Download Comparative Vertebrate Physiology

Comparative Vertebrate
Physiology
Homeostasis
Course Outline


Systems
 Nervous, Muscular, Circulatory, Respiratory,
Osmoregulatory, Digestive, Reproductive
Processes
 Thermoregulation
 Metabolism
Course content




Structure - what does it look like?
Function- how does it work?
How and Why?
The comparative approach
Homeostasis
Large
external
fluctuations
Control
systems
Small
internal
fluctuations
Homeostasis




Claude Bernard’s concept
All organs interact
All cells of organs bathed in internal fluid
Cells exist if fluid remains constant in quantity
and quality - quality affects quantity
Fluctuations occur within narrow limits
Feedback mechanisms
Disturbance
Negative feedback
Control
system
Sensor
Set point
adjustment
Error
signal
Inverted
amplifier
Negative feedback



Beneficial - Example: perspiration
Doesn’t prevent displacement
Restores stability close to operating
parameters
Feedback mechanisms
Disturbance
Positive feedback
+
Control
system
Output
Sensor
Signal
Amplifier
Positive feedback

Rare and mostly destructive


e.g. congestive heart failure
Some are beneficial

e.g. vomiting
Control systems
Response
Stimulus
Integration
(CNS)
Receptor
(cell)
Afferent
Effector
(muscle, gland)
Efferent