Term
What is seen when there is problems with the Pituitary-Thryoid axis? |
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Definition
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Term
What is seen with problems in the Pituitary-Adrenal axis? |
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Definition
Cushing's and Addison's disease? |
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Term
What is seen with problems in the Pituitary-Gonadal axis |
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Definition
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Term
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Definition
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Term
Hypothalamic - Pituitary - Adrenal axis |
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Definition
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Term
Hypothalamic - Pituitary - Gonadal axis |
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Definition
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Term
List the anterior pituitary hormones, their regulatory hormones |
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Definition
• Thyroid stimulating hormone (TSH; TRH) • Adrenocorticotrophin (ACTH; CRH) • Luteinizing hormone (LH; GnRH) • Follicle stimulating hormone (FSH; GnRH) • Growth hormone (GH; GHRH & GHRIH) • Prolactin (PRL; Dopamine) |
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Term
Which two ant pit hormones are under negative feedback? |
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Definition
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Term
What is different about PRL regulation, compared to regulation of the other ant pit hormones? |
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Definition
PRL is primarily under inhibitory control by dopamine, rather than being released upon stimulation |
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Term
List 5 symptoms of pituitary tumours (adenomas)? |
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Definition
• Headache (intracranial pressure) • Drowsiness • Seizure • Visual defects (pressure on optic chiasm) • Abnormal hormone secretion |
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Term
Why are adenomas considered benign, when they are associated with malignancies? |
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Definition
Because they are not metastatic (don;t cause cancer) |
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Term
What are the most common hormonal problems related to an adenoma? |
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Definition
1. Hyperprolactinemia 2. ACTH hypersecretion 3. GH hypersecretion |
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Term
(T/F) Hyperprolactinemia is the most common type of pituitary tumour |
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Definition
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Term
What is seen in galactorrhea, and what sexes can have it? |
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Definition
- Men and women - Spontaneous flow of milk from the tumour |
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Term
What is seen in amenorrhea, and what sexes can have it? |
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Definition
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Term
What is caused by oversecretion of ACTH? |
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Definition
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Term
What is the cause of gigantism? |
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Definition
Pre-pubertal GH oversecretion |
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Term
What is the cause of acromegaly? |
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Definition
Post-pubertal GH oversecretion |
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Term
How can a pituitary tumour destroy the gland? |
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Definition
- Compression compromises vascular suppl - Disruption of the pituitary-hypothalamic axis |
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Term
What is the end result of this? |
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Definition
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Term
(T/F) Hypopituitaryism is always caused by a pituitary tumour |
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Definition
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Term
What are two other causes? |
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Definition
1. Sheehan's syndrome 2. Pit stalk transection |
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Term
What is the cause of Sheehan's syndrome, and which sex does it occur in? |
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Definition
Vascular collapse following an obstetrical hemmorrhage, causing death of the pituitary; women only |
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Term
What can cause a pit stalk transection? |
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Definition
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Term
What is a unique characteristic of a pituitary stalk transection, and why does it occur? |
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Definition
Panhypopituitaryism, except PRL is elevated. PRL is elevated because dopamine can no longer reach the pituitary gland, and thus, PRL secretion is constant |
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Term
If the adenoma causes a hormone deficiency, how is it treated? |
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Definition
Hormone replacement of downstream hormones (no point replacing the pituitary hormones) |
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Term
If the adenoma causes a hormone excess, how is it treated? |
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Definition
1. Inhibitory drug therapy 2. Ablation therapy |
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Term
What is bromocryptine used for? |
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Definition
Treatment of hyperprolactinemia |
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Term
(T/F) Hypothyroidism is very rare |
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Definition
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Term
Which sex is it more common in? |
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Definition
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Term
What is the cause of primary hypothyroidism? Secondary? Which is more common |
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Definition
Primary (90% of cases): Thyroid gland malfunction Secondary: Pituitary deficiency of TSH |
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Term
What are the 4 causes of hypothyroidism? |
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Definition
1. Autoimmune 2. Thyroiditis 3. Congenital 4. Surgical |
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Term
What is hashimotos disease? |
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Definition
Hypothyroidism caused by autoimmune attack on thyroid gland |
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Term
What are the clinical symptoms of hypothyroidism? |
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Definition
- Goiter - Reduced metabolism |
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Term
What symptoms are seen because of the reduced metabolism? |
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Definition
– Pale, cool, edematous – Cold intolerant – Slow heart rate (bradycardia) – Lethargic – Decreased appetite/weight gain |
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Term
(T/F) Goiter is seen in both primary and secondary hypothyroidism |
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Definition
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Term
Why does goiter only occur in primary hypothyroidism? |
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Definition
Only in primary because it is caused by overstimulation by TSH, and in secondary hypothyroidism there is reduced TSH |
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Term
If someone has a goiter, does this confirm that they have hypothyroidism? |
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Definition
No, because hyperthyroidism is also characterized by a goiter |
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Term
Why does lack of iodine in the diet lead to formation of a goiter? |
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Definition
Because no TH can be made due to the iodine deficiency, so overstimulation by TSH occurs |
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Term
What is the cause of cretinism? |
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Definition
Congenital hypothyroidism |
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Term
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Definition
Mental retardation and growth restriction caused by untreated congenital hypothyroidism |
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Term
What two congenital defects can give rise to cretinism? |
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Definition
- Iodine deficiency - Thryoid gland malformation |
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Term
What are two therapies, and do any of them have any stipulations? |
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Definition
- Thyroxine supplement - Iodine replacement (only if cretinism is caused by iodine deficiency) |
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Term
(T/F) Neonatal screening can test for congenital hypothyroidism |
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Definition
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Term
What precautions can the mother take? |
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Definition
Ensure adequate iodine in diet |
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Term
What is the most common form of hyperthyroidism? |
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Definition
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Term
What is the cause of graves disease? |
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Definition
Autoimmune - Ab's generated that chronically stimulate TSH receptors |
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Term
What other 3 ways can hyperthyroidism occur? |
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Definition
- Thyroid nodules - Latrogenic - TSH secreting adenoma |
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Term
What is a thyroid nodule? |
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Definition
An adenoma that secretes TH |
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Term
What is the latrogenic cause of hyperthyroidism? |
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Definition
Overmedication of hypothyroidism |
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Term
What are the symptoms of hyperthyroidism? |
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Definition
- Goiter - Increased metabolism - Exophthalmus |
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Term
What are the signs of hyperthyroidism related to increased metabolism |
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Definition
- Weight loss without appetite loss - Fatigue/muscle weakness - Tachycardia - Nervousness - Heat intolerance - Osteoperosis |
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Term
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Definition
Tissue behind the eye grows and pushes the eye forward |
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Term
Describe what occurs in graves disease? |
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Definition
Constant TH production, even in the presence of a proper regulatory pathway and no TSH secretion |
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Term
(T/F) Graves is easily classed as primary or secondary |
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Definition
False, it behaves secondary (constant stimulation from an outside source), but is similar to primary because there is no problem in the feedback mechanism. However, there is no pathology of the thyroid. |
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Term
What 3 things are used for the treatment of hyperthyroidism? |
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Definition
1. Radioactive iodine 2. Medication 3. Surgery |
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Term
(T/F) Radioactive iodine treatment usually produces hypothyroidism, which requires thyroxine therapy |
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Definition
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Term
What two medications are used in treatment of hyperthyroidism? What does each do? |
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Definition
1. Beta blocker - alleviates symptoms 2. Anti-thyroid drugs (propylthiouracil and methimazole) |
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Term
How do anti thyroid drugs work? |
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Definition
They interfere with thyroperoxidase, and thus prevents activation of iodine and iodination of tyrosine |
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Term
What is surgery used to treat? |
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Definition
- Cancerous thyroid nodules - Goitre |
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Term
What is pheochromocytoma? |
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Definition
A tumour of the adrenal medulla that secretes catecholamines |
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Term
What are two diseases related to pathologies with the adrenal cortex? |
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Definition
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Term
What is the cause of Chushings? |
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Definition
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Term
What causes the excess glucocorticoids? |
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Definition
- ACTH secreting tumour - Glucocorticoid secreting adrenal tumour - Glucocorticoid therapy of chronic inflammatory conditions |
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Term
What are the two types of ACTH secreting tumours? |
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Definition
1. Pituitary 2. Paraneoplastic (in the lung) |
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Term
Which of these causes is related to primary cushings? Secondary cushings? |
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Definition
Adrenal tumour is related to primary; all other causes are related to secondary |
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Term
List the clinical features of Chushings |
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Definition
- Obesity - Moon face - Buffalo hump - Reduced muscle mass in limbs - Stria - Increased hair growth |
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Term
(T/F) The obesity cause by cushings is limited to abdominal areas |
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Definition
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Term
List 4 other features of chushings |
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Definition
1. Osteoperosis 2. Insulin resistance 3. Delayed healing/increased infection 4. Reduced stress response |
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Term
Why does insulin resistance develop? |
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Definition
Because cortisol triggers gluconeogenic effects |
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Term
What is addisons disease? |
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Definition
A deficiency of adrenocortical hormones |
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Term
Which 3 hormones are missing in primary addisons? Secondary? |
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Definition
– Glucocorticoids (primary & secondary) – Mineralocorticoids (primary only) – Androgens (primary only) |
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Term
What are the 3 causes addisons? |
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Definition
- Autoimmune reaction - Destructive tumours - Adrenal gland infection |
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Term
List 6 clinical features of addisons? |
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Definition
• Wgt loss/Anorexia • Weakness/fatigue • Hypotension (salt loss) • Hyperpigmentation • Body hair loss • Hypoglycemia |
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