Exam 3 Study Guide PET3323 Part 2 Energy Balance and Weight Control 1 Understand the balance of energy intake and output Energy Intake Energy Output Intake the calories we consume Output Heat Work Energy Stored Energy Intake Energy Output Weight Gain Energy Intake Energy Output Weight Loss 2 Understand the role of the hypothalamus in hunger and feeding behaviors i e arcuate nucleus NPY AgRP and POMC CART neuron groups The hypothalamus particularly its arcuate nucleus ARC and 2 other areas the lateral hypothalamic area LHA and the ventromedial nucleus VMN release several peptides that influence feeding behavior this activity reflects 2 distinct sets of neurons Exam 3 Study Guide PET3323 Part 2 3 Know the peptides that are released from the neurons of the hypothalamus and whether they suppress or enhance appetite Hunger Promoters The NPY AgRP group of ARC release neuropeptide Y NPY and agouti related peptides Collectively enhancing appetite and food seeking behavior by stimulating 2nd order neurons of the LHA Appetite Suppressors Also released from ARC POMC CART neurons release pro opiomelanocortin POMC and cocaine and amphetamine regulated transcript CART These peptides act on the VMN causing its neurons to release CRH corticotropin releasing hormone an appetite suppressing peptide 4 Explain other factors that will assist in regulating food intake To indicate hunger Eat Something Glucagon Epinephrine Ghrelin Decreased body temperature To indicate satiety Stop Eating Nutrient Signals related to Energy Stores Insulin CCK and PYY Leptin Increased body temperature Exam 3 Study Guide PET3323 Part 2 5 Know the components that contribute to total metabolic rate e g BMR Thermic effect of food physical activity and factors that will affect basal metabolic rate Total amount of heat produced by all chemical reactions and mechanical work of the body Components Basal Metabolic Rate Food Induced Thermogenesis Exercise Total Metabolic Rate BMR TEF PA 6 Know the mechanisms by which the body will exchange heat with the external environment right side of scale radiation loss of heat in the form of infrared waves thermal energy conduction transfer of heat from a warmer object to a cooler one convection the warm air around the body is replaced by cool air molecules evaporation H2O evaporates because of added energy from the environment Exam 3 Study Guide PET3323 Part 2 7 Understand the physiological mechanisms that will decrease or increase core temperature left side of scale Shivering muscle tone reaches sufficient levels to alt stimulate stretch receptors in antagonistic muscles muscle activity produces large amounts of heat Increase in metabolic rate cold stimulates the release of epinephrine and nor epinephrin which elevates the metabolic rate and enhances heat production infants only Enhanced thyroxine release transition into colder weather triggers the hypothalamus in infants to release thyrotropin releasin hormone which activates the anterior pituitary to release thyroid stimulating hormone which increases metabolic rate Exam 3 Study Guide PET3323 Part 2 8 Be familiar with the imbalances of the thermoregulatory system presented in class Hyperthermia Elevated body temp above 105 F Heat control mechanisms are suspended Heat Stroke Neurological and physical symptoms accompany Organ damage is possible Hypothermia Lowered body temperatures All processes stop when temp is below 21 C Fever Urinary System 1 Be familiar with the gross anatomy of the urinary system e g renal pelvis hilum major and minor calyces etc covered in class renal hilum vertical cleft in the concave portion of the kidney that leads to an internal space within the kidney called the renal sinus renal pelvis funnel shaped tube that is continuous with the ureter leaving the hilum major calyces branching extensions of the pelvis minor calyces cup shaped subdivisions of the major calyces that enclose the papillae Exam 3 Study Guide PET3323 Part 2 2 Be familiar with the internal anatomy of the kidneys cortex medulla renal pyramids renal columns pictured above renal cortex most superficial region light in color granular appearance renal medulla deep to the cortex reddish brown and exhibits cone shaped tissue masses renal pyramids cone shaped tissue masses Base towards cortex and the apex or papilla points internally renal columns inward extensions of cortical tissue separates the pyramids 3 Be familiar with the blood supply of the kidneys The renal arteries deliver 1 4 of total cardiac output to the kidneys each minute The right renal artery is longer than the left because the aorta is to the left of the midline Exam 3 Study Guide PET3323 Part 2 4 KNOW THE PARTS OF THE NEPHRON and the two different types of neprhon different characteristics for each type The nephron are the structural and functional units of the kidneys Renal corpuscle filters blood plasma Glomerulus capillary network Glomerular Bowman s capsule double walled cup surrounding glomerulus Renal tubule receives filtered fluid Proximal convoluted tubule Descending and ascending loop of Henle nephron loop Distal convoluted tubule Renal corpuscle and both convoluted tubules in cortex loop of Henle extend into medulla Distal convoluted tubule of several nephrons empty into single collecting duct Cortical nephrons 80 85 of nephrons Renal corpuscle in outer portion of cortex and short loops of Henle extend only into outer region of medulla Juxtamedullary nephrons other 25 20 Renal corpuscle deep in cortex and long loops of Henle extend deep into medulla Receive blood from peritubular capillaries and vasa recta Ascending limb has thick and thin regions Enable kidney to secrete very dilute or very concentrated urine 5 Know what the juxtamedullary apparatus is and the specific cells associated with this area and their functions Juxtaglomerular apparatus helps regulate blood pressure in kidney Macula densa cells in final part of ascending loop of Henle Cells act as chemoreceptors that respond to changes in the NaCl content of the filtrate Juxtaglomerular cells cells of afferent and efferent arterioles contain modified smooth muscle fibers Granular cells act as mechanoreceptors that sense the blood in the afferent arteriole Exam 3 Study Guide PET3323 Part 2 Question 4 graphic Question 5 graphic Exam 3 Study Guide PET3323 Part 2 6 Understand Glomerular Filtration including the characteristics of the filtration membrane the pressures that drive glomerular filtration and where it occurs
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