Chapter 8- Endocrine System Flashcards
What hormones does the thyroid gland produce, and what are their functions?
The thyroid produces T3 (Triiodothyronine) and T4 (Thyroxine), which regulate metabolism, growth, and heat production. It also produces Calcitonin, which helps lower plasma calcium levels.
How does the thyroid affect metabolism?
T3 & T4 increase metabolism, leading to higher oxygen consumption, heat production, and regulation of protein, carbohydrate, and fat metabolism.
Which dietary component is necessary for thyroid hormone production?
Iodine is essential for the synthesis of T3 & T4. A deficiency can lead to hypothyroidism or goiter.
Thyroid Disorders-
autoimmune disorder of hyperthyroid
?
🃏 A: Graves’ disease (autoimmune), toxic nodular goiter, thyroid cancer, and thyroiditis.
What are the hallmark symptoms of Graves’ disease?
Exophthalmos (bulging eyes), heat intolerance, weight loss, palpitations, tachycardia, and pretibial myxedema (thick scaly skin).
What condition results from extreme untreated hyperthyroidism?
Thyroid Storm – A medical emergency characterized by severe tachycardia, high fever (40.7°C), agitation, confusion, and possible heart failure.
Common disease of hypothyroidism?
Hashimoto’s thyroiditis (autoimmune disease), iodine deficiency, thyroidectomy, radioactive iodine therapy.
What are common symptoms of hypothyroidism?
Cold intolerance, weight gain, fatigue, dry skin, slow heart rate, constipation, and myxedema (severe cases).
What is myxedema coma, and what causes it?
A life-threatening condition due to untreated severe hypothyroidism. It is triggered by infection, trauma, cold exposure, or stopping thyroid medications.
How do TSH levels differ in primary levels?
- Primary Hypothyroidism: High TSH, Low T3/T4
- Primary Hyperthyroidism: Low TSH, High T3/T4
Adrenal Disorders- What are the two major disorders of the adrenal cortex?
- Cushing’s Syndrome – Excess cortisol (too much cortisol)
- Addison’s Disease – Deficient cortisol & aldosterone
What are key physical signs of Cushing’s Syndrome?
Moon face, buffalo hump, purple striae, truncal obesity, muscle wasting, and fragile skin.
What are major complications of excess cortisol?
- Osteoporosis
- Increased infection risk
- Diabetes (insulin resistance)
- Hypertension (fluid retention from aldosterone effects)
- Delayed wound healing
What lab tests confirm Cushing’s Syndrome?
- 24-hour urine cortisol
- Low-dose dexamethasone suppression test
- Saliva cortisol test
- CT/MRI of pituitary or adrenal glands
What is the primary cause of Addison’s Disease?
Autoimmune destruction of the adrenal glands when body does not make enough of certain hormones (or cortisol)
What is an Addisonian Crisis, and why is it an emergency?
A sudden, life-threatening drop in cortisol levels, leading to severe hypotension, electrolyte imbalance, and shock.
How is Addison’s Disease diagnosed?
- ACTH stimulation test
- Serum sodium, potassium, and cortisol levels
- CT/MRI for gland assessment
What is the treatment for Addison’s Disease?
Lifelong corticosteroid replacement therapy (e.g., hydrocortisone, fludrocortisone) and stress dose adjustments.
A patient presents with fatigue, weight gain, dry skin, and cold intolerance. What is the likely diagnosis?
Hypothyroidism
A patient has rapid heart rate, exophthalmos, heat intolerance, and weight loss. What is the likely diagnosis?
Hyperthyroidism (Graves’ disease)
A patient has a round face, thin extremities, truncal obesity, and high blood sugar. What is the likely diagnosis?
Cushing’s Syndrome
A patient reports salt cravings, extreme fatigue, and has hyperpigmented skin. What is the likely diagnosis?
Addison’s Disease
Cushing’s Syndrome Signs?
C- Cortisol too much
U- Unusual fat distribution (moon face, buffalo hump, truncal obesity
S- Skin fragile (thin, bruises easily, purple)
H- High BP, hypergylcemia, hirsutism)
I- Infections & Slow wound healing
N- Neuro changes (Irratability, mood swings, depression)
G- Glucose high, Gain weight
ADDison’s Disease (Add Hormones) - Signs
A- Autoimmune destruction (common cause)
D- Dark pigmentation (bronze skin)
D- Decreased BP, dehydration (Hypotension)
I- Insufficient cortisol &aldosterone
S-Salt craving, sodium low, sugar low (hyponatremia, hypoglycemia
0- Opposite of Cushing’s *Weight loss, weakness)
N- Needing steroids for life (Hyrdrocortisone, Hludrocortisone)
thyroid secretes what 3 hormones?
Triiodothyronine (T3)-help regulate growth development, metabolism and controls heat regulation (thermoregulating center)
Thyroxine (T4)-influences metabolic rate, regulates lipid & carbohydrate metabolism
Calcitonin- responds to hypercalcium, lowers plasma calcium and phosphate levels, inhibits reabsorption of calcium into bones
T4- thyroxine?
Thyroxine (T4) controls metabolism by regulating how the body uses fats and carbohydrates for energy.
T3?
help regulate growth development, metabolism and controls heat regulation (thermoregulating center)
Calcitonin?
Calcitonin responds to high calcium levels by lowering blood calcium and phosphate and preventing bone reabsorption.
Differences bw hyperthyroid vs hypothyroid?
Metabolism, Temp tolerance, Skin /Hair
Hyperthyroidism: 🔥 Fast metabolism, weight loss
Hypothyroidism: ❄️ Slow metabolism, weight gain
🔹 Temperature Sensitivity:
Hyperthyroidism: Heat intolerance (sweating)
Hypothyroidism: Cold intolerance (feeling cold often)
🔹 Skin & Hair:
Hyperthyroidism: Smooth, moist skin, fine hair, hair loss
Hypothyroidism: Dry, coarse skin, brittle hair, hair loss
Similarities between hypothyroid and hyperthyroidism?
✅ Both can cause a goiter (thyroid enlargement)
✅ Both can be caused by autoimmune diseases (Graves’ for hyper, Hashimoto’s for hypo)
✅ Both can lead to menstrual irregularities
✅ Both affect heart rate (Hyper = fast, Hypo = slow)
✅ Both require lifelong hormone regulation treatments
✅ Both diagnosed through TSH, T3, and T4 levels
Differences bw hypo and hyperthyroidism?
HR, energy levels, BM
Hyperthyroidism: Fast heart rate (tachycardia), palpitations
Hypothyroidism: Slow heart rate (bradycardia)
🔹 Energy Levels:
Hyperthyroidism: Nervousness, insomnia, tremors
Hypothyroidism: Fatigue, lethargy, slow thinking
🔹 Bowel Movements:
Hyperthyroidism: Frequent diarrhea
Hypothyroidism: Constipation
Hyperthyroidism: TSH Levels
Hypothyroidism: TSH levels
Complications of Hyperthyroidism leads to?
Hyperthyroidism: Low TSH, High T3 & T4
Hypothyroidism: High TSH, Low T3 & T4
🔹 Complications:
Hyperthyroidism: Thyroid Storm (severe hypermetabolism)
Severe Metabolic breakdown?
Hypothyroidism: Myxedema Coma (severe metabolic slowdown)
