Tissue Injury and Repair

Question 1

Tissue’s Crimp

Answer 1

Collagen fibers have a wavy or folded appearance at rest (slack). When a force lengthens the collagen fibers this slack is taken up. This slack is called the tissue’s crimp. Crimp is different for each type of connective tissue and this provides each of these tissues with different viscoelastic properties.

Question 2

Ligament injuries are called _______

Answer 2

Sprains

Question 3

Tendinitis

Answer 3

Implies an inflammatory reaction to a tendon injury- a microscopic tearing and inflammation of the tendon tissue, commonly resulting from tissue fatigue rather than direct trauma

Question 4

Tenosynovitis

Answer 4

Tenosynovitis/tenovaginitis, peritendinitis, and paratenonitis, indicate an inflammatory disorder of tissues surrounding the tendon such as the tendon sheath-usually the result of a repetitive friction of the tendon and its sheath

Question 5

Tendinosis

Answer 5

Refers to a degenerative process of the tendon. Characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen

Question 6

Wolff’s Law

Answer 6

Forces applied to bone, including muscle contractions and weight bearing can alter bone the internal and external configuration of bone through adaptation to these stresses

Question 7

Decreased Adaptation in Bone

Answer 7

If the adaptations of a bone to stress do not occur fast enough, the bone is resorbed faster than it is replaced, and bone strength is compromised. Causes of decreased adaptation include: an increase in the applied load, an increase in the number of applied stresses, a decrease in the size of the surface area over which the load is applied.

Question 8

Muscle injury can result from

Answer 8

1. Excessive strain
2. Excessive tension
3. Contusions
4. Lacerations
5. Thermal stress
6. Myotoxic agents (local anesthetics, escessive use of corticosteroids, snake and bee venoms)

Question 9

Hematoma

Answer 9

Contusion to a muscle belly.

Question 10

Intramuscular Hematoma

Answer 10

Associated with a muscle strain or bruise. The size of the hemotoma is limited by the muscle fascia

Question 11

Intermuscular Hematoma

Answer 11

This type of hematoma develops if the muscle fascia is ruptured and the extravasated blood spreads into the interfascial and interstitial spaces

Question 12

Muscle Strain Grade I

Answer 12

Involves a tear of a few muscle fibers with minor swelling and discomfort. Associated with no or minimal loss of strength and restriction of movement.

Question 13

Muscle Strain Grade II

Answer 13

Greater damage of the muscle and clear loss of strength and some loss of function

Question 14

Muscle Strain Grade III

Answer 14

Involves a tear extending across the whole muscle belly. Characterized by severe pain or loss of function.

Question 15

What are the 3 main phases of wound healing?

Answer 15

1. Inflammatory
2. Proliferative
3. Remodeling

Question 16

Inflammatory Phase of Wound Healing

Answer 16

Reaction that occurs immediately after wounding includes a series of defensive events that involves the recognition of a pathogen and the mounting of a reaction against it. This reaction involves both coagulation and inflammation.

Coagulation. Apart from an initial period of vasoconstriction lasting 5-10 minutes, tissue injury causes vasodilation, the disruption of blood vessels and extravasation of blood constituents, including platelets.

Question 17

What are the main functions of the exudate of the inflammatory phase?

Answer 17

1. Provide cells capable of tissue reconstruction
2. Dilute microbial toxins
3. Remove contaminants present in the wound

Question 18

Inflammation phase in the Inflammatory phase

Answer 18

Inflammation is mediated by chemotactic substances, including anaphylatoxins, which attract neutrophils and monocytes.

Question 19

Neutrophils

Answer 19

White blood cells that bind to microorganisms, internalize them, and kill them

Question 20

Monocytes

Answer 20

White blood cells that develop into macrophages, and provide immunological defences against many infectious organisms

Question 21

Time period of Inflammatory Phase

Answer 21

This stage can last 1-6 days to longer than 6 months

Question 22

Proliferative Phase

Answer 22

Characteristic changes during phase include: capillary growth, granulation tissue formation, and fibroblast proliferation with collagen synthesis and increased macrophage and mast cell activity.

Lasts from 5 to 15 days, and often up to 10 weeks depending on the type of tissue, and the extent of damage

Question 23

Remodeling Phase

Answer 23

Involves a conversion of the initial healing tissue to scar tissue. Tissue remodeling and increasing tensile strength in the wound lasts for up to a year. Imbalances in collagen synthesis and degradation during this phase of healing may result in hypertrophic scarring or keloid formation. If left untreated the scar formed is less than 20% of its original size

Question 24

Primary Bone Healing

Answer 24

Involves a direct attempt by the cortex to reestablish itself once it has become interrupted. Bone on one side of the cortex must unite with bone on the other side of the cortex to reestablish mechanical continuity

Question 25

Secondary Bone Healing

Answer 25

Involves responses in the periosteum and external soft tissues with the subsequent formation of a callus. The majority of fractures heal by secondary fracture healing.