Shrinking?

[Count]

I recently brought up in my class that as people grow older, they become slightly shorter. My friends all challenged it, and due to sheer numbers, I gave up. The main argument they put up was that a science textbook defined growth as the "irreversible increase in size of an organism".

However, was I right or wrong? If I was right, can you please give me a link to some "official" website that says so (like perhaps Britannica or something), so that I can print it out, and go nyah nyah nyah nyah nyah in their face? j/k

Thanks in advance,
Count

[InfiniteNow]

You are correct.

Senior Citizens Do Shrink – Just One of the Body Changes of Aging

As we age, we experience decreases in everything from hair and hearing to memory and muscle. Height is also on the list. Starting at about age 40, people typically lose about half an inch each decade, with some faster shrinkage after age 70. Senior citizens may shrink as much as three inches.

The above information was taken from the December 2005 issue of the Harvard Health Letter.

Standing tall | Harvard Health Publications

Why most people lose height as they age, and ways to prevent this process.

MedlinePlus Medical Encyclopedia: Aging changes in the bones - muscles - joints

AGING CHANGES

Bone mass or density is lost as people age, especially in women after menopause. The bones lose calcium and other minerals.

The spine is made up of bones called vertebrae. Between each bone is a gel-like cushion (intervertebral disk). The trunk becomes shorter as the disks gradually lose fluid and become thinner.

In addition, vertebrae lose some of their mineral content, making each bone thinner. The spinal column becomes curved and compressed (packed together). Bone spurs, caused by aging and overall use of the spine, may also form on the vertebrae.

The shoulder blades (scapulae) and other bones may become porous - on an x-ray they may look "moth-eaten." The foot arches become less pronounced, contributing to slight loss of height.

The long bones of the arms and legs, although more brittle because of mineral losses, do not change length. This makes the arms and legs look longer when compared to the shortened trunk.

The joints become stiffer and less flexible. Fluid in the joints may decrease, and the cartilage may begin to rub together and erode. Minerals may deposit in some joints (calcification). This is common in the shoulder.

Hip and knee joints may begin to lose structure (degenerative changes). The finger joints lose cartilage and the bones thicken slightly. Finger joint changes are more common in women and may be hereditary.

Some joints, such as the ankle, typically experience little change with aging.

Lean body mass decreases, caused in part by loss of muscle tissue (atrophy). The rate and extent of muscle changes seems to be genetically determined. Muscle changes often begin in the 20s in men and the 40s in women.

Lipofuscin (an age-related pigment) and fat are deposited in muscle tissue. The muscle fibers shrink. Muscle tissue is replaced more slowly, and lost muscle tissue may be replaced with a tough fibrous tissue. This is most noticeable in the hands, which may appear thin and bony.

Muscle tissue changes, combined with normal aging changes in the nervous system, cause muscles to have reduced tone and contractility. Muscles may become rigid with age and may lose tone even if exercised regularly.

EFFECT OF CHANGES

Bones become more brittle and may break more easily. Height decreases, primarily caused by shortening of the trunk and spine.

Inflammation, pain, stiffness and deformity may result from breakdown of the joint structures. Almost all elderly people are affected by joint changes, ranging from minor stiffness to severe arthritis.

The posture may become progressively stooped (bent) and the knees and hips more flexed. The neck may become tilted, and the shoulders may narrow while the pelvis, on the other hand, may become wider.

Movement slows and may become limited. The walking pattern (gait) becomes slower and shorter. Walking may become unsteady, and there is less arm swinging. Fatigue occurs more readily, and overall energy may be reduced.

Strength and endurance change. Loss of muscle mass reduces strength. However, endurance may be enhanced by changes in the muscle fibers. Aging athletes with healthy hearts and lungs may find that performance improves in events that require endurance, and decreases slightly in events that require short bursts of high-speed performance.

[Count]

Thanks a lot!

Now all I need to do is print i out...