The non-regulation of food intake in humans - Levitsky
Stable Internal State can be achieved:
1. Regulatory mechanism (an active process)
2. Settling of opposing forces (a sum of two independent processes)
Social Facilitation: Another variable that appear
Decerebrate Rat & Learning
Conditioned Taste aversion
Form of associative learning
An animal learns to avoid taste (conditioned stimulus, CS) that has previously been
paired with a toxin/ malaise-inducing (e.g., LiCl) agent (unconditioned stimulus, US)
Glucose Insulin Glycogen
Glucose glucagon Glycogen
Left to right: storage
But right to left: release of glucose back into the blood
*Glucagon can also activate gluconeogenesis (glucose synthesis from noncarbohydrates)
Control of stora
Leptin & Parabiosis of Mice
The ob/ob mice are a mutant strain caused by a mutation on the gene, obese (ob).
The ob/ob mice:
type II diabetes
The db/db mice are a mutant strain caused by a mutation on the gen
Topic 3: Central Nervous System Control: Brainstem and Hypothalamus
Brainstem & Control of Feeding & Body Weight Regulation
The brainstem receives sensory input & has motor output
Motor neurons and motor pattern generators located in the brain
Reading: Stellar - From Lesions to Leptin: Hypothalamic Control of Food Intake and
The hypothalamus contains centers for initiation and cessation of feeding
There is one center for hunger and one
Meal Size & CCK
To what extent does bite size affect ingestion rate?
How does a change in bite size affect meal duration?
Are lean or obese people more or less susceptible to the bite-rate manipulation?
Does a reduction in ingestion rate ac
Homeostasis Role in Eating
Why do we eat?
A fundamental purpose of eating is to replenish used energy.
Food also provides micronutrients, which are essential building blocks for cellular
Why do we need energy?
Digestive System Signals (Gut peptides)
a. Decrease food intake
a. Increase food intake
Stimulates feeding and growth hormone (GH) secretion - GH releasin
Peptide hormone produced by stomach
Acts through the CNS