HOMEOSTASIS TO MAINTAIN AN INTERNAL BALANCE ALL LIVING

HOMEOSTASIS TO MAINTAIN AN INTERNAL BALANCE

ALL LIVING THINGS MUST MAINTAIN HOMEOSTASIS. IMPORTANT VARIABLES WITHIN THE BODY: �BLOOD SUGAR �FLUID BALANCE �BODY TEMPERATURE �OXYGEN LEVELS �BLOOD PRESSURE � PH • THESE VARIABLES MUST STAY WITHIN CERTAIN RANGES OR CELLS/ORGANISMS COULD DIE. • CHANGES IN THE EXTERNAL ENVIRONMENT CAN CAUSE THESE VARIABLES

ALL LIVING THINGS MUST MAINTAIN HOMEOSTASIS • REMEMBER THAT ALL LIVING THINGS ARE MADE UP OF CELLS. • CELLS MUST ALSO MAINTAIN HOMEOSTASIS • CELL MEMBRANES ALLOW SUBSTANCES TO MOVE IN AND OUT OF THE CELL

RALLY ROBIN • GO BACK AND FORTH LISTING 6 THINGS (3 THINGS EACH) YOUR BODY NEEDS TO KEEP AT AN INTERNAL BALANCE • PERSON WITH LONGEST HAIR START

NEGATIVE FEEDBACK • NEGATIVE FEEDBACK: • RESPONSE TRIGGERED BY CHANGED CONDITIONS. • SERVES TO REVERSE THE CHANGE • EXAMPLE: BODY TEMPERATURE INCREASES SKIN BLOOD VESSELS DILATE BODY TEMPERATURE DECREASES

HUMAN BODY SYSTEMS INVOLVED IN HOMEOSTASIS • THE SKIN, KIDNEYS, LIVER, ENDOCRINE SYSTEM, NERVOUS SYSTEM AND SENSORY SYSTEM ALL PLAY A PART IN MAINTAINING THE INTERNAL ENVIRONMENT WITHIN NARROW LIMITS

SHOULDER PARTNER A • EXPLAIN THE PURPOSE OF A NEGATIVE FEEDBACK SHOULDER PARTNER B GIVE AN EXAMPLE OF A NEGATIVE FEEDBACK IN THE HUMAN BODY

WHY IS BODY TEMPERATURE IMPORTANT? • MANY METABOLIC REACTIONS ARE INFLUENCED BY TEMPERATURE. • ESSENTIAL LIFE FUNCTIONS CAN BE CARRIED OUT MOST EFFICIENTLY WHEN AN ANIMAL’S INTERNAL BODY TEMPERATURE IS WITHIN A CERTAIN RANGE. • HUMAN’S NORMAL BODY TEMPERATURE IS 98. 6 OF OR 37 C O • PROTEINS DO NOT WORK RIGHT OUTSIDE OF NORMAL BODY TEMPERATURE. • WHAT OUR BODY DOES: • SWEATING AND DILATING BLOOD VESSEL.

KIDNEYS • GET RID OF WASTE (UREA AND OTHER SUBSTANCES) • MAINTAIN STABLE AMOUNTS OF WATER IN YOUR BODY. • EXCRETE EXCESS WATER • RETAIN NEEDED WATER

BLOOD SUGAR LEVELS • INSULIN AND GLUCAGON HELP KEEP THE LEVEL OF GLUCOSE IN THE BLOOD STABLE. • WHEN YOU EAT: • BLOOD GLUCOSE LEVELS INCREASE • THE PANCREAS RELEASES INSULIN. • THIS TELLS CELLS TO TAKE GLUCOSE OUT OF THE BLOODSTREAM • TELLS THE LIVER TO STORE IT AS GLYCOGEN AND SKELETAL MUSCLE AS LIPIDS IN FAT TISSUE. • TOO MUCH OR TOO LITTLE GLUCOSE IN THE BLOOD CAN BE DANGEROUS

POSITIVE FEEDBACK • POSITIVE FEEDBACK: THE RESPONSE TRIGGERED BY CHANGING CONDITIONS SERVES TO CONTINUE MOVING THE VARIABLE EVEN FURTHER AWAY FROM ITS STEADY STATE • EXAMPLE: UTERINE CONTRACTIONS ARE STIMULATED BY OXYTOCIN BABY MOVES TOWARDS CERVIX MORE OXYTOCIN IS RELEASED

• AMOEBA SISTERS HOMEOSTASIS