Unit 2-7 Flashcards
Homeostasis
Critical physiological need that drives behavior, balanced internal environment that is optimized for cellular activities, affects motivation
Endotherms
Heat body from within by burning chemical energy (food) (humans)
Ectotherms
Rely on the environment to regulate body temperature (fish, reptiles, amphibians)
Pros of endotherm
Don’t have to rely on outside environment
Cons of endotherm (2)
- Too hot = proteins malfunction due to loss of shape
- Too cold = proteins malfunction , moves to slowly
Negative feedback
Deviation from a desired point or range triggers a compensation from the system that drives it the opposite way (body temp low during sleep to conserve energy, body temp high during fever to boost immune response)
Allostasis
Changing homeostatic needs (homeostatic needs are constantly influx, flexible and dynamic to adjust to current levels)
Allostatic overload
Chronic physiological stress, leads to poor mental and physical health
Obligatory losses
Body’s water is depleted through things I can’t be avoided; urination, breath, perspiration
Thirst
Adjust our behavior to take an appropriate amount of water so our cells can dilute saltwater inside and outside to survive; salt ions and water are balanced (evolutionary to oceanic origins)
Osmosis
Diffusion of water
Too little water in extra cellular fluid
Cells shrivel up
Too much water in extra cellular fluid
Cells swell or explode
Osmotic thirst
- Excess salt (too much salt/water loss)
- Osmosensory neurons, detect access, saltiness (Present in hypothalamus and ventricular system)
- Project to cortex giving us perception of
- Hypothalamus releases, antidiuretic hormone, tells kidneys to slow down urine production
Hypovolemic thirst
- Sudden, dramatic fluid loss (hemorrhage, vomit, diarrhea, intense sweating
- baroreceptors in blood vessels detect loss of volume, signal brain to perceive thirst and salt craving
- hormone angiotensin II constricts blood vessels—> increase blood pressure
- aldosterone directs kidneys to preserve sodium
How do we know to stop drinking water (3)
- Vagus nerve - Monitors saltiness of fluids in the gut
- Mouth/ throat moisture sensations
- Osmoreceptors and baroreceptors
- must all come to agreement
Hunger
Drive to consume food
Nutrients
Chemicals required for the appropriate functioning, growth, and maintenance of the body
Nutrients needed (3)
- Amino acids (can’t be synthesized by the body and must be acquired from food)
- Vitamins and minerals
- Energy sources (sugars, fats)
Glucose
Simple sugar
Glycogen
Glucose stored in liver and muscles (promotes by insulin)
Glucagon
Coverts glycogen back to glucose if cells need it
For longer term storage, glucose is
Stored in adipose tissues as lipids (fats)
Basal metabolism
Energy goes to keeping us alive and warm and keeping our cells functioning (fights changes in weight)