introduction to physiology Flashcards
homeostasis
homeo = similar
regulated variables: temop, pH, ion concentration, nutrient availability
what happens if you cannot maintain homeostasis?
dysfunction, disease, and death
homeostasis examples
- you breathe faster
- HR increases
- you get hot
- you get thirsty
Bodys’ internal state
Goal; keep regulated variable w/in desired range of set point
- you have a certain threshold, but you have a range in which you can deviate.
Control systems that monitor and regulate
regulated variable deviates from set point -> stimulus -> sensor -> input signal -> integrating center -> output signal -> target -> response
sensor
sensory receptors, constantly monitors and reports on regulated variable
interating center
integrator, often a neuron or endocrine cell.
- evaluates all inputs and sends instructions
Target
Effector, brings about physiological response
Types of sensors
central receptors: eyes, ears, nose, tongue, chemo receptors, osmoreceptors, thermoreceptors
Peripheral receptors: chemoreceptors(pH, chemicals), osmoreceptors, thermoreceptors(temp), baroreceptor(pressure), proprioceptor(body position), mechanoreceptors(pain)
Feed forward
occurs in anticipation of change
feedback
occurs in response to change
negative- restore(either too high or too low)
positive -enhance response, moving away from setpoint, need outside factor to stop positive feedback
control strategies of the body
feedforward and feedback
Homeostatic dysregulation
body cannot maintain homeostasis, impaired function of homeostatic system leads to disease
ex: hyperglycemia(diabetes)
What happens when you have diabetes?
Healthy response to glucose concentration- keeps glucose concentrations within threshold. Negative feedback.
Diabetes- Glucose concentrations start off higher, body doesn’t respond to the stimulus, keep increasing.
