FoM:L1- Homeostasis Flashcards
1
Q
What is autocrine cell communication?
A
communication with same cell
2
Q
What is paracrine cell communication?
A
communicating with neighbouring cells
3
Q
What is endocrine cell communication?
A
communication with distant cells, via circulation
4
Q
What 4 elements are required to regulate a parameter?
A
- sensor/detector for parameter
- internal standard or set point
- output signal/response
- effector
5
Q
Outline the concept of priority in homeostasis
A
- some feedback loops oppose others
- competing priorities from parameters
- more important parameter will be maintained as responses to changes in these with supersede the others
6
Q
Outline the concept of hierarchy in homeostasis
A
- loops function in a hierarchal fashion
- secretion in response to one gland, which was stimulated by another gland
7
Q
What is a diurnal rhythm?
A
feedback causes levels to change throughout the day
8
Q
Outline the concept of redundancy in homeostasis
A
- multiple systems regulate a given parameter
- some are redundant
- if a system should fail, an alternative can take over
9
Q
Why is short-term adaptation needed?
A
- respond to changes in external environment
- overrides normal homeostatic mechanism for a short period of time
10
Q
Why is acclimatisation needed?
A
long term changes in homeostatic mechanisms and set-points
11
Q
What is positive feedback?
A
- physiological change leads to an even greater change in the same direction
- activation of the sensor amplifies the response
- have an end point
12
Q
Outline the concept of complexity in homeostasis
A
- things rarely happen in isolation
- feedback loops operate as part of a larger feedback system
- some loops can be synergistic or antagonistic
