Homeostasis and Organisation of Matter Flashcards
(20 cards)
What is homeostasis?
Maintaining a stable internal environment despite a changing external environment.
What are the key components of a feedback system?
- A stimulus (e.g. change in blood pressure)
- A receptor
- An afferent pathway
- A control centre
- An efferent pathway
- A response
How does a negative feedback system affect the initial stimulus?
Opposes/reverses it.
What are the four main chemical elements in the human body?
Oxygen, carbon, hydrogen, nitrogen.
What is the difference between a covalent bond and an ionic bond?
In a covalent bond the electrons are shared.
In an ionic bond the electrons are transferred completely.
What are the levels of organisation of the human body, from smallest to largest?
Atoms, molecules, cells, tissues, organs, organ systems, whole organism.
This organ system provides a physical barrier between our internal environment and the external world.
The integumentary system
This system carries blood throughout the body as well as nutrients and oxygen.
The cardiovascular/circulatory system.
This system takes in oxygen from the atmosphere and expels carbon dioxide.
Respiratory system.
This organ system uses electrical signals to coordinate bodily functions, and also gives rise to higher functions like thought and memory.
The nervous system.
This organ system takes, breaks down, and absorbs nutrients.
The digestive system.
This organ system supports the shape of the body and gives protection to delicate organs.
The skeletal system.
This system enables movement and works with the skeletal system.
The muscular system.
This system involves chemical messages in the blood that regulate bodily processes.
The endocrine system.
This system secretes wastes and regulates fluid balance and blood pressure.
The renal/urinary system.
This system creates offspring through the combining of gametes.
The reproductive system.
This system helps return fluid from tissues into the blood.
The lymphatic system.
Water is a unique molecule because it is polar. What does this mean?
Electrons are shared unevenly creating partial charges.
What are the 3 main fluid compartments of the body?
Intracellular fluid (ECF), interstitial fluid, plasma. (Last 2 are part of the extracellular fluid (ECF))
Blood clotting is an example of what kind of feedback system?
Positive feedback.
