CHAPTER 9 What is homeostasis Which brain region is most important for maintaining homeostasis How are feedback loops between the brain and periphery related to homeostasis Homeostasis a physiological state of equilibrium Feedback loops negative when what is created inhibits the system positive when what is created activates Which brainstem region is important for stimulating feeding behavior by sensing low levels of glucose in the Hypothalamus the system body Nucleus of the solitary tract in the brainstem glucoreceptors Know the main hormonal signals that come from the periphery and regulate feeding and satiety leptin and ghrelin and whether they increase feeding or decrease feeding Where are these hormones generated Where in the brain do these hormones act Leptin secreted by fat cells help body regulate fat stores communicates with neurons in the arcuate nucleus of the hypothalamus when levels are low in the blood use NPY and AgRP to communicate with LH found in blood when fat levels are high decreases feeding increases energy expenditures and glucose metabolism Ghrelin produced in lining of stomach and pancreas increases feeding receptors in arcuate nucleus and ventromedial hypothalamus levels are highest during fasting In the hypothalamus there are 2 types of first order neurons involved in hunger satiety POMC CART and AGRP NPY Which type of first order neuron increases food intake Which decreases POMC CART inhibit feeding raising metabolic rate and body temperature AGRP NPY increases food intake slows energy usage What is the role of hypocretin aka orexin in feeding How does hypocretin contribute to the rewarding properties of eating and dopamine increases feeding neurons are activated in response to rewarding stimuli which is the reward center levels and dopamine receptor levels Obese people afferents from the lateral hypothalamus innervate dopamine neurons of the ventral tegmental area How are reward responses in the brain to eating different in obese vs non obese individuals Think both dopamine less dopamine action because of impaired gut brain communication fewer dopamine receptors in brain so they need to eat to get more feelings of reward Non obese increased dopamine action because of gut brain communication resistance Not a good treatment for obesity already have abnormally high levels of leptin bc of lots of fat so body is constantly in starvation mode which leads to eating Since leptin is a satiety hormone would it make a good treatment for obesity Why or why not What is leptin Leptin resistance analogous to insulin resistance in type 2 diabetes no amount of leptin will lead to satiety decrease leptin resistance What is the difference between body weight and metabolic health as predictors of overall health Do gastric bypass and gastric banding impact body weight alone or both body weight and metabolic health Metabolic health predicts overall health low body weight metabolically unhealthy overall unhealthy high body weight metabolically healthy overall healthy Gastric bypass impacts body weight alone metabolic health based on muscle What is anorexia Which other mental health disorder is anorexia most closely related to Anorexia self starvation and distorted body image Most related to OCD anxiety disorders CHAPTER 10 What are hormones How do they differ from neurotransmitters think site of action and distance travelled from release site Are they made by the brain peripheral organs or both Hormones long distance transported by blood produced by glands to affect organs slower in speed than neurotransmitters control target organ Made in glands pituitary gland on hypothalamus pineal gland in brain What are the three main classes of hormones Protein Hormones Amine Hormones Steroid Hormones receptors are and what effects Protein Hormones How do the classic mechanisms of hormone action differ between protein hormones and steroid hormones where Receptors embedded in cell membrane activate second messenger system that affects various processes inside the target cell Steroid Hormones diffuse passively bind to large receptor molecules binds to DNA altering gene expression Know how hormone release is stimulated starting at the hypothalamus pituitary and ending at the peripheral endocrine gland testis ovary etc Which site produces releasing hormones Tropic hormones Hormone release Neuroendocrine cell bodies in the hypothalamus produce releasing hormones releasing hormones released from axon terminals that terminate on the portal system the hormones travel via the portal veins to the anterior pituitary Hormone producing cells in the anterior pituitary respond to the hypothalamic hormones by releasing or inhibiting the release of their own hormones known as tropic hormones Tropic hormones travel through the blood stream and regulate endocrine glands Releasing hormones produced in neuroendocrine cell bodies in hypothalamus Tropic hormones produced in anterior pituitary by hormone producing cells What is the difference between how hormones are released from anterior and posterior pituitary Which two hormones are released from the posterior pituitary Release from anterior Release from posterior increase in brain activity increases input to hypothalamus cells produce hormone in hypothalamus released from the posterior pituitary no hormone produced here simply stored and releases ones from hypothalamus Lutenizing hormone follicle stimulating hormone tropic hormones FSH LH Growth hormone thyroid stimulating hormone TSH Know basics of sex determination sex chromosomes SRY gene and gonadal differentiation determined at time of fertilization because depends if sperm carries an X or Y Hormones from posterior oxytocin WHAT IDK Hormones from anterior Sex chromosomes XX girl XY boy SRY gene presence indicates testes absence indicates ovaries encodes testes determining factor Gonadal differentiation gonads become ovaries without SRY testis determining factor protein turns gonads into testes How are the processes of masculinization and defeminization distinct masculinization due to testosterone defeminization anti mullerian hormone promotes development of Wolffian system seminal vesicles vas deferens prostate prevents mullerian systems from developing uterus upper vag fallopian tubes What are organizational and activational effects of hormones How are they different and when in life do they occur Which type of effect has a sensitive or critical period Organizational hormonal effects on the