Science (Homeostasis) Flashcards
Why do most living organisms regulate their internal environment?
To maintain a stable, constant condition
Why does the body need to maintain a stable, constant condition?
Allows organisms to function in a broad range of environmental conditions
What system does homeostasis need?
A sensor, effector and integrator
- What system controls mechanisms involved in homeostasis?
2. This system has a direct effect over what kind of distances?
- Nervous system
2. Short distances
- What secretes chemicals directly into the bloodstream?
- What are these chemicals called?
- These chemicals can affect various parts of the body over ________ distances
- Endocrine glands
- Hormones
- Long
- Where is the hypothalamus located?
- What does it link to?
- What secretes hormones when the hypothalamus stimulates it?
- What does the hypothalamus do?
- Brain
- Nervous and endocrine system, via the pituitary glands
- Pituitary glands
- It is like a detector; detects change in the body and then acts to regulate it
What are negative feedback mechanisms?
Mechanisms which resist or regulate a change in the system
What are positive feedback mechanisms?
Mechanisms which enhance or amplify a change in the system
Name the 5 negative feedback examples
- thermoregulation
- blood pressure regulation
- blood pH regulation
- blood sugar regulation
- blood water regulation
Thermoregulation
What 3 things happen if you get too cold?
- surface blood vessels constrict
- shivering
- piloerection (goosebumps)
Thermoregulation
What 3 things happen if you get too hot?
- surface blood vessels dilate
- sweat
- hairs lie flat
What happens if your body gets too cold or too hot?
Your body wont be able to compensate=death
What are 3 examples of positive feedback?
- Childbirth
- Lactation
- Blood platelet formation
