1. Chapter 1- Intro Flashcards
What is physiology?
The study of the normal functioning of a living organism and its component parts (including all chemical and physical processes)
What are emergent properties?
Properties of a system that cannot be explained by knowing the systems individual components
Ex: can’t know emotion or intelligence in humans by examining the properties of nerve cells
What is a teleological approach compared to a mechanistic approach?
Which one does physiology focus on?
Teleological- the “why” approach, finding adaptive significance
Mechanistic- the “how” approach, examines process
Physiology focuses on the mechanistic approach
What is homeostasis?
The ability to maintain a relatively stable internal environment in spite of exposure to internal variability
What does an internal change do to homeostasis? (Loss or gain of homeostasis)
Internal change is a loss of homeostasis
What is extracellular fluid (ECF)?
A buffer between cells and the external environment
Positive, has more cations
It surrounds the outer membrane of cells
What is the law of mass balance?
Says that if the amount of a substance in the body is to remain constant, any gain must be offset by an equal loss
Adding intake or metabolic production must be countered with excretion or metabolic removal
Is homeostasis the same as equilibrium?
No. The body compartments are in a dynamic steady state but are not in equilibrium but rather stable disequilibrium
What is local control and reflex control?
Local control- simplest control where an isolated change occurs in a tissue and a nearby group of cells senses the change and respond
Reflex control- uses long distance signalling that uses the nervous or endocrine system
What are the three components all control systems have?
- An input signal
- A controller or integrating centre that integrates info
- An output signal that triggers a response
What are the two parts reflex control is broken down into?
- Response loop- has the main three control system components but can expanded to stimulus, sensor, input signal, integrating centre, output signal, target, response
- Feedback loop- same as response loop but feeds back to influence the input
See slide 18-19 on sept 7
What is a negative feedback loop?
Is it homeostatic?
Removes a stimulus to return a variable to its normal value
This is homeostatic since it stabilizes a system
What is a positive feedback loop?
Is it homeostatic?
Reinforce a stimulus to drive a variable away from its normal value
Requires intervention or event outside the loop to cease the response
Not homeostatic
What is feed forward control?
A few reflexes have evolved that allow the body to predict a change is about to occur
Increase in heart rate and ventilation at start of exercise before you actually start but are in the gym
What are biorhythms?
Variables that change predictably and create repeating patterns or cycles of changes
Ex: circadian rhythms
