Chapter 6: Motivation and Regulation of Internal States

Question 1

What is motivation?

Answer 1

An invented concept, it is a set of factors that initiate, sustain and direct behaviors, it explains our internal factors in behavior

Question 2

What is instinct?

Answer 2

Complex behavior that is unlearned, automatic and unmodifiable and occurs in all member of a species. All members of a species have the same instincts, for example parental care and migration patterns

Question 3

Do humans rely more or less on instincts over time?

Answer 3

Less, we begin to rely more on learned behavior

Question 4

What is drive theory?

Answer 4

Theory that all behaviors are to maintain a condition of homeostasis, where your body is in balance/equilibrium. Any deviations from this balance, produces a drive which is an aroused condition and it drives us to maintain homeostasis

Question 5

How is the drive theory different from the incentive and arousal theories?

Answer 5

Incentive and arousal theories draw attention to the brain and brain states, and things unrelated to the bodies needs, and drive theory focuses only on the bodies needs.

Question 6

What is incentive theory?

Answer 6

People are motivated by external stimuli, not just our bodies internal needs. Environment plays a role.

Question 7

What is arousal theory?

Answer 7

People behave in ways that keep them at a preferred level of stimulation, not necessarily homeostasis. For example satisfying cravings.

Question 8

What is a set point?

Answer 8

The point of homeostasis to which a system returns

Question 9

What are two simple and one complex homeostatic drive?

Answer 9

Thirst and temperature are simple homeostatic drives, and hunger is a complex homeostatic drive.

Question 10

What is the difference between exothermic and endothermic animals? What are two examples of each exothermic and endothermic animals?

Answer 10

Exothermic animals depend on behavioral measures to regulate their body temperature, whereas endothermic animals depend on energy reserves as well as environment to regulate body temp, they also use fat stores. Lizards and snakes are exothermic and birds and mammals are endothermic.

Question 11

What is the brain region called that is only in mammals and plays a role in temperature sensing? What does it do?

Answer 11

It is the preoptic area, it is in the mammalian hypothalamus and it contains separate heat sensing and cold sensing cells

Question 12

What is thirst? What are the two types?

Answer 12

Thirst is a simple homeostatic drive that it dry mouth and throat which influence when to drink BUT not what to drink or how much. The two types are hypovolemic thirst and osmotic thirst.

Question 13

What is hypovolemic thirst? Can it occur without the other type of thirst?

Answer 13

Hypovolemic thirst is when blood volume drops due to the loss of extracellular fluid, for example when you are sweating. It cannot occur without osmoticthirst

Question 14

What is osmotic thirst? Can it occur without hypovolemic thirst?

Answer 14

Osmotic thirst arises when there is a drop in the fluid content inside the bodies cells. This happens because the the outside of the cell is too salty therefore water flows out of the cell to dilute it. It can occur without hypovolemic thirst

Question 15

What are the two brain regions involved in sensing and regulating internal water balance? Where are they located?

Answer 15

The SFO which is the Subfornical organ and the OVLT which is the Organum vasculosum lamina terminalis and they are both located adjacent to the third ventricle (midbrain)

Question 16

What does it mean when it is said that the SFO and the OVLT are circumventricular?

Answer 16

This means that they lie outside the blood brain barrier, therefore they have direct contact with blood circulation to sense fluid levels.

Question 17

What is an osmoreceptor? Are they present in the SFO and OVLT neurons?

Answer 17

An osmoreceptor is a receptor that fires more when volume decreases due to fluid loss, and they are on some SFO and OVLT neurons, they are not killed by blood contact

Question 18

What does MnPO stand for? What does it do in relation to thirst?

Answer 18

Median preoptic nucleus, and it is also located adjacent to the third ventricle, and they integrate information received from the SFO and the OVLT. It also gets input from baroreceptors.

Question 19

What type of thirst is signaled by the baroreceptors on the arteries of the heart?

Answer 19

HYPOVOLEMIC THIRST

Question 20

What is the role of angiotensin II in regulating thirst? What is it?

Answer 20

It is a hormone that informs the brain of the drop in blood volume, released into blood and travels to the brain, stimulates receptors on the SFO and OVLT which then sends the info to the MnPO

Question 21

How long does it take for the body to realize that the deficit (thirst) has been eliminated? Or in other words, how long does it take the body to stop sending stimulatory signals after drinking water?

Answer 21

10-20 minutes, therefore it is very easy to drink too much.

Question 22

Does your brain or your body longer to realize that your thirst is satisfied?

Answer 22

Takes body longer, brain gets inputs from the MnPO which will inhibit the SFO therefore the brain knows that you are no longer thirsty.

Question 23

What are the five taste primaries?

Answer 23

Sweet, sour, umami, bitter, salty

Question 24

What are the bumps on your tongue called? Where are taste buds located and where do they send info?

Answer 24

The bumps are papilla which contain taste receptors/buds, and they send information to the NST (nucleus solitary tract)

Question 25

What is sensory specific satiety?

Answer 25

Behavioral pattern that means the more you eat a specific food, the less appealing it becomes. It becomes not as rewarding to you OR we have had enough of that nutrient

Question 26

What is learned taste aversion?

Answer 26

Avoidance of foods associated with illness or poor nutrition, related to survival instincts which keep us away from foods we have had bad experiences with

Question 27

What is learned taste preference?

Answer 27

Preference for the flavor of the food containing a nutrient, NOT THE NUTRIENT ITSELF

Question 28

What senses is flavor a combo of?

Answer 28

Touch, taste and smell

Question 29

What is the area postrema responsible for?

Answer 29

Region in the brain, outside the BBB, induces vomiting in response to toxins

Question 30

What is the duodenum and its purpose?

Answer 30

It is the first 25cm of the small intestine, where majority of digestion occurs

Question 31

What are the four products of digestion? What are they the products of? Where are they all absorbed into and transferred to?

Answer 31

Glucose is the product of carb digestion, amino acids are the product of protein digestion, fatty acids are the result of fat digestion in the intestine, and glycerol is the result of fat digestion in the liver. They are all absorbed into the blood stream and transported to the liver via the hepatic portal vein

Question 32

What is the role of the small intestine and the large intestine? What NS are they controlled by and how does stress effect it?

Answer 32

Small intestine absorbs nutrients, large intestine absorbs water, and they are controlled by the autonomic nervous system therefore stress and excitement cause irregularities

Question 33

What are the four steps of the absorption phase? When in relation to eating does this phase occur.?

Answer 33

Occurs a few hours after eating, when body is using energy from the digestion of food. First glucose levels increase, then parasympathetic NS is activated, then the pancreas releases insulin, then glucose is taken up into cells and stored as glycogen in the liver/muscles and fat stored as triglycerides in adipose tissue

Question 34

What are the four steps of the fasting phase? When does this phase occur in relation to eating?

Answer 34

Occurs when not eating and body is relying on energy stores. First glucose levels decrease, then activation of the sympathetic nervous system, then pancreas releases glucagon, this then causes conversion of glycogen back into glucose to be used by the brain, and stored fat to be released as fatty acids for use in the body and glycerol for use in the brain

Question 35

What is diabetes?

Answer 35

Condition where your body is either incapable of producing insulin (type 1) or your body is insensitive to insulin (type 2). This means that your cells cannot take up insulin or have no insulin to take up, therefore glucose cannot get into your cells and causing low blood sugar, and low glycogen stores.

Question 36

What are the four brain regions involved in hunger?

Answer 36

Arcuate nucleus (ARC), lateral hypothalamus (LH), the ventromedial hypothalamus (VHM), and the paraventricular nucleus (PVN)

Question 37

What is the role of ARC? What neurons and peptides does it contain and what do they do?

Answer 37

It is the master hypothalamic center that controls food intake. It contains AgRP neurons and NPY, which increase eating by decreasing metabolism (release of NPY). It also contains POMC neurons which decrease eating when released, they go to the VMH, and they increase metabolism. GABA neurons increase eating and Glu neurons decrease eating.

Question 38

What is the role of the lateral hypothalamus?

Answer 38

It initiates eating and controls feeding behaviors and metabolic processes. It controls chewing, swallowing, gastric secretions, salivary secretions, etc

Question 39

What is orexin and what does it do?

Answer 39

Orexin is a neuropeptide that increases eating and increases wakefulness in response to food deprivation, it excited NPY neurons and inhibits POMC neurons.

Question 40

What is the role of the paraventricular nucleus?

Answer 40

It is a brain region that regulates eating and metabolic processes such as body temp, fat storage and cellular metabolism, POMC neurons activate the PVN therefore decreasing eating, and AgRP and NPY inhibit the PVN therefore increasing eating

Question 41

What is the role of the ventromedial hypothalamus?

Answer 41

It is the brain region that produces satiety and increase metabolism, it only receives input from POMC therefore stopping eating.

Question 42

What is ghrelin? Where is it secreted from? Where does it travel to?

Answer 42

This is an orexigenic peptide hormone that is secreted from the stomach and released into the bloodstream to the ARC when fasting. It is anticipatory and it increases hunger and peaks right before a meal, and then decreases once you start eating.

Question 43

How does ghrelin relate to stomach stretch?

Answer 43

When the stomach begins to be stretched when eating, ghrelin is not releases therefore decreasing hungriness.

Question 44

Where does nutrient monitoring occur?

Answer 44

In the PNS

Question 45

Where does detection of nutrient levels occur?

Answer 45

On receptors in the vagus nerve as well as on receptors on the hepatic portal vein

Question 46

What does CCK stand for? What does it do and what area of the brain is it transported to?

Answer 46

It is a peptide hormone synthesized in the intestines and stomach, it is the satiety signal and it is released into the bloodstream as food passes into the duodenum, therefore decreasing eating.

Question 47

Does CCK decrease meal size AND absolute amount of food eaten in a day?

Answer 47

NO, it only decreases meal size

Question 48

Is CCK for short term or long term regulation of hunger?

Answer 48

short term

Question 49

What are the peptide hormones involved in long term regulation of hunger? How are they different?

Answer 49

PYY and Leptin are involved in long term hunger. PYY is released from the intestines in response to food, suppressing appetite over long periods, therefore decreasing amount of food eaten in one day. Leptin is secreted by fat cells that inhibits eating and decreases meal size as well as amount of food eaten in a day.

Question 50

What three things happen during initiation of eating?

Answer 50

Glucose and fatty acid levels drop and this is detected by the vagus nerve, send signals to the ARC, VHM, and LH to increase eating, and ghrelin is released by the stomach and sent to the ARC to stimulate release of NPY

Question 51

What are four things that happen during termination of eating?

Answer 51

Stretch receptors send signals to NST via vagus nerve about stomach volume, CCK is released into bloodstream and travels to the brain to activate the PVN via POMC, PPY is released and carried to ARC to inhibit NPY release, and leptin is released by fat cells and carried to the ARC to inhibit NPY release and stimulate POMC neurons.

Question 52

What is BMI? Why is it inaccurate?

Answer 52

Body mass index, it is a measure of leanness or obesity and is calculated by dividing weight in kg by height squared, but does not account for the fast that muscle weighs more than fat

Question 53

What are two genes that have been identified in rats but not humans?

Answer 53

Obesity gene on chromosome 6 and diabetes gene on chromosome 4

Question 54

What is basal metabolism?

Answer 54

The energy required to fuel the brain and other organs and to maintain body temp.

Question 55

What is anorexia nervosa?

Answer 55

Starving disease, restriction of food, women more likely to be diagnosed, restrictors only restrict food and binge purgers restrict as well as vomit and use laxatives, exercise lots, dysfunctional reward pathway and amygdala, long recovery, has highest morbidity of all psych disorders

Question 56

What is bulimia nervosa?

Answer 56

Weight control is linked to binging and purging, eat lots in short time and then vomit and use laxatives, many people over eat therefore they are still overweight, do not often see restriction, very high ghrelin between meals that does not decrease therefore always hungry, PYY low, high relapse rate

Question 57

What is binge eating disorder?

Answer 57

People eat large amounts of food during short period of time, cannot control how much they eat or what, NO PURGING OR RESTRICTION, feel shame and disgust at themselves, overweight

Question 58

What are four other eating disorders?

Answer 58

Pica, rumination, night eating disorder, avoidant/restricting food intake disorder (do not care to eat)