Homeostasis Lesson 1 Flashcards
What is homeostasis? What does it maintain?
A constant physiological adjustment of the body in response to external environment changes
Although the world varies around us over time, our bodies maintain a stable internal environment!
37° C, 0.1% blood glucose and a blood pH of 7.35!
What happens when you exercise?
1- body temperature increases
2- O2 levels are used up
3- increased cellular metabolism
4- evaporation of sweat to cool off
5- heat rate increases to increase blood flow (to get O2 levels back up)
6- pancreas signals breaking down of bio molecules to get energy needed to exercise
Homeostatic control system
1 - receptors or sensors — organs that detect changes or sense when conditions are not within the normal range
2 - control centre or integrator — organs which process information or receives from the receptor and sends signals to another part of the body
Effector — coordinating centre sends signals to an organ / tissue which will normalize original organ
Coordination of Body Functions
The activity of various specialized parts of an animal are coordinated but the two major systems of internal communication
The nervous system — involved with high- speed messages
The endocrine system — involved in the production, release and movement of chemical messengers
Chemical signs?
Hormones = produced by the endocrine system convey information between organs of the body
Pheromones = chemical signals used to communicate between different individuals
Neurotransmitters = chemical signals between cells on a localized scale (over short distances; between neurons)
Feedback systems (negative)
Buildup of the end product of the system shuts the system off
The response counteracts further change in the same direction
Negative feedback process
—> decreases an action
—> stops when return to normal
—> most homeostatic control mechanisms are negative feedback
Feedback systems (positive)
A change in some variable that triggers mechanisms that amplify the change
Positive feedback steps
—> increase an action
—> must be turned off by outside event
—> decrease an action
—> could run away = death
Why is Homeostasis referred to as a “dynamic equilibrium”
Homeostasis is a dynamic equilibrium that is maintained in body tissues and organs. It is dynamic because it is constantly adjusting to the changes that the systems encounter. It is an equilibrium because body functions are kept within a normal range, with some fluctuations around a set point.
Explain/draw out how homeostasis is maintained through an example in regards to temperature / BP… etc?
Answer’s may vary
Why is it important to maintain the primary homeostatic conditions?
1- 37 degrees, as too hot of temperatures, can cause enzymes to denature, and become either faulty or stop working completely
2- 0.1 BS - prevents tissue death and diseases like CD and Heart attack
3- Blood pH of 7.35 - allows for the proper functioning of many metabolic processes, as the human body is sensitive to temperature changes
Why is homeostasis not always constant?
Homeostasis is variable to changes in conditions. Simple actions in our everyday lives can cause homeostasis to go out of balance, like eating a meal and having sugar levels rise. Therefore, it is absolutely impossible for homeostasis to always be constant, unless we were to never engage in any sort of activity.
What is the thermostat analogy? Explain
Slideshow 1; Slide 6
Give an example of a negative feedback system + explain
Temperature or BP
