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19 Cards in this Set
- Front
- Back
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1. What are the effects of thyroid hormones (T3/T4)?
7 things... |
1. Increase BMR
2. Increase O2 consumption 3. Increase cardiac output 4. Stimulates metabolism of fat, carb, and proteins 5. Induces many enzymes In children: 6. Growth and maturation of skeletal bone 7. Vital for development of the CNS |
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2. What are signs of excess thyroid hormone?
What are signs of a decrease in thyroid hormone? |
Sweating, hot, arm shaking
Mentally slow, lowered body temp, cold |
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3. Where are T3/T4 synthesized and stored?
How is thyroid hormone secreted? What stimulates T3/T4 biosynthesis? Which is the more potent form? Which do we make more of? |
Synthesized and stored on Tgb (thyroid globulin protein)
Partly synthesized in follicular lumen Secreted doubly TSH (thyroid stimulating hormone form anterior pituitary) T3 (more potent) T4 (mostly make) |
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4. Describe the biosynthesis of thyroid hormone.
Five steps |
1. Tgb with Tyr residue iodination
2. Coupling with Na (K, Na ATPase) 3. Tgb with T4 enters cells 4. Digestion by lysosomal proteases 5. T3/T4 diffuse out of cell **T4 gets iodinated to T3 (more active form) |
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5. How is there feedback regulation of thyroid hormone?
What types of hypothyroidism is there? |
1. T3 inhibits TRH
2. T3/T4 inhibits TSH Primary, secondary, and tertiary |
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6. What is primary hypothyroidism?
What can be some causes of it? |
Defect in thyroid gland
Cannot make thyroid homrone Defect with thyperoxidase, iodine deficient diet |
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7. What is secondary hypothyroidism?
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Defect in anterior pituitary
Cannot make TSH even though have low thyroid hormone levels |
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8. What is tertiary hypothyroidism?
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Defect in hypothalamus
Get delayed response |
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9. Hypothyroidism graphed as [TSH] vs time
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10. What effect does glucocorticoids have on fuel metabolism?
What are glucocorticoids produced in response to? |
1. Liver
-increase gluconeogensis -increase glycogen storage 2. Muscle -increase protein degradation -decrease protein synthesis and glucose utilization 3. Adipose -increase lipolysis -decrease glucose utilization **redistribute fuels Stress (epinephrine) |
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11. What initiates cortisol release?
What are signals that stimulate CRH release from the hypothalamus? What does CRH stimulate? What does this stimulate? How does cortisol provide feedback inhibition? |
Initiated by a chain of chemical messengers that starts in the brain
Hypoglycemia, cold, exercise, pain, trauma Anterior pituitary to release ACTH (from POMC) ACTH stimulates cortisol release from adrenal gland Cortisol inhibits release of CRH and ACTH |
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12. What is Cushing's syndrome?
What causes it? What are some symptoms of it? |
Hypercortisolism
Tumor on anterior pituitary causing increase in release of cortisol 1, Weigh gain 2. Fatigue 3. Muscle weakness (due to protein degradation) 4. Pink or purple stretch marks (b/c breaking down collagen) 5. Slow healing of cuts |
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13. How are cortisol and aldosterone similar?
How can cortisol affect blood pressure? |
Similar structure
Cortisol in excess can give high blood pressure b/c it can bind to aldosterone receptors |
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14. What is the purpose of the renin-angiotensin-aldosterone system?
What activates it? What is angiotensin II? What does it stimulate? (three things) |
Increase Na levels, BP
Activated by decrease in Na or BP Peptide hormone 1. Increases BP 2. Stimulates aldosterone synthesis/release 3. Stimulates ADH release |
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15. What does aldosterone stimulate?
What does low BP stimulate the kidney to release? What does renin do? What converts A-I to A-II? What senses a decrease in BP? |
Na+ resoprtion, K+ excretion
Release of renin Converts angiotensinogen (pro-hormone) to A-I ACE Juxtaglomeulus (secrete renin) **rate limiting step |
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16. What type of hormone is aldosterone?
What does the aldosterone-receptor complex stimulate? (what 3 genes) What is the net effect of aldosterone? |
Steroid hormone
Stimulates gene transcription Stimulates 1. Na+ channels 2. Na/K ATPase 3. Citrate synthase (TCA cycle) Increase Na retention |
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17. What is Addison's disease?
What are some symptoms? |
Adrenal insufficiency
Don't produce cortisol and aldosterone 1. Muscle weakness and fatigue 2. Weight loss and decrease appetite 3. Darkening of your skin 4. Low BP |
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18. What is an eicosanoids?
What is arachadonic acid? |
20C FA that has a short lift time and local effects
Sn2 position in PL Released by phospholipase A2 GC inhibits GC inhibits COX2 expression (suppresses immune system) |
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19. What are PGs/Thromboxanes? What inhibits them?
What is leukotrienes? What are PGs/leukotrienes involved in? |
Cyclooxygenases
Inhibited by aspirin, NSAIDS Lipoxygenase Inflammatory response (inhibited by CG) |
