NR 283 Final Exam: Questions &
Answers
What regulates the release of hormones?(Ans - feedback systems
Positive Feedback (Ans - tells a hormone to make more
Negative Feedback (Ans - stops making a hormone
Secreting Cells (Ans - what is pumped out of the cells (ADH released from the posterior pituitary gland)
Receiving Cells (Ans - what cells the hormones target (ADH targets the kidney)
Why are hormones are released?(Ans – -altered cell environment (increases intake of glucose leads to a release of insulin) -maintaining levels of other hormones (cascades trigger the release of
other hormones, ex: TRH)
-neural control (autonomic NS - not in control)
Non-steroidal hormones (Ans – -water soluble, can float around blood stream with no issues since the blood stream is made up of water, but cannot get through phospholipid bilayer - which is why we need receptors on the cells and second 1 / 3
messengers (proteins that live inside the cells to help get the message to the nucleus) -ex: insulin: freely moves around bloodstream but has to connect with a second messenger
Steroidal Hormones (Ans – -lipid soluble, fatty hormones floating around bloodstream cannot float around easily so they need carrier proteins to carry them. When they get to the cell, they dont have any issues getting into the cell they can deliver the message straight to the nucleus
ex: sex hormones (estrogen, testosterone)
regulation (Ans - refers to the receptivity of cells, how open is that cell to allow a hormone in
Upregulation (Ans – if we starve a cell of a hormone, they will be much more likely to get a hormone in -this is why type II diabetes can be reversible, if the cells haven't seen insulin in a while, the pancreas isn't overworking to pump out insulin
Downregulation (Ans – -happens with type II diabetes, have tons of glucose in bloodstream, in response the pancreas (beta cells) pump out insulin, in a normal state the pancreas is able to pump out insulin, but since there is so much excess glucose in the blood, insulin comes to the cell receptor and they wont let glucose in because they have become sensitized. Now it will take more insulin to do the same job.-also happens with narcotic addiction
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Thyroid Cascade (Ans - thyroid hormone helps us make ATP, the target cells for thyroid hormone is every cell in the body so it affects many things.-need more ATP? positive feedback loop is started. Hypothalamus release TRH which reaches pituitary gland and then releases TSH, TSH reaches thyroid and the thyroid gland release TH and then goes to target cells (all cells in the body), once we have enough, negative feedback loop is initiated to stop making TRH
Cause of Endocrine Disorders (Ans – -autoimmune -most common cause is a tumor on gland (pituitary) -target cell resistance (type II diabetes) -congenital defect -hyperplasia (increase in cell number - goiter)
Hyperthyroidism
(Ans - (graves disease) -only affects women, autoimmune -body produces antibodies (normally fight infection), but this AB's instead will go to the thyroid and will mimic the cascade. They tell the thyroid to produce more thyroid hormone, even when negative feedback is taking place
-Sx: exophalmos (bulging of the eyes caused by inflammation from cell
mediators), toxic goiter, symptoms are also due to everything speeding up (hot because of increased metabolism which makes more ATP - ATP releases heat, shaky: everything is moving fast through body, weight loss:
crazy fast metabolism, tachycardia, increased BP: thyroid hormone helps
maintain BP
-Tx: iodine (kill part of thyroid) or surgically remove part of thyroid
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