Organ Systems Working Together
Name: ____________________________
As the world changes around you, your body must respond to those changes to continue to function
properly. Your body also has a range of chemical and physical conditions in which it can function
properly
For example:
blood pH, O2 level, body temperature, glucose level.
When the conditions within your body are in the appropriate ranges, it is in its steady-state
(or equilibrium
).
HOMEOSTASIS: keeping the body’s conditions within their acceptable range
Each body system can be activated independently or working with other systems to help maintain
this steady-state. They are interdependent systems.
Some strongly interdependent systems include:
1. Circulatory and Respiratory System: Supply the body with Oxygen
•
Circulatory system moves blood through the body providing O2 to cells and
carrying away CO2
•
Respiratory system supplies the blood with O2 and gets rid of CO2
•
connection is between alveoli and capillaries
• The body responds to changes in the steady state (e.g. exertion) by
 Heart rate changes to pump more or less oxygen to the cells
 Respiration rate changes to bring more oxygen into the lungs
2. Circulatory and Digestive System: Supply body with Glucose, minerals, vitamins
•
Circulatory system moves blood through the body providing glucose to cells
•
Digestive system supplies the blood with glucose
•
connection is through the villi and capillaries
• The body responds to changes in the steady state by
 Heart rate changes to pump more or less glucose to the cells
 More or less sugar is release into the blood so it can be taken to the cells
3. Integumentary and skeletal systems: Help bone growth

Sunlight on skin causes chemical reactions that produce vitamin D

Vitamin D carried to bones (circulatory)

Vitamin D helps bones absorb calcium (from digestive system)
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Organs and Systems working together to maintain Homeostasis
Body Temperature Homeostasis
•
Body temperature must be maintained within a few degrees of the normal 37C
•
Heat in the body is generated by cellular respiration
• hypothalamus (endocrine system - in brain) monitors body temperature and
regulates by changing the rate of cellular respiration reactions in skin
(integumentary).
• If the body becomes too hot
 blood vessels near skin dilate (open up), allows more heat loss from the
blood (circulatory)
 perspiration from the skin causes evaporative cooling
• When cold
 shivering uses rapid muscle action to produce heat
 blood vessels contract, less surface to lose heat
Glucose Level in Blood
•
When glucose levels are too high in the blood, a hormone called insulin is secreted by
the pancreas
(endocrine). Insulin stimulates the absorption of glucose by cells
•
causes liver’s conversion of glucose into glycogen
•
If glucose levels are too low, hormone called glucagon
causes the liver to convert glycogen back to glucose.
(stored form of glucose)
is produced, which in turn
Lactates in Muscles (tells you to stop exertion)
• When working hard, one of the chemical reactions that release energy produces
a chemical called lactate which builds up in the muscle.
• Lactates can cause muscle fatigue and pain, which triggers a signal from your muscles to your
brain to stop the exercise and allow more oxygen to reach the muscles.
• Once the exercise stops, lactates are carried away from muscles to the liver, and pain stops.
pH level (7.2 – 7.6
)
• regulated by lungs which controls amount of CO2 leaving blood (affects reactions of acids)
• kidneys get rid of excess acids or bases through urine
Water and mineral minerals: controlled by kidneys
Most of these organs are controlled by hormones secreted from the pituitary
gland
, which
in turn is directed by the hypothalamus.
Homework: Read Section 2.3, Do Learning Checkpoint # 1 – 5 p. 83, and # 4, 6, 9, 15 p. 86
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