Block IV - Endocrine Flashcards
10. Function and regulation of hormones 11. Major endocrine organs
Where is the adrenocorticotropic hormone (ACTH) secreted from?
Pituitary gland
Where is progesterone secreted from?
Ovaries
Which hormones regulate calcium absorption?
Vitamin D (calcitrol) increases calcium absorption; parathyroid hormone (PTH) increases vitamin D synthesis
Where is insulin secreted from?
Pancreatic Beta-cells
What class does the receptor of testosterone belong to?
Nuclear receptor
Compare endocrine and nervous system
Nervous sends signals via neurons to specific targeting cels. Endocrine sends hormones through blood that affect near and far cells nonspecifically; its action is slower and longer in comparison
What is the hormone secreted from the adipose tissue that controls food intake?
Leptin
What is the pituitary peptide that stimulates the thyroid gland?
Thyroid stimulating hormone
What is the largest class of hormones, in terms of number of hormones/class?
The protein or peptide hormones
Are steroid hormones made by enzymatic conversion from cholesterol?
Yes
What is the type of chronotropic control observed within the endocrine system that is episodic and occurs at a pulse frequency of 24 hours?
Circadian secretion
Amino acid derivatives include:
Thyroid hormones are basically “double” tyrosine with the critical incorporation of 3 or 4 iodine atoms. Catecholamines include eli, norepi, dopamine, which are used as both hormones and neurotransmitters. Others: serotonin, melatonin, etc.
What is the receptor of catecholamine?
Adrenergic receptor that is a 7-trans-membrane spanning protein
What does a shift of the hormone dose response curve to the right from the control biologic response curve indicate?
An ED50 dose of hormone that is greater than before the shift occurred. The response of receptor (binding, activity etc) is reduced for the same concentration of hormonal stimulation.
What is the relationship between the metabolic clearance of hormone and its half-life?
The shorter the half-life, the higher the metabolic clearance number
Give examples of the way that the nervous system integrates its control with the classical endocrine system
Hypothalamus secretion of releasing hormones, hypothalamus secretion of posterior pituitary hormones, adrenal medulla secretion of catecholamines, autonomic nervous system control of endocrine secretion
In complex control systems there are usually 3 hormones secreted in a consecutive relationship. Where is the tertiary endocrine gland found in this arrangement.
At the hypothalamus
In the negative feedback of complex neuroendocrine control systems; what happens if negative feedback from the primary gland hormone decreases for some reason?
The secondary gland increases secretion of its tropic hormone
Assume there is a primary hypo secretion of a hormone (i.e. the peripheral endocrine gland such as the adrenal, thyroid, and gonads). Which hormone patter of the primary and secondary gland best describes this clinical event?
The tropic hormone is high because of lack of negative feedback by the primary gland which is low
Where is the corticotropin releasing hormone secreted from?
Hypothalamus
What is the peptide hormone secreted by the panaceas alpha-cells that raises plasma glucose by its action in the liver?
Glucagon
What is the relationship among insulin, glucagon, and somatostatin?
All inhibit to each other except glucagon stimulates the other two.
What is the critical step by which 25-OH-D is converted to the active form 1,25-(OH) D?
In the kidney, the enzyme 1alpha-hydraxylase converts 25-OH-D to the 1,25-(OH) D
Which class size does the steroid hormone belong to?
The intermediate class size (hormone number/class) of hormones
What is the function of T3 thyroid hormone?
Decrease TSH from the anterior pituitary, increases basal metabolism all over the body, plays a significant role in brain growth and development.
What are the characteristic actions and functions of prolactin?
Stimulation of milk secretion by the mammary glands, a synergistic action with LH and FSH with on the ovary or testis causing gamete and hormone production by these tissues, acting as an immune boosting hormone
What is the indole hormone secreted from the pineal gland?
Melatonin, which is a tryptamine derivative
Can you give examples of hormones that act mainly through nuclear receptor?
T3 and T4, testosterone, vitamin D, estradiol, cortisol, progesterone, aldosterone
What is ultradian rhythm?
Type of chronotropic control observed with the endocrine system that is episodic and occurs at a pule frequency of less than 24 hours and greater than 1 hour
What is primary hypo secretion?
Condition whereby the primary endocrine gland (i.e. the 3rd gland from the hypothalamus) hypo secretes its hormone
What is the steroid hormone secreted by the adrenal that regulates sodium reabsorption by the kidney?
Aldosterone, which is secreted form Zona glomerulosa
What is the location of receptor of protein hormone?
Membrane
What is the hormone that specifically inhibits the pituitary secretion of ACTH?
Cortisol
In complex control systems there are usually three hormones secreted in a consecutive relationship. Where is the primary endocrine gland located?
Periphery (i.e. away from the brain)
What is the other name of vasopressin?
ADH (antidiuretic hormone)
What is Cushing syndrome and Addison’s disease?
Cushing: hypersecretion of cortisol
Addison: hyposecretion of cortisol
What is the effect of plasma thyroid hormone on TSH and TRH secretion?
Inhibition
How many hormones are released from pituitary gland?
Anterior (6): FSH, LH, GH, TSH, Prolactin, ACTH
Posterior (2): oxytocin, vasopressin
How many hormones are released from hypothalamus?
(6) GnRH, GHRH, SS, TRH, DA, CRH
What are the common stimulators for insulin release from human pancreatic Beta-cells
Glucagon, potassium, glucose, amino acids, fatty acid
What are the common inhibitors for insulin release from human pancreatic Beta-cells?
Somatostatin, epi, norepi
What hormones are secreted from adrenal gland?
Aldosterone, cortisol, androgen, epi, norepi
What are the major differences between type I and type II diabetes mellitus?
Type I (insulin-dependent) is a defect in beta-cells, which are largely missing due to auto-immune attack. Type II (insulin-independent) is a defect on non-beta-cells (muscle, liver, adipose) where insulin receptor and its signaling pathways are damaged.
Name 3 major functions of glucocorticoid.
anti-inflammatory, suppress immune system, increase CBG
What are the major defective sites of Type I and Type II diabetes?
Type I: lacks pancreatic beta-cells so it is insulin-dependent
Type II: fails in function of insulin receptor
