Brain and Behavior Chap 10

Food Path Through Digestive System

Begins at mouth (mechanical chewing and Saliva Chemical), hydrochloric acid and enzymes in stomachs (proteins), sml intestine digest fats and carbs absorbs nutrients into BS, lrg intestine absorbs water and minerals.

What are the 2 types of thirst? What is the difference between them?

Osmotic Thirst - a thirst resulting from eating salty foods Hypovolemic Thirst - a thirst resulting from loss of fluids due to bleeding or sweating

What is the difference between a poikilothermic and homoeothermic critter?

Poikilothermic matches the outside environments temp while homoethermic requires energy for the animal to maintain internal temp.

Hydration is important! Why? How much water is the mammalian body composed of?

The correct amount of fluid/hydration is needed to maintain blood pressure. 70%

What hormone is crucial for maintaining hydration?

Vasopressin (aka. anti-diuretic hormone) - released by pituitary; if not enough water, vascular pressure constricts blood vessels → raises blood pressure, to compensate for decreased volume; lets kidneys reabsorb water from urine

Define Set Point

a single value that the body works to maintain

Leptin- where does it come from and roles?

comes from adipose (fat) tissue; fat cells. notifying body of current fat supplies.

Ventromedial Hypothalamus (VMH

damage leads to faster stomach emptying and increased secretion of insulin

Lateral Hypothalamus (LH)

important for the control of eating and drinking.

Paraventricular Nucleus (PVN)

inhibits the lateral hypothalamus, an area important for eating. determines meal size

arcuate nucleus

of the hypothalamus and has one set of neurons sensitive to hunger signals and a second set sensitive to satiety signals

What part of the hypothalamus controls body temperature? How does it monitor temperature?

preoptic area/anterior hypothalamus. The POA/AH monitors body temperature partly by monitoring its own temperature and Cells of the POA/AH also receive input from temperature receptors in the skin and spinal cord

Define Homeostasis

refers to temperature regulation and other biological processes that keep body variables within a fixed range

Ghrelin where does it come from and roles?

released by the stomach. triggers stomach to contract, hypothalamus decreases appetite, and Acts on the hippocampus to enhance learning

Cholecystokinin (CCK) where does it come from and roles?

secreted from the duodenum. Closes sphincter between stomach and duodenum, Sends a satiety signal to the brain (via the vagus nerve), Inhibits food intake, and Injection of CCK in humans inhibits food intake

Glucagon where does it come from and roles?

secreted from the pancreas when body needs energy. Breaks stored glycogen down to glucose when energy is required Rises when we need food/energy/fuel

Insulin where does it come from and roles?

secreted from the pancreas. Facilitates glucose entry into peripheral cells for immediate use as fuel and Converts glucose into glycogen for short-term energy storage

Define Allostasis

the adaptive way in which the body changes its set points depending on the situation