L3.1 Pathology I- Cell Injury, Inflammation and Recovery

Question 1

define hypertrophy

Answer 1

increase cell and tissue size

Question 2

define hyperplasia

Answer 2

increase in cell numbers (cell division)

Question 3

define atrophy

Answer 3

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

Question 4

define metaplasia

Answer 4

change in cell differentiation, better equipped for environmental stress

Question 5

define dysplasia

Answer 5

distorted growth pattern, pre-neoplastic, often increased mitoses

Question 6

disease progression depends on…

Answer 6

• cause of injury, its duration and severity
• cell type, stage of cell cycle, and cell adaptability (consider heart, brain, versus skin, liver)
• critical biochemical and molecular damage

Question 7

what are the different cell types/populations

Answer 7

• labile: continuous cell proliferation (skin, gut, respiratory tract, bone marrow, seminiferous tubules in testis, lymph nodes). particular risk of cancer and radiation damage
• stable: do not normally proliferate (adult) but are able to undergo cell proliferation (liver, kidney, smooth muscle)
• permanent: no (or little) capacity to divide in adult tissue (neurons, cardiac muscle)

Question 8

what are the two types of cell death

Answer 8

• necrosis (lose energy)

- apoptosis (rather than lose energy, the cells use the energy and own proteins “suicide”, uses what they go to die)

Question 9

what are some major issues to patients from cell and tissue injury, cell death?

Answer 9

pain, nausea, fatigue, weakness, lack of mobility, lack of confidence, muscle wasting, cachexia

Question 10

what are the response to cell and tissue injury and cell death?

Answer 10

we want to repair the injury, want to regenerate whatever tissue we can or we want to rebuild the ‘fibre;

Question 11

what are the types of inflammation?

Answer 11

acute (short term) or chronic (protracted)

Question 12

what is the aim of inflammation?

Answer 12

aims: to wall off, remove, dilute and start the process of healing

Question 13

what are general signs of acute inflammation?

Answer 13

• heat: because of local reaction
• redness: blood slows because vessels dilate
• swelling: fluids leak from vessels to dilute the damage
• pain and loss of function: this allows time to heal

Question 14

what are some systemic signs of acute inflammation?

Answer 14

• fever (pyrogens- good or bad)
• leucocytosis (increase leukocyte count- leucocytes are white blood cells)
• acute phase proteins
• acute phase reactions such as sleepiness, hypotension

Question 15

what are factors that influence healing?

Answer 15

nutrition, age, adequate blood supply, disease, hormones, infection, mechanical factors, foreign bodies, size and location

Question 16

what are macrophages and what are their cytokines and how do they play a central role in chronic inflammation?

Answer 16

• macrophages become activated from blood monocytes
• they increase in size, have large lysosomes, have a greater ability to ingest and kill microbes and digest cell debris than neutrophils (they also get rid of old neutrophils which have a much shorter life span)
• they produce pro-fibrotic messenger molecular (cytokines) like tumour necrosis factor-alpha

Question 17

explain healing/recovery by 1st and 2nd intention

Answer 17

see notes