Chapter 12 - Hunger, Eating, and Health Flashcards
Digestion
The process by which food is broken down and absorbed through the lining of the gastrointestinal tract.
Lipids
Fats.
Amino acids
The building blocks and breakdown products of proteins.
Glucose
A simple sugar that is the breakdown product of complex carbohydrates; it is the body’s primary, directly utilizable source of energy.
Cephalic phase
The metabolic phase during which the body prepares for food that is about to be absorbed.
Absorptive phase
The metabolic phase during which the body is operating on the energy from a recently consumed meal and is storing the excess as body fat, glycogen, and proteins.
Fasting phase
The metabolic phase that begins when energy from the preceding meal is no longer sufficient to meet the immediate needs of the body and during which energy is extracted from fat and glycogen stores.
Insulin
A pancreatic hormone that facilitates the entry of glucose into cells and the conversion of bloodborne fuels to forms that can be stored.
Glucagon
A pancreatic hormone that promotes the release of free fatty acids from adipose tissue, their conversion to ketones, and the use of both as sources of energy.
Gluconeogenesis
The process by which protein is converted to glucose.
Free fatty acids
The main source of the body’s energy during the fasting phase; released from adipose tissue in response to high levels of glucagon.
Ketones
Breakdown products of free fatty acids that are used by muscles as a source of energy during the fasting phase.
The primary function of the _______ is to serve as a storage reservoir for undigested food.
stomach
Most of the absorption of nutrients into the body takes place through the wall of the _______, or upper intestine.
duodenum
The phase of energy metabolism that is triggered by the expectation of food is the ______ phase.
cephalic
During the absorptive phase, the pancreas releases a great deal of _______ into the bloodstream.
insulin
During the fasting phase, the primary fuels of the body are _______.
free fatty acids
During the fasting phase, the primary fuel of the brain is _______.
glucose
The three components of a set-point system are a set-point mechanism, a detector, and an _______.
effector
The theory that hunger and satiety are regulated by a blood glucose set point is the _______ theory.
glucostatic
Evidence suggests that hunger is greatly influenced by the current _______ value of food.
positive-incentive
Most humans have a preference for sweet, fatty, and _______ tastes.
salty
There are two mechanisms by which we learn to eat diets containing essential vitamins and minerals: one mechanism for _______ and another mechanism for rest.
sodium
Satiety that is specific to the particular foods that produce it is called _______ satiety.
sensory-specific
As a consequence of digestion, energy is delivered to the body in three forms:
- lipids (fats),
- amino acids (the breakdown products of proteins),
- glucose (a simple sugar the is the breakdown product of complex carbohydrates, that is, starches and sugars).
Energy is stored in three forms:
- fats
- glycogen
- proteins
Most of the body’s energy reserves are stored as:
fats
Two reasons why fat, rather than glycogen, is the primary mode of energy storage:
- a gram of fat can store almost twice as much energy as a gram of glycogen.
- glycogen, unlike fat, attracts and holds substantial quantities of water. Consequently, if all your fat calories were stored as glycogen, you would likely weigh well over 600 pounds.
Three phases of energy metabolism (the chemical changes by which energy is made available for an organism’s use):
- cephalic phase,
- absorptive phase,
- fasting phase.
The flow of energy during the three phases of energy metabolism is controlled by two pancreatic hormones:
- Insulin
- glucagon
Set-point assumption
The assumption that hunger is based on set-point (add more!!!! Not finished)
Lipogenesis
The production of body fat.
Lipolysis
The breakdown of body fat to utilize forms of energy.
Adipsia
A complete cessation of drinking.
Basal metabolic rate
The rate at which energy is utilized to maintain bodily processes when resting.
Aphagia
A complete cessation of eating.
The classic study of Washburn and cannon
Ballon in stomach to measure stomach contractions
The expectation of a meal normally stimulates the release of _______ into the blood, which reduces blood glucose.
insulin
In the 1950s, the ________ hypothalamus was thought to be a satiety center.
ventromedial
A disorder characterized by a complete cessation of eating is called ________.
aphagia
________ is the breakdown of body fat to create useable forms of energy.
Lipolysis
The classic study of Washburn and cannon was the perfect collaboration: Cannon had the ideas, and Washburn could swallow a _______.
balloon
CCK is a gut peptide thought to be a ________ peptide.
satiety
________ is the monoaminergic neurotransmitter that seems to playa role in satiety.
Serotonin
Okinawans eat less and live _______.
longer
Experimental studies of calorie _______ have shown that typical ad libitum (free feeding) levels of consumption are unhealthy in many mammalian species.
restriction
As an individual grows fatter, further weight gain is minimized by diet-induced _______.
thermogenesis
_______ models are more consistent with the facts of body-weight regulation than are set-point models.
Settling-point
________ are to set points as leaky barrels are to settling points.
Thermostats
Diet induced thermogenesis
The mechanism by which the body adjusts the efficiency of its energy utilization in response to its levels of body fat.
Basal metabolic rate
The rate at which energy is utilized to maintain bodily processes when resting.
Settling point theory
Body weight drifts around a natural settling point– the level at which the various factors that influence body weight achieve an equilibrium.
The idea is that as body-fat levels increase, changes occur that tend to limit further increases until a balance is achieved between all factors that encourage weight gain and all those that discourage it.
Fat is more than a passive storehouse of energy; it actively releases a peptide hormone called _______.
Leptin (thought to act as a negative feedback fat signal, reducing consumption).
ob/ob mice
Nice that are homozygous for the mutant ob gene; their body fat produces no leptin, and they become very obese.
The following findings supported the hypothesis that insulin serves as a negative feedback signal in the regulation of body fat:
- brain levels of insulin were found to be positively correlated with levels of body fat.
- receptors for insulin were found in the brain.
- infusions of insulin into the brains of lab animals were found to reduce eating and body weight.
Leptin levels are more closely correlated with ________, whereas insulin levels are more closely correlated with ________.
Subcutaneous fat (fat stores under the skin)
Visceral fat (fat stores around the internal organs)
Receptors for both leptin and insulin are found in many parts of the nervous system, but most are located in the ________, particularly in the ______.
hypothalamus,
arcuate nucleus.
Injections of _______ have shown to suppress eating and promote weight loss.
a-melanocyte-stimulating hormone
Cholecystokinin (CCK)
A peptide that is released by the gastrointestinal tract and is thought to function as a satiety signal.
Hormone _________
Energy storage _________
Hormone = Glucagon
Energy store = Glycogen
