4.1 Homeostasis Introduction Flashcards
What does homeostasis mean?
Relative consistency in internal fluid environment
Who first used the term homeostasis? When was it first used?
Walter Bradford Canon in the 1920s
Homeostasis using fish tank analogy to represent human body? (7)
- Water body fluid-internal environment
2.glass bowl - skin-barrier/interior vs exterior
- Fish - cells - staying alive
- Air pump- lungs - keep oxygen levels high and constant
- Filter - kidney- keep nitrogen waste constant (low)
6.heater - muscles - keep constant temperature high
- Feeder - digestive system - keep constant nutrient levels high
What are the five key components of homeostasis and what do they represent?
- Variable (stimulus) the characteristic of the internal environment that is being controlled
-internal temperature
- Sensor (Receptor) attribute that detects changes in the variable and feeds information to the integrator (control center)
-thermorecptors (nerves)
- Integrator (control center) integrates (puts together) sensor and stored setpoint data
-hypothalamus of the brain
- Setpoint the ideal value of a variable that has been previously stored in variable memory
-human body temperature remaining at 37 degrees
- Effector/ Reponse process that effects variable
Muscles shivering to provide heat to the body
Negative feedback analogy using respiratory system (-includes setpoint, control center and response
Setpoint: blood oxygen 94%-98%
Control center: Medulla Oblongata which is the breathing center of the brain
Response: diaphragm and intercostal muscles contractions trigger inhalation and relaxation of these muscles trigger exhalation
When does negative feedback occur?
When signals from sensor to integrator cause the reversal of direction of deviation
What is the benefit of negative feedback?
Stabilizes system by correcting deviations from the setpoint
Ex shivering of body as response to being in cold weather
When does positive feedback occur?
When signals from the sensor to the receptor amplify deviation causing the change occurs in the same directions as the deviation from the setpoint
Ex when amplified sound is picked up by a microphone and continuously amplified so the noise gets louder
How does an organism die?
When the organism loses homeostatic consistency
What are the six factors in the human body that must constantly be homostatically regulated?
- Concentration of nutrients and oxygen
Vital that the body has certain
amount of oxygen, glucose and proteins
- Concentration of salts and electrolytes
Body needs to have a certain amount of salts such as potassium and sodium
- Concentration of waste
Waste products must be monitored to ensures that they do not exceed and certain amount. Particularly harmful in high concentrations of urea, CO2 and bile
- Acid and Base concentrations
A very delicate equilibrium must be traced between the levels of acids and bases present in the fluids of the body. Particular areas of the body have their own unique acid and base concentrations that must be contained
- Temperature
The internal temperature of the human body must remain at a fairly constant level. The average human body temperature of 98.6 degrees Fahrenheit - Pressure and volume
The pressure of fluids and gases in the body need to be at equilibrium in the body. Particularly using when balancing pressure between in the inside and outside of the cell and inside of the lungs and outside air pressure
What we will be learning?
- Maintaintaining body fluid using the kidneys
The formation of urine by the kidneys helps concentration waste, maintain ion and electrolyte concentrations, and maintain acid base
Which hormone stimulates uterine contractions during labour
Oxytocin
