Homeostasis Flashcards
(13 cards)
What is homeostasis?
The regulation and maintenance of a stable internal environment, regardless of changes to the external environment.
Homeostasis ensures the body functions optimally despite external fluctuations.
What does the term ‘homeostasis’ derive from?
‘Homeo’ means ‘unchanging’ or ‘the same’ and ‘Stasis’ means ‘to stay’.
This etymology reflects the concept of a stable internal environment.
What are some conditions that must be maintained for homeostasis?
- Body temperature
- Glucose concentration
- Water levels
These conditions must remain within a narrow range for optimal cellular function.
Which organ systems play a role in maintaining homeostasis?
- Skin
- Kidneys
- Liver
- Endocrine system
- Nervous system
- Sensory system
All these systems work together to keep the internal environment stable.
What are negative feedback loops?
Mechanisms necessary to maintain homeostasis that counteract changes.
They reverse any detected change and return the body to its set point.
Give an example of negative feedback.
If the body gets too cold, it starts shivering until normal temperature is restored.
This response helps to return body temperature to its set point.
What is the role of insulin?
Insulin is a hormone produced by the pancreas that helps lower blood glucose levels.
It facilitates the uptake of glucose by body cells.
What is the role of glucagon?
Glucagon is a hormone produced by the pancreas that raises blood glucose levels.
It triggers the release of stored glucose into the bloodstream.
What is positive feedback?
A response that reinforces the change detected, amplifying the change.
It contrasts with negative feedback, which counteracts changes.
Provide an example of positive feedback.
- Childbirth
- Lactation
- Blood clotting
These processes enhance the initial stimulus, leading to a greater response.
What is the endocrine system?
A collection of glands that make and release hormones.
Hormones act as chemical messengers traveling through the bloodstream.
How do hormones reach their target cells?
Hormones travel through blood vessels to target cells that have matching receptors.
This specificity is crucial for the appropriate response.
How fast is the response of the endocrine system?
The speed of response is slow, but the duration is long.
Hormones can remain in the blood for an extended period.
