Cell and tissue injury, inflammation

Question 1

cell adaptation

Answer 1

cells can adapt to injury or stress, often as a reversible process

Question 2

DISEASE DEVELOPMENT DEPENDS ON:

Answer 2

Cause and its duration and severity
• Cell type, stage of cell cycle, and cell adaptability (consider heart, brain, versus skin, liver)
• Disease changes (cellular) occur only after critical biochemical and molecular damage

Question 3

Cell types/populations - Labile

Answer 3

Continuous cell proliferation (rapid increase in the number or amount of something.)
eg skin, gut, respiratory tract, bone marrow, seminiferous tubules in testis, lymph nodes). Particular risk of cancer and radiation damage.

Question 4

Cell types/populations - Stable

Answer 4

Do not normally proliferate (adult), but are able to undergo cell proliferation (liver, kidney, smooth muscle)

Question 5

Cell types/populations - Permanent

Answer 5

No (or little) capacity to divide in adult tissue (neurons, cardiac muscle)

Question 6

Growth patterns = Hypertrophy

Answer 6

increase in cell & tissue size

Question 7

Growth patterns = Hyperplasia

Answer 7

increase in cell numbers (cell division)

Question 8

Growth patterns = Atrophy

Answer 8

decrease in cell size, numbers (cell death), tissue size

Question 9

Growth patterns = Metaplasia

Answer 9

Metaplasia – change in cell differentiation, better equipped for environmental stress
eg smoker to stop smoking

Question 10

Growth patterns = Dysplasia

Answer 10

distorted growth pattern, pre-neoplastic, often increased mitoses (may be considered abnormal hyperplasia)
all considered reversible except dysplasia

Question 11

How are cells and tissues injured ?

Answer 11

Lack of oxygen (ischemia), lack of nerve stimulation Toxicity of chemicals/drugs
Heat/cold; Immune reaction

Question 12

what is the outcome of injured cells?

Answer 12

Depletion of energy, ATP 
Mitochondrial damage
Free radical formation,
 Build-up of intracellular Ca++ 
Cell signalling pathways

Question 13

Cell death: Apoptosis

Answer 13

programmed cell death = uses on energy to suicide, pumps water out of itself and shrinks allowing for phagocytes to come in and destroy the cell

Question 14

Cell death: Necrosis

Answer 14

Cells that die as a result of acute injury typically swell and burst. They spill their contents all over their neighbors causing a potentially damaging inflammatory response.

Question 15

Major issues to patients from cell and tissue injury, cell death

Answer 15

Pain, Nausea Fatigue, Weakness, Lack of mobility, Lack of confidence, Muscle waisting

Question 16

CELLS AND TISSUES ARE INJURED AND/OR DYING

• What is the response?

Answer 16

We want to repair the injury
• We want to regenerate whatever tissue we can
• Or rebuild with extracellular matrix proteins like collagen when we can’t regenerate the cells

Question 17

Inflammation

Answer 17

Literally “heat within”
Aims to wall off, remove, dilute and start the process of healing.
Occurs in vascularized tissues and involves fluid, protein and leucocytes (phagocytes) that originate from the nearby vessels.
can be acute or chronic