Homeostasis Flashcards
What is homeostasis?
The body’s attempt to adjust to a fluctuating external environment
Homeostasis is also maintaining an _________ balance.
Internal
Examples of homeostasis.
kidneys maintain water balance
- evaporation of water helps regulate body temperature
- hypothalamus regulates temperature and changes in
osmotic pressure
- pancreas regulates blood sugar
- skeletal muscles contract and release heat
- blood distributes heat throughout the body
Why does homeostasis refer to the body’s attempt to adjust to a fluctuating external environment?
In order to maintain a constant
balance or steady state.
Homeostasis is also referred as..
DYNAMIC EQUILIBRIUM
Three parts of feedback system?
- Sensor
- Integrator
- Effector (regulator)
What is sensor in feedback system?
sensors located throughout the body that identify changes and sends a signal to the coordinating center (Integrator)
What is integrator in feedback system?
relays the information to the appropriate regulator
Example of integrator in feedback system.
Hypothalamus
What is regulator in feedback system?
Takes action to restore the normal balance
Examples of regulator in feedback system.
Skin blood vessels, skeletal muscles, sweat glands
What are the two types of feedbacks?
Positive and negative
What is negative feedback?
A process by which a mechanism is activated to restore conditions to their original state.
What is negative feedback designed to do?
Resist change.
What systems, does Body temperature feedback loop involve?
It involves the
integumentary system (skin), the nervous system, and the endocrine system
What is positive feedback?
In response to a perturbation, it acts to increase the intensity of the perturbation.
Process by which a small effect is amplified
What does positive feedback reinforce?
change and less common in the body.
An example of positive feedback (1)?
A person gets cut, chemicals are
released to activate the platelets.
In positive feedback, what happens after a person gets cut and the chemicals are released to activate the platelets?
The activated platelets then release more chemicals to stimulate more platelets until the bleeding is stopped.
Another example of positive feedback (2) ?
Regulating contractions during childbirth
Positive feedback only works in systems that have a…..
definite endpoint.
What is an example of definite endpoint?
Like the bleeding stops or the baby is
born.
What is
thermoregulation?
Maintenance of body temperature within a range that enables cells to function efficiently
What are ectotherms?
Cold blooded. When they must thermoregulate through
behaviour changes
In ectotherms, body temperature depends on what?
the environment
What are endotherms? Examples?
Warm blooded. Having internal mechanisms to control body temperatures
Speeding up cellular respiration
What are some examples that are animal, that are ectotherms.
Fishes, reptiles
What are some examples that are animal, that are endotherms
mammals, birds
What is hypothalamus?
The control centre for thermoregulation
What part of our body is hypothalamus?
It is the part of the brain responsible for coordinating many nerve and hormone functions
check slide 5, 6, 8, 10, 11, 12 for diagrams.
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