Endocrine Flashcards

(173 cards)

1
Q

Cushing’s disease vs Cushing’s syndrome

A

The disease is the most common cause of Cushing’s syndrome

Disease is ACTH-secreting pituitary adenoma that causes increase in cortisol

Syndrome is hypercortisol state

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2
Q

Causes of Cushing’s Syndrome

A

Cushing’s disease (pituitary adenoma, most common cause)
Chronic steroid use
Adrenal tumor
Ectopic production by ACTH-secreting tumor (often small lung cell carcinoma)

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3
Q

Patients most commonly affected by Cushing’s Syndrome

A

premenopausal women

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4
Q

Hallmark findings of Cushing’s Syndrome

A
buffalo hump
moon face
proximal muscle weakness
pigmented striae
obesity - centrally located with skinny limbs
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5
Q

Best lab to dx Cushing’s Syndrome

A

24 hr urine for free cortisol

> 125 is diagnostic

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6
Q

How does overnight dexamethasone suppression test help dx Cushing’s Syndrome?

A

Distinguishes pituitary vs ectopic cause of cortisol elevation

Patient gets 1 mg of dexamethasone at 12pm. 8am plasma ACTH measured

Pituitary tumor (Cushing's Disease) - low ACTH; negative feedback
Ectopic tumor - no ACTH change
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7
Q

How is Cushing’s Disease treated?

A

transsphenoidal resection with hydrocortisol replacement, but if tumor cannot be removed chemo or radiation therapy useful

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8
Q

How is Cushing’s Syndrome treated?

A

Metyrapone and Ketoconazole may suppress hypercortisolism

Parenteral octreotide may suppress ACTH

Often patients treated for Cushing’s syndrome will go into cortisol withdraw and require steroid tapering therapy with hydrocortisone or prednisone

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9
Q

Clinical findings of Addison’s Disease

A

Sparse axillary and pubic hair
Hyperpigmentation of skin, esp. creases or pressure areas (waist band/bra line)
Hypotension and small heart

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10
Q

What chemicals/lytes are low in Addison’s Disease? which are elevated?

A

Low – Na and glucose

Elevated – K+, Ca2+ and BUN

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11
Q

Diagnostic lab test for Addison’s disease

A

low plasma cortisol and aldosterone with elevated ACTH

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12
Q

Treatment of Addison’s disease

A

Replacement with oral hydrocortisone or prednisone

Fludrocortisone also useful for sodium retention

DHEA may also be given

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13
Q

Difference between pathophysiology of primary and secondary hyperthyroidism

A

Primary hyperthyroidism: problem with thyroid

Secondary hyperthyroidism: problem with pituitary

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14
Q

___________ is the most common cause of hyperthyroidism. It is an autoimmune disease in which the body creates antibodies that bond to the TSH receptors and force excessive T3/T4 production.

A

Graves’ disease

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15
Q

20-40% of patients with Grave’s disease have what findings that can distinguish from other hyperthyroid issues?

A

conjunctivitis
exophthalmos (bulging of eyes)
pretibial myxedema (non-pitting edema of knee)
thyroid bruit

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16
Q

Some of the many symptoms of hyperthyroidism

A

Eyes: stare, lid lag, diplopia
CV: Tachycardia, A-fib, palpitations, chest pain
Skin: Fine hair, warm/moist skin, onycholysis
Mental changes: irritability, Nervousness, fatigue
Heat intolerance, sweating
Weight loss, increased appetite
Hyperreflexia
Goiter

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17
Q

What is a thyroid storm?

A

very rare but severe form of hyperthyroidism

risk factors include stressful illness, thyroid surgery, radioactive iodine treatment

symptoms: fever, tachycardia, vomiting/diarrhea, dehydration, muscle weakness, confusion

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18
Q

How does hyperthyroidism affect TSH, T3, T4

A

TSH decreased (primary) or elevated (secondary)
T4 elevated
T3 elevated

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19
Q

What is specifically elevated in Graves’ disease?

A

anti-TSH receptor antibodies

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20
Q

Radioactive iodine uptake scan results of Graves disease

A

thyroid has increased iodine uptake

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21
Q

First line treatment for acute hyperthyroidism and thyroid storm? Long term control?

A

Acute: beta blockers (especially propanol)

Long term: Methimazole and propylthiourcial (PTU)

Definitive tx: Radioactive iodine ablation

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22
Q

How to treat A-fib of hyperthyroidism?

A

Digoxin

Warfarin to prevent possible clotting

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23
Q

Pathway of T3/T4 production from hypothalamus signaling

A

Hypothalamus → thyroid releasing hormone → pituitary → thyroid stimulating hormone → thyroid → T3 and T4

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24
Q

Why might a patient have hypothyroidism?

A

Thyroiditis
Patient doesn’t have thyroid
Meds: amiodarone, lithium, PTU & Methimazole
Iodine deficiency

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25
Some of the many hypothyroidism symptoms:
cold intolerance, puffy face, fatigue, pale/cool skin, thin brittle nails, depression, dementia, weakness, anorexia, constipation, weight gain, bradycardia, hyporeflexia +/- Goiter
26
TSH, T3, and T4 levels in hypothyroidism
- TSH elevated (primary) or decreased/normal (secondary) - T4 decreased - T3 may be normal
27
Treatment of hypothyroidism
Thyroid hormone replacement: Levothyroxine (synthetic T4) Treatment is for life Thyroid levels checked yearly Watch for signs of hyperthyroidism
28
thyroid storm : hyperthyroidism | __________ : hypothyroidism
myxedema
29
Patients with myxedema will have symptoms of hypothyroid as well as what?
``` mental changes ranging from confusion to coma convulsions hypotension hypothermia hypoventilation rhabdomyolysis and AKI hyponatremia ```
30
Treatment of myxedema
IV levothyroxine intubation prn slow warming with warm blankets prn
31
What is Hashimoto's thyroidits?
- Autoimmune disease causing partial or complete impairment of thyroid gland; hypothyroid sx's - Typically occurs with other autoimmune problems like Sjorgren's, MG, DM-I, celiac disease, Addison's, etc.
32
Clinical presentation of thyroiditis
enlarged, firm, nodular thyroid dysphagia +/- pain
33
What condition has increased anti-thyroperoxidase and anti-thyroglobulin antibodies?
Hashimoto's thyroiditis
34
What imaging is used to differentiate thyroiditis from nodular goiter or malignancy?
Thyroid U/S | Radioiodine uptake scan
35
Why is a fine needle aspiration done for patients with Hashimoto's or thyroid nodule?
significant risk of thyroid cancer
36
Why is a fine needle aspiration done for patients with suppurative thyroiditis?
suppurative thyroiditis is likely bacterial infection, so FNA can be helpful for gram stain and culture
37
How is postpartum thyroiditis treated?
self-limiting | symptomatic treatment prn
38
How is subacute thyroiditis treated?
Aspirin first line for pain and inflammation Propranolol for hyperthyroid sx's Levothyroxine for hypothyroid sx's
39
How is Hashimoto's thyroiditis treated?
If patient hypothyroid -> Levothyroxine If patient has large goiter -> Levothyroxine in effort to shrink goiter Otherwise monitor for hypothyroid
40
Which thyroiditis is due to a bacterial infection?
Suppurative thyroiditis
41
How can you tell if Hashimoto's thyroiditis has Sjogren's as well?
dry eyes dry mouth ** 33% of Hashimoto's will also have Sjogren's syndrome
42
You believe a patient presenting to you has relatively severe hypothyroidism. You send off a thyroid panel as well as CBC and BMP. What abnormality do you expect to find on BMP?
decreased sodium
43
Different types of thyroiditis
``` Hashimoto’s - autoimmune issue (most common) Suppurative - bacterial infection Subacute/ de Quervain's - viral Riedel - fibrous infiltration Postpartum ```
44
3 hormones that regulate calcium levels in the blood?
PTH and Vit D increase calcium | Calcitonin decreases calcium
45
Primary hyperparathyroidism typically caused by what?
adenoma in 1 of 4 parathyroid glands could also be from hyperplasia or carcinoma
46
What is secondary hyperparathyroidism caused by what?
overstimulation of parathyroid glands - Chronic renal failure and poor Vit D production which decreases calcium - Malignant tumor (breast, lung, pancreas) - Calcium deficiency
47
"moans, (abdominal) groans, stones, and bones" =
hyperparathyroidism
48
What lab value differentiates primary and secondary hyperparathyroid?
serum phosphate low in primary and elevated in secondary both have elevated serum PTH
49
Because serum calcium is high in hyperparathyroid, what is low?
Vit D
50
Possible XR findings of hyperparathyroid
demineralization subperiosteal bone resorption, especially fingers cysts of jaw salt and pepper skull
51
What is the recommended definitive treatment for symptomatic and some asx hyperparathyroidism?
- parathyroidectomy (94% success rate) | - monitor complications of hypocalcemia with Ca2+ supplements and hyperthyroidism with propranolol
52
How can one acquire hypoparathyroidism?
``` *Post thyroidectomy Heavy metal damage Low magnesium Granulomas Infection ```
53
Congenital cause of hypoparathyroidism
DiGeorge Syndrome (chrom 22 defect) and other genetic disorders
54
Acute hypoparathyroid symptoms
Irritability Tetany - involuntary contractions Carpopedal spasms Tingling (circumoral, distal extremities)
55
Chronic hypoparathyroid symptoms
``` Lethargy Parkinsonism Mental retardation Anxiety Cataracts Dry skin, brittle nails ```
56
What is Trousseau sign?
blood pressure cuff placed around arm and inflated to pressure > systolic BP and held in place for 3 min to occlude brachial artery -> spasm of hand and forearm observed in patient's with low calcium
57
What is Chvostek sign?
sign of existing tetany seen in hypocalcemia facial muscles contract when facial nerve tapped at masseter
58
What do a positive Trousseau and Chvostek signs indicate?
hypocalcemia
59
What labs values are low in hypoparathyroidism?
Serum and urinary Ca PTH Magnesium
60
ECG findings of hypocalcemia
prolonged QT | T wave abnormalities
61
Emergency treatment of hypoparathyroidism
Airway maintenance | IV calcium gluconate
62
How is hypoparathyroidism managed long term?
Calcium and Vit D supplements Magnesium if appropriate Close monitoring of calcium
63
What is pseudohypoparathyroidism?
patient makes enough PTH, but receptors don't respond presents just like hypoparathyroidism except PTH is elevated
64
Non-surgical treatment of hyperparathyroidism and high calcium
Fluids!!!! (1st line if extremely high Ca levels) IV Bisphosphonates Cinacalcet (calcimimetic) Vit D Estrogen to decrease Ca in postmenopausal woman Propranolol to protect heart from elevated Ca
65
What is the most common and least aggressive type of thyroid cancer?
papillary carcinoma (80%)
66
What is the second most common thyroid cancer that is more aggressive and may secrete enough T4 to cause thyroid storm?
Follicular thyroid cancer
67
Thyroid cancer that may be associated genetics or MEN type 2
Medullary thyroid cancer
68
What characteristics of thyroid suggest malignancy?
single palpable nodule painless neck swelling may cause dysphagia, hoarseness, dyspnea, or hyperthyroid sx's
69
How are suspicious thyroid nodules diagnosed?
Fine needle aspiration
70
TSH and T4 are normal in all thyroid cancers except for _______.
follicular cancer; produces excess T4 which suppresses TSH
71
Best to image metastasis in lungs with _____ and metastasis in bone with _____.
CT | MRI
72
Treatment of thyroid cancer
Total or near total thyroidectomy Neck dissection and lymph node removal if indicated Post op: Levothyroxine (synthetic T4) if thyroidectomy Radioactive iodine ablation for residual dz, metastatic dz and to prevent recurrence Monitor with whole body radioactive iodine scans and monitor TSH for levothyroxine dose
73
Which type of thyroid cancer is least common but most aggressive?
anaplastic
74
How is thyroid cancer remission defined?
Two consecutive negative whole body radioisotope scans
75
Leading cause of blindness in U.S.
diabetes
76
Type I DM is secondary to autoimmune disease affecting what in body?
islet beta cells of pancreas, so patient can't produce enough insulin
77
What gene is a risk factor for DM-I?
HLA
78
Signs of DKA
N/V polyuria and polydipsia change in mental state fruity breath
79
Clinical findings of Type 1 DM
``` Signs of ketoacidosis Weight loss despite normal diet Blurry vision Poor wound healing Acanthosis nigricans Neuropathy ```
80
Ways to dx diabetes
1) fasting blood glucose levels >126 mg/dL on more than one occasion 2) non-fasting blood glucose of >200 mg/dL 3) oral glucose tolerance; fasting patient consumes 75 g oral glucose and 2 hrs later glucose level > 200 mg/dL
81
What is hemoglobin A1c? What is normal?
indicates sugar levels over previous 3 months and is used for monitoring glucose control Normal is 3.8-6.3%
82
Diet and Education for diabetes management
Increase fiber and complex carbs Monitor carb intake Monitor glucose Eat snacks and meals at regular intervals
83
Examples of rapid acting insulin
Lispro, Humalog, Novolog
84
Onset, peak, and effective duration of rapid acting insulin?
Onset: 5-15 minutes Peak: 1-1.5 hours Duration: 3-4 hours
85
Examples of short acting insulin
Human Regular
86
Onset, peak, and effective duration of short acting insulin?
Onset: 30-60 minutes Peak: 2 hours Duration: 6-8 hours
87
Examples of intermediate acting insulin
Human NPH (Neutral protamine hagedorn) and Lente
88
Onset, peak, and effective duration of intermediate acting insulin?
Onset: 2-4 hours Peak: Flat Duration: about 24 hours
89
Examples of long acting insulin
Lantus, Ultralente
90
Onset, peak, and effective duration of long acting insulin?
Onset: 30-180 minutes Peak: Lantus no peak, Ultralente 10-20hrs Duration: 20-36 hrs
91
Which type of insulin is used before meals?
Short acting insulin, Human Regular
92
Which insulin is typically two doses daily and used in conjunction with a short acting insulin?
Intermediate acting insulin, Human NPH
93
What are routine exams all diabetic should have?
Regular visits to podiatrist for foot care | Regular diabetic eye exams
94
How many units of regular or Lispro insulin should be used based on carbs eaten?
1 unit for every 10-15 grams
95
How does DM-2 present differently than DM-1?
``` dx'd later in middle age or later insidious onset (usually asx) abdominal obesity functioning pancreas that produces insulin, but receptors and tissues do not respond (insulin resistance) ```
96
Type of neuropathy in diabetes
stocking-glove distribution
97
What races are more susceptible to DM-2?
African American, Hispanic, Pima Indians
98
Lipid panel changes in DM-2?
Elevated triglycerides 300-400 mg/dl | Low HDL
99
Most common drug class used to stimulate insulin secretion
sulfonylureas (glypburide, glipizede, glimepiride)
100
First line therapy for DM-2
Metformin
101
Meds that lower glucose? How?
Metformin – reduces hepatic glucose production alpha-Glucosidase inhibitors (Acarbose)– decrease carb absorption from intestines
102
Thiazolidinediones MOA for treating DM-2
increase tissue sensitivity to insulin ex: rosiglitazone and pioglitazone
103
Treatment of DM-1
NEED INSULIN
104
Treatment of DM-2
1) Diet and exercise to improve insulin resistance 2) Oral meds: Metformin 1st line; others are sulfonylureas, alpha-glucosidase inhibitors, thiazolidinediones 3) Insulin therapy
105
Patients with metabolic syndrome are at higher risk for what?
``` DM 2 Elevated triglycerides Lower HDL Elevated LDL HTN Blood clots Atherosclerosis ```
106
What is clinical definition of metabolic syndrome?
3 or more of following: ``` BP > 130/85 Fasting glucose > 100 Waist circumference - M > 40 inches - W > 35 inches Low HDL - M less than 40 - W less than 50 Triglycerides > 150 ```
107
What is postprandial hypoglycemia?
blood sugar drop after eating ``` Early = 2-3 hours after Late = 3-5 hours after ```
108
Causes of hypoglycemia
``` Exogenous insulin overdose Insulinoma Addison’s disease (hypopituitarism) Renal failure Liver problem Glycogen storage Alcohol related ```
109
How can alcohol cause hypoglycemia?
Liver problems Alcohol inhibits gluconeogenesis N/V – gastritis
110
How does Addison's disease cause hypoglycemia?
hypopituitarism -> adrenal insufficiency -> low cortisol no cortisol to break down glycogen in liver into glucose and no cortisol to convert fats, proteins, and carbs into glucose
111
Clinical presentation of hypoglycemia
``` Often symptoms occur after missing a meal Sweating Palpitations Anxiety Blurred vision Weakness Light headed Slurred speech Loss of consciousness ```
112
Clinical definition of hypoglycemia
low blood sugar below 70 mg/dl
113
What blood sugar levels can cause someone to lose consciousness?
about 50 mg/dl
114
Whipples Triad
1) history of hypoglycemia 2) low serum glucose at time of event 3) immediate recovery on administration of glucose suggest a patient's symptoms are due to hypoglycemia; or may indicate insulinoma
115
How to treat hypoglycemia based on cause?
Exogenous insulin overdose – eat a cookie :) Insulinoma – surgically resect if possible Postprandial hypoglycemia – small meals every 2-3 hours Addison’s – oral steroid
116
What is ACTH? and what does it do?
adrenocorticotropic hormone; stimulates increased production and release of corticosteroids by adrenal glands
117
What are hormones released by posterior pituitary? What are their functions?
ADH (antidiuretic, vasopressin) – increases water absorption in kidneys Oxytocin – increases uterine contractions, milk release
118
Pathophysiology of acromegaly
usually a pituitary adenoma which secretes excess GH
119
Acromegaly vs Gigantism
excess GH during child before epiphyses closure -> Gigantism excess GH as adult after epiphyses closure -> Acromegaly
120
____ levels 5x higher than normal in Acromegaly and Gigantism.
IGF-1
121
MRI will show _________ in about 90% of patients with Acromegaly.
pituitary adenoma
122
Treatment of Acromegaly and Gigantism
Primary treatment is trans-sphenoidal resection of pituitary adenoma ``` Dopamine agonist (Cabergoline) to help normalize GH Somatostatin analog (Octreotide, Lanreotide acetate) GH receptor antagonist (Pegvisomant) ```
123
Diabetes insipidus is a deficiency in what?
ADH
124
Signs of Diabetes Insipidus
THIRSTY!!! 2-20 Liters per day | Polyuria
125
What is the vasopressin challenge test and how does it help determine cause of DI?
Urine volume for 12 hours Desmopressin acetate is given Urine volume over next 12 hours if urine volume improves with Desmopressin then pituitary or hypothalamus issue = central if no improvement, kidney tubules = nephrogenic
126
Treatment of diabetes insipidus
Central DI (Pituitary/Hypothalamus decreased ADH production) Desmopressin Acetate HCTZ ``` Nephrogenic DI (ADH resistance) Indomethacin HCTZ ```
127
__________ is abnormal mineralization of bones AFTER closing of epiphyseal plates. __________ is abnormal mineralization BEFORE closing of plates.
Osteomalacia Rickets
128
Causes of Rickets
Vit D deficiency - sun exposure, nutrition, malabsorption, chronic renal failure Calcium or phosphate deficiency Phenytoin – seizure med
129
Location of bone pain in Rickets and Osteomalacia mostly where?
pelvis
130
Classic XR findings of Rickets and Osteomalacia
Decrease in bone density Milkman lines Looser zones
131
Treatment of Rickets and Osteomalacia
Ergocalciferol (as Vit D supplement) Phosphate supplement Calcium supplement
132
Patient comes in c/o deafness and arthralgia. XR shows bony lesions with hyper-density and bowing. Serum calcium and phosphate normal, but alk phos elevated. Likely dx?
Paget's Disease
133
Paget's Disease treatment
1st line: Oral bisphosphonates (Alendronate, Tiludronate, Risedronate) IV Bisphosphonates (Zoledronic acid or Pamidronate)
134
Most common cause of secondary hyperthyroidism?
pituitary tumor
135
Anti-arrhythmic drug that can cause hyper or hypothyroidism?
Amiodarone "iod" = iodine, thyroid
136
What are 3 zones of the adrenal cortex and what does each secrete?
zona glomerulosa - aldosterone zona fasciculata - glucocorticoids (cortisol) zona reticularis - sex hormones
137
What does the adrenal medulla secrete?
epinephrine and norepinephrine with sympathetic stimulation
138
What stimulates aldosterone secretion from adrenal gland?
Hypotension (renin -> angiotensin -> ADH) Hyperkalemia Hyponatremia
139
______ prevent angiotensin-stimulated aldosterone release.
ACE inhibitors
140
Why is there hyperpigmentation in Addison's disease?
ACTH and MSH (melanocyte stimulating hormone) share common precursor POMC When ACTH increases so does MSH
141
Aldosterone production in primary and secondary adrenal insufficiency
Primary - aldosterone and cortisol decrease since whole adrenal gland not working Secondary - aldosterone normal since its stimulate by RAAS; only cortisol decreases
142
Over-secretion of epinephrine occurs in __________.
pheochromocytoma
143
Location of tumors of MEN 1
3 P's: parathyroid, pituitary, pancreas
144
What does MEN stand for?
= multiple endocrine neoplasia
145
Which endocrine hormone is not regulated by the pituitary?
PTH; secretes from parathyroid in response to low calcium
146
How does PTH increase calcium?
- stimulates osteoclasts to break down bone - increases reabsorption of calcium by kidneys - decreases reabsorption of phosphate by kidneys - increases conversion of inactive Vit D to active form (absorption of calcium in GI tract)
147
PTH and Vit D effects on phosphate levels
Vit D increases serum phosphate | PTH decreases serum phosphate
148
How does calcitonin decrease calcium levels?
secreted by thyroid when calcium blood levels high increases bone absorption of calcium and decreases renal absorption of calcium
149
Serum and urine findings in primary hyperparathyroidism
Serum: calcium and PTH high, phosphate low Urine: calcium, phosphate, and cAMP high
150
Pathologies that cause elevated Vitamin D
TB, sarcoidosis, lymphoma, Milk-Alkali syndrome
151
How does elevated PTH affect Vit D?
increase conversion of 25-vit D to 1,25-vit D = increased Vit D
152
How does elevated Vit D affect PTH?
increased Ca2+ = decreased PTH
153
What is DiGeorge Syndrome?
congenital absence of parathyroids and thymus
154
Causes of Vitamin D deficiency
decreased UV exposure inadequate dietary intake malabsorption liver or renal disease
155
What is Hungry Bone Syndrome?
sudden decrease in PTH after hyperparathyroid treatment causes bones to be "hungry" for calcium
156
How do calcium levels affect ECG readings?
high calcium shortens QT | low calcium prolongs QT
157
Hormone/chemical issues that cause osteoporosis
low estrogen high cortiso low calcium/Vit D
158
Genetic pathology with osteoclast dysfunction and uncontrolled bone formation?
Osteopetrosis
159
Hormones released by anterior pituitary?
"FLAT PEG" ``` FSH LH ACTH TSH Prolactin * Endorphins GH ```
160
The pituitary gland sits beneath the ________ attached to the brain.
optic chiasm
161
Why is GH level not a reliable dx test? What is measured instead?
GH has pulsatile release | IGF-1 used instead (stimulated by GH)
162
Dx tests for suspected GH-secreting tumor?
IGF-1 level | Glucose challenge test (high glucose normally decreases GH)
163
How is prolactin secretion controlled?
dopamine released from hypothalamus inhibits prolactin release from anterior pituitary until postpartum when high estrogen levels stimulate its secretion for lactation
164
Sheehan's syndrome
postpartum hemorrhage in mother results in hypovolemia and subsequent pituitary damage (hypopituitarism)
165
Effects of insulin and glucagon on blood sugar levels
Insulin: glucose into cell (lowers sugar) Glucagon: glucose to blood (raises sugar) * "Is your glucose gone? Get glucagon!" * INsulin sugar goes IN
166
What other hormones, apart from glucagon, raise blood sugar levels?
cortisol GH Nor/epinephrine
167
How does insulin reduce glucose levels?
increases glycogenesis (glycogen storage) and glycolysis (glucose breakdown)
168
How does glucagon lower glucose levels?
``` decreases glycolysis increases gluconeogenesis (glucose formation) and glycogenolysis (glycogen breakdown into glucose) ```
169
cosyntropin (ACTH) stimulation test =
Addison's
170
dexamethasone suppression test =
Cushing's Syndrome
171
vasopressin challenge test =
Diabetes Insipidus
172
Side effects of Methimazole
rash **agranulocytosis** lupoid hepatitis renal failure
173
PTU instead of Methimazole in what patients?
pregnancy