Chapter 6 - Innate Immunity: Inflammation & Wound Healing Flashcards
Innate immunity involves the ____ and ____ lines of defense
first and second
What is the first line of defense?
physical (skin), mechanical (mucous membrane), biochemical barriers
What is the second line of defense?
the firing squad - inflammation response, macrophages, and neutrophils
Adaptive immunity is the ____ line of defence.
third
What is the third line of defense?
acquired or specific immunity via B and T cells
Which type of T cell is involved in both innate and adaptive immunity?
Natural Killer T Cell
What do Mast cells release?
histamines (cytokines)
What does histamine do?
induce vasodilation
What do platelets do?
induce clotting to stop blood loss
What is the role of macrophages and neutrophils during the inflammatory response?
phagocytosis of the pathogen
What element do macrophages follow?
cytokines
What is pus accumulation?
the gathering of dead phagocytes and pathogens
What leaks out and is followed by fluid to induce swelling?
ions, followed by water
What is the role of prostaglandins in the inflammatory response?
Overseer/coordinator of events
What is another principal coordinator during inflammation?
vascular epithelium
What 2 cells are contained in the tissue close to vessels?
mast and dendritic cells
Which cells are an inflammation activator? What do they release?
mast cells release cytokines
Dendritic Cells
connect the innate and adaptive immune response
What recruits the innate and adaptive immune systems?
chemical molecules
Where are chemical molecules released from?
Damaged or destroyed cells
What are cytokines?
a general term for released chemical molecules (messengers) that regulate innate and adaptive immunity
Cytokines can be ___inflammatory or ___-inflammatory
pro or anti (shut down)
Lymphokines
cytokines released from lymphocytes
Monokines
cytokines released from monocytes
What do monocytes change into?
macrophages
What produces IL-1?
macrophages
What produces IL-6?
macrophages, lymphocytes, fibroblasts
What is different about interleukins than cytokines?
ILs have self-limiting abilities
What is the order of cells in the immune response?
mast cell, neutrophil, macrophage, basophil, eosinophil, natural killer cell
Cytokine Storm Syndrome
activated by Covid-19, a severe systemic immune response that can be damaging to the body
What is the cytokine released during CSS?
IL-6 (lymphokine) which plays a major role in the excessive recruitment of lymphocytes
What is the treatment for Covid-19?
IL-6 antibody production to counteract the effects
TNF-a is a _____ but not an _______
cytokine but not an interleukin
What releases TNF-a?
macrophages and mast cells
What are the pro-inflammatory effects of TNF-a?
fever, cachexia, fatal shock (gram- bacteria), granuloma
Cachexia
muscle wasting
What is a main anti-inflammatory cytokine?
IL-10 aka lymphokine
How do monocytes move out of blood vessels?
through interstitial spaces between cells
How does capillary permeability change during inflammation?
increased permeability
Capillary widening = ______ blood flow
increased
Increased permeability = _____ _____ into tissues
fluid release
Attraction of leukocytes = leaking of leukocytes to…
injury site
Systemic response = _____ and increase in _____
fever and increase in leukocytes
What are the signs and symptoms of inflammation?
heat, redness, swelling, tenderness, pain
What is the goal of the inflammatory response?
limit and control bleeding and infection
Interventions for Inflammation:
clean wound (saline), remove loose debris, treat with antibiotics
What does “itis” tell us?
Where the inflammation is (ie. tonsilitis)
What activates inflammation?
cell injury or death
What are 5 things that cause cell death?
infection, damage, ischemia, temperature, radiation
Erythrocyte Sedimentation Rate (ESR)
determination of the rate of RBC settling in saline solution
An increase in infection affects RBCs how?
RBCs bind to each other, making them heavier and settle in saline faster
Increased ESR = ______ infection
increased
Sed Rate
distance (in mm) the RBCs fall in 1 hour
What causes the C-reactive protein?
the effect of acute inflammation on the liver
C-reactive protein ____ in response to inflammation
increases
Is CRP specific to the disease?
no
What do CRP tests monitor?
disease progress and flares
What does blood work for WBC count measure?
increase in neutrophils (bands)
What does it mean if there is an increase of neutrophils in the blood?
we have not got a hold of the infection yet
How long does acute inflammation last?
less than 2 weeks
Symptoms of acute inflammation?
swelling, pain, heat, redness
Is acute inflammation localized or systemic?
localized
What are the 3 main systemic changes due to acute inflammation? (Hint: temp, WBC, protein)
fever, leukocytosis, increase in circulating proteins
Leukocytosis
increase in circulating leukocytes
When can acute inflammation become chronic?
if the response is unsuccessful
How long does chronic inflammation last?
longer than two weeks, up to months or years
Does chronic inflammation occur only after acute inflammation?
no, it can occur without previous inflammation
What is 3 things cause of chronic inflammation?
microorganisms that resist phagocytosis, survive in a macrophage, and/or produce toxins
How does chronic inflammation present?
as a dense infiltration of macrophages and lymphocytes
When do granulomas form?
if macrophages are unable to stop damage, the body walls off the infected area
Which cytokine drives granuloma formation?
TNF-a
Granuloma
cluster of WBCs and other tissues
If acute inflammation resolves, what is restored?
cellular and tissue homeostasis
What is the first cell to arrive at the inflammation site, and the fastest to leave?
platelets
What is the first white blood cell on scene?
neutrophils
Which WBC arrives second to neutrophils?
macrophages
Fibroblasts arrive after _______ and do what?
after macrophages and begin repairing the tissue
Which WBC arrives last and what does it do?
lymphocytes (B and T cells) arrive if the problem isn’t under control and…
The transition from acute inflammation to healing begins…
IMMEDIATELY
What do platelets do in wound healing?
initiate clot formation and formation of undamaged cells
What do neutrophils do in wound healing?
clean wound of debris and bacteria
What do macrophages do in wound healing?
-release growth factors
-recruit fibroblasts
-promote angiogenesis
Angiogenesis
development of new blood vessels
What 3 cells are involved in the ‘inflammation’ phase of wound healing?
platelets, neutrophils, macrophages
How long does the ‘proliferation and new tissue formation’ phase of wound healing last?
starts at 3 days and lasts 2 weeks
What do fibroblasts do in the ‘proliferation and tissue formation’ stage of wound healing?
collagen synthesis
What is “epithelialization”? When does it occur?
epithelial cells migrate to the wound during the proliferation and new tissue formation stage
When does cellular differentiation and macrophage secretions occur?
proliferation and new tissue formation stage
How long does the “remodelling and maturation” phase of wound healing last?
weeks to years
Cellular differentiation during the remodelling and maturation phase:
unspecialized cells (stem cells) mature and perform important cellular functions
When does scar tissue formation and remodelling occur?
during the remodelling and maturation phase of wound healing
What is the major remodelling cell?
fibroblasts
What is the primary intention of tissue repair?
-clean incision
-early suture
Why is early suture the best choice?
leaves a fresh wound with sufficient vascularization
What is the result if primary tissue repair intentions are successful?
fine scar
Secondary intention of tissue repair involves g_________ for gaping wounds
granulation
Why is granulation a secondary intention?
the wound is extensive and the edges can’t be brought together to suture
Secondary intentions are ideal for c________ or i__________ wounds because the wound is left open to heal spontaneously.
contaminated or infected
Tertiary tissue repair intentions are used when delayed ______ closure happens
primary closure
Tertiary intentions are used on open but not ________ wounds
gaping
Tertiary intentions for tissue repair allow for ________ and ________
granulation and observation
Tertiary intentions: when the wound is clean…
it is sutured closed but has a wider scar than primary
Adhesions
abnormal union of membranous surfaces
When are adhesions common?
bowel surgery
When are adhesions painful?
when they stop the normal movements of the intestinal system
Wound Contraction
healing cells pull other cells together and contract the tissue
Wound contractions are common with ____ injuries
burn
Infections
wound is reinfected with the initial or new pathogen
Dehiscence
incision separates following surgery – wound is “dehisced”
Evisceration
surgical complication where the incision opens and abdominal organs protrude
What is the result of dehiscence and/or evisceration?
excess scar formation caused by excess tension or movement
Low blood supply during wound healing…
inhibits the recovery process
High blood supply during wound healing…
increases risk for blood clots
Being obese predisposes wound to possible _______
infections
When fibrin (clotting factor) doesn’t get reabsorbed it causes…
fibrous adhesions
Why does having diabetes prolong wound healing?
hyperglycaemia suppresses macrophages
Hyperglycaemia
excess glucose in blood due to malfunction of insulin
Why is nutrition important during wound healing?
to meet metabolic needs
How can being on steroids impact wound healing?
steroids prevent macrophages from migrating to infection site
Antineoplastic drugs used for cancer treatment to slow cell division impact wound healing by…
blocking neoplasm formation (new abnormal tissue growth)
