Pathophys

Question 1

Benefits of Exercise

Answer 1

Increased insulin sensitivity, reduction in BP, improved lipids, reduction in inflammation in synovial fluid, and increased lean muscle mass

Question 2

FAST TWITCH (muscle fibers)

Answer 2

Type II - Energy from short term glycolysis, creates forceful contractions, suited for short-term sprint activities requiring forceful muscle contraction

Question 3

SLOW TWITCH (muscle fibers)

Answer 3

Type 1 - abundant mitochondria, energy from oxidative metabolism, fatigue resistant, suited for prolonged PA, slow contraction and increased oxidation (SO)

Question 4

GLP-1

Answer 4

Glucagon-Like Peptide 1 - produced in L cells and secreted in response to food (c, p, f); Glucose-dependent insulin secretion, suppresses glucagon, delayed gastric emptying and increased satiety, reduced appetite

*GLP-1 levels increase significantly after bypassing the proximal small intestine thus DM improves immediately after gastric bypass

Question 5

CCK

Answer 5

Cholecystokinin - produced in i cells and secreted in response to fat and protein ingestion, short acting; slows gastric emptying, reduces appetite

Question 6

Small Intestine Hormones (ANOrexic)

Answer 6

CCK, GLP, OXM, PYY

Question 7

Factors that Reduce Ghrelin

Answer 7

Meals (Carbs suppresses fast, but rebounds fast; protein suppresses longer), Weight gain, Leptin, Gastric sleeve surgery

Question 8

Factors that Increase Ghrelin

Answer 8

Fasting/prolonged fasting, Weight Loss, Stress/Sleep deprivation, Genetics/syndromes (i.e. Prader Willi)

Question 9

OREXigenic Pathway (Hunger)

Answer 9

Ghrelin ==> NPY/AgRP in the CNS (also may reach brain from vagal nerve and nucleus tractus solitarius) ==> increase food intake and weight gain

Question 10

Ghrelin

Answer 10

Growth Hormone RELease Inducing Peptide - only circulating OREXigenic gut hormone = hunger

Question 11

Orexin A/Orexin B

Answer 11

Orexigenic - found in 2nd order neurons in lateral hypothalamus, stimulated by NPY and AgRP, increased arousal

Question 12

MCH

Answer 12

Melanin Concentrating Hormone - orexigenic; 2nd order neurons in lateral hypothalamus, stimulated by NPY/AgRP; increases food intake, acts on higher order neurons to stimulate cognitive function for feeding, pleasure reward; inhibited by leptin

Question 13

AgRP

Answer 13

Agouti-related Peptide - orexigenic, found in arcuate nucleus, with NPY, stimulated by ghrelin, inhibits MC3R, MC4R; inhibited by insulin, leptin, PYY, and serotonin; decreases energy expenditure, oxygen consumption

Question 14

NPY

Answer 14

Neuropeptide Y; orexigenic, in arcuate nucleus, found with AgRP; most abundant central neuropeptide and most potent orexigen; stimulated by ghrelin, inhibited by insulin, leptin, PP, PYY, and serotonin

Question 15

Anorexigens - reduce intake

Answer 15

Propiomelanocortin (POMC), Cocaine amphetamine regulating transcript (CART), a-melanocyte stimulating hormone (a-MSH), Brain derived neurotrophic factor (BDNF), Serotonin

Question 16

Orexigens (increase intake)

Answer 16

Neuropeptide Y (NPY), Agouti-related protein (AgRP), Orexin-A, Orexin-B, Melanin-concentrating hormone

Question 17

Second Order Neuron

Answer 17

Deeper in the hypothalamus; receive signals from the 1st order neurons and relay to other parts of the brain; NPY acts on Y1 and Y5 receptors while AgRP blocks MC4R; POMC ==> a-MSH ==> MC4R

Question 18

First order neurons

Answer 18

Receive signals from the periphery to the arcuate nucleus (AN); 2 neuron systems: NPY/AgRP (weight gaining); POMC/CART (weight losing)

Question 19

Adiponectin

Answer 19

Made only in white adipose tissue; most abundantly secreted; inversely related to body fat mass (higher body fat = lower adiponectin); enhances insulin sensitivity in the liver, stimulates glucose use in the muscle, and reduces vascular endothelium inflammation

Question 20

Orexigenic (Gain weight)

Answer 20

Gold Star: Ghrelin; acute appetite stimulatory hormone, increase energy balance, Stomach, Acts on Hypothalamus and vagal nerve

Ghrelin ==> NPY, AgRP, Orexin; ==} POMC, CRH

Question 21

Anorexigenic (reduce weight)

Answer 21

Gold star: Leptin - long term energy balance; decreased energy balance, release from adipocytes and acts on hypothalamus

Leptin ==> POMC, CART, CRH; ==} NPY, AgRP, Orexin

Question 22

Leptin Resistance

Answer 22

Increased levels of leptin higher than anticipated for body fat mass, but do NOT cause the anticipated anorexic weight loss effects; could be related to over-stimulation of the leptin receptor may cause, impairment of leptin crossing the blood brain barrier (BBB) which inhibits the effectiveness of leptin signaling

Question 23

Brown Adipose Tissue

Answer 23

Heat production, abundant mitochondria, dense nerve supply, high-volume capillaries, UCP1, decreases with age, women>men, and young>old

Question 24

White Adipose Tissue

Answer 24

Energy storage, mostly made of triglycerides, Leptin, increase with age relative to total body weight

Question 25

Leptin

Answer 25

Anorexigenic, secreted ONLY by white adipose tissue, long term signaling, metabolic signal of energy sufficiency, levels are directly proportional to body fat mass, reduced food intake, increased energy expenditure, crosses BBB, stimulates POMC/CART (1st order) and inhibits NPY/AgRP (1st order), Turns off GABA inhibition of POMC (1st order), Inibits Orexin (2nd order), Stimulates neurotrophic factor (2nd order)

Question 26

Adipocyte Hormones

Answer 26

Leptin, Adiponectin, Inflammatory Cytokines (IL6, TNF, etc)

Question 27

What is the largest endocrine gland in the body?

Answer 27

Adipose (body fat)

Question 28

Amylin

Answer 28

Robin to insulin's batman, co-secreted with insulin, reduces food intake, slow down gastric emptying, suppresses glucagon production, similar to GLP-1; helps make insulin more effective for glucose lowering

Question 29

Glucagon

Answer 29

Secreted by alpha cells, stimulated by low glucose; inhibited by high glucose, GLP-1, amylin; acts on liver and stimulates gluconeogenesis, maintains blood sugar levels between meals

Question 30

Insulin

Answer 30

secreted by beta cells, 1 of 2 long term adiposity signaling hormones (with leptin), centrally reduces appetite, uptake of glucose into glycogen, stimulates fat synthesis

Question 31

Pancreatic Polypeptide (PP)

Answer 31

Secreted by F cells, reduces gastric emptying, reducing hunger, obesity and prader willi are associated with low levels of PP

Question 32

Pancreatic Hormones

Answer 32

Pancreatic polypeptide (F cells), Insulin (Beta), Amylin (Beta), Glucagon (alpha cells)

Question 33

PYY

Answer 33

Peptide YY - produced in L cells of distal small bowel, colon and rectum, potent appetite suppression, delays gastric emptying; ileal brake with GLP-1

Question 34

OXM

Answer 34

Oxyntomodulin - produced in L cells, distal small bowel, co-secreted with GLP-1, unique to increase energy expenditure

Question 35

GLP-1

Answer 35

Glucagon-Like Peptide 1 - produced in L cells and secreted in response to food (c, p, f); Glucose-dependent insulin secretion, suppresses glucagon, delayed gastric emptying and increased satiety, reduced appetite *GLP-1 levels increase significantly after bypassing the proximal small intestine thus DM improves immediately after gastric bypass

Question 36

Glucagon

Answer 36

Secreted by alpha cells, stimulated by low glucose; inhibited by high glucose, GLP-1, amylin; acts on liver and stimulates gluconeogenesis, maintains blood sugar levels between meals

Question 37

POMC

Answer 37

Propiomelanocortin - anorexigenic, 1st order neuros in ARC, found with CART, releases a-MSH which acts on MC3R and MC4R, stimulated by serotonin, leptin, and insulin, inhibited by NPY and GABA

Question 38

Orexigenic pathway

Answer 38

NPY/AgRP ==> Neuropeptide Y ==> Y1, Y5

Question 39

Anorexigenic Pathway

Answer 39

POMC/CART ==> a-MSH ==> MC3R, MC4R

Question 40

CART

Answer 40

Cocaine and Amphetamine Regulated Transcript (CART) - anorexigenic, found with POMC, located in ARC or lateral hypothalamus, may involve central release of GLP-1, stimulated by serotonin, leptin, and insulin, inhibited by NPY and GABA

Question 41

Brown Adipose Tissue

Answer 41

Heat production, abundant mitochondria, dense nerve supply, high-volume capillaries, UCP1, decreases with age, women>men, and young>old