94. Wound healing by primary and secondary intention: definition of concepts, causes, pathogenesis, morphogenesis, outcomes, complications.

Healing by primary tension is the most functionally advantageous, it occurs in a shorter time with the formation of a thin, relatively durable scar.

Surgical wounds heal by primary tension when the edges of the wound come into contact with each other (connected by sutures). The amount of necrotic tissue in the wound is small, and the inflammation is insignificant.

After the phenomena of inflammation subside and the wound is cleansed of non-viable cells in the regeneration phase, connective tissue junctions form between the walls of the wound canal due to collagen formed by fibroblasts and germinating vessels. At the same time, the epithelium grows from the edges of the wound, which serves as a barrier to the penetration of microbes.

Accidental superficial wounds of small size with a margin divergence of up to 1 cm can also heal by primary tension without suturing. This is due to the convergence of the edges under the influence of edema of the surrounding tissues, and in the future they are held by the resulting "primary fibrin spike".

Primary tension heals only uninfected wounds: aseptic surgical or accidental wounds with minor infection, if microorganisms die within the first hours after damage.

In order for the wound to heal by primary tension, the following conditions must be met:

- absence of infection in the wound,

- tight contact of the wound edges,

- absence of hematomas and foreign bodies in the wound (because they can serve as a source of infection and cause a rejection reaction, accompanied by severe, long-term inflammation and necrosis of surrounding tissues)

- absence of necrotic tissues in the wound,

- satisfactory general condition of the patient (absence of general adverse factors).

Healing by primary tension takes place in the shortest possible time, practically does not lead to the development of complications and causes less functional changes.

Healing by secondary tension is healing through suppuration, through the development of granulation tissue. In this case, healing occurs after a pronounced inflammatory process, as a result of which the wound is cleared of necrosis.

Conditions of healing by secondary tension:

- significant microbial contamination of the wound,

- a significant defect in the size of the skin,

- the presence of foreign bodies in the wound, hematomas,

- the presence of necrotic tissues,

- the unfavorable state of the patient's body

95. Hypertrophy and hyperplasia: definition of the concept, types, significance for the body.

Hypertrophy is an increase in the volume of cells, tissues, and organs due to an increase in the size of each cell. The organ cavity is expanding (eccentric)or it decreases (concentric)hypertrophy.

Highlight:

1.Physiological

- hormonal

-compensatory (working) - the reason for it is an increased load on an organ or tissue (hypertrophy of skeletal muscles and heart in athletes