Tissue injury and repair

Question 1

What’s the 4 stage response to cell injury

Answer 1

1 cell adaptaton
2 Cell/tissue injury and death
3 Inflammation
4 Tissue repair

Question 2

1. How does a cell ADAPT to stress

Answer 2

Hypertrophy, hyperplasia, Atrophy, metaplasia

Question 3

Hypertrophy / Atrophy

Answer 3

Cell increases / decreases in size

Question 4

Hyperplasia

Answer 4

Cells increase in number

Question 5

metaplasia

Answer 5

cells change type

Question 6

Dysplasia

Answer 6

Disordered cellular prolferation

Question 7

2. Cell injury and death main causes

Answer 7

Physical agents – trauma, temperature changes, and radiation. ​

Chemical agents – toxins, oxidative stress, and chemotherapy.​

Microbial agents - pathogenic microorganisms (viruses, bacteria, fungi, etc.).​

Immunological agents – autoimmune reactions, hypersensitivity states, normal immune reactions against foreign antigens.​

Nutritional imbalances – protein malnutrition, excessive intake of single nutrient groups, e.g. fats, carbohydrates, and proteins.​

Genetic defects – inborn errors in metabolism, gross malformations, etc.

Hypoxia
Free radical mechanisms

Question 8

Main causes of intracellular damage x 6

Answer 8

ATP depletion
Mitochondrial damage
Increased ca2+
Increased Ros
membrane damage
DNA and protein damage

Question 9

Ischaemia cascade.

Question 10

necrosis v Apoptosis

Answer 10

Size
Uptake
Membrane
Organelles

Question 11

3. Inflammation

Answer 11

A protective mechanism, kills pathogens cleans damage, kickstarts healing.

Question 12

5 x cardinal signs

Answer 12

Redness (due to increased blood flow)
Heat (also from increased blood flow)
Swelling (from fluid and immune cells entering the tissue)
Pain from chemical signals and pressure on nerves)
Loss of funtion (sometimes temporary, like trouble moving a swollen joint)

Question 13

What is released when tissue is damaged and what do they do

Answer 13

Autocoids - cause changes to the surroundsing of uninjured cells

Question 14

Examples of autocoids

Answer 14

Plasma derivied, cell derived, inflammatory cells

Question 15

2 tyes of inflammation

Answer 15

1. Acute (short -cut)
2. Chronic (long - arthritis/asthma)

Question 16

Comparison of Acute vs Chronic

Answer 16

TOPROS
Time, onset,purpose, response,outcome,symptoms

Question 17

What does the vascular response do

Answer 17

Walls off damage& forms a scaffold for tissue repair
Vasodilation
Increased capillary permeability

Question 18

Acute only

What induces the vascular response

Answer 18

Prostoglandins, kinins, histamine, complement cascade

Question 19

4. tissue regeneration and repair

Answer 19

Bodies natural process of restoring damaged tissue. FIlls the gap.

Question 20

regeneration

Answer 20

Completely replacing lost tissue throgh parenchymal cells (100% funciton)

Question 21

Repair

Answer 21

Patching up with scar tissue - connective tissue

Question 22

What 3 things does regeneration and repair need

Answer 22

1. Stem cells
2. Extracellular matrix
3. Growth factors

Question 23

2 unique features of stem cells

Answer 23

1) Self renewal
2) Multipotentiality ( can become any type of cell)

Question 24

What are the 6 functions of extracellular matrix

Answer 24

1. Mechanical support
2. Controls cellular growth
3. Controls cellular differntiation
4. Scaffold
5. Establishes the tissue micorenvironment
6. Storage / presentaiton of regulatory proteins

Question 25

Growth factors

Answer 25

1. Attract inflammatory cells 1. Stimulate cellular prolifieration and differentiation 1. Signalling molecules

Question 26

4 overlapping phases of tissue repair

Answer 26

1. Haemostatic 1. Inflammatory 1. Proliferative 1. Remodelling

Question 27

6 factors that influence wound healing

Answer 27

1. Concurrent/recurrent infection.​ 1. Nutritional factors (protein & vitamin C).​ 1. Rx glucocorticoids (anti-inflammatory effects  may result in poor wound strength due to diminished fibrosis).​ 1. Age.​ 1. Mechanical factors (Increased pressure or torsion on the wound (mobilisation vs immobilisation debate).​ 1. Tissue factors (Oxygenation; Chronic immune/autoimmune reactions).