Unit #1 Wellness & Homeostasis “Homeostasis” Biology 30S Unit #1 Wellness & Homeostasis “Homeostasis”

Homeostasis “Homeo” means same “stasis” means state The Body’s ability to maintain its internal environment within acceptable ranges despite the changing external environment The body’s ability to maintain “normal” physiological conditions

Homeostatic Conditions: (1) Body Temperature Homeostatic mechanisms must allow the body to maintain the following condititions: The body must maintain an internal temperature of approximately 37 degrees Celsius This is maintained by a homeostatic mechanism called Thermoregulation

The body must maintain a constant water balance 78% of the human body is made up of water A 1% drop in fluid body mass causes thirst A 5% drop causes extreme pain and collapse A 10% decrease often results in death Water balance is maintained by a homeostatic mechanism called Osmoregulation

The body must maintain an internal blood pressure of 120/80 kPa The body must maintain a blood pH level near 7.4 Blood glucose (blood sugar) levels must be maintained at concentrations around 100mg/ml (3) Blood Pressure (4) Blood pH (5) Blood Glucose

(6) Respiratory Gasses Oxygen (O2) and Carbon Dioxide (CO2) levels must be balanced in the cells and bloodstream These levels are maintained by a homestatic mechanism called Respiration

(7) Waste Management The ability of the body to remove harmful wastes is essential to maintaining homeostasis Often cellular metabolism results in the production of harmful waste Organs such as the liver, lungs, kidneys, skin and stomach help the body regulate and reduce waste levels in the body

(8) Immunity (9) Repairs Death Homeostatic mechanisms regulate the body’s response to pathogens Homeostatic mechanisms regulate the body’s ability to repair injuries and “heal” The failure of Homeostasis (more or less)