HomeostasisGwen, Sarita, Tommy, and Joe

HomeostasisHomeostasis is your bodies ability to maintain

internal conditions in the body.The two most important systems in maintaining

homeostasis are the nervous and the endocrine systems.

Homeostasis In The Body

Digestive System

Digestive SystemThe digestive system

contributes to homeostasis by regulating the intake of

nutrients, breaking down food particles, and absorbing them

into the cells. It also helps regulate the water intake.

Digestive System

• Matter moves into the body and continues down a chain of organs that break down food completely before it leaves the body.

• Helpful bacteria also are used to maintain homeostasis in the digestive system.– These bacteria aid in digestion, to help

produce vitamins, help formulate waste matter, and guard against harmful bacteria.

How it Regulates Nutrients

Digestion involves mixing food with juices moving it through the

digestive tract and breaking it down into smaller ones. Digestion begins in

the mouth when you chew and swallow, and is completed in the

smaller intestine.

Endocrine System

Endocrine SystemMany endocrine glands are connected to

nervous system control centers by homeostatic feedback mechanisms. The two types of feedback mechanisms are

negative and positive feedback. Negative feedback decreases the

difference from an ideal normal value, so it’s important in maintaining

homeostasis. Almost all of the endocrine glands are under control of negative

feedback mechanisms.

Negative Feedback

Negative mechanisms are like a thermostat. When the temperature rises (difference from the ideal normal level), the thermostat senses the change and triggers the air conditioning to

cool the house. When the temperature reaches its thermostat setting (ideal normal

value), the AC turns off again.

Negative FeedbackSomething like this also occurs in your body. An example of

negative feedback is the control of the blood calcium level. Parathyroid glands produce parathyroid hormone, which is what regulates the blood calcium amount. If the

calcium decreases, the parathyroid glands detect the decrease and secrete more parathyroid hormone. This

hormone stimulates calcium release from the bones while increasing the calcium uptake into the bloodstream from the collecting tubules found in the kidneys. On the other hand, if the blood calcium amount increases too much,

the parathyroid glands reduce hormone production. Both of these responses are examples of negative feedback

because the effects are negative (opposite to the stimulus) in both cases.

Positive FeedbackPositive feedback mechanisms control events

in the body that can be out of control and don’t require constant adjustment. In positive mechanisms, the initial stimulus is promoted

rather than neglected. Positive feedback is rarely used to maintain homeostasis, because

it increases the difference from the ideal normal level instead of keeping it the same.

Positive Feedback

An example of positive feedback is in childbirth, when the body needs to produce more

hormones than usual.

Urinary System

Urinary SystemThe urinary organs include the kidneys,

ureters, bladder, and urethra. The urinary system works with the organs to maintain homeostasis, but the main organs are the

kidneys. Because they are the main organs, they maintain acid balance and salt water

balance in the blood.

Urinary System

The urinary system contains the kidneys, which are the organs of homeostasis mostly because they control the electrolyte balance

in the blood, water retention in the body, and that they also play a role in maintaining blood

pressure.