Homeostasis

L.O:
1.An awareness of the relevance of Physiologyto health and disease within an osteopathic context.

●

2.An understanding of the concept of Homeostasis, its importance in healthy functioning, and the consequences of homeostatic dysfunction.

●

3.The ability to describe the components of a Control System, an appreciation of Open vs. Closed systems and an awareness of biological rhythms.

●

4.An awareness of the human organism in an Ecological context.

Ecology

• Homeostasis has enabled the human body to be an 'open' system, where the systems of the body interact with the environment/ ecosystem
• Therefore, the physiology of the human individual must be appreciated in the broader context of human populations, communities and environment. Such an approach is of value in analysing the complexity of influences concerning health and disease and in the context of an osteopathic clinic.
• An open system differs from a closed one in that while boundaries exist it exchanges energy and information with its environment. We survive not because we are totally enclosed in a protective armour.
  
  

Homestasis

• Homeostasis is vital for adaptation
• Examples of homeostatic processes in the body: blood pressure, blood pH, blood glucose, temperature, ventilation.
• There is a dynamic equilibrium within living (open) organisms, as the variable in homeostasis is constantly fluctuating eg body temperature. This is why homeostasis occurs. 
• Dynamic Equilibrium requires the existence of a Control (feedback) System. This must have five basic components:
• 1. a)  Receptors (sensors) that respond to an increase or decrease in the variable, or its rate of change and transduce this information;
  2. b)  Effectors, that bring about a response. Effectors are muscles, or glands;
  3. c)  A Control Centre, or Co-ordinating Centre, that controls the onset and magnitude of the
     response, such that the response is proportional to the stimulus;
  4. d)  An Afferent Pathway, that conveys information from the receptors to the control centre;
  5. e)  An Efferent Pathway that conveys information from the control centre to the effectors.
  Afferent and efferent pathways consist of nerve fibres, or hormones.
• The body has numerous mechanisms by which any stress that causes a deviation from equilibrium, or optimum state, results in a response that restores that state. Optimum conditions are particularly essential for the optimal functioning of enzymes, which are sensitive to changes in their environment.
• There a few situations in which the response enhances the stimulus. This ‘avalanche’ situation is described as Positive Feedback, e.g. the process of blood clotting, or labour contractions. In these situations positive feedback is advantageous in effecting rapid change and an amplified response.
• Negative feedback refers to when effector mechanisms operate to oppose the effect of the initial stimulus, eg. if blood pressure rises, mechanisms operate to reduce blood pressure

Biological rhythms

•Time Interval (hourly, circadian, monthly, seasonal)

•Chronopharmacology

•Endocrine/ CVS/ Respiratory/ Immune/ Fluid&Electrolyte/ Temperature (&enzyme activity) Rhythmicity

•Melatonin

•Chronotherapy