Lecture 1 Flashcards
Physiology
How the parts work
Define anatomy
Study of the structure
Define pathology
Study of abnormalities from normal function
List the 7 characteristics of life.
Metabolism Responsiveness Movement Reproduction Growth Differentiation Vital force/life force/chi
Define metabolism
All the chemical processes in the body
Define differentiation
Development of specialised cells
Define 4 characteristics of death
Loss of heartbeat
Absence of breathing
Loss of brain function
No vital force/chi
What is the definition of homeostasis
Homeo - sameness
Stasis - standing still
Define homeostasis
The condition of equilibrium in the human body’s internal environment maintained by the body’s own regulatory processes.
It’s is dynamic and ever changing whilst always remaining within certain narrow limits to ensure optimal functioning of all life processes.
When lost, there is a serious risk to the well-being of the individual.
Which physiological variables must be kept within homeostatic balance in the body? List 7
Core temperature Water electrolyte balance PH of body fluids Blood glucose levels Blood and tissue 02/CO2 levels Blood pressure Life force flow
What is homeostasis maintained by?
Control systems (feedback loops) that detect and respond to changes in the internal environment
What are the control systems that maintain homeostasis made up of
DETECTORS (nerve receptors/sensors) which sense changes and send info to
CONTROL CENTRE (often hypothalamus in brain) which sets the limits to be maintained.
Control centre then processes incoming info and if adjustment needed it will send output instructions to the EFFECTORS to cause a change.
It is a DYNAMIC process - constant readjustment.
Describe a positive feedback mechanism
Output reinforces the input
Also known as amplifier/cascade systems
Stimulus progressively increases the response and the response is progressively amplified
Only a few of these systems exist in the body eg - blood clotting, labour contractions, milk production, enzyme reactions, immunity.
Most PFM are harmful as no stop mechanism, ie too much histamine after bee sting can cause allergy
Define a negative feedback mechanism
Output reverses input
Effectors decrease/negate the effect of original stimulus, restoring homeostasis.
Goes back to normal when homeostasis has been restored.
Eg, core temperature - works like central heating system
Describe the 7 levels of organisation in the body
Chemical - atoms and molecules Cells Tissues Organs Systems Vital force Organism
