BIOL 121 Lecture Notes - Lecture 29: Thyroid, Adrenal Medulla, Catecholamine
Document Summary
The thyroid gland straddles the trachea in the throat. The thyroid gland is stimulated to produce and secrete its hormones via actionof. Tsh is release is triggered by trh. Stimulates activity of na/k atpase throughout the body. Requited for normal production of gh and for normal nervous system development. The body must be able to maintain homeostasis in the face of many different stressors. Changes in nutrient status, hydration, blood pressure, temp, activity levels, infection, sleep deprivation, anxiety etc. Responses to these different stressors varies but there are common elements to all responses. Cortisol release controlled by acth which is in turn controlled by crh. Permissive actions on catecholamines (important to blood pressure. Breakdown of body protein to amino acids. Physiological stress leads to chronically elevated cortisol levels and. Single celled organism rely on diffusion for delivering nutrients and removing wastes. In multi-cellular organisms diffusion is too slow, therefore substances must be transported via bulk flow.
