Cellular Adaptation Chapter 3 Flashcards

Questions and Answers

What responses can occur when there is cellular stress?

Adapt or die

What are 5 types of cellular adaptation?

Atrophy, hypertrophy, hyperplasia, dysplasia, metaplasia

What is atrophy?

Decrease in cell size

When does physiologic atrophy occur?

Early development Signup and view all the answers

Give an example of physiologic atrophy.

Thymus - decrease in size as age increases (during childhood) Signup and view all the answers

When does pathologic atrophy occur?

Disuse, lack of nerve stimulation, loss of endocrine stimulation, inadequate nutrition, ischemia Signup and view all the answers

What is hypertrophy?

Cell size increases because workload demand increases Signup and view all the answers

What are two triggers for hypertrophy?

Mechanical signals, trophic signals Signup and view all the answers

Give an example of physiologic hypertrophy.

Increase in exercise, increase in growth of uterus and mammary glands during pregnancy Signup and view all the answers

Give 2 examples of pathologic hypertrophy.

One leg increases in size due to a break in the other leg, kidney taking on larger workload due to loss of another kidney Signup and view all the answers

What is hyperplasia?

Excessive growth or proliferation, increase in number of cells Signup and view all the answers

Give an example of physiologic hormonal hyperplasia.

Uterus during pregnancy, mammary glands and endometrium thickening Signup and view all the answers

Give an example of physiologic compensatory hyperplasia.

Organ regeneration (liver), callus of skin Signup and view all the answers

What is pathologic hyperplasia?

Abnormal proliferation of normal cells, increases chance of cancer Signup and view all the answers

What triggers pathologic hyperplasia?

Excessive hormone stimulation, effects of growth factors Signup and view all the answers

Give an example of pathologic hyperplasia.

Endometriosis Signup and view all the answers

What is dysplasia?

Abnormal changes in the size, shape, and organization of cells, increases chance of cancer Signup and view all the answers

Where does dysplasia often occur?

Cervix and respiratory tract Signup and view all the answers

What is an example of pathologic dysplasia?

Cells of cervix becoming abnormal due to a virus Signup and view all the answers

What is metaplasia?

Reversible replacement of one mature cell for another Signup and view all the answers

Give an example of metaplasia.

Chronic irritation due to smoking leading to replacement of cells Signup and view all the answers

What are the causes of cell injury?

Hypoxic injury, free radicals, chemicals, radiation, physical injury, nutritional imbalances, genetic abnormalities, biologic agents Signup and view all the answers

What is hypoxia?

Lack of oxygen to cells Signup and view all the answers

What is ischemia?

Reduced blood supply Signup and view all the answers

What is a free radical?

Electrically uncharged atom or group of atoms having an unpaired electron that damages DNA Signup and view all the answers

What are some examples of chemical cellular injury?

Medications, lead, carbon monoxide, ethanol, mercury Signup and view all the answers

What are some examples of radiation cellular injury?

UV radiation, ionizing radiation, non-ionizing radiation Signup and view all the answers

What is hypothermia?

Drop in core temperature Signup and view all the answers

What is hyperthermia?

Elevated body temperature Signup and view all the answers

What is a contusion?

(Bruising) bleeding into the skin or tissues Signup and view all the answers

What is a hematoma?

Collection of blood in a confined space Signup and view all the answers

What is an abrasion?

Superficial layer of skin removed due to friction Signup and view all the answers

What is a laceration?

Tearing or ripping of skin (jagged wound) Signup and view all the answers

What is an incised sharp injury?

Longer on surface than deep Signup and view all the answers

What is a stab wound?

Deeper than longer Signup and view all the answers

What is a puncture wound?

Sharp points but without sharp edges Signup and view all the answers

Study Notes

Cellular Stress and Adaptation

Responses to cellular stress can lead to adaptation or cell death.
Five types of cellular adaptation: atrophy, hypertrophy, hyperplasia, dysplasia, and metaplasia.

Atrophy

Atrophy is characterized by a decrease in cell size.
Physiologic atrophy occurs during early development.
Example: Thymus reduction in size with age during childhood.
Pathologic atrophy is caused by:
- Disuse of organs or tissues.
- Lack of nerve stimulation.
- Loss of endocrine stimulation (e.g., vagina, uterus, gonads).
- Inadequate nutrition.
- Ischemia (decreased blood flow).

Hypertrophy

Hypertrophy involves an increase in cell size due to increased workload demand.
Two main triggers for hypertrophy:
- Mechanical signals.
- Trophic signals (growth factors, hormones, vasoactive agents).
Physiologic hypertrophy examples:
- Increased muscle mass from exercise.
- Growth of uterus and mammary glands during pregnancy.
Pathologic hypertrophy can occur when:
- A limb is immobilized, causing compensatory growth in the non-injured limb.
- A kidney takes on more workload after the loss of another kidney.

Hyperplasia

Hyperplasia is the excessive proliferation of cells, resulting in an increased number of cells.
Physiologic hormonal hyperplasia: uterus during pregnancy and thickening of mammary glands and endometrium.
Physiologic compensatory hyperplasia: liver regeneration and skin calluses.
Pathologic hyperplasia is the abnormal growth of normal cells, increasing the risk of cancer. Triggers include:
- Excessive hormone stimulation.
- Effects of growth factors.
Example of pathologic hyperplasia: endometriosis.

Dysplasia

Dysplasia involves abnormal changes in cell size, shape, and organization, with an increased cancer risk, though it can revert to normal.
Commonly occurs in the cervix and respiratory tract.
Pathologic dysplasia example: cervical cells becoming abnormal due to viral infection.

Metaplasia

Metaplasia is the reversible replacement of one mature cell type by another.
Example of metaplasia: Chronic irritation from smoking leading to the replacement of mucus-producing cells with non-mucus-producing cells. This can be reversed if smoking is stopped.

Cell Injury and Causes

Causes of cell injury include:
- Hypoxic injury (most common, usually due to ischemia).
- Free radicals.
- Chemicals (e.g., medications, lead, carbon monoxide).
- Radiation (UV, ionizing, non-ionizing).
- Physical injury and nutritional imbalances.
- Genetic abnormalities.
- Biological agents (e.g., bacteria).
Hypoxia refers to a lack of oxygen to cells.
Ischemia indicates reduced blood supply.

Free Radicals and Chemical Injury

Free radicals are uncharged atoms or groups with unpaired electrons, causing cellular damage by stealing electrons from neighboring atoms.
Examples of chemical cellular injury:
- Medications like Tylenol.
- Lead (especially harmful to children).
- Carbon monoxide, ethanol (alcohol), and mercury.

Radiation and Physical Injuries

Examples of radiation cellular injury:
- UV (sun exposure, tanning beds).
- Ionizing (x-rays, CT scans).
- Non-ionizing (microwaves, cell phones).
Types of physical injuries include:
- Contusion: bruising with bleeding into skin or tissues.
- Hematoma: collection of blood in a confined space (e.g., brain).
- Abrasion: removal of the superficial layer of skin due to friction.
- Laceration: tearing or ripping of skin, resulting in jagged wounds.
- Incised wound: longer on the surface than deep.
- Stab wound: deeper relative to length on the surface.
- Puncture wound: sharp points without sharp edges (such as nails).

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Test your knowledge on cellular adaptation concepts with these flashcards. Covering types of adaptations like atrophy and hypertrophy, this quiz provides a quick review of critical cellular responses to stress. Perfect for students studying cellular biology.