Principles of Physiology Flashcards
What is physiology?
The study of the functions of living things
Physiology describes how processes in the body work by explaining their…
mechanisms of action
What are the levels of organisation in the body?
Cells
Tissues
Organs
Organ systems
What is a cell?
The basic unit of life
What is a tissue?
Groups of cells with similar specialisation
What are the four primary types of tissue in the human body?
Epithelial
connective
muscle
nervous
What is the function of epithelial tissue?
Provide protection
secretion
absorption
What is the function of the connective tissue?
To provide structural support
What is the function of muscular tissue?
For movement
What is the function of the nervous tissue?
Involved in communication coordination and control
Name an organ which is made up of all four primary types of tissue
The stomach
What is an organ?
A unit made up of several tissue types - >2
What is a body system?
A collection of related organs
How many body systems exist?
11
List the 11 body systems
nervous immune reproductive circulatory respiratory muscular skeletal integumentary urinary endocrine digestive
Why do body systems not act in isolation?
There are complex body processes which require an interplay between different body systems
Give an example of a regulatory process which requires more than one body system
Regulation of blood pressure nervous system circulatory system endocrine system urinary system
What is the external environment?
The surrounding environment in which an organism lives
What is the internal environment?
The fluid that surrounds cells
Why do living organisms need to communicate with the external environment?
Obtain nutrients and o2 and to eliminate waste
Why is it easier for unicellular organisms to communicate with the external environment?
They can communicate directly whereas multicellular organisms have to communicate via the internal environment
What two parts make up the internal environment?
The intracellular fluid and the extracellular fluid
What is intracellular fluid?
Fluid that is contained within body cells
What is extracellular fluid?
fluid that is contained outside cells but is still in the internal environment
What two parts make up the extracellular fluid?
The plasma and the interstitial fluid
What is the plasma?
The fluid portion of the blood
What is the interstitial fluid?
The fluid that surrounds and bathes cells
The interstitial fluid is key to
homeostasis
What is homeostasis?
The maintenance of a stable internal environment
What does the homeo and the stasis part of homeostasis mean?
Homeo means similar and stasis means to stand or stay
Why is homeostasis often said to be the foundation of physiology?
Cells make up the body systems and the functions of each body system contribute to homeostasis
Homeostasis is not rigid, it is a
dynamic process
Many factors are homeostatically maintained, give some examples.
Nutrient molecules o2 and co2 concentration conc of waste products pH conc of h20, salts and other electrolytes vol and pressure temperature
Why does the concentration of nutrients have to be maintained?
Cells need a constant supply of nutrient molecules for energy production
Why does the concentration of oxygen and carbon dioxide need to be maintained?
Oxygen - for energy yielding reactions
Carbon dioxide - must be removed so acid forming co2 does not increase the acidity of the internal env
Why does the conc of water products need to be maintained?
some chemical reactions produce end products that are toxic if accumulated
Why does the pH have to be maintained?
Changes in pH of ECF adversely affect nerve cell functions and wreck havoc with enzyme activity of all cells
Why does h20/salt concentration need to be maintained?
Relative conc of h20 and salts influences how much watr enters or leaves cells. must be maintained as cells don’t function normally when they are swollen or shrunken
Why do electrolytes need to be maintained?
Some perform vital functions for example the rhythmic beating of the heart depends on a relatively constant concentration of K+ ions in the ECF
Why does volume and pressure need to be maintained?
The plasma must be maintained at adequate volumes to ensure bodywide distribution. blood pressure must be maintained for bodywide distribution.
What happens if the temperature is too high?
The structural and enzymatic proteins of cells are impaired or destroyed
What happens if the temperature is too low?
The cells slow down