Exam 1 Flashcards
What levels do hormones work on?
Whole body, molecular, cellular levels
Activin has what effect on the anterior pituitary
Enhances FSH synthesis
Inhibin has what effect on the anterior pituitary
Diminishes FSH synthesis
What anterior pituitary hormone is under separate stimulatory and inhibitory hypothalamic control?
Growth hormone
What anterior pituitary hormone is under stimulatory hypothalamic control?
FSH, LH, prolactin
What is the metabolic clearance rate equation
MCR= rate of disappearance / concentration
How does the liver normally get rid of steroid hormones? What happens when it is diseased?
Conjugation and excretion in the bile.
When you have liver disease, the steroid hormones go up b/c inability to conjugate
What second messenger signaling uses inositol 1,4,5 triphosphate which causes a release of Ca++ and what does it do?
Phospholipase C which ultimately phosphorylates proteins to induce physiologic effects
What hormone acts directly on genes, affecting transcription
T3, goes straight to the nucleus
What does radio immunoassay use
Radioactivity and labeling, for a known amount of hormone is labeled with radioactive iodine which is used to generate a standard curve
What inhibits prolactin release by anterior pituitary gland
Dopamine from the hypothalamus
Which two anterior pituitary hormones, share the same stimulatory hypothalamic factor
FSH and LH
What are 3 of the functions of growth hormone
Stimulates protein synthesis, cell multiplication, cell differentiation, and fat utilization for enhancing production of glucose
What hypothalamic factor inhibits the release of growth hormone
Somatostatin
What is associated with “metabolic syndrome”
Increased clotting risk
Growth hormone increases the use of what for energy decreasing carbohydrate utilization
Fatty acids
What is a major function of somatomedin C
Prolongs the effects of growth hormones, pygmys lack somatomedin C
When is the largest burst of growth hormone secretion in a young child
Within one hour after onset of sleep
What is a deficiency in thyroid hormone associated with?
Mental retardation
What is associated with a deficiency in growth hormones in children
Short, delayed puberty, mild obesity
What endocrine gland increases iodide trapping in glandular cells
Thyroid
What hormones are a part of the POMC family
MSH, B lipotropin, B endorphin, ATCH
What hormone stimulates uterine contraction
Oxytocin
What does prolactin do?
Stimulates milk secretion, inhibits ovulation, enhance aspects of the immune response
What hormone produces milk letdown and is released in response to suckling, and promotes bonding of mother and baby
Oxytocin
What is the fate of most of the T4 that is secreted by the thyroid gland at target tissues
Converted to T3
What hormone is produced by pineal gland, especially during sleep
Melatonin
After a traumatic brain injury, how common is pituitary dysfunction
25-40%
Which is more potent T3 or T4
T3 is 4x more potent
What thyroid hormone is important in regulation of calcium levels in the body
Calcitonin
What are calcitonin and PTH’s affect on calcium levels
Calcitonin lowers levels, PTH raises
Hasimoto does what to the thyroid
Destroys it
What does addison’s disease do
Autoimmune destruction of the adrenal cortex
What does graves disease do?
Hypersecretion of TRH by hypothalamic neurons in response to abnormal antibodies that form against the TSH receptor
What is associated with cretinism
Mental retardation, inhibited skeletal growth, treated with thyroxine
What are symptoms of hypothyroidism
Fatigue, constipation, weight gain, myxedema
What are symptoms of hyperthyroidism
Weight loss, diarrhea, exophthalmos, inability to sleep
What is the direct precursor for aldosterone
Corticosterone
What are functions of glucocorticoids
Gluconeogenesis, anti-inflammatory effects, suppression of immune response
How are glucocorticoids involved in the maintanance of normal blood pressure
Up regulate alpha 1 adrenergic receptors
A patient with elevated cortisol levels undergoes dexamethasone suppression test. Neither a low or high does suppresses cortisol
The hypercortisolism is likely due to adrenal cortical cortisol secreting tumor
Low dose doesn’t, high dose does = hypercortisolism is likely due to anterior pituitary ACTH secreting tumor
Aldosterone is mainly under control of what?
Angiotensin 2
Precusor cortisol makes ACTH renin and corticosterone
What are functions of mineralocorticoids
Control ECF volume, stimulate renal K+ excretion, increase H+ secretion
Autoimmune destruction of the entire adrenal cortex with decreased synthesis of all adrenocortical hormones is a characteristic of what
Addison’s disease
Which class of hormones is synthesized from cholesterol
Steroid hormones
What usually prevents over activity of hormone secretions
Negative feedback
Plasma proteins binding T4 in the blood serves what function
Slows clearance of T4
Why can liver disease cause abnormally high levels of steroid hormones
Decreased conjugation and decreased excretion of steroids in bile
Name some key parts of adenylyl cylase-cAMP 2nd messenger signaling
Use a Gs protein, inactivated by phosphodiesterase, phosphorylates proteins
What hormone acts directly on genes, affecting transcription and where does it go?
T3 goes to nucleus
What inhibits prolactin released by the ant. Pituitary gland
Dopamine from hypothalamus
Which two ant. Pituitary hormones share the same stimulatory hypothalamic factor and what is the factor
FSH and LH, factor is GNRH
What hypothalamic factor inhibits the release of growth hormone
Somatostatin
Growth hormone increases the use of _____ _______ for energy by decreasing ______ utilization
Fatty acids….. carbohydrate
What is the major function of somatomedin C
Prolongs the effects of growth hormone
What endocrine gland increases iodide trapping in glandular cells and what is the ratio
Thyroid, 1/5th take, 4/5th get rid of
Name the hormones of the POMC family
MSH, B-lipotropin, B-endorphin, ACTH
What autoimmune disease destroys the thyroid and is preceded by thyroiditis
Hashimoto’s disease
The direct precursor for aldosterone is what?
Corticosterone
What are functions of glucocorticoids
Gluconeogenesis, anti-inflammatory effects, suppression of the immune response
How are glucocorticoids involved in the maintenance of normal blood pressure
Up regulate a1 adrenergic receptors
Aldosterone is mainly under the control of which of the following
Angiotensin 2
What are major functions of mineral-corticoids
Control ECF volume, stimulate renal K+ excretion, increase H+ secretion
What would be the result of 17a-hydroxylase deficiency in adrenal cortex
Decreased levels of aldosterone(indirectly)
Autoimmune destruction of the entire adrenal cortex with decreased synthesis of all adrenocortical hormones is characteristic of what?
Addison’s disease
