HOMEOSTASIS

Why is it important to maintain blood glucose

If blood glucose conc is too high then water potential of blood = reducedso water molecules diffuse out of cells and into blood by osmosis. This causes the cells to shrivel up and die. If glucose is too low cells= unable to carry out normal activities as theere isnt enough glucose for respiration to provide energy.

what isnt possitive feedback involved in and why

homeostasis because it doesnt keep your internal environment constant

What is the optimum PH

usually 7 but in the stomach its lower

When else can possitive feedback occur

when a homeostatic system breaks down

What is homeostasis

The process by which organisms maintain a relatively stable internal environment.

what do possitive feedback mechanisms do

amplify a change from the normal level, some changes trigger a p. feedback

What does homeostasis involve

control systems that keep your internal environment roughly constant with certain limits

What do homeostatic Systems do

detect a change and respond by negative feedback

What do multiple negative feeback mechanisms do

give more control

Hypethermia and possitive feedback

heat is lost quicker than it can be produced as temp falls brain doesnt work so shiverong stopscausing temp to fall further possitive feedback occurs and takes level further away from the normal level and continues to decrease unless action is taken.

Why is it important to maintain blood PH

if blood ph is too high or low enzymes become dennatured. The H bonds are effected and the 3D shape is changed changing the shape of the active site meaning the enzyme no longer works as a catalyst. Therefore metabollic reactions are less efficient.

Why is it important to maintain body temp

if temp becomes to high enzymes become dennatured. Enzymes molecules vibrate too much and the H bonds that hold their 3D shape break changing the shape of the active site so enzyme can no longer work as a catalyst. Therefore metabollic reactions are less efficient.

What does the homeostatic system involve

receptors a coomunication system and effectors

What are the three key things that are important to maintain

temperature ph and glucose

How does a possitive feedback work

the effector responds to further increase the level away from the normal level

What is negative feedback

the mechanism that restores the level to normal receptors detect whether the levels of something are too high the nervous system or hormonal system send info to the effectors and the effectors respond to counteract the change

Why have multiple negative feedback mechanisms

to actively increase or decrease a level so it returns to normal

Why does homeostasis involve multiple negative feedback mechanisms

to control each thing because more than one mechanism gives more control over the changes in the internal environment

Why is it vital to keep your internal evironment constant

to keep cells functioning normally and to prevent damage

what is possitive feedback useful for

to rapidly activate something e.g a blood clot after an injury

Where does negative feedback work

within certain limits if the change is too big the effectors wont be able to counteract it

What would happen if you only had one negativive feeback mechanism

you could only turn it on or off youd only be able to change a level in one direction so it returns to normal it gives a slower response and less control