Endocrine 2 Flashcards
What feedback system are most hormones regulated by?
Negative feedback
What is the function of a negative feedback?
Reverses the stimulus back to the original set point regardless of whether the stimulus increases or decreased a change
Why are sufficient blood calcium levels needed?
Bone hardness, clotting, neurotransmitter release, muscle contractions
High levels of calcium may cause?
Bone deformity, kidney stones, abnormal HR, mineral deposits, & kidney stones
What hormone is released due to low Ca+2?
Parathyroid hormones stimulate osteoclast activity increasing Ca+2
What hormone is released due to high Ca+2?
Calcitonin CT from thyroid gland which inhibits osteoclast activity decreasing Ca+2
What hormone is released due to low glucose levels?
Alpha cells in pancreases to release glycogen by converting it into glucose & creating glucose from other sources
What hormone is released due to high glucose levels?
Beta cells in pancreas beta cells in the pancreas releases insulin which increases cell uptake of energy and glycogen conversion
What hormone is released due to dehydration or high blood osmolarity?
ADH causes hypothalamic osmoreceptors to stimulate neurosecretory cells in the hypothalamus that produce & secrete ADH to signal the posterior pituitary gland that contains the axon terminal of these cells, and release ADH
What hormone is released due to hyperhydration or low blood osmolarity?
The low blood osmolality inhibits the stimulation hypothalamic osmoreceptors to stimulate neurosecretory cells in the hypothalamus that produce & secrete ADH and as a result decreases or stops ADH release
What hormones are released by the thyroid gland?
T3, T4 & Calcitonin
What hormones are released due to low metabolism?
Low levels of T3 & T4 hormones, metabolic rate or puberty, or pregnancy stimulate the secretion of Thyrotropin-releasing-hormone TRH in the hypothalamus
What is the effect of Thyrotropin-releasing-hormone TRH?
TRH travels from the hypothalamus to the anterior pituitary gland and activates the release of thyroid-stimulating-hormones or TSH by thyrotrophs into the bloodstream which acts on thyroid gland to release more TH.
What is GnRH?
Gonodotropin -releasing hormone
What happens in the MRS when there is low testosterone?
Stimulates the hypothalamus to secrete GnRH which travels to anterior pituitary and causes it to release FSH & LH
What is the effect on FSH in MRS?
Sperm cells
What is the effect of LH on the MRS?
Stimulates cells in the testes to secrete testosterone – which generate prenatal male sex organs, develop & enlarge MR organs & secondary S characteristics, & protein synthesis
What do FSH & LH together do in MRS?
Generate Spermatogenisis
What are the two female hormones?
Oestrogen & progesterone and produced by ovaries
What happens during high oestrogen levels?
As follicles which contain oocytes in their centre, in the ovaries almost mature, the increase in oestrogen levels stimulate the release of GnRH from the hypothalamus & LH from the anterior pituitary glands.
What is the effect of LH in FRS?
Generates ovulation and causes the follicles to rupture and releases the oocytes
What are the functions of oestrogen & progesterone on FRS?
Stimulate the development of prenatal FR organs, F secondary S characteristics & the MC regulation.
What are two positive hormonal feedback systems?
Oxytocin -CB, oestrogen - MC
What hormones do the pineal glands secrete & function?
Melatonin which regulates circadian rhythms or sleeping-waking patterns (biological clock).
What are the 5 hormone producing tissue?
Heart, Skin, GI, Kidneys & Adipose tissue
What is the function of the heart hormone?
Atrial natriuretic peptide lowers blood pressure & BP & Na+ concentration by increasing the excretion of Na+ and water from kidneys
What is the function of the skin hormone?
Cholecalciferol – inactivate Vit D. which increases calcium absorption
What is the function of the adipose hormone?
Leptin – decreases appetite
