Ch 4: Cell Injury, Aging, and Death

What does healing depend on?

Where the injury takes place and how serious the injury is

What three kinds of cells help repair damaged tissue?

Fibroblasts, endothelial cells, and myofibroblasts

What do fibroblasts do?

Produce collagen and connective tissue

What does the collagen and connective tissue produced by fibroblasts do?

It helps provide strength and structure to the healing tissue

What do endothelial cells do?

Help form new blood vessels

Why are new blood vessels important for healing?

They bring oxygen and nutrients to the damaged tissue, which supports tissue repair

What do myofibroblasts do?

Contract and pull damaged tissue together

Where do myofibroblasts develop?

On the edge of a wound

How do myofibroblasts help close a wound?

When myofibroblasts contract, they pull the damaged tissue together, which helps close the wound

What is an exudate?

A fluid that leaks out of blood vessels and into the affected tissue during inflammation or injury

What can inflammatory exudate transport to the affected area?

leukocytes (WBCs), antibodies, and nutrients

How can exudate help with harmful substances?

The fluid can dilute harmful substances in the affected area

What does serous exudate look like?

Thin, Clear, and watery

Serous exudate has little ________ in it:

Protein

Which exudate is commonly seen during mild inflammation?

Serous exudate

The contents of a blister are an example of a _________ exudate:

Serous

Name this exudate:

Serous

What does serosanguineous exudate look like?

Serous exudate mixed with a little bit of blood

Name this exudate:

Serosanguineous

What does fibrinous exudate look like?

Sticky

Fibrinous exudate is __________ because it has more ________ than serous exudate:

Sticky; protein

Name this exudate:

Fibrinous

What kind of exudate is commonly found from bigger injuries?

Fibrinous exudate

What needs to happen to fibrinous exudate for the wound to heal?

The fibrinous exudate must be cleaned or removed

What does purulent exudate look like?

thick, yellowish/brownish pus

What is purulent exudate made of?

Neutrophils, protein, and tissue debris

Which exudate indicates a severe bacterial infection?

Purulent exudate

Name this exudate:

Purulent

What does hemorrhagic exudate look like?

Exudate with a large amount of blood

Which exudate occurs due to a severe leak or breakdown of blood vessels?

Hemorrhagic

Name this exudate:

Hemorrhagic

IgG antibody = ___________

General/Most common antibody

IgM antibody = ___________

First antibody made during a new infection

IgA antibody = ___________

Areas with secretions, found mainly in mucus, saliva, tears & breast milk

IgD antibody = ___________

B-cell development, found on B cells and helps with their activation

IgE antibody = ___________

Involved in allergic reactions and also helps defend against parasites/worms

Cells can swell, collect substances, shrink, get bigger, or increase in number when the body ______ or is under ______:

Changes; stress

What is hydropic swelling?

When a cell fills with too much water and swells up

Why does hydropic swelling happen?

When a cell gets injured and cannot properly control the amount of water inside it, too much water may enter and cause the cell to swell

What are intracellular accumulations?

When substances build up inside the cell that should not be there in large amounts

Fat building up inside of a cell is an example of ___________________:

Intracellular accumulation

What happens when too much fat builds up inside a cell?

An intracellular accumulation occurs and can injure the cell

What is atrophy?

When a cell shrinks and does not function as well

What two things can cause cell atrophy?

Disuse or ischemia

f you stop using your leg because it is in a cast, the muscles are not being used, so the muscle cells _________, which is called ________:

Shrink; atrophy

When a cell does not get enough _______ and ________, it can cause the cell to shrink, which is called __________:

Blood and oxygen; atrophy

Less work & not enough blood/oxygen = cells get _______

Smaller

What is hypertrophy?

An increase in cell mass

What happens to cells during hypertrophy?

They become larger

You lift weights which means your muscles have to work harder, this helps the muscle cells grow _______, which is called _________:

Larger; hypertrophy

If the heart has to work harder for a long time, its muscle cells can become ________, which is called ___________:

Larger; hypertrophy

More work/ heavy workload = cells get ________

Bigger

What is hyperplasia?

An increase in the number of cells

What happens during hyperplasia?

The body makes additional cells

How does hyperplasia happen?

Cells divide and make more cells

When your skin gets injured, your body needs ________ to repair the area, so cells divide and make more cells, which is called _______:

More cells; Hyperplasia

What is metaplasia?

A change in which one mature, differentiated cell type is replaced by another cell type

Why does metaplasia occur?

When the new cell type is better able to tolerate a chronic irritation or stressor

Is metaplasia reversible?

Yes

Long-term smoking can irritate the bronchial airways and cause the normal cells to change into a different type of cell that can better tolerate the irritation. This is called ________:

Metaplasia

What can happen to cells if the irritation causing metaplasia stops?

The cells may change back to their original cell type

What is dysplasia?

An abnormal and disorganized growth of cells

How can cells look during dysplasia?

The cells may vary in size, shape, and arrangement

Can mild dysplasia go away?

Yes

What can happen if severe dysplasia is untreated?

It can potentially progress toward cancer

Cervical _________ occurs when cells on the cervix begin to grow abnormally, causing the tissue to become disorganized:

Dysplasia

What is irreversible cell injury?

Irreversible cell injury is when a cell is damaged so severely that it cannot recover and will eventually die

What are the two types of irreversible cell injury?

Necrosis and apoptosis

What is necrosis?

Uncontrolled cell death

During necrosis, a cell gets damaged and dies ___________ usually die to a severe injury:

Unexpectedly

A blood vessel supplying the heart becomes blocked, therefore heart cells don’t receive enough _________. Eventually, the cell ______.

Oxygen; dies

What is apoptosis?

planned, programmed, controlled cell death

What happens during apoptosis?

The cell receives signals telling it that it should die in an organized way

During apoptosis, the cell breaks _______ down:

Itself

Why is apoptosis important?

It is a normal process that helps remove old, damaged, or unnecessary cells

Is necrosis controlled or uncontrolled?

Uncontrolled

Is apoptosis controlled or uncontrolled?

Controlled

What is ischemia?

not enough blood flow to a tissue

What is hypoxia?

not enough oxygen reaching the cells

Why do cells need oxygen?

to make ATP

What is a cells main source of energy?

ATP

Without enough oxygen, cells cannot make enough _______, which causes cell injury:

ATP

A blood vessel becomes blocked > _______ cannot reach the cells > the cells do not get enough _________ > cell injury:

Blood; oxygen

What is reperfusion?

When blood flow returns to an area after being blocked

Reperfusion injury occurs when resorting ____________ to an area after a blockage actually causes additional cell damage:

Blood flow

Infections like _______ and _______ can damage cells/ cause cell injury:

bacterial; viral

How do bacteria usually damage cells?

From outside

How can viruses damage cells?

From within by entering the cell and using the cell's machinery to reproduce inside the cell

Cells need the right amount of _________ to function properly. Cell injury can happen from not having enough, or having too much.

nutrients

What is immunologic injury?

when the immune system, which is supposed to protect the body, causes damage to the body's own cells

What is chemical injury?

When certain chemicals directly injure or kill cells

How can physical and mechanical forces cause cell injury?

Cells can be damaged by physical forces or trauma

What are examples of physical and mechanical injuries?

Cold, cuts, crushing, blows, electricity, and radiation

As we age, cells gradually become less able to _______, _________, and ____________:

Grow, repair themselves, and recover from damage

As we get older, cells become less able to ___________ (proliferate):

Reproduce

Throughout our life, cells have been exposed to ____________ that cause damage over time like sunlight and polluion:

Environmental factors

What is somatic death?

The death of the entire person or organism

Somatic death means the whole ______ has died:

Body

What is rigor mortis?

When the muscles become stiff after death

After death, the muscles can no longer properly produce/use ________ needed for normal muscle relaxation, so they become stiff and rigid.

Energy