Control Of Body Energy Supplies

Front 1

Which part of the brain is crucial to the regulation of body weight?

Back 1

Hypothalamus

Front 2

What are the 3 outflow regulations of body weight from hypothalamus?

Back 2

Behavioral (cortical), autonomic, hormonal pathways.

Front 3

What is the role of the arcuate nuclei?

Back 3

Relay for hormonal signals from periphery.

Front 4

How are hormones able to pass BBB?

Back 4

Leaky area around 3rd ventricle in the brain.

Front 5

What are the lateral hypothalamic nuclei associated with and what are the effects do stimulation and destruction?

Back 5

Behavior associated with hunger.
Stimulation-hunger/eating
Destruction-loss of hunger/weight

Front 6

What are the ventromedial hypothalamic nuclei associated with and what is the effect of stimulation/destruction?

Back 6

Behavior associated with satiety.
Stimulation-satiety/stop eating
Destruction- loss of satiety, weight gain

Front 7

What are the dorsomedial hypothalamic nuclei associated with and what are the effects of stimulation/destruction?

Back 7

Control of metabolism
Stimulation- Increased metabolic rate
Destruction- weight gain via decrease in metabolic rate

Front 8

Describe negative feedback between the lateral and medial nuclei.

Back 8

Lateral and medial nuclei send axons to one another, when 1 is activated, other is inhibited.

Front 9

What are orexigenic chemicals?

Back 9

Chemicals that increase the sensation of hunger and produces eating behavior.

Front 10

What are the 3 orexigenic chemicals?

Back 10

Neuropeptide Y, Agouti-Related Peptide (AGRP), and Ghrelin.

Front 11

Where are NPY produced and where do their axons go?

Back 11

Subset of neurons in arcuate nuclei which axons go to lateral hypothalamic nuclei.

Front 12

What happens when NPY is released as a neurotransmitter?

Back 12

Produce activation of lateral nuclei (and hunger) via NPY1 receptor.

Front 13

Where is AGRP produced and where do their axons go?

Back 13

Same neurons in arcuate nuclei that produce NPY with axons going to lateral nuclei.

Front 14

What do the co-nuerotransmitters NPY and AGRP produce?

Back 14

Activation of the lateral nuclei (and hunger)

Front 15

Where is ghrelin produced?

Back 15

Hormone produced by stomach during fasting.

Front 16

Where does Ghrelin bind?

Back 16

To growth hormone secretagogue receptors on neurons in arcuate nuclei.

Front 17

What do the neurons with ghrelin receptors produce?

Back 17

Produce NPY and AGRP

Front 18

What are anorexigenic chemcials?

Back 18

Chemical that decreases sensation of hunger (produces satiety) and inhibits eating behavior.

Front 19

What are the 5 main anorexigenic substances?

Back 19

CCK
Serotonin
Leptin
Cocaine and amphetamine related transcript (CART)
Melanocortinin

Front 20

How does the CCK directly effect the brain?

Back 20

Directly activated neurons of ventro medial nucleus of hypothalamus

Front 21

What effect does CCK have on intestinal and hepatic chemoreceptors?

Back 21

Sensitize them that detect ingested (intestinal) and absorbed (liver) nutrient, which is sent to hypothalamus.

Front 22

Where is leptin created and what do amounts circulating in the blood correlate with?

Back 22

Adipocytes
Circulation amounts correlates with amount of adipose tissue.

Front 23

How does leptin cross the BBB?

Back 23

Region near arcuate nuclei, cells express a transporter protein that moves leptin into CSF.

Front 24

What effect does leptin have on the axons to the ventromedial hypothalamic nuclei?

Back 24

When activated by leptin binding to its receptor, axons will release CART and MSH which causes sensation of satiety.

Front 25

What is Serotonin?

Back 25

A neurotransmitter in the brain that has been localized to axons terminating in the ventromedial nuclei where it promotes satiety.

Front 26

What are the 3 'events' the brain monitors when eating?

Back 26

How Much food do I neat when I sit down to eat?
How long do I go between meals?
What are my current energy stores?

Front 27

What are the 2 major players in short-term control of body energy?

Back 27

Mechanoreceptors in the stomach and small intestine and CCK

Front 28

Describe short-term control of body energy via mechanoreceptors.

Back 28

1. Ingested food causes stomach distension.
2. Activates mechanoreceptors which relay info to hypothalamus via brainstem.
3. Synapse in brainstem produces activation of ventromedial nuclei, inhibition of lateral nuclei.
4. Sensation of satiety.

Front 29

What is required for intermediate control of body energy?

Back 29

Hepatic and intestinal chemoreceptors and hypothalamic chemoreceptors (glucostats)

Front 30

Describe the mechanism of intermediate control via intestinal and hepatic chemoreceptors.

Back 30

1. Hepatic chemoreceptors are sensitive to nutrients delivered to liver (glucose).
2. Afferents from hepatic chemoreceptors travel to brainstem, synapse.
3. Secondary axons to hypothalamus activate medial nuclei and inhibit lateral regions.
4. Sensation of satiety.

Front 31

Describe the mechanism of intermediate control via glucostats.

Back 31

1. Hypothalamic glucostate use glucose metabolites for energy and express Glucokinase.
2. Glucokinase important in ATP production.
3. High ATP= K+ channel to shut down.
4. Accumulated K+ depolarizes neuron
5. Neuron releases serotonin in medial nuclei to produce satiety.

Front 32

What is required for long term control of body energy?

Back 32

Hormonal signals from the body.

Front 33

What is leptin an important cue for?

Back 33

Adequacy of energy stores but excess energy stores are not signaled via leptin.