erythropoiesis Heinz body formation Stress leukogram
28
T/F: increases with ALT can be associated with hyperthyroidism
True | -severity correlates with TT4 levels
29
How does hyperthyroidism mask azotemia
Increased GFR due to increased cardiac output Less muscle mass -> lower basal CREA Will be unmasked with hyperthyroidism is treated!
30
What is the single, reliable test for diagnosing feline hyperthyroidism ?
Total T4 Will be increased (duh)
31
What is the most common chemistry abnormality associated with feline hyperthyroidism ?
Hypocholesterolemia
32
Parathyroid hormone is produced by the _________cells
Chief
33
Primary hyperparathyroidism will cause what to the Ca and Phos?
Increase Ca | Decrease Phos
34
What does hypoparathyroidsim cause to the Ca and Phos?
Decreased Ca | Increased Phos
35
Is primary hyperparathyroidism usually a adenoma or carcinoma ?
Adenoma
36
What are your top DDx for hypercalciemia?
Lymphoma Perianal gland adenocarcinoma Mammary carcinoma HyperPTH ``` Hypoadrenocorticism Renal secondary hyperparathyroidism Vit D toxicosis Granulomatous inflammation Osteolytic disease Thiazide diuretic/toxin ```
37
Ca increased Phos decreased PTH increased PTHrp zero
Primary hyperPTH
38
Ca High Phos Low PTH in reference range PTHrp zero
Primary hyperPTH
39
Ca low Phos high PTH low PTHrp zero
Primary hypoPTH
40
What are the two types of diabetes insipidus ?
``` Central DI (CDI) - deficiency of ADH Nephrogenic DI (NDI)- no response to ADH ```
41
In health, how does ADH regulate water balance?
ADH binds to receptor Upregulate cAMP AQP transported to cell membrane H20 resorption
42
What will the USG be in a patient with DI?
Isosthenuric or hyposenuric
43
What is the other DDx you may have along with DI?
Psychogenic polydipsia
44
How are CDI and NDI differentiated?
ADH response test Water deprivation test -DANGER DONT DO THIS Modified water deprivation test
45
What is the ADH response test?
Administer desmopressin - > if USG increase -> central DI - > if USG is still low -> nephrogenic DI
46
What is the theory behind the water deprivation test?
Dehydrate animal Does the animal release ADH and concentrate urine? Yes-> psychogenic PD No-> DI
47
What are the three forms of canine hyperadrenocorticism (HAC)
Pituitary-dependent hyperadrenocorticism (PDH) Functional adrenal tumor (AT) Iatrogenic
48
What is the most common form of canine hyperadrenocorticism
Pituitary tumor -> produce high levels of ACTH -> bilateral adrenal hypertrophy -> negative feedback ineffective
49
What is the pathogenesis of adrenocortical tumor leading to hyperadrenocortism
adrenal tumor constantly produce cortisol -> feedback to pituitary -> no ACTH production -> atrophy of other gland
50
What is the pathogenesis of iatrogenic hyperadrenocortisim?
Steroids animinstered -> constant negative feedback to pituitary -> no ATCH produced -> atrophy of both adrenal glands ** this is why we taper off of glucocorticoids **
51
Clinical signs associated with hyperadrenocorticism
``` PU/PD/PP Pot-bellied appearance Panting Muscle and ligament weakness Alopecia Calcinosis cutis Cutaneous hyerpigmentation ```
52
What CBC and Biochemical changes would you see with hyperadrenocortism?
Stress leukogram Increase ALP Increase ALT Increase Cholesterol
53
What will the USG be in a cushings dog ?
Low (1.004-1.020)
54
T/F: UTIs can commonly be associated with HAC
True Steroids increase insulin resistance -> glucosuria -> bacterial infection
55
Why do we need to differentiate between pituitary-dependent and primary adrenal tumors?
Different therapies! Pituitary -> medically managed Adrenal -> surgery possible
56
What are the screening tests for HAC?
ALP activity Urine cortisol: creatinine ratio (UCCR) Not specific for HAC
57
What test do you use to confirm HAC
Low dose desamethasone suppression test (LDDST)
58
LDDST Serum cortisol decreases. What does this mean?
Healthy dog Steroid -> neg feedback on pituitary -> pituitary secretes LESS ACTH -> lower cortisol
59
T/F: with a LDDST test in a dog with a pituitary tumor, will result in suppression of cortisol
False Cortisol will remain high
60
LDDST test At 8hrs, cortisol is increased At 4hrs, cortisol is increased What this this
HAC - could be pituitary or adrenal
61
LDDST test At 8hrs, Increased cortisol At 4hrs, decreased cortisol
Pituitary dependent HAC ***an adrenal tumor will NEVER have suppression with steroid admin, can sometimes occur with LDDST***
62
What is the ACTH stimulation test? When do we use it?
Administer ACTH -> in healthy dog should result in cortisol increase Used in patient with concurrent non-adrenal disease Only test that will identify iatrogenic HAC
63
ACTH stimulation test No increase in serum cortisol
Iatrogenic HAC
64
ATCH test Serum cortisol is significantly increased. (>20ug/dL)
HAC Hypersecreted cortiosl when given ACTH
65
About 30% of dogs with pituitary tumors do not suppress with either LDDST or HDDST. In these cases, what test to we use to differentiate adrenal tumors from pituitary tumors?
Measure ACTH
66
In a ACTH concentration test, if [ACTH] is increased/normal it is _______ HAC, but if the [ACTH] is decreased it is a _______ HAC
Pituitary-dependent (intermittently secrete ATCH) adrenal tumor (negative feedback of cortisol from tumor lowers ACTH)
67
Hypoadrenocorticism usually affects what dogs?
Females Young and middle aged Mixed breed most prevalent
68
What is a primary vs secondary hypoadrenocorticism ?
Primary- immune mediated destruction of adrenal cortices Secondary- destructive lesions in hypothalamus or pituitary resulting in less CRH or less ACTH
69
Hypoadrenocorticism causes what hormonal imbalances
Low Aldoserone -> loss of Na and water and retention of K+ Low cortisol
70
Clinical signs associated with hypoadrenocorticism
``` Poor appetite Lethargy Thin Vomiting Weakness ```
71
Clinical signs associated with hypovolemic crisis (aka addisonian crisis) ?
Dehydration Shock Bradycardia (due to hyperkalemia) Weak femoral pulse Melena
72
What may you see on a CBC that can indicate Addison's disease ?
Lack of a stress leukogram in a very sick patient (due to lack of cortisol)
73
What chemistry changes are associated with hypoadrenocorticism ?
Pre-renal azotemia Increased [BUN] - dehydration - gastrointestinal hemorrhage (melena) Hypoglycemia
74
What is the test of choice for hypoadrenocorticism ?
ACTH stimulation test Primary hypoadrenocorticism has atrophied adrenals --> administration of ACTH will not cause a response
75
What electrolyte abnormality will be present in an addisons patient?
Hyponatremia Hyperkalemia

RUSVM Clinical Pathology (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions