Motivation (4)

Question 1

what are regulatory behaviors

Answer 1

behaviors that are controlled by a homeostatic mechanism

example: temperature, eating, fluid regulation, salt regulation

Question 2

what are non-regulatory behaviors

Answer 2

behaviors not controlled by homeostatic mechanisms

example: sex behaviors, parental behaviors, aggression

Question 3

which brain region is important in the regulation of regulatory and non-regulatory behaviors

Answer 3

hypothalamus

Question 4

what is homeostasis

Answer 4

processes that maintain the internal environment of the body within a narrow physiological range; maintained by humoral (hormone) responses, visero-motor (autonomic) functions, and somatic (voluntary) responses

Question 5

what are the main regions of the brain controlling humoral balance

Answer 5

hypothalamus via pituitary gland and feedback (when hormones get to a high enough level, will stop the release

Question 6

how is the digestive system organized to provide the nutrients necessary for life

Answer 6

the digestive system brings the macromolecules into the body via breakdown (hydrochloric acid, pepsin) and absorption of essential nutrients and energy molecules

Question 7

how is energy balance controlled through prandial and postabsorptive states

Answer 7

prandial state (anabolism): in this state when eating/intestines are full; energy storage as glycogen and triglycerides/fats during and shortly after food intake
postabsorptive state (catabolism): converts macromolecules to energy; breaking down complex macromolecules from storage

Question 8

how is leptin involved in the long-term regulation of body weight

Answer 8

the leptin signal in the blood regulates the production of body fat;
more leptin = less likely to eat
less leptin = more likely to eat

Question 9

what is the signal pathway of leptin

Answer 9

the leptin hormone is in adipose tissue, signals to the arcuate nucleus to increase/decrease feeding behaviors, neurons in arcuate nucleus signal to the lateral hypothalamus

Question 10

lesions in what part of the brain lead to anorexia

Answer 10

lateral hypothalamus

Question 11

lesions in what part of the brain lead to obesity

Answer 11

ventromedial nucleus (in hypothalamus)

Question 12

what are shorter-term hunger signals regulation food intake

Answer 12

leptin, blood sugar

AGRP and NPY

Question 13

what are shorter-term satiety signals regulating food intake

Answer 13

leptin, blood sugar

CART, alpha MSH, POMC

Question 14

what is reinforcement and what part of the brain is it associated with

Answer 14

the process in which there is an increase in the likelihood of occurrence of most recent behavior preceding reinforcement
associated with the medial forebrain bundle (MFB)

Question 15

what brain/NT system is associated with the “wanting” aspect of reward

Answer 15

mesolimbic dopamine pathway (starts in midbrain)

Question 16

what is the mesolimbic dopamine pathway

Answer 16

begins in ventral tegmental area and when stimulated, produces dopamine

Question 17

how was reward discovered by Olds and Milner

Answer 17

electrodes were implanted in the medial forebrain bundle in rats and the rats pressed a lever thousands of times to receive the electrical stimulation

Question 18

how can wanting be disrupted without disrupting liking

Answer 18

dopamine receptor antagonists in the nucleus accumbens would disrupt the self-stimulation and the wanting of rewards

Question 19

what is hypovolemic thirst

Answer 19

decrease in overall blood volume

Question 20

how is hypovolemic thirst signaled to the brain (two pathways)

Answer 20

1. reduced blood flow in renal system produces the release of angiotension II from kidneys, which is sensed from hypothalamic neurons in the subfornical region
2. mechanoreceptors in wall of large blood vessels and heart signal loss of blood pressure to hypothalamus via vagus nerve and nucleus of the solitary tract

Question 21

what is osmotic thirst

Answer 21

cellular dehydration/changes in the concentration of salts

Question 22

how is osmotic thirst signaled to the brain (1 pathway)

Answer 22

specialized hypothalamic neurons in the OVLT sense changes in salt concentration –> paraventricular neurons produce/release vasopressin –> increased water retention by kidneys and reduced urine production

Question 23

what is diabetes mellitus

Answer 23

not enough insulin is produced

Question 24

what is diabetes insipidus

Answer 24

too much insulin produced –> loss of vasopressin

Question 25

which part of the brain releases vasopressin

Answer 25

paraventricular nucleus releases vasopressin from posterior pituitary gland