Stages of tissue injury and repair

Question 1

What are the 4 stages of tissue repair?

Answer 1

bleeding, inflammation, repair and remodeling

Question 2

Definition and purpose of inflammation

Answer 2

reaction of body tissues to protect, localize and fight either an acute or chronic irritant or injury and to prepare for healing

Question 3

Purpose of inflammation?

Answer 3

protective mechanism to rid body of the irritant and to promote repair and healing of damaged tissues.

Question 4

What are the signs and symptoms of inflammation?

Answer 4

heat, readness, swelling, pain and loss of function.

Question 5

What accompanies every injury?

Answer 5

some amount of tissue damage.

Question 6

what are the three phases of tissue injury and repair?

Answer 6

1) acute inflammatory, 2) repair , 3) remodeling

Question 7

what can the repair of injury sometimes involve?

Answer 7

regeneration of native cells, but mostly scar tissue.

Question 8

What is the purpose of the Phase 1 inflammatory response?

Answer 8

defend against infection, dispose of dead tissues, imobilize. compartementalize

Question 9

three physiological events in acute inflammation?

Answer 9

neurologic, hemodynamic and cellular

Question 10

What are the neurologic evens of Phase 1, inflammation?

Answer 10

initial vasoconstrictions (30sec) followed by gradual vasodilation, bleed may start then.

Question 11

Hemodynamic events of phase 1, inflammation?

Answer 11

vasoconstriction, vasodilation, slowing of flood, margination of leukosites, permeable changes.

Question 12

Cellular events of phase 1, inflammation?

Answer 12

mast cells (histamine) circulating leukocytes, monocytes and mactophages (5 hours post injury)

Question 13

Phase 1 inflammation chemical events?

Answer 13

More than 180 different chemicals., but also serotonin, heparin, histamine, bradykinins, prostoglandins.

Question 14

Phase 2, what is the purpose?

Answer 14

Regenerate or repair lost and damaged tissues

Question 15

Time frame of phase 1?

Answer 15

hours to a few days

Question 16

How does tissue repair happen for Phase 2?

Answer 16

Regenerate native cells in some tissue, in others repairs are made with connective tissue

Question 17

What tissues regenerate native cells?

Answer 17

skin, bone, lymph, liver, kidney

Question 18

What tissues repair with connective tissue and scar formation?

Answer 18

Musculoskeletal tissues.

Question 19

Time frame of phase 2?

Answer 19

begins in 24 hours, lasts between 2 days and 6 weeks.

Question 20

What is the halmark of the phase 2?

Answer 20

Physiological events: synthesis and deposition of collagen.

Question 21

cells envolved in the repair stage?

Answer 21

macrophages, granulation tissue, fibroblasts.

Question 22

when does wound contract in phase @?

Answer 22

4 days from injury but it can take 6 - 12 months reducing wound size 5-10%

Question 23

What is the purpose of phase 3?

Answer 23

reorganiation of collagen so it can withstand stress.

Question 24

How long does stage 3, remodeling take?

Answer 24

8-10 week window for remodeling, will still only be 80% as strong as original.

Question 25

What are the three types of factors that delay healing?

Answer 25

Intrinsic, extrinsic, iatrogenic

Question 26

What is an intrinsic factor to delay healing?

Answer 26

age, nutrition, nature of injury, level of damage.

Question 27

Extrinsic factors that can delay healing?

Answer 27

degree of immobilization, infection, immune levels, stress

Question 28

Iatrogenic factors that can delay healing?

Answer 28

medications, ischemia

Question 29

How well does cartilage heal?

Answer 29

limited healing because of poor vascularity

Question 30

How weel do ligaments heal?

Answer 30

slow because of poor vascularity, may slowly form scar

Question 31

How well does skeletal muscle heal?

Answer 31

same rate as vascular tissues, forms scars.

Question 32

Nerve tissue, how well does it heal?

Answer 32

peripheral nerves - fair healing depending on damage, CNS nerves heal poorly

Question 33

Can phycosocial factor affect healing?

Answer 33

Yes, can complicate and delay healing.