Chapter 6 Flashcards
motivation
factors that sustain and initiate behaviour
instinct
complex, automatic, unlearn behaviour
Drive theory
body maintains a condition of homeostasis
incentive theory
people motivated by external stimuli
arousal theory
people behave in ways that keep them at there preferred level of stimulation
set point
point of homeostasis which the system tries to return to
Ectothermic animals
external stimuli to regulate body temp
Exothermic animals
maintain body temp ourselves
preoptic area
brain area in mammal hypothalamus that contains separate warmth and cold sensitive cells
hypovolemic thirst
thirst when blood volume drops (due to loss of extracellular water)
Osmotic thirst
thirst occuring when fluid content decreases inside the body’s cells (usually happens with hypovolemic thirst)
Subfornical organ (SFO)
brain structure adjacent to third ventricle that sense and regulates internal water balance with OVLT
organum vasculosum lamina terminalis (OVLT)
brain structure adjacent to third ventricle that sense and regulates internal water balance with SFO
Circumventricular
outiside blood-brain barrier with direct access to blood circulation (SFO and OVLT)
Osmoreceptors
fires more as volume decrease due to fluid loss (Some SFO and OVLT)
Median preoptic nucleus (MnPO)
brain structure adjacent to third ventricle that integrates info form SFO and OVLT (like the middle man)
Angiotensin ll
hormone that informs brain of drop in blood volume (stimulates receptors in SFO and OVLT)
satiety
the satisfaction of appetite
learned taste aversion
avoidance of food associated with a bad memory
learned taste preference
preference for flavor of food, (good memories)
Area postrema
region in brain outside blood-brain barrier that induces vomiting if activated by toxins
five tastes
sour, sweet, bitter, salty, unami
sensory-specific satiety
the more you eat it, the less appealing it becomes
Duodenum
initial 25 cm of the small intestine (most digestion occurs here)
glucose
simple sugar (end products of all carbs)
amino acids
end product of all proteins
fatty acids
end product of fat (digested in intestine)
Glycerol
end product of fat (digested in the liver)
Absorptive phase
hours after a meal when the body lives off the nutrients arriving from the digestive system
insulin
enables body cells to take up glucose for energy and to store nutrients
diabetes type 1
pancreas is unable to produce enough insulin
diabetes type 2
body’s tissues are relatively unresponsive to insulin
Fasting Phase
period where blood glucose drops and the body falls back on it’s energy stores
glycogen
converted form of glucose, stored in reservoirs around body
glucagon
hormone that gets glycogen turned back into glucose
Arcuate nucleus (ARC)
master hypothalami centre for food intake control (how we eat, when we eat) (neurons that increase eating behaviour)
PON C neurons
decrease eating behaviour (in ARC)
Lateral hypothalamus
brain region that initiates eating and controls feeding behaviour and metabolic responses
NPY/AgRP neurons
neurons that increase eating behaviour and hunger (in ARC)
Orexin
increases eating and increases wakefulness in response to food deprivation
Paraventriculare nucleus (PVN)
brain region that regulates eating and metabolic processes
cholecystokinin (CCK)
best known satiety signal
Ventromedial hypothalamus (VMH)
brain region that produces satiety and increases metabolism
Ghrelin
when stoamche shrinks ghrelin activates
Leptin
hormone secreted by fat cells that inhibits eating (activates pon c neurons and tells ghrelin no)
Peptide YY3-36
hormone released in intestine in response to food, suppresses appetite
