Chapter 6: Motivation and Regulation of Internal States Flashcards
What is motivation?
An invented concept, it is a set of factors that initiate, sustain and direct behaviors, it explains our internal factors in behavior
What is instinct?
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
Do humans rely more or less on instincts over time?
Less, we begin to rely more on learned behavior
What is drive theory?
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
How is the drive theory different from the incentive and arousal theories?
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.
What is incentive theory?
People are motivated by external stimuli, not just our bodies internal needs. Environment plays a role.
What is arousal theory?
People behave in ways that keep them at a preferred level of stimulation, not necessarily homeostasis. For example satisfying cravings.
What is a set point?
The point of homeostasis to which a system returns
What are two simple and one complex homeostatic drive?
Thirst and temperature are simple homeostatic drives, and hunger is a complex homeostatic drive.
What is the difference between exothermic and endothermic animals? What are two examples of each exothermic and endothermic animals?
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.
What is the brain region called that is only in mammals and plays a role in temperature sensing? What does it do?
It is the preoptic area, it is in the mammalian hypothalamus and it contains separate heat sensing and cold sensing cells
What is thirst? What are the two types?
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.
What is hypovolemic thirst? Can it occur without the other type of thirst?
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
What is osmotic thirst? Can it occur without hypovolemic thirst?
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
What are the two brain regions involved in sensing and regulating internal water balance? Where are they located?
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)
What does it mean when it is said that the SFO and the OVLT are circumventricular?
This means that they lie outside the blood brain barrier, therefore they have direct contact with blood circulation to sense fluid levels.
What is an osmoreceptor? Are they present in the SFO and OVLT neurons?
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
What does MnPO stand for? What does it do in relation to thirst?
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.
What type of thirst is signaled by the baroreceptors on the arteries of the heart?
HYPOVOLEMIC THIRST
What is the role of angiotensin II in regulating thirst? What is it?
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
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?
10-20 minutes, therefore it is very easy to drink too much.
Does your brain or your body longer to realize that your thirst is satisfied?
Takes body longer, brain gets inputs from the MnPO which will inhibit the SFO therefore the brain knows that you are no longer thirsty.
What are the five taste primaries?
Sweet, sour, umami, bitter, salty