Injury & necrosis

To injure good tissues you need
Mechanical forces and speed
Incise laceration
Contusion abrasion
Destroy and cause vessels to bleed.

Such lesions will swell and give pain
If they cut through a nerve you'll be lame
And when they're internal
Effects are infernal
Especially within the brain.

Temperatures high or too low
Bring cellular death fast or slow
Like incineration
Ice crystal formation
Frostbite can cost you a toe.

Chemical injury's widespread
Affects tissues from gut to head
Outside and in
Uremia and gin
It's a major cause cells become dead.

That is why we have kidneys and livers
They detoxify what blood delivers
With routines enzymatic
In milieu aquatic
Preventing pollution of "rivers".

Concerned with changes called lesions
Their size shape and color their regions
They give diagnosis
Determine prognosis
For tumors infarcts and adhesions.

Sunshine in excess is drastic
It damages tissues elastic
So the price of a tan
Is a wrinkled old man
With skin lesions that are neoplastic.

For injury from radiation
Your best bet is ionization
It's silent and clean
An agent unseen
Can't be beat when you need penetration.

Its effects are most often delayed
From cellular damage that's made
With vascular lesions
Serosal adhesions
The piper of course must be paid.

But the master of all that is toxic
Is the making of tissues hypoxic
And the main cause of death
As we reach our last breath
Is because we are cells now anoxic.

Tissues when injured may die
Necrosis the word we apply
May be soft or be firm
May be caused by a germ
Can be seen by the unaided eye.

When due to a decrease in flow
Of the blood too obstructed or slow
Infarction's the term
It is pale often firm
Seen in heart brain spleen kidney and toe.

Liquefactive necrosis confined
Has polys and cocci combined
Seeks a surface to drain
Abscess its name
In the skin you will most often find.

A particular type of necrosis
Looks like cheese with some white calcinosis
Such foci are found
In the lung and are round
They are typically tuberculosis.