Flashcards in Chap.20: HormoneNotes Deck (54)
Where is the pituitary gland located?
within the sella turcica of the skull's sphenoid bone
THe thyroid gland normally produces 90% ____ and 10% ____. In the body tissues, however ____ is converted to ____, and ____ has the greatest metabolic effect!!!
**FILL IN THE BLANKS USING T3 & T4.
90% = T4
10% = T3
T4 is converted T3 and T3 has the greatest metabolic effect
The posterior pituitary thus can be seen as a storage and releasing site for hormones synthesized in the _______.
What does not require insulin for glucose transport?
Brain & Red Blood Cells
The pancreas is located behind the stomach, behind the spleen and the duodenum. It houses the ISLETS OF LANGERHANS!!! What is the function of the islet of Langerhans?
secrete glucagon and insulin
What inhibits the releases of Growth Hormone and TSH?
1. What exits within the ACTH amino acid sequence?
2. What are derived form Beta-Lipotropin?
1. Melanocyte-stimulating hormone (MSH)
2. Beta-Endorphin & Metenkephalin
What are the 3 factors that are primarily involved in regulating the secretion of adrenocorticotropic hormone (ACTH)?
1. circulating levels of cortisol and synthetic glucocorticoids suppress corticotropin-releasing hormone (CRH) and ACTH, whereas low cortisol levels stimulate their secretion.
2. Diurnal rhythms affect ACTH and cortisol levels
3. Stress has been shown to increase ACTH secretion, leading to increased cortisol levels.
What are the major products secreted by the medulla of the adrenal gland?
Catecholamines, epinephrine (adrenaline) & norepinephrine, although the medulla is only a minor source of norepinephrine
What is the effect of ADH have on electrolyte levels?
it has no direct effect on electrolyte levels, BUT by increasing WATER REABSORPTION, serum electrolyte concentrations may DECREASE because of a dilutional effect.
What is the effect of calcitonin on serum calcium levels?
Calcitonin, also called thyrcalcitonin, acts to LOWER serum calcium levels by INHIBITIONOF BONE RESORBING OSTEOCLASTS!!!!
**high levels of calcitonin are required
T/F Deficiencies of calcitonin lead to hypocalcemia.
FALSE!!!!!!!!! it does NOT lead to hypocalcemia
T/F Investigation into the role of the endocrine glands and their interaction in the aging process has generated much data, although the evidence is contradicotry.
What is the overall effect of PTH on serum calcium and serum phosphate concentration?
INCREASE serum calcium
DECREASE serum phosphate
An example of neural regulation is the release of epinephrine from the adrenal medulla as a result of activation of the sympathetic division of the autonomic nervous system in response to ____
What are some examples of a peptide or protein hormone?
insulin, pituitary, hypothalamic and parathyroid
___ hormones are water soluble and circulate free in the unbound form.
What are examples of lipid soluble proteins?
cortisol and adrenal androgens
__ hormones are circulated bound to a carrier or binding protein.
Direct effects are the obvious changes in cell function that specifically results from stimulation by ____
a particular hormone
In a __ feedback system, plasma levels of one type of hormone influence the level of other types of hormones
___ hormones easily diffuse across the plasma membrane and bind to either cytosolic or nuclear receptors
___ molecules are the initial link between the first signal and in the inside of the cell
SECOND - MESSENGER
What is a great example of a second messenger?
The binding of a hormone to a surface receptor activates the enzyme ___ through a G Protein inside the plasma membrane
Name the 2 hormones the posterior pituitary secrete.
ADH and Oxytocin
In extremely high doses, this hormone cause vasoconstriction and a resulting increase in arterial blood pressure
______ secreted by the anterior pituitary stimulates secretion of prolactin.
Where is ADH synthesized?