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Unformatted text preview: Adrenal gland; functions of adrenal medulla and cortex; response to stress; adrenal gland diseases (Plates 125-128) Adrenal glands and stress response Know parts of the adrenal gland Two paired endocrine glands that sit on top of kidneys, each adrenal has two glands from different origins- outer adrenal cortex and inner adrenal medulla Which part secretes catecholamines and which steroids? Adrenal medulla secretes catecholamines (epinephrine and norepinephrine), dopamine and endorphin Which part is an extension of the sympathetic nervous system? How is this part modified to be a gland? Adrenal medulla is extension of sympathetic NS, the secretary chromaffin cells are postganglionic neurons that lack axons, they are activated by preganglionic neurons coming from the hypothalamus What are the parts (zones) of the adrenal cortex? Outer zone- zona glomerulosa, middle zone- zona fasciculate, inner zone- zona reticularis Is there an anatomic connection between adrenal cortex and the kidneys? How about a physiological connection? There is no anatomic connection but there is a connection between the function of outer zone secretion of aldosterone and the kidneys. Aldosterone acts on the kidneys for reabsorption of sodium into the blood system and potassium secretion into the kidneys. Adrenal Medulla. What general term do we apply to the hormones of the adrenal medulla? Catecholamines Which original amino acid is used for synthesis of the hormones of the adrenal medulla? Tyrosine Know how effects of epinephrine on lipolysis, glycogenolysis, vasodilation in muscles, bronchiole dilation and vasoconstriction in periphery (kidney, skin) and pupils of the eye -- help the animal in fight and flight responses and in strenuous physical stresses In response to physical stresses animals need increased oxygen and nutrients to the muscles and heart. To accomplish this, epinephrine activates dilation of the blood vesicles to the heart and muscles and norepinephrine activates constriction of blood vesicles to the periphery so that the blood is directed to the heart and muscles. For greater oxygen, epinephrine acts on lung bronchioles to dilate them. Glycogen breakdown and lipolysis are increased by catecholamines to support the greater demand of nutrients. Epinephrine acts on eyes to dilate them allowing for more light to enter the eyes for better peripheral vision. Are there any differences in the effects of epinephrine compared to norepinephrine? Norepinephrine activates alpha adrenergic receptors and epinephrine activates alpha and beta receptors. Epinephrine dilates the heart, muscles and lung bronchioles as wells as pupil dilation, receptors....
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- Spring '08
- Cortisol, blood glucose