Homeostasis

Homeostasis

Homeostasis

• The regulation of conditions inside the body to maintain a stable internal environment.

• In response to both internal and external conditions.

True or false our body need certain conditions to function properly

True

Examples of what conditions our body’s want

• Not Too hot hot or cold

• Not Too acidic or too alkaline

• Good supply of glucose and water

How does the body achieve the certain conditions

By regulating, to make sure the conditions are around the right levels.

The body does not keep everything constant, what are the examples

• Glucose and temperature levels fluctuate. - only within small bounds

True or false our body do not have a automatic control systems

false - they do

How does the automatic control system work

• The body recognise a change from optimal conditions

• Then it sends a signal to reverse that change

• So the levels go back to normal

How many components do automatic control system have?

three

What are the three main component of automatic control systems and describe them.

• Receptors - detect a change

• Coordination centres - interpret the change, and decides what needs to be done

• Effectors - carry out the change

Give an example where receptor will detect a change

e.g. temperature

What are the coordination centres in the body

Brain and spinal cord

What are the two examples of effectors in the body

• Muscles

• Gland

Why do we need the nervous and endocrine system?

• The three components might be located in different parts of the body

• So, we need some way to send signals between them

What does the nervous system do?

• sends very fast and precise electrical impulses through nerves

• Allows us to respond quickly

Describe the Endocrine system

• Relies on hormones

• These hormones travel throughout the entire body

• And only affect certain cells

• Slower

• Long-lasting

• More generalised

What are hormones

small chemicals released into the bloodstream.

What makes hormones unique

Even though they travel throughout the entire body, they only affect certain cells that have the right receptors.

How does automatic control system work?

Negative feedback

Explain negative feedback

• whenever the levels of something gets too high

• Negative feedback acts to decrease it again

• If the level is too low negative feedback increases it again

describe negative feedback

Does the opposite of whatever the change was

Explain negative feedback when someone walks to a room that is really cold and then we get too hot. (6 marks like question)

• Low temperature is detected by receptors in our skin

• and the nervous system will then send impulses to coordination centres (brain and spinal cord).

• These interpret the information and send another set of signals to the effectors, our muscles

• The muscles can carry out shivering

• The shivering increase our body temperature.

• If we get too hot (a different set of) receptors would detect this rise in temperature and send their own signals to our coordination centres

• This would cause a different group of effectors to carry out their response which is sweating

• This decreases the temperature

• This happens in a loop