Page 9 - 84 human physiolofy part-1

Homeostasis

Skeletal System

The skeletal system serves as an important mineral reserve. For example, if blood levels of calcium
or magnesium are low and the minerals are not available in the diet, they will be taken from the bones.
On the other hand the skeletal system provides Calcium needed for all muscle contractions.
Lymphocytes and other cells relating to the immune response are produced and stored in the bone
marrow. The skeletal system aids in protection of the nervous system, endocrine organs, chest and
pelvic regions - all of these are vital organs.

Muscular System

The muscular system is largely responsible for maintaining body temperature through heat
production. It also contributes to blood glucose balance by storing energy as glycogen. Indirectly it
contributes to the well-being of the organism by simply allowing a person to move about (to find and
consume food, find shelter from weather extremes, etc.) by having our skin intact to muscles help us
with our facial expressions. In the nervous system it helps monitor body position. Muscles provide us
with protecting our endocrine glands and digestive organs. They also contol contractions during sex
producing sensations, and controls muscles that allow you to hold your urine when you are thousands
of miles away from the nearest bathroom or without toilet paper. Muscles also aid in moving blood
through veins, protect deep blood vessels and help the lymphatic system move lymph.

Cardiovascular System

The cardiovascular system, in addition to needing to maintain itself within certain levels, plays a
role in maintenance of other body systems by transporting hormones (heart secretes ANP and BNP)
and nutrients (oxygen, EPO to bones,etc.), taking away waste products, and providing all living body
cells with a fresh supply of oxygen and removing carbon dioxide. Homeostasis is disturbed if the
cardiovascular or lymphatic systems are not functioning correctly. Our skin, bones, muscles, nervous
system, endocrine, lymphatic system, lungs, digestive tract, urinary system and reproductive use the
cardiovascular system as its "road" or "highway" as far as distribution of things that go on in our body.
There are many risk factors for an unhealthy cardiovascular system. Some diseases associated are
typically labeled "uncontrollable" or "controllable." The main uncontrollable risk factors are age,
gender, and a family history of heart disease, especially at an early age.

Lymphatic System

The lymphatic system has three principal roles. First is the maintenance of blood and tissue
volume. Excess fluid that leaves the capillaries when under pressure would build up and cause edema.
Secondly, the lymphatic system absorbs fatty acids and triglycerides from fat digestion so that these
components of digestion do not enter directly into the blood stream. Third, the lymphatic system is
involved in defending the body against invading microbes, and the immune response. This system
assists in maintenance such as bone repair after injuries and muscle repair after an injury. Another
defense is maintaining the acid pH of urine to fight infections in the urinary system. The tonsils are our
bodies helpers to defend us against infections and toxins absorbed from the digestive tract. The tonsils
also protect against infections entering into our lungs.

Wikibooks | 9