HOMEOSTASIS

Homeostasis:

• Maintaining stable internal conditions within an organism.

• Process by which an organism maintains a constant internal environment despite changing external conditions.

• Constant adjustment to change in the environment.

HYPOTHALAMUS

• The hypothalamus is the part of the brain that controls many body functions.

• The main function of the hypothalamus is homeostasis.

• The hypothalamus controls such things as body temperature & blood pressure,

SWEAT GLANDS

• Sweating is the primary way we lose body heat.

• When sweat evaporates from your skin, you lose heat & cool down.

HAIR & FEATHERS

Life on earth exists within a narrow range of temperature which is stabilized by the unique properties of water within the bodies of organisms.

Birds and mammals are endothermic (maintain a constant internal temperature)

HAIR & FEATHERS

• Feathers trap warm air acting as excellent insulators.

• Hair is a good insulator.

• Insulating fat (blubber) beneath the epidermis in mammals acts as an insulator.

BLOOD

• Blood is the medium by which necessary materials are delivered to cells.

• Blood carries glucose and oxygen.

• Hormones, such as insulin, are released to regulate the amounts of certain substances in the blood.

LIVER

• The liver regulates the amount of glucose in the blood.

• If the level of glucose is too high, the liver will store it as glycogen.

• If the level of glucose is too low, the liver will break down some of the glycogen to release glucose into the blood.

KIDNEYS

• The kidney is the organ most responsible for maintaining water balance in the body.

• The kidney can excrete any substance in excess from the body.

GREEN PLANTS

• Green plants maintain homeostasis of gases and water through structures called stomata.

• The stomata open to allow an exchange of carbon dioxide and oxygen.

• Water balance is also controlled through the stomata.

PARAMECIA

• Paramecia and other single-celled organisms (protozoa) have a contractile vacuole.

• This structure functions to pump excess water out of their cells so these organisms do not gain too much water.

SEA TURTLE

• Sea turtles shed tears to remove salt.

• Living in a salt water environment puts sea turtles in danger of losing water.

• Sea turtles have salt glands in the corner of their eyes that excrete excess salt out of their bodies.

KANGAROO RAT

• Kangaroo rats are small seed-eating rodents that live in arid climates.

• Kangaroo rats have the ability to obtain water internally from the dry, starchy seeds they eat.

HONEY BEES

• Honey bees are social insects.

• Honey bees maintain a constant warm temperature by huddling in a large group.

• Periodically, the bees switch places, with the inner most bees moving to the outside and rest moving inward.

TERMITES

• Termites also are social insects.

• Chemicals called pheromones influence the behavior of these insects.

• A termite may have one of the following roles within the hive: worker, soldier, or reproductive.

• At birth, diet and pheromones play a part in which role the termite will have.

TERMITES

• If there are too many soldiers and not enough workers, pheromones will be released to produce more workers and less soldiers.

• The pheromones basically affect the numbers and kinds of individuals in the nest.

IN SUMMARY:

• Homeostasis is a vital process among living things.

• It allows living things to adjust and maintain a constant internal environment despite the changing external environment.

• Living organisms cannot tolerate significant alterations in their environments.

• Homeostasis allows organisms to adjust to short term changes which happen continuously.