Kaplan Biology: Chapter 5 Endocrine System Flashcards
Peptide vs Steroid hormones rapidness of onset
peptides are quick acting and steroid hormones are slow acting.
2 main secretions of the posterior pituitray.
1) ADH
2) oxytocin.
the posterior pituitary does NOT make these hormones. they are made by the hypothalamus and are stored and released by the posterior pituitary.
explain the oxytocin loop
oxytocin is on a positive feedback loop. oxytocin stimulates more oxytocin release. this facilitates the contraction of uterine smooth muscle and also promotes milk ejection.
when the hypothalamus releases gonatotropic release hormone (GnrH), what occurs?
the ANTERIOR PITUITARY RESPONSE.
1) FSH release
2) LH release
when growth hormone releasing hormone is released by the hypothalamus, what is stimulated?
the ANTERIOR PITUITARY releases GROWTH HORMONE.
when thyroid releasing hormone is released by the hypothalamus, what is stimulated?
the ANTERIOR PITUITARY RELEASES
THYROID STIMULATING hormone.
when corticotropin-releasing factors is released by the hypothalamus, what is stimulated?
the anterior pituitary releases ADENOCORTICOTROPIC (ACTH) HORMONE.
the anterior pituitary gland releases ACTH in response to ctrh release from the hypothalamus; then what happens?
ACTH stimualtes the ADRENAL COREX to secrete cortisol. this is known as the HPA axis.
name the anterior pituitary hormones
FLAT PEG F= fsh L= LH A = Acth T = thyroid stimulating hormone P= prolactin E =endorphins G = growth hormones.
FLAT = tropic (causes cascade) PEG = direct hormones.
the thyroid is controlled by ____ from the anterior pituitary gland.
TSH : thyroid stimulating hormone.
3 main products of the thyroid
T3, T4 and calcitonin.
T3 and T4 are made in the thyroid by ____ cells.
follicular cells
calcitonin is made in the thyroid by __ cells
C cells.
role of calcitonin
decreases plasma calcium level, increases calcium storage in bone
what triggers calcitonin release
too much calcium in blood. causes it to be stored in bone.
is calcitonin and peptide or steroid hormone
peptide hormone.
role in parathyroid hormone
INCREASES calcium plasma levels, causes bone resorption and breaks DOWN BONE.
parathyroid hormone causes Ca2+ levels in the blood to -__, calcitonin causes Ca2+ levels in the blood to ____
parathyroid hormone causes Ca2+ levels in the blood to INCREASES, calcitonin causes Ca2+ levels in the blood to DECREASE
the adrenal cortex secretes ____ where as the adrenal medulla secretes ____
the adrenal cortex secretes CORTICOSTEROIDS where as the adrenal medulla secretes EPINEPHRINE (AND NE)
name a mineralcorticoid secreted by the adrenal cortex
aldosterone. increases sodium resorption in the distal convoluted tubule by exchanging Na+ ions for K+
name a glucosteroid secreted by the adrenal cortex
a glucosteroid is a steroid that regulates glucose levels by increase gluconeogenesis and decreasing protein synthesis. includes cortisol and cortisone.
3 hormones secreted by the pancreas
1) glucagon- alpha cells
2) insulin - beta cells
3) somatostatin - D cells
role of alpha cells
inhibits alpha and beta cells and thus glucagon and insulin release. also inhibits G cells in the stomach and prevents overall digestion by means of reducing acid secretion.
what stimulates somatostatin
stimulated by increased glucose levels and amino aicds in blood.
Type 1 diabetes
autoimmune destruction of BETA cells, so that you cannot produce your own insulin. you are still responsive to it, so you need to inject yourself with insulin after meals.
type 2 diabetes
receptor level resistance to insulin. you cannot drive sugar out of your blood stream into your cells. often caused by ovesity.
testes secrete _____ in respnose to ___ and ___ from the anterior pituitary
secretes testosterone in respnse to LF and FSH from anterior pituitary.
pineal gland is located ____
what does it secrete
located deep in the brain under the circle of willis and secretes melatonin
the pineal gland receives projections from the __ and the -__
retina and hypothalamus. regulates melatonin secretion and sleep-wake cycle.
JGA cells in the kidneys secrete ____ to increase sodium and water resorption
renin
ANP secreted by atrial cells in the heart does what
regulates salt and water balance. when atria is STRETCHED from excess blood volume, they release ANP to promote the EXCRETION OF SODIUM, making water follow with it, cause more diluted urine.
essentially the opposite of aldosterone, which increases sodium concentration in the body.
MAIN secretion of the thymus
thymosin. plays a role in T cell development and differentiation.
