Chapter 8 Flashcards
what does an RQ of 1.0 suggest?
that carbohydrate is being oxidized because the amount of oxygen required for the combustion of glucose equals the amount of carbon dioxide produced
what are the 3 primary components of daily total energy expenditure?
basal metabolic rate, physical activity and the thermic effect of food
what is basal metabolic rate (BMR)?
the amount of energy needed to sustain basic life processes such as respiration, heartbeat, renal function, brain and nerve function, blood circulation, active transport, and synthesis of proteins and other complex molecules
what factors can affect BMR?
body composition, surface area, age, gender, pregnancy, lactation, environmental temperature and dietary energy restriction
what is the thermic effect of food?
represent the increase in energy expenditure associated with the body’s processing of food, including the work associated with the digestion, absorption, transport, metabolism, and storage of energy from ingested food
what are the anatomical sites commonly used for measuring skinfold thickness?
triceps, subscapular, suprailiac, abdomen and thigh
what is the DEXA?
the gold standard technique for diagnosing osteoporosis and osteopenia and is a commonly used method for body composition measurements
what does essential fat include?
the fat that is associated with bone marrow, the central nervous system, internal organs, and the cell membranes
what are orexigenic peptides?
appetite-stimulating hormones
what are examples orexigenic peptides?
neuropeptide Y (NPY) and agouti-related peptide (AgRP)
what are anorexigenic peptides?
appetite-inhibting
what are examples of anorexigenic peptides?
pro-opiomelanocortin (POMC) family
what are examples of gut hormones?
ghrelin, cholecystokinin, peptide YY, and glucagon-like peptide-1
what is leptin?
a hormone secreted by white adipose tissue that interacts with the hypothalamus to reduce hunger
what is the mechanism of leptin?
binds to its receptors, the orexigenic neurons are inhibited and the production of NPY and AgRP declines, while the anorexigenic neurons are stimulated and release POMC peptides
what does leptin do in skeletal muscle?
activates AMP-activated protein kinase (AMPK) and thus promotes fatty acid oxidation and utilization for energy
what occurs when AMPK is active (phosphorylated)?
fatty acid oxidation is stimulated and fatty acid synthesis is inhibited
what does leptin inhibit?
the synthesis and secretion of insulin by the pancreas, while insulin signaling is suppressed in the liver and white and brown adipose tissue
what does insulin binding stimulate the release of?
POMC peptides and inhibits the release of NPY and AgRP?
what does insulin binding to hypothalamic receptors transmit signal too?
peripheral tissues, which inhibit gluconeogenesis and proteolysis in the liver and stimulate lipogenesis and triacylglycerol accumulation in adipose tissue
Where does adiponectin binds too?
receptors in the hypothalamus, where it suppresses NPY neurons
what is ghrelin?
produced predominantly in the stomach and, unlike the other regulatory hormones, stimulated the feeling of hunger
what receptors does ghrelin bind too?
in the orexigenic neurons of the hypothalamus, causing the release of NPY and AgRP
what does CCK bind too?
receptors in the hypothalamus and inhibits NPY production by down-regulating mRNA expression
