Brain and Behavior Exam # 3
Homostasis correct answers -Biological process that keep body variables within a fixed
range
Set point correct answers -A single variable that the body works to maintain [levels of
water, oxygen, glucose, calcium, protein, fat, acidity]
-Often maintained through negative feedback
Allostasis correct answers The adaptive way in which the body changes its set point in
response to changes in life of the environment.
Thermoregulation correct answers The process that allows the human body to maintain
its core internal temperature
Why do we maintain our body temp so close to the high end of safe? correct answers
Muscle activity benefits from being as warm as possible and ready for vigorous activity.
How does the hypothalamus get temperature info? correct answers -Cytokines attack
intruders and stimulate vagus nerve, the vagus stimulates the hypothalamus (informs it
that there is a problem) and then the hypothalamus changes (increases) its set point.
How does the Hypothalamus heat or cool you? Are the same parts involved in heating
as in cooling? correct answers -Decrease temp: Sweat, pant, increase of blood flow to
the skin.
-increase temp: shiver, increase metabolic rate, decreasing blood flow to the skin.
-Preoptic areal anterior hypothalamus (POH/AH) cools you off when you are hot.
-Posterior hypothalamus warms you when you are cold.
-Some neurons of the POA are directly warm sensitive; activate these cells -> sweating
& vasodilation
-Cells of the POH/AH also receive input from thermometers in the skin
Why do you feel cold at the beginning of a fever? Why do you sweat when it breaks?
correct answers -Feel cold so your body begins to heat itself up.
-When you have a fever, the warmer temp enhances the activity of the immune system
and helps slow bacterial growth.
-sweat to cool body back down.
Compare/ contrast osmotic thirst/ hypovolemic thirst correct answers -Osmotic thirst
caused by: eating salty foods.
detected by: neurons in SFO and OVLT
thirst for: plain water
, -Hypovolemic thirst:
caused by: low volume of body fluids.
detected by: vasopressin and angiotensin II
thirst for: salty water
What are some signals to eat? correct answers -The desire to taste and other mouth
sensations, such as chewing.
-Social, and environmental cues
-peripheral hormones (ghrelin, etc)
-metabolic signals (drop in glucose or lipids)
-Neurotransmitters/ brain mechanisms (NPY, Orexin, etc)
Relationship between insulin/ glucose correct answers -Insulin is released by the
pancreas to help glucose enter cells for more storage. H insulin levels stay high, the
body continues rapidly moving blood glucose into the cells after a long meal.
What is leptin correct answers -Peptide(short series of amino acids connected by
bonds) produced by fat cells.
What is the first hypothalamic region to receive hunger and satiety signals? correct
answers Articulate nuceleus
What are the 2nd and 3rd hypothalamic regions to receive hunger and satiety signals?
(in hypothalamus) correct answers -Paraventricular nucleus(inhibits lateral
hypothalamus)
-lateral hypothalamus(promotes feeding behavior)
Lateral hypothalamus
role vs lesion correct answers role: hunger promoting
when in lesion: deficit in osmotic thirst due partly to interruption of passing axons.
Paraventricular nucleus
role vs lesion correct answers role: satiety
when in lesion: Increased meal size, especially increased carb intake during the first
meal of the active period of the day.
Ventromedial hypothalamus
role/lesion correct answers Role: satiety
lesion:
-increased meal frequency, weight gain, high insulin level.
-increased stomach secretions & mobility stomach empties faster than usual.
-increased insulin production so much of meal is stored as fat.
-much of this because of damage to passing noradrenergic axons axons.
Strengths / weakness of legion studies correct answers Strength: General idea of
things going wrong.
Homostasis correct answers -Biological process that keep body variables within a fixed
range
Set point correct answers -A single variable that the body works to maintain [levels of
water, oxygen, glucose, calcium, protein, fat, acidity]
-Often maintained through negative feedback
Allostasis correct answers The adaptive way in which the body changes its set point in
response to changes in life of the environment.
Thermoregulation correct answers The process that allows the human body to maintain
its core internal temperature
Why do we maintain our body temp so close to the high end of safe? correct answers
Muscle activity benefits from being as warm as possible and ready for vigorous activity.
How does the hypothalamus get temperature info? correct answers -Cytokines attack
intruders and stimulate vagus nerve, the vagus stimulates the hypothalamus (informs it
that there is a problem) and then the hypothalamus changes (increases) its set point.
How does the Hypothalamus heat or cool you? Are the same parts involved in heating
as in cooling? correct answers -Decrease temp: Sweat, pant, increase of blood flow to
the skin.
-increase temp: shiver, increase metabolic rate, decreasing blood flow to the skin.
-Preoptic areal anterior hypothalamus (POH/AH) cools you off when you are hot.
-Posterior hypothalamus warms you when you are cold.
-Some neurons of the POA are directly warm sensitive; activate these cells -> sweating
& vasodilation
-Cells of the POH/AH also receive input from thermometers in the skin
Why do you feel cold at the beginning of a fever? Why do you sweat when it breaks?
correct answers -Feel cold so your body begins to heat itself up.
-When you have a fever, the warmer temp enhances the activity of the immune system
and helps slow bacterial growth.
-sweat to cool body back down.
Compare/ contrast osmotic thirst/ hypovolemic thirst correct answers -Osmotic thirst
caused by: eating salty foods.
detected by: neurons in SFO and OVLT
thirst for: plain water
, -Hypovolemic thirst:
caused by: low volume of body fluids.
detected by: vasopressin and angiotensin II
thirst for: salty water
What are some signals to eat? correct answers -The desire to taste and other mouth
sensations, such as chewing.
-Social, and environmental cues
-peripheral hormones (ghrelin, etc)
-metabolic signals (drop in glucose or lipids)
-Neurotransmitters/ brain mechanisms (NPY, Orexin, etc)
Relationship between insulin/ glucose correct answers -Insulin is released by the
pancreas to help glucose enter cells for more storage. H insulin levels stay high, the
body continues rapidly moving blood glucose into the cells after a long meal.
What is leptin correct answers -Peptide(short series of amino acids connected by
bonds) produced by fat cells.
What is the first hypothalamic region to receive hunger and satiety signals? correct
answers Articulate nuceleus
What are the 2nd and 3rd hypothalamic regions to receive hunger and satiety signals?
(in hypothalamus) correct answers -Paraventricular nucleus(inhibits lateral
hypothalamus)
-lateral hypothalamus(promotes feeding behavior)
Lateral hypothalamus
role vs lesion correct answers role: hunger promoting
when in lesion: deficit in osmotic thirst due partly to interruption of passing axons.
Paraventricular nucleus
role vs lesion correct answers role: satiety
when in lesion: Increased meal size, especially increased carb intake during the first
meal of the active period of the day.
Ventromedial hypothalamus
role/lesion correct answers Role: satiety
lesion:
-increased meal frequency, weight gain, high insulin level.
-increased stomach secretions & mobility stomach empties faster than usual.
-increased insulin production so much of meal is stored as fat.
-much of this because of damage to passing noradrenergic axons axons.
Strengths / weakness of legion studies correct answers Strength: General idea of
things going wrong.
