Term
| What are the adrenal glands? |
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Definition
| small triangular shaped organ that sits on top of the kidneys |
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Term
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Definition
| inner medulla and outer cortex |
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Term
| What are they controlled by? |
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Definition
- Medulla - controlled by nervous system
- Cortex - controlled by the endocrine system |
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Term
| What does adrenal medulla produce? |
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Definition
| adrenaline (epinephrine) and noradrenaline (nor epinephrine) |
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Term
| What does the nervous system produce? |
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Definition
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Term
| What does adrenaline and noradrenaline belong to? |
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Definition
| "flight or fight" hormones (short term stress) |
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Term
| What happens during a stressful situation? |
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Definition
| sensed by brain → sympathetic nerves → adrenal medulla → releases noradrenaline & adrenaline |
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Term
| What is the short term response to stress? |
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Definition
adrenaline and nor adrenaline:
- stimulates the liver to convert glycogen to glucose → increased blood glucose levels
- increases heart rate, breathing rate, and cell metabolism
- dilates blood vessels → increased blood flow (oxygen and nutrients) to the tissues
- pupils dilate → more light to the retina |
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Term
| What does the adrenal cortex produce |
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Definition
| glucocorticoids, mineral corticoids, small amount of sex hormones |
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Term
| What kind of stress response is it involved in? |
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Definition
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Term
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Definition
| an important glucocorticoid |
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Term
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Definition
- increases AA levels: liver then converts AA to glucose for ready energy source
→ also means increased protein synthesis, which is needed for cell repair
- increases fat breakdown to fatty acids
- inhibits glucose uptake into many cells, especially muscles (thus blood glucose level is high)
→ BUT it does not inhibit glucose uptake into brain cells
- suppresses inflammatory response of the immune system |
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Term
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Definition
| most important mineral corticoid from adrenal cortex |
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Term
| What does aldosterone do? |
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Definition
| - increases Na+ retention from kidneys → increases water retention → maintain blood pressure |
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Term
| What happens in long-term stress response? |
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Definition
- brain identifies stressful situation - hypothalamus sends message (a releasing hormone) to the anterior pituitary to release ACTH (adrenocorticotropic hormone)
- ACTH acts on adrenal cortex to secrete mineral corticoids (aldosterone) and glucocorticoids (cortisol) |
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Term
| What does long-term stress response result in? |
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Definition
- increased blood pressure (since increased blood volume)
- increased blood glucose
- suppressed inflammatory response |
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Term
| How does cortisol negatively feed back? |
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Definition
| when it increases, it tells hypothalamus to decrease releasing factors and thus ACTH from the anterior pituitary |
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Term
| What does the thyroid gland regulate? |
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Definition
| metabolism, growth, and differentiation of tissues |
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Term
| How does the thyroid gland regulate metabolic rate? |
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Definition
| ↓ metabolic rate → hypothalamus to secrete thyroid releasing hormone (TRH) → causes anterior pituitary to release TSH (thyroid stimulating hormone) → TSH causes thyroid gland to release thyroxine →cells to increase metabolism (↑ sugar utilization by body cells) |
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Term
| What happens when thyroxine levels increase? |
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Definition
| it will inhibit TRH from the hypothalamus |
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Term
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Definition
| hormone produced by the thyroid gland |
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Term
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Definition
- lowers blood calcium and phosphate levels
- promotes bone formation |
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Term
| What is special about calcitonin? |
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Definition
| one of the treatments for osteoporosis |
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Term
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Definition
| condition when there is too much thyroxine produced |
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Term
| What are some symptoms of hyperthyroidism? |
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Definition
- weight loss
- heat intolerance
- rapid heart rate
- fatigue, nervousness, irritability, insomnia, headache
- tremor
- proptosis (bulging eyes)
- changes in menstrual cycle |
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Term
| What are the three causes? |
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Definition
1) Grave's disease (most common)
2) Certain thyroid nodules producing too much thyroxine
3) Thyroiditis |
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Term
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Definition
| autoimmune disorder, maybe familial |
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Term
| Who is more prone to Grave's disease? men or women? |
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Definition
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Term
| What happens in Grave's disease? |
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Definition
- own antibodies attack the thyroid gland, stimulating too much thyroxine to be produced
- can affect muscles behind the eyes to give proptosis |
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Term
| What happens in thyroiditis? |
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Definition
| - for unknown reasons, sometimes the thyroid gland can become inflamed & cause release of more thyroxine |
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Term
| When can thyroiditis occur? |
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Definition
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Term
| What are some treatments for hyperthyroidism? |
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Definition
- medications
- radioactive iodine - taken by mouth
→ the radioactive iodine is absorbed by the thyroid gland where it destroys thyroid tissue
→ will often become hypothyroid afterwards and need to take thyroxine pills
- hormones (less side effects) |
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Term
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Definition
| the thyroid gland cannot produce enough thyroxine, resulting in lower metabolism |
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Term
| What are the symptoms of hypothyroidism? |
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Definition
- weight gain
- cold intolerance
- fatigue
- skin changes
- puffy face
- heavy periods
- depression |
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Term
| What are the causes of hypothyroidism? |
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Definition
1) Hashimoto's thyroiditis (most common)
2) Congenital
3) Tumour of pituitary so that not enough TSH is produced
4) During or after pregnancy
5) previously irradiated thyroid gland
6) Iodine insufficiency |
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Term
| What is Hashimoto's thyroiditis? |
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Definition
- autoimmune
- own antibodies attacking the thyroid gland |
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Term
| Why is iodine insufficiency a cause for hyperthyroidism? |
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Definition
- iodine mainly found in seafood and iodized salt
- iodine needed for production of thyroid hormones
- not a problem in North America due to iodized salt
- may result in a goitre (abnormally enlarged thyroid gland, independent of the cause) |
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Term
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Definition
| - thyroxine pills (often life-long) |
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Term
| What are parathyroid glands? |
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Definition
4 small glands hidden within the thyroid gland
→ often removed in thyroidectomy |
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Term
| What do parathyroid glands do? |
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Definition
- regulates calcium levels
- low blood Ca levels
→ stimulates parathyroid gland to release parathyroid hormone (PTH) directly
→ not go through hypothalamus |
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Term
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Definition
→ acts on kidneys, intestine, and bone
→ increases blood Ca and decreases blood phosphate
→ activates vitamin D |
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Term
| What needs to occur to negatively feedback PTH release? |
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Definition
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