HomeostasisFever & Vomiting

Eeeeewwww, gross!!!!!

Is it ever good to feel bad? 2.5

Homeostasis

• Everyone has been sick before

• In your lab-book: write about one particular instance where you were (or became) sick/ill

• Why does this memory stand out?

• Although it may not seem like it, these two body responses are normal, healthy and useful!

• Fever and vomiting are your body’s response to certain internal stimuli

• Your body is trying to maintain homeostasis.

• Homeostasis is the maintenance of a stable internal environment… (BALANCE / EQUILIBRIUM)

• Hunger, thirst, sweating, shivering are other examples.

Fever and Vomiting: Why o Why???

• You may call it something else: throw-up, barf, upchuck, hurl, puke... But the actual term is emesis.

• Whatever you call it, it’s all the same: a mix of soggy, half-digested food along with stomach mucus, saliva, stomach acids and other materials.

What is vomit???

• There are many reasons, including: food poisoning, illness, feeling scared or nervous, eating too much, pregnancy, and motion sickness are a few.

• Whatever the reason, warning signals are sent to a part of your brain (called the emetic center). The brain tells your body to quickly get rid of whatever is upsetting you… and you vomit.

Why do we vomit???

• Normally the muscles in your throat and stomach work to move food down and through your digestive system, but when you’re sick…

• the muscles of your stomach and throat work in reverse, pushing food back towards the mouth to get rid of it

How does it happen???

• Even though it’s pretty gross and smelly, most people feel much better after vomiting.

• If you’re lucky, most of the bad stuff is gone, and your body can go back to normal.

After we vomit???

• When the body temperature rises above normal (98.6o F), you have a fever.

• In the very center of your brain is the hypothalamus. It is like a thermostat, constantly working to maintain your correct body temperature.

What is a fever???

•Teacher Domain Body Control Center

Body Heat Regulation

• Many things can cause your temperature to rise. Many times fevers occur when your body’s immune response is triggered by pyrogens (fever-producing substances).

• Sources of pyrogens can include: viruses, bacteria, fungi, drugs, toxins

• Examples include: cold, flu, ear infections, etc.

Why do we get a fever???

• When the body senses pyrogens, the hypothalamus raises the body temperature on purpose.

• Shivering may also occur- the muscle action produces more heat.

• The extra heat often weakens or destroys the pyrogens.

• Fever video clip from teachers domain

How does a fever happen???

• Up to 100.8o F- low grade fever

• Between 101o F and 102o F- mild fever

• Between 102o F and 103o F- moderate fever

• Anything above 104o F- high fever

• High fevers for extended time periods can cause brain damage and other problems

How hot can it get???

• Once the fever-producing agents are gone, the hypothalamus will reset your body temperature back to normal.

• When your fever “breaks”, you may start to feel warm and you may sweat. Don’t worry, these are signs that things are returning to normal.

After a fever???

• You may feel lousy, but your body is trying to help.

• Stimuli are things that cause an organism to perform an activity or to change in some way.

• Fever and vomiting are reactions- things that occur in response to stimuli

Fever and Vomiting: Why o Why???