Homeostasis Flashcards
What is human pathophysiology?
The study of disordered body function
What are the different body systems?
Reproductive
Urinary
Endocrine
Digestive
Nervous
Skeletal
Integumentary
Cardiovascular
Respiratory
What percentage of the human body is fluid?
60%
What percentage of fluid is intracellular and extracellular?
2/3
1/3
What is the structural hierarchy in the multicellular animal?
Organ systems
Organs
Tissues
Cells
Subcellular organelles
Basic biostructures
Macromolecules
Simple molecules
Atoms
What 4 tentative propositions did Cannon present to describe homeostasis?
Homeostasis does not occur by chance
Constancy in an open system requires mechanisms that act to maintain this constancy
Steady-state conditions require that any tendency towards change automatically meets with factors that resist change
The regulating system that determines the homeostatic state consist of a number of cooperating mechanisms
How do ions in the extracellular fluid relate to those intracellularly?
Extracellular has higher in sodium, chloride, bicarbonate
Intracellular has higher in potassium, magnesium and phosphates
What three mechanisms are used to maintain homeostasis?
Negative feedback
Feed forward
Positive feedback
What is feed forward?
The system anticipates the need for change
What is the set point of thermoregulation?
Around 3 degrees
What is the main sensor thermoregulation?
Skin sensor
What is the control sensor thermoregulation?
Hypothalamus
What is the regulated variable of thermoregulation?
Temperature
What is the effector in thermoregulation?
e.g muscle activation for when too cold
Skin through sweating for too hot
What are the different chains for homeostasis circuit?
Sensor
Set-point
Control Centre
Effector
Regulated variable
