9.2 Flashcards
(8 cards)
Homeostasis Mechinisms are described as _____ or ____
Detection-correction or feedback systems
Negative Feedback Systems
- Primary Mechanisms for homeostasis
Stimulus, Sensor, Intergrator, Effector, Response
Stimulus: Change in internal/External enrv.
Sensor: Tissue/organic detecting that change
Integrator: (the brain) processing information and formulating response. Comparing information from sensory and comparing it to the desired set points.
Effector: Organ system attempting to put measured conditions into desired set points
Response: Output
Ex. Shivering
What do Neg. feedback mechanisms use?
Antagonist Effectors
Effectors that produce the opposite effect of the change recorded by the sensory
Negative Feedback Mechanisms in Animals
- Manny animals use body temp to maintains homeostasis
- Have body temps with very narrow tolerable ranges
- Neurons recieves info from thermoreceptors in sensor organs
Changes in set points
- THere are ties where ideal set points are changed in order to maintain homeostasis
Ex. Fever
- Effectors will attempt to increase your body temp into to help fight the infection
- Once the fever breaks out, than body temp. is readjusted back to normal
Other Animal’s Methods of Maintaining Homeostasis
Dogs: Pant to release thermal energy
Reptiles: Bask under rocks or hide under the shade
Terrestrial Vertberbre: Use water to cool off
Large Fish (sharks): Contracts swimming muscles to maintain a body temp above water tmp
Insects: Bask in sun to general heat b/c flight muscles works best in higher temp, or contract flight muscles
Positive Feedback Systems
- Works to increase changes in environment
- Usually does not result in homeostasis because it becomes unstable
- Almost always operates when continueal increase in internal variable is reqiured
EX. Adrenaline release when being attacked by an animal
Examples of Positive Feedback Mechanisms
Childbirth and oxytocin
Breastfeeding and stimulation
