Altered Tissue and Cellular Proliferation (RRD #2)

What are some examples of types or causes of injury to a cell?

ischemia / hypoxia, carbon monoxide poisoning, free radicals, abnormal cellular accumulations such as uric acids and fats, abnormal cellular proliferations (cancer), etc.

What is apoptosis?

A form of normal programmed cell death or cell suicide.

What is necrosis?

Abnormal cell death. Occurs when injurous changes are irreversible. Synonym: infarction.

What happens when a cell experiences an injury?

1.) Inflammation, with various degrees of cell swelling and cellular leakiness, depending on the severity of the injury.

2.) Some level of disruption to the metabolic pathway, again, depending on the severity of injury.

What is creatine kinase (CK)?

An enzyme found in most muscle cells (including the heart) that catalyzes transference of phosphate groups back and forth between ADP and ATP.

What is myoglobin?

A type of protein found in most muscle cells.

What is troponin?

A type of protein molecule found only in heart muscle.

What is ischemia?

Oxygen deprivation to cells (which experience hypoxia) due to a decrease or interruption of arterial circulation to the area.

There are many etiologies for hypoxia of tissue: anemia, lung diseases, etc, but ischemia due to narrowed or blocked arteries is most common.

What causes acute ischemia?

Hypoxia to tissues from sudden lack or diminishment of blood supply due to an arterial embolus or sickle cell crisis.

What causes chronic ischemia?

A gradual ischemia from a gradual narrowing of arteries due to atherosclerosis or a slow-developing clot (thrombus) in an artery.

What is hypoxia?

Cellular oxygen deprivation. Remember: hypoxia of tissue leads to tissue death / necrosis / infarction.

Why is carbon monoxide dangerous?

CO has a high affinity for hemoglobin and will "bump off" the oxygen that should bind there. When carboxyhemoglobin forms and travels to the tissues, the tissues will be hypoxic because less oxygen has been carried to the tissue.

What symptoms would you expect to see in carbon monoxide poisoning?

Initial symptoms would be related to the central nervous system: headache, giddiness, confusion, seizures, coma and depends on the % of HgCO in the body.

Treat them with 100% O2 by oxygen mask and / or hyperbaric chamber until the HgCO levels come down to normal.

What is gout?

A systemic disease caused by the buildup of uric acid in the blood (hyperuricemia).

Where do free-radicals come from?

Aging, environmental pollutants, certain drugs and alcohol abuse, radiation exposure / damage, foods that are high in preservatives / charred meats.

What is superoxide?

A free radical that is created in our own body during the especially rapid redox reactions of the electron transport chain.

How do we counteract free-radicals?

Using certain vitamins: C & E

Specialized enzymes created by the body: superoxide dismutase

What is cellular proliferation?

The multiplication or reproduction of cells, resulting in a rapid expansion of a cell population. This is a part of normal growth and development of cells.

What is a tumor?

An abnormal mass of tissue. Synonym: neoplasm

Tumors may be benign (non-cancerous) or malignant (cancerous).

What are characteristics of benign tumors?

slow growing

area of growth well encapsulated and non-metastasizing

cells in the tumor are fairly well differentiated and closly resemble the tissure they arose from.

What are characteristics of malignant tumors?

very rapid growth rate of cells that are poorly differentiated

may be specific to one location or spread to distant sites

some cancers are by nature wide-spread (leukemia)

What are the etiologies of cancer?

normal aging / wear & tear of cells

heredity (ie. certain types of breast cancers run in families)

environment / lifestyle choices

invading organisms (ie. viruses)

What is an oncogene?

A genetic mutation that sets cancer into motion.

What is clonal proliferation?

A rapid increase in the growth and development of cells. This includes:

wild, rapid duplication with no differentiation (anaplasia)

no normal "braking signals" to stop the replication process

creation of a blood supply for the tumor (angiogenesis)

What are tumor markers?

Substances in the body produced by cancer cells or released by cancer-damaged tissue that can be found in blood, spinal fluid, or urine. It may be a hormone, enzyme, antigen, antibody, or gene.

What are genetic markers?

Genetic abnormalities that are found in some people that prediuct the odds of having certain types of cancers.

What does "TNM" mean?

TNM is a system for staging cancer. Using this system helps us understanding prognosis and treatment. Each letter is rated on a 0 to 3 scale with higher number representing increasing severity.

T = size of tumor

N = extent of lymph node involvement

M = distal metastasis

What are some general s / sx of cancer?

S / sx of cancer vary according to the cancer's location. Some general symptoms of cancer may include: pain, fatigue, cachexia, and hematologic alterations.

What is the difference between pathologic atrophy and hypertrophy?

atrophy = shrinkage of cells in size due to immobility or disuse. Example: one forearm is smaller than another after a cast is removed.

hypertrophy= increase in size of cells caused by hormonal stimulation or increased functional demand. Often results in an increase in the size of the organ. Example: hypertrophy of the left ventricle from hypertension.

What is hyperplasia?

An increase in the number of cells resulting from an increased rate of cell division. Example: benign prostatic hyperplasia.

What is metaplasia?

The reversible replacement of one mature cell by another type of mature cell. Example: changes in the cells of the lungs of people who smoke.

What is dysplasia?

Abnormal changes in size, shape, and organization of mature cells due to persistent, severe cell injury or irritation. AKA: a pre-cancerous change or state.

What is immobility?

An alteration in mobility as a result of an acute (recent surgery, bone fracture, pneumonia, or new disease state) or chronic illness (sequela from a stroke, brain attack, or long standing disease).

What are some potential complications of immobility?

skin breakdown / pressure ulcer development

atrophy of muscle cells

Identify nursing interventions for immobility.

frequent repositioning of bed bound patients

encourage early activity / ambulation

check for skin breakdown

use protective devices on the skin, esp. on feet, heels, elbows

ensure adequate nutrition / hydration

educate patients and families on the risks of immobility