Tissue Repair

tissues

cells + matrix (extracellular material)

matrix

ground substance, proteins, collagen fibers

true

true or false: tissues are NOT isolated

• repair must take place in a coordinated and orderly process to maintain homeostasis

inflammatory phase and regeneration

phases of tissue repair from 1 to 2

inflammation

inflammatory response

cause of inflammation

anything that causes cell or fiber damage; injury to tissue

• extreme temperature changes

• pathogens (bacteria/viruses)

• mechanical factors

• internal nutritional imbalances

redness, swelling, heat, pain, and loss of function

what are the 5 cardinal signs of inflammation in order 1 to 5?

redness

dilation of blood vessels in inflammation

(one of the 5 cardinal signs)

swelling

increased permeability of blood vessels

fluid accumulates

(one of the five cardinal signs)

heat

increased blood flow

(one of the five cardinal signs)

pain

damage to tissues

increased pressure of fluids and chemical messengers

caused by damage to nerve endings

nerves detect changes in chemical status of tissues

(one of the five cardinal signs)

loss of function

as tissues are damaged this occurs

(one of the five cardinal signs)

prostaglandis

SOS signal

released from a cell when it is damaged

emergency signal, acts like a hormone to signal the body to initiate the inflammatory response

infection

inflammation (inflammatory response) due to bacteria or other pathogens are involved

phase 1: inflammatory response

body works to isolate the damaged area and prevent pathogens or chemicals from spreading

phase 1 of tissue repair

autolysis

occurs within a few hours

lysosomes release enzymes to kill its own damaged cells (and tissues)

part of phase one of tissue repair

necrosis

death of cells in living tissue

part of phase one of tissue repair

pus

accumulation of dead cells, cellular debris, and fluids

part of phase one of tissue repair

mast cells

cells that quickly respond

recognize emergency signals from damaged cells

release pro-inflammatory chemicals

• histamine (dilates blood vessels - vasodilation)

• heparin

• additional prostaglandis (positive feedback loop)

part of phase one of tissue repair

vasodilation

brings blood flow and nutrients to the area (redness) also creates heat

helps remove toxins

promotes waste removal therefore increased phagocytosis

makes it like a highway to the injury for the blood vessels

increased permeability

allows cells and fluid to travel through capillary walls to the injury site

contributes to the swelling

increased ability to deliver oxygen and nutrients

macrophages

engulf and destroy pathogens, injured cells

once dead and damaged cells are removed, the body can start to replace these cells

part of phase one of tissue repair

regeneration

restores original function to the tissue

phase two of tissue repair

fibroblasts

secrete new collagen into the space with the shape of the old tissue

collagen framework supports the tissue matrix until new cells are fully matured

critical cells in wound healing

involved in phase two of tissue repair

tissue repair

1. person injured

2. exposure to pathogens and toxins

   1. from the abnormal concentration of pathogens, toxins, wastes and chemicals from the injured cells

3. stimulates…..

4. mast cell activation

   1. release a variety of chemicals (heparin, histamine prostaglandin)

5. stimulates…

6. inflammation (inflammatory response)

7. leads to increased blood flow, increased permeability, and pain

   1. in response to chemicals blood vessels dilate

   2. dilation is accompanied by increase in permeability of capillary walls and plasma now diffuses into the injured tissue so the area becomes swollen

   3. abnormal conditions and chemicals released by mast cells stimulate nerve endings that produce pain

8. leads to….

9. increased phagocytosis (phagocytes are activated, increase in temperature (vasoldilation and permeability), increase in oxygen and nutrients (vasodilation), removal of toxins and waste (enhances circulation to carry them away)