Injury and Phases of Healing

Vocabulary flashcards covering cellular injury factors and the four main phases of tissue healing.

Ischemia

Insufficient blood flow for homeostasis, leading to hypoxia/anoxia, decreased nutrients, and decreased waste removal.

Helminths

Parasitic worms that function as infectious agents capable of invading and killing cells.

Prions

Protein-based infectious agents that invade and kill cells.

Chemical Factors of Injury

Causes of cell injury including heavy metals (Mercury), overdose, and free radicals (body by-products).

Physical/Mechanical Factors of Injury

Causes of tissue injury including trauma, elements, temperature, and repetition.

Hemostasis and Degeneration

The first phase of healing occurring immediately after injury, marked by the formation of a hematoma and activity of fibroblasts within the first 24 hours.

Inflammation Phase

The second phase of healing occurring from Day 0 to 3-6 after clot formation, involving vasodilation, increased vessel permeability, and short-lived macrophages and leukocytes producing weak tissue.

Acute Inflammation

Inflammation characterized by sudden onset and short duration that subsides with the removal of the injurious agent.

Chronic Inflammation

Inflammation that persists over time due to repetitive injury.

Erythema

Redness of tissue, serving as one of the four cardinal signs of inflammation.

Heat (Sign of Inflammation)

One of the four cardinal signs of inflammation, caused by cytokines which also induce fever.

Edema

Swelling that occurs as a cardinal sign of inflammation due to vasodilation and increased permeability mediated by histamine, serotonin, and other factors.

Pain (Sign of Inflammation)

A cardinal sign of inflammation mediated by bradykinin.

Proliferation and Migration

The third phase of healing starting at Day 3 to 21, characterized by continued movement of needed cells and synthesis of a new cellular matrix.

Remodeling and Maturation

The fourth phase of healing beginning at Day 9-21 to months or years, involving tissue contraction, regeneration, and repair (scar formation).