ULL Biol 220 Exam 3 full solution packxam Questions and Answers 2024

4 principle avenues of communication in the body - 1. gap junctions (cytoplasm to cytoplasm) 2. neurotransmitter (synaptic cleft) 3. paracrines 4. hormones absorption of fats - 1. enter brush border cells through diffusion 2. enter the ER and recombined into triglycerides 3. in the golgi, triglycerides, cholesterol and phospholipids are packaged into protein coated chylomicrons 4. chylomicrons are released by exocytosis and enter lacteal (lymphatic capillary) acromegaly - a pituitary disorder caused by hypersecretion of growth hormone in adulthood resulting in think bones and tissues activation of (IP3) and (DAG) - second messenger system 1. receptor activates G protein 2. G protein activates phospholipase 3. phospholipase splits a membrane phospholipid into 2 pieces (IP3 and DAG) adrenal cortex - outer portion of the adrenal glands. produces more than 25 steroid hormonescorticoids adrenal glands - a pair of endocrine glands that sit just above the kidneys and secrete hormones. adrenal medulla - The core of the adrenal gland; it is activated by stimulation of the nerve fibers in situations of fear, pain or other stress and release epinephrine, norepinephrine and dopamine. fight or flight cells of pancreas - secrete glucagon between meals alveoli type 1 cells - simple squamous cells make up 95% of surface area - needed for rapid gas exchange alveoli type 2 cells - cuboidal cells account for 5% of surface area but are actually more numerous their job is to repair alveolar epithelium when type 1 cells are damaged they secrete pulmonary surfactant (lipids and proteins that coat alveoli) surfactant prevents the walls of the alveoli from sticking together amplification of hormone signal - one hormone molecule triggers many enzymes. for example 1. one glucagon triggers formation of 1000 cAMP molecules 2. each cAMP activates 1000 kinase 3. each kinase activated 1000 other enzymes 4. each enzyme produced 1000 reaction products Each glucagon results in 1 billion products hormones are effect in small qualities amylin - stimulates fullness feeling, slows digestive activity are hormones constantly secreted? - no nor do they have constant levels in the bloodstream throughout the day beta cells of pancreas - secrete insulin during and immediately following a meal and stimulates cells to absorb glucose, fatty acids and amino acids bile - watery solution of minerals, cholesterol, neutral fats, phospholipids, bile pigment, bile acid bile secretion from the liver - bile canaliculi into bile ductules between the lobes and into bile ductsBilirubin - orange-yellow pigment in bile; formed by the breakdown of hemoglobin when red blood cells are destroyed blood flow of small intestine - to intestine-superior mesenteric artery from intestine to liver-hepatic portal vein