Tissue Injury and Repair Flashcards
inflammation
- standard, initial response of body to injury
- limits the extent of injury, partially or fully eliminates the cause of injury, and initiates repair and regeneration of damaged tissue
- acute: resolves over time by healing of tissue
- if persists: becomes chronic and leads to disease conditions
- ‘-itis’: denotes inflammation of specific organ or type
EX chronic inflammation: arthritis and tuberculosis
necrosis
- accidental cell death
- causes inflammation
apoptosis
- programmed cell death
- normal step-by-step process that destroys cells no longer needed by the body
- does not initiate inflammatory response
what are the 4 cardinal signs of inflammation
redness, swelling, pain and local heat
—— loss of function
vasodilation
- the widening of the blood vessels
- evoked by damaged cells in tissue injury
- increased blood flow leads to apparent redness and heat
histamine
- potent vasodilator
- released by mast cells present in tissue degranulate
- makes endothelium lining blood vessels become leaky, which allows neutrophils, macrophages, and fluid to move from the blood into interstitial tissue spaces
- antihistamines decrease allergies by blocking histamine receptors
edema (swelling)
- caused by excess liquid in tissue
- swollen tissues squeeze pain receptors and cause pain
-prostaglandins
- released from injured cells
- activate pain neurons
- Non steroidal anti inflammatory drugs (NSAIDS) reduce pain and inflammation bc they inhibit synthesis of prostaglandins
what happens after containment of injury?
- tissue repair phase starts w removal of toxins and waste produces
clotting (coagulation)
- reduces blood loss from damaged blood vessels and forms network of fibrin proteins that trap blood cells and bind edges of wound together
- scab forms when clot dries —> reduces risk of infection
- sometimes, a mix of dead leukocytes and fluid (pus) accumulates in the wound
angiogenesis
- growth of new blood vessels
- results in vascularization of new tissue (granulation tissue)
- clot pulls edges of the wound together, and it dissolves as tissue is repaired
primary union
- healing of wounds where edges are close together
secondary union
- as edges of the wound are pulled together by wound contraction
- stitches are recommended to promote primary union and avoid scar
atrophy
- many tissues, including those in muscles, loss mass
- often as you age
what happens to tissue as you age
lumps and rigitiy become widespread
- passageways, blood vessels and airways become more rigid, brain and spinal cord lose mas
- nerves don’t transmit as fast or clearly, loss of clarity and memory
- cells begin to function abnormally (leads to diseases)
true false all cells expereience changes with aging
true
telomeres
- regions of chromosomes necessary for cell division, shorten each time cells divide
- cells are less able to divide and regenerate
cancer
- generic term for many diseases where cells escape regulatory signals
- uncontrolled growth invasion into adjacent tissues, colonizaiton of other organs
- tumors rob blood supply from the normal organs
mutation
- permanent change in dna of cell
epigenetic modifications
- do not affect code of dna but alter how the dna is coded
- known to generate abnormal cells
alteration in genetic material
- caused by environmental agents, infectious agents, errors in replication of DNA that accumulate with age
what would cause cell to start to divide abnormally
- ## if modication affects key proteins that impact cells ability to proliferate in orderly fashion
when does a tumor become malignant or cancerous
- when it breaches the confines of its tissue
- promotes angiogenesis
- attracts growth of capillaries
- metastasizes to other organs
cancer treatment
- surgery, radiation, chemotherapy, hormonal therapy: aim to remove or kill rapidly dividing cancer cells
- difficult and often impossible to target only cancer cells
