Chapter 3 Exam Review Sheet

Inflammation and Tissue Repair

Roadmap Focus: Modules 1, 2, 4 — especially burns and arthritis

This chapter is about how the body responds when tissue is injured.

This chapter connects hard to:

• Chapter 1: etiology, pathogenesis, clinical manifestations, acute vs chronic, local vs systemic.

• Chapter 2: cellular injury, necrosis, apoptosis, ischemia, ATP loss, cellular adaptation.

• Chapter 4: immune response and autoimmunity.

• Chapter 5: infection and chain of infection.

• Chapter 8: fluid shifts, edema, hypovolemia, dehydration, perfusion.

• Chapter 19: aging delays healing because of reduced tissue repair and immune efficiency.

Big Picture: What This Chapter Is About

Inflammation is the body’s second line of defense.

It happens after tissue injury and has three major goals:

1. Bring blood flow to the injury

2. Bring healing/defense cells to the site

3. Remove damaged tissue and prepare for repair

The problem: inflammation is helpful, but it is also destructive.

Roadmap Module Map

Normal A&P Foundation

Epithelial Tissue

Epithelial tissue:

• covers body surfaces

• lines hollow organs

• forms glands

• creates barriers

• protects against invasion

• supports secretion and absorption

Examples:

• skin

• respiratory tract lining

• GI tract lining

• urinary tract lining

Basement Membrane

The basement membrane separates epithelial tissue from underlying tissue.

It supports:

• tissue structure

• re-epithelialization

• wound healing

• regeneration

Why this matters

If the basement membrane remains intact, tissue can often regenerate better.

If the basement membrane is destroyed, healing is harder and scarring is more likely.

This connects to Chapter 2: cells need structure and support to regenerate properly.

Three Lines of Defense

Critical Thinking

If the skin is intact, microbes cannot easily enter.

If the skin is burned, cut, ulcerated, or broken:

• first line is damaged

• second line activates inflammation

• third line may activate immunity

• infection risk increases

This connects directly to Chapter 5 infection because broken skin becomes a portal of entry.

MODULE 1: Acute Inflammation

What Module 1 Is Showing

Module 1 shows how the body responds immediately to injury.

Acute inflammation is:

• fast

• nonspecific

• protective

• necessary for healing

• potentially damaging if excessive

Acute Inflammation: Definition

Acute inflammation is the immediate inflammatory response triggered by tissue injury.

Injury can include:

• microorganisms

• hypoxia/anoxia

• physical trauma

• chemical damage

• nutritional deficiencies

• cellular mutations

• burns

• ischemia

Memory Anchor

Three Goals of Acute Inflammation

Step 1: Vascular Response

Normal Concept

Blood vessels normally keep blood cells and plasma inside the vascular space.

Alteration During Injury

In inflammation, blood vessels:

1. Dilate

2. Become more permeable

3. Allow fluid, proteins, and cells to leave the bloodstream

4. Bring clotting/healing products to the injury

Vasodilation

Dilation means widening.

When blood vessels dilate:

• more blood flows to injury

• tissue becomes red

• tissue becomes warm

Clinical cues

Increased Vascular Permeability

Permeable means substances can pass through.

During inflammation, vessel walls loosen so:

• fluid leaves blood vessels

• proteins leave blood vessels

• WBCs move into tissue

• exudate forms

Exudate

Exudate is protein- and leukocyte-rich fluid that seeps into injured tissue.

Critical thinking

Exudate is not random “drainage.”

It means:

Edema

Edema is swelling from fluid accumulation in tissue.

Cause:

• vascular permeability increases

• protein-rich fluid leaves vessels

• fluid accumulates in tissue spaces

This connects to Chapter 8 fluids/electrolytes because fluid shifts out of the vascular space can reduce circulating volume.

Step 2: Inflammatory Mediators

What They Do

Inflammatory mediators are chemical messengers that control inflammation.

They help cause:

• vasodilation

• increased permeability

• clotting

• WBC attraction

• pain

• fever

• immune activation

Key Sources

Mast Cells and Basophils

Mast Cell

Mast cells are WBCs located in connective tissue near blood vessels.

They are like first responders already stationed at the injury site.

Degranulation

Degranulation is when mast cells release granules containing inflammatory mediators.

Mast cells release:

• histamine

• leukotrienes

• prostaglandins

Critical thinking

Mast cells are fast because they are already near blood vessels.

That is why allergic/inflammatory reactions can happen quickly.

Cytokines

Cytokines are cell proteins that regulate inflammation.

They can:

• start inflammation

• increase inflammation

• attract cells

• regulate immune responses

• help shut inflammation down

Examples:

Memory Anchor

Arachidonic Acid

Arachidonic acid comes from injured cell membranes.

It can generate inflammatory mediators such as:

• prostaglandins

• leukotrienes

• thromboxane

• lipoxins

These affect:

• vasodilation

• vasoconstriction

• vascular permeability

• bronchoconstriction

• WBC attraction

Why this matters

Corticosteroids reduce inflammation partly by blocking arachidonic acid production.

Do not over-study the drugs, but know the logic:

Plasma Protein Systems

Three plasma systems regulate inflammation:

1. Clotting system

2. Complement system

3. Kinin system

What to know

You do not need tiny details tonight.

Know this:

Critical thinking

Inflammation must be activated and shut off.

If it does not activate enough:

• poor blood flow

• poor phagocytosis

• poor clotting

• impaired healing

If it does not shut off:

• tissue damage

• chronic inflammation

• autoimmunity risk

• protein depletion

This connects to Chapter 4 immunity because poor regulation can contribute to autoimmune damage.

Step 3: Cellular Response

What Module 1 Is Showing Here

Once blood vessels are open and permeable, WBCs need to reach the injury.

Three steps:

1. Chemotaxis

2. Cellular adherence

3. Cellular migration/diapedesis

Chemotaxis

Chemotaxis is movement of cells toward the injury site.

Chemical signals attract specific cells.

Memory Anchor

Cellular Adherence

Cellular adherence is when WBCs stick to endothelial cells near the injury.

This is necessary before they can exit the bloodstream.

Diapedesis

Diapedesis is movement of cells through/between endothelial junctions into injured tissue.

Cause → effect

Injury
→ inflammatory mediators
→ vasodilation + permeability
→ WBCs stick to vessel wall
→ WBCs migrate into tissue
→ phagocytosis begins

Key Cells in Acute Inflammation

Phagocytosis

Phagocytosis is engulfing and digesting harmful substances.

This connects back to Chapter 2 because phagocytosis is a type of endocytosis.

Important

Phagocytosis helps clean the injury, but it can also damage healthy tissue because inflammatory cells release destructive enzymes.

Cardinal Signs of Acute Inflammation

The five cardinal signs:

1. Redness

2. Heat

3. Swelling

4. Pain

5. Loss of function

Memory Anchor

Local vs Systemic Inflammation

This connects to Chapter 1 local vs systemic manifestations.

Local manifestations

• erythema

• heat

• edema

• pain

• loss of function

• lymphadenitis

Systemic manifestations

• fever/pyrexia

• leukocytosis

• increased acute phase reactants

• fatigue/malaise

Lymphadenitis

Lymphadenitis is inflammation/enlargement of nearby lymph nodes.

Why?

Lymph nodes filter harmful substances draining from the injury site.

This connects to Chapter 4 immunity because lymph nodes are major immune activation sites.

Fever/Pyrexia

Pyrexia means fever.

Fever occurs because inflammatory mediators act on the hypothalamus.

The hypothalamus controls body temperature.

Why fever can help

Fever can:

• stimulate phagocytosis

• slow growth of some microorganisms

But excessive fever can increase metabolic demand.

Leukocytosis

Leukocytosis means elevated WBC count.

Typical WBC count:

Leukocytosis often means:

Critical thinking

Leukocytosis tells you inflammation or infection may be present, but it does not tell you where.

Acute Phase Reactants

Acute phase reactants are plasma proteins that rise during inflammation.

Main tests:

• CRP

• ESR

CRP

CRP rises with inflammation and is often preferred for acute inflammation.

ESR

ESR measures how quickly RBCs settle.

Inflammation increases fibrinogen, causing RBCs to stack and settle faster.

Exam Trap

CRP and ESR indicate inflammation, but they do not identify the exact source.

Treatment Logic for Acute Inflammation

Keep this light.

Treatment aims to:

1. reduce blood flow locally

2. decrease swelling

3. block inflammatory mediators

4. decrease pain

RICE

Critical thinking

RICE works because acute inflammation causes vasodilation and fluid leakage.

You are trying to slow excessive fluid accumulation.

Resolution of Acute Inflammation

Acute inflammation should be self-limited.

Once the injury is removed:

• mediators deactivate

• inflammation shuts down

• healing begins

If it does not shut down or injury persists, it can become chronic.

MODULE 2: Healing and Tissue Repair

What Module 2 Is Showing

This module shows how the body:

1. seals the wound

2. clears debris

3. rebuilds structure

4. restores function

5. scars if regeneration is not possible

Three Phases of Tissue Repair

1. Inflammatory phase

2. Proliferative phase

3. Remodeling phase

Simple version

Healing Goal

Tissue repair aims to:

• seal the wound

• clear debris

• restore structural integrity

• restore functional integrity

Step 1: Sealing the Wound

Hemostasis

Hemostasis is stopping blood flow by forming a clot.

Platelets and clotting factors help form a clot/scab.

Thrombus

A thrombus is the clot/scab barrier formed from dried blood and exudate.

Why the scab matters

The scab:

• prevents more fluid/plasma loss

• blocks microorganisms

• protects new epithelial growth underneath

Exam-style reasoning

Picking off a scab early is bad because it:

• disrupts re-epithelialization

• reopens the wound

• increases infection risk

• delays healing

Step 2: Clearing the Debris

Neutrophils and macrophages remove:

• dead cells

• debris

• microorganisms

• necrotic tissue

Healing cannot proceed properly until necrotic tissue is removed.

This connects to Chapter 2 necrosis: dead tissue triggers inflammation and must be cleared.

Step 3: Restoring Structural Integrity

Structural repair depends on rebuilding the extracellular matrix.

Extracellular Matrix

The extracellular matrix, or ECM, supports cells and tissue architecture.

Includes:

• basement membrane

• connective tissue

• collagen

• elastin

• glycoproteins

Basement Membrane

The basement membrane:

• supports tissue structure

• supports re-epithelialization

• stores growth factors

• supports parenchymal tissue development

• helps restore function

High-yield point

If the basement membrane is destroyed, scarring is more likely.

Fibroblasts

Fibroblasts make collagen.

They are stimulated by macrophages.

Collagen

Collagen fills gaps left after damaged tissue is removed.

Too much collagen causes:

• fibrosis

• scarring

• keloids

• adhesions

• contractures

Critical thinking

Collagen is useful, but it does not perform the original tissue’s specialized function.

A scar can close the wound, but it may not restore full function.

Elastin

Elastin allows tissues to stretch and recoil.

It is hard to replace.

If elastin is lost, tissue becomes less flexible.

This matters a lot in full-thickness burns, where loss of elasticity contributes to contractures.

Provisional Matrix

A temporary matrix that:

• decreases blood/fluid loss

• attracts fibroblasts

• attracts endothelial cells

• supports early healing

Granulation Tissue

Granulation tissue contains:

• macrophages

• fibroblasts

• new capillaries

It supports healing and angiogenesis.

Angiogenesis

Angiogenesis is formation of new blood vessels.

Why it matters:

• brings oxygen

• brings nutrients

• supports new tissue

• removes waste

This connects to Chapter 8 perfusion and fluid balance because tissue cannot heal without oxygenated blood.

Restoring Functional Integrity

Functional tissue is called parenchyma.

Examples:

• neurons

• myocardial cells

• epithelial cells

• liver cells

• kidney cells

Healing can occur by:

1. Resolution

2. Regeneration

3. Replacement

Resolution

Resolution is healing after mild injury with minimal disruption.

Example:

• superficial scratch

• mild sunburn

Fast healing. Minimal damage.

Regeneration

Regeneration is replacement of damaged tissue with the same functional tissue.

Requires cells that can divide.

Labile Cells

Labile cells constantly regenerate.

Examples:

• skin epithelial cells

• GI tract lining

• urinary tract lining

• blood cells in bone marrow

Stable Cells

Stable cells usually do not divide unless injured.

Example:

• liver cells/hepatocytes

Permanent Cells

Permanent cells do not regenerate well.

Examples:

• neurons

• cardiac myocytes

• lens of eye

Critical thinking

If permanent cells are damaged, they are replaced by scar tissue, not functional tissue.

This connects to Chapter 2 cerebral atrophy/cardiac hypertrophy: neurons and cardiac myocytes have limited regenerative ability.

Replacement

Replacement means damaged functional tissue is replaced by connective scar tissue.

This occurs when:

• injury is severe

• basement membrane is destroyed

• permanent cells are damaged

• regeneration is not possible

Example

After myocardial infarction:

• cardiac muscle cells die

• they do not regenerate

• scar tissue replaces them

• scar tissue does not contract

• cardiac function may decrease

Primary vs Secondary Intention

Primary Intention

Wound edges are close together.

Examples:

• paper cut

• surgical incision

Healing is:

• faster

• lower infection risk

• less granulation tissue

• minimal scarring

Secondary Intention

Wound edges are separated/open.

Examples:

• pressure ulcer

• large burn

• crater-like wound

Healing is:

• slower

• from bottom up

• more granulation tissue

• higher infection risk

• more scarring

Memory Anchor

Conditions Needed for Wound Healing

Healing requires:

• adequate blood flow/perfusion

• oxygen

• water

• protein

• carbohydrates

• fats

• vitamins

• minerals

• effective inflammation

• effective immune response

Nutrition High-Yield

Exam logic

Poor nutrition + poor perfusion = poor wound healing.

This connects to Chapter 8 because fluid volume and perfusion directly affect tissue repair.

Complications of Healing

Dehiscence vs Keloid

Memory Anchor

Adhesions

Adhesions are fibrous connections between tissues that should move freely.

Common after abdominal surgery.

They can cause:

• pain

• restricted organ movement

• bowel obstruction risk

• loss of function

Chronic Inflammation — Only What You Need for RA

Roadmap does not center Module 3, but RA requires chronic inflammation.

Chronic Inflammation

Chronic inflammation is persistent or recurrent inflammation lasting weeks or longer.

Causes:

• persistent infection

• unrelenting injury

• autoimmune disease

• chronic irritants

Main cells

• macrophages

• monocytes

• lymphocytes

• fibroblasts

Major outcomes

• ongoing tissue destruction

• fibrosis/scarring

• granuloma formation

• loss of function

• deformity

Critical thinking

Acute inflammation is usually short and neutrophil-heavy.

Chronic inflammation is longer and macrophage/lymphocyte/fibroblast-heavy.

MODULE 4: Applied Clinical Models

Roadmap Focus: Burns and Arthritis Especially

I’m not giving full sinusitis/gastritis/pancreatitis/IBD review because your roadmap says burns and arthritis especially, and your exam is tomorrow. You need the high-yield patho hitters.

Clinical Model 1: Burns

What Burns Are Showing

Burns show what happens when the first line of defense is destroyed and inflammation becomes severe enough to cause:

• fluid shifts

• edema

• hypovolemia

• infection risk

• impaired thermoregulation

• necrosis

• scarring

• contractures

• shock

This connects to:

• Chapter 2: thermal injury, necrosis, ischemia

• Chapter 3: acute inflammation, tissue repair

• Chapter 5: portal of entry/infection

• Chapter 8: fluid shifts, hypovolemia, dehydration

Normal Skin Function

Skin normally:

• protects against microorganisms

• prevents dehydration

• regulates body temperature

• protects internal structures

• produces vitamin D

• acts as a physical barrier

Skin layers:

Burn Etiologies

Burns can result from:

• thermal injury

• electrical injury

• chemical injury

• radiation exposure

• inhalation of noxious fumes

Important burn patho

Temperature above 45°C / 113°F causes protein denaturation and irreversible cell damage.

Burn Depth Classification

Superficial Partial-Thickness Burns

Pathophysiology

Damage is limited to epidermis.

Inflammatory response causes:

• vasodilation

• capillary permeability

• erythema

• pain

• swelling

No necrosis or scarring because deeper structures remain intact.

Example

Mild sunburn.

Deep Partial-Thickness Burns

Pathophysiology

Damage enters epidermis and dermis.

Epidermis and dermis separate
→ fluid accumulates between layers
→ blisters form

Key cues

• blisters

• erythema

• warmth

• pain

• edema

• serous exudate

Why infection risk rises

The skin barrier is broken.

Microorganisms can enter.

This connects to Chapter 5 chain of infection:

Full-Thickness Burns

Pathophysiology

Damage destroys:

• epidermis

• dermis

• blood vessels

• nerve endings

• sweat glands

• hair follicles

• sometimes subcutaneous tissue

Key cues

• eschar

• edema

• exudate

• less pain in the deepest burned area due to nerve destruction

• pain around surrounding partial-thickness areas

Exam Trap

A full-thickness burn may be less painful in the center because nerve endings are destroyed.

But the patient is not pain-free because surrounding partial-thickness burns are painful.

Eschar

Eschar is thick, coagulated dead tissue/crust formed from dead tissue and exudate.

Why it matters:

• traps bacteria

• delays healing

• restricts circulation

• may need removal/debridement

Burn Fluid Shifts

This is a major critical-thinking point.

Cause → Effect Chain

Burn injury
→ inflammatory mediators released
→ massive capillary permeability
→ fluid and proteins leave blood vessels
→ edema in tissues
→ decreased vascular volume
→ hypovolemia
→ thicker blood/hemoconcentration
→ poor perfusion
→ shock risk
→ organ damage

Hematocrit Question

The textbook asks whether hematocrit increases or decreases in burns covering 20% BSA.

Answer: hematocrit increases initially.

Why?

• plasma fluid leaves blood vessels

• RBCs stay in circulation

• blood becomes more concentrated

• hematocrit rises

Critical thinking

This is not because the patient made more RBCs.

It is because the patient lost plasma volume into tissues.

This connects to Chapter 8 dehydration/hypovolemia.

Burns and Shock

Shock = inadequate tissue perfusion.

Severe burns cause shock because:

• fluid leaves bloodstream

• circulating volume falls

• blood becomes viscous

• perfusion drops

• oxygen delivery decreases

• tissues become hypoxic

• necrosis can worsen

This connects to Chapter 2 ischemia:

Burns and Infection

Burns increase infection risk because:

• skin barrier is destroyed

• dead tissue supports microorganism growth

• exudate can feed bacteria

• immune/metabolic stress is high

• extensive wounds are portals of entry

Severe burns can lead to:

• sepsis

• septic shock

This connects to Chapter 5 infection and Chapter 4 immune response.

Burns and Metabolic Demand

Severe burns increase demand for:

• oxygen

• calories

• protein

• fluid

• repair materials

If needs are not met:

• tissue hypoxia

• tissue wasting

• infection

• delayed healing

• poor repair

Nutrition exam hitter

Burn healing needs high protein because protein supports:

• collagen

• ECM

• angiogenesis

• tissue repair

Burns and Contractures

Contractures are thick, shortened, rigid tissue areas.

Cause:

• full-thickness injury

• elastin loss

• collagen replacement

• scar tightening

Result:

• reduced mobility

• deformity

• loss of function

This connects back to Module 2: collagen repair can close tissue but does not restore original elasticity/function.

Burn High-Yield Cues

Clinical Model 2: Arthritis — Rheumatoid Arthritis

What RA Is Showing

RA shows chronic inflammation caused by autoimmunity.

The body attacks synovial tissue.

This causes:

• synovial inflammation

• hyperplasia

• exudate

• pannus formation

• cartilage destruction

• bone erosion

• fibrosis

• ankylosis

• deformity

This connects to:

• Chapter 1: chronic disease, exacerbations/remissions, systemic manifestations

• Chapter 2: hyperplasia, atrophy, tissue destruction

• Chapter 4: autoimmunity, antibodies, T cells

• Chapter 3: chronic inflammation and tissue repair gone wrong

Normal Synovial Joint A&P

Synovial joints provide:

• stability

• mobility

• cushioning

• low-friction movement

Common sites:

• knees

• wrists

• hands

• fingers

• feet

Synovial Membrane

The synovial membrane lines the joint capsule.

It contains:

• connective tissue

• elastin

• adipocytes

• fibroblasts

• macrophages

• mast cells

• synovial cells

Synovial Fluid

Synovial fluid:

• nourishes the joint

• cushions

• protects

• supports movement

Cartilage

Cartilage:

• distributes body weight

• decreases friction

• supports smooth movement

Cartilage contains:

• chondrocytes

• collagen

• water

• proteoglycans

Important

Chondrocytes do not regenerate well.

So cartilage damage can become permanent.

Rheumatoid Arthritis Definition

Rheumatoid arthritis is a systemic autoimmune disease causing chronic inflammation of synovial tissue.

It leads to:

• synovial swelling

• thickening

• joint erosion

• pain

• deformity

• systemic symptoms

RA Etiology

Exact cause is unknown.

Likely combination of:

1. genetic susceptibility

2. immune-triggering event

3. autoimmunity against synovial cells

Critical thinking

RA is idiopathic-ish/multifactorial in etiology, but the pathogenesis is autoimmune inflammation.

Do not say “wear and tear.” That is osteoarthritis logic, not RA logic.

RA Pathophysiology

Step-by-step chain

Genetic susceptibility + trigger
→ immune system targets synovial tissue
→ CD4+ helper T cells activate inflammatory response
→ cytokines released
→ B cells/plasma cells form antibodies
→ immune complexes form
→ complement activates
→ exaggerated inflammation
→ vasodilation + permeability
→ joint becomes warm, red, swollen, painful
→ synovial exudate accumulates
→ synovial cells undergo hyperplasia
→ pannus forms
→ cartilage/bone erosion
→ fibrosis
→ ankylosis
→ deformity/loss of function

Rheumatoid Factor

Rheumatoid factor, or RF, is an autoantibody.

It means antibodies are acting against other antibodies, mainly IgG.

High-yield

RF is common in RA and may indicate more severe disease, but it is not perfectly specific.

Do not treat RF as the only diagnostic proof.

Immune Complexes

Immune complexes are antigen-antibody complexes.

In RA, they deposit in the synovium and activate complement.

This worsens inflammation.

This connects directly to Chapter 4 hypersensitivity/autoimmunity.

Synovial Hyperplasia

In RA, synovial cells rapidly regenerate and thicken.

This is hyperplasia from Chapter 2.

Why this matters

More synovial tissue
→ more inflammatory activity
→ more joint destruction
→ more pannus formation

Pannus

Pannus is granulation tissue that forms over inflamed synovium and cartilage.

It contains:

• synovial cells

• new blood vessels

• macrophages

• lymphocytes

• mast cells

• giant cells

Why pannus is dangerous

Pannus:

• separates cartilage from synovial fluid/nutrients

• releases destructive enzymes

• erodes cartilage

• erodes bone

• narrows joint space

• causes deformity

Memory Anchor

RA Joint Damage Chain

Inflammation
→ pannus
→ cartilage erosion
→ bone erosion
→ collagen/fibrosis
→ ankylosis
→ deformity
→ decreased movement
→ muscle atrophy

This connects to Chapter 2 atrophy:

Ankylosis

Ankylosis is joint fixation/stiffening.

Cause:

• fibrosis

• chronic inflammation

• joint destruction

Result:

• loss of mobility

• deformity

• functional impairment

RA Clinical Cues

RA typically causes:

• symmetrical joint involvement

• joint pain

• joint swelling

• warmth

• erythema

• decreased mobility

• morning stiffness

• stiffness after immobility

• joint deviation/malalignment

• low-grade fever

• fatigue

• anorexia

• weight loss

• weakness

High-yield cue

RA Systemic Manifestations

RA is not just a joint disease.

It is systemic autoimmune inflammation.

Systemic cues include:

• low-grade fever

• fatigue

• anorexia

• weight loss

• weakness

• depression/isolation from chronic pain

• nodules/granulomas

• vasculitis

RA vs Acute Inflammation

Burns vs RA Comparison

Light Coverage: Other Module 4 Models You Should Recognize

Do not deep-study these unless your teacher mentioned them separately. Just know what they demonstrate.

Sinusitis

Shows inflammation of sinus mucosa.

Key patho:

• mucus drainage blocked through ostia

• mucus stagnates

• viral infection often primary

• bacterial infection can complicate

• chronic sinusitis involves persistent low-grade inflammation

Cues:

• facial pain/pressure

• nasal congestion

• drainage

• cough

• fatigue

• fever more common in acute

• hyposmia in chronic

Gastritis

Shows inflammation of gastric mucosa.

Key patho:

• stomach lining loses protection

• irritants like aspirin, alcohol, microbes, or autoimmunity injure mucosa

• acid damages tissue

• ulcers/bleeding can occur

Cues:

• dyspepsia

• nausea

• vomiting

• anorexia

• hematemesis if bleeding

• occult blood possible

Critical connection:

NSAIDs reduce prostaglandins. Prostaglandins protect gastric mucus barrier. Less prostaglandin → more gastritis/ulcer risk.

Pancreatitis

Shows inflammation caused by pancreatic enzyme autodigestion.

Key patho:

• digestive enzymes activate too early

• pancreas starts digesting itself

• gallstones and alcohol are common causes

• severe cases can cause necrosis, shock, multiorgan failure

Cues:

• sudden upper abdominal pain radiating to back

• nausea/vomiting

• anorexia/diarrhea

IBD: Crohn vs Ulcerative Colitis

Shows chronic GI inflammation.

High-yield comparison:

High-Yield Vocabulary

Module 1: Acute Inflammation

Module 2: Healing and Repair

Module 4: Burns and RA

Critical Thinking Chains to Memorize

Acute Inflammation Chain

Tissue injury
→ inflammatory mediators
→ vasodilation
→ increased permeability
→ exudate/edema
→ WBC migration
→ phagocytosis
→ debris removal
→ healing or scarring

Burn Shock Chain

Burn injury
→ capillary permeability
→ fluid/protein shift into tissue
→ edema
→ decreased intravascular volume
→ hypovolemia
→ decreased perfusion
→ shock
→ cell hypoxia/necrosis

Wound Healing Failure Chain

Poor perfusion/nutrition/immune response
→ weak inflammation or weak collagen formation
→ delayed healing
→ infection/dehiscence/ulcer/scarring
→ loss of function

RA Joint Destruction Chain

Autoimmune trigger
→ immune complexes
→ complement activation
→ chronic synovial inflammation
→ synovial hyperplasia
→ pannus formation
→ cartilage/bone erosion
→ fibrosis
→ ankylosis/deformity
→ muscle atrophy

Common Exam Traps

Trap 1: Inflammation is always bad

Wrong.

Inflammation is necessary for healing.

Correct:

Trap 2: ESR/CRP tell you where inflammation is

Wrong.

Correct:

Trap 3: All burns hurt the same

Wrong.

Correct:

Trap 4: Burn edema means the patient has too much vascular fluid

Wrong.

Correct:

This is a huge exam concept.

Trap 5: Bigger cardiac/joint tissue means stronger function

Wrong.

Correct:

Trap 6: RA is wear-and-tear arthritis

Wrong.

Correct:

Trap 7: Wound closure means function is restored

Wrong.

Correct:

Mnemonics

Cardinal Signs

Cellular Response

Wound Repair Goals

Burn Depth

Primary vs Secondary Intention

RA Damage

Put This in Your Notes

Chapter 3 Must-Know Exam Hitters

• Inflammation is the second line of defense.

• Acute inflammation is triggered by tissue injury and is necessary for healing.

• The first line of defense is skin/mucous membranes.

• The third line of defense is the immune response.

• Acute inflammation has vascular and cellular responses.

• Vascular response = vasodilation + increased permeability.

• Cellular response = chemotaxis + adherence + diapedesis.

• Exudate is protein- and leukocyte-rich fluid at the injury site.

• Mast cells release histamine, leukotrienes, and prostaglandins through degranulation.

• Cytokines regulate inflammation.

• Arachidonic acid products help produce inflammatory effects.

• Cardinal signs are redness, heat, swelling, pain, loss of function.

• Fever occurs when mediators affect the hypothalamus.

• Leukocytosis means WBC elevation.

• CRP and ESR show inflammation but not location.

• Healing requires hemostasis, debris removal, ECM repair, and functional tissue repair.

• Basement membrane is needed for re-epithelialization.

• Fibroblasts produce collagen.

• Too much collagen can cause keloids, adhesions, fibrosis, and contractures.

• Primary intention heals faster with less scarring.

• Secondary intention heals slower with more infection risk/scarring.

• Burns destroy the skin barrier and trigger local/systemic inflammation.

• Severe burns cause capillary leak, edema, hypovolemia, shock, and infection risk.

• Full-thickness burns may not hurt in the deepest area because nerves are destroyed.

• Burn patients can be swollen but intravascularly depleted.

• RA is systemic autoimmune chronic inflammation of synovial tissue.

• RA causes synovial hyperplasia, immune complexes, complement activation, pannus, erosion, fibrosis, ankylosis, and deformity.

• Symmetric joint pain, morning stiffness, swelling, warmth, and systemic fatigue are classic RA cues.

One-Line Memory Anchor

Mini Practice Questions

Question 1

A client sprains an ankle and develops redness, warmth, swelling, and pain. Which process primarily causes the redness and warmth?

A. Decreased blood flow
B. Vasodilation
C. Fibrosis
D. Necrosis

Answer: B

Rationale: Redness and warmth occur because inflammatory mediators cause vasodilation, increasing blood flow to the injured area.

Question 2

A wound has protein-rich drainage with many leukocytes. Which term describes this fluid?

A. Transudate
B. Exudate
C. Thrombus
D. Collagen

Answer: B

Rationale: Exudate is protein- and leukocyte-rich fluid that accumulates at the injury site due to increased vascular permeability.

Question 3

Which sequence correctly describes the cellular response of acute inflammation?

A. Diapedesis, adherence, chemotaxis
B. Chemotaxis, adherence, diapedesis
C. Fibrosis, angiogenesis, necrosis
D. Apoptosis, necrosis, regeneration

Answer: B

Rationale: Cells are chemically attracted to the site, adhere to the endothelium, then migrate through the vessel wall.

Question 4

A client has elevated ESR and CRP. What does this indicate?

A. The exact location of infection
B. The presence of inflammation
C. The type of pathogen causing disease
D. The presence of cancer

Answer: B

Rationale: ESR and CRP indicate inflammation but do not identify its exact source or cause.

Question 5

A client has a surgical incision with approximated edges and minimal scarring. Which type of healing occurred?

A. Primary intention
B. Secondary intention
C. Replacement only
D. Chronic inflammation

Answer: A

Rationale: Primary intention occurs when wound edges are close together and heal quickly with reduced infection risk.

Question 6

A severe burn client has generalized edema and low blood pressure. Which mechanism best explains this?

A. Increased red blood cell destruction
B. Fluid shift from blood vessels into tissues
C. Increased insulin secretion
D. Decreased inflammatory mediator release

Answer: B

Rationale: Burns cause massive capillary permeability, shifting fluid and proteins from vascular space into tissue, causing edema and hypovolemia.

Question 7

A full-thickness burn area has little pain in the center. Why?

A. The inflammatory response is absent
B. The tissue is healing normally
C. Nerve endings have been destroyed
D. Blood flow is increased

Answer: C

Rationale: Full-thickness burns destroy nerve endings, so the deepest area may have reduced pain sensation.

Question 8

A client with rheumatoid arthritis develops pannus formation. Why is pannus harmful?

A. It increases synovial fluid nutrition to cartilage
B. It protects cartilage from inflammation
C. It erodes cartilage and bone
D. It prevents immune complex formation

Answer: C

Rationale: Pannus is destructive granulation tissue that spreads over cartilage, deprives it of nutrients, and releases enzymes that erode cartilage and bone.

Question 9

A client with rheumatoid arthritis has decreased joint movement and surrounding muscle atrophy. What explains the muscle atrophy?

A. Increased workload on muscle cells
B. Decreased use of muscles around the painful joint
C. Increased cartilage regeneration
D. Excessive oxygen delivery

Answer: B

Rationale: Pain and joint fixation decrease movement. Decreased workload causes muscle cell atrophy, connecting back to Chapter 2.

Question 10

Which statement shows correct understanding of wound healing?

A. Scar tissue performs the same function as original tissue.
B. Basement membrane destruction improves re-epithelialization.
C. Collagen helps close wounds but excessive collagen can impair function.
D. Permanent cells regenerate quickly after injury.

Answer: C

Rationale: Collagen is necessary for repair, but excessive collagen can cause fibrosis, keloids, adhesions, scarring, and contractures.

Chapter 3 Final Exam Focus

Study this chapter in this order:

1. Three lines of defense

2. Acute inflammation goals

3. Vascular response

4. Cellular response

5. Cardinal signs

6. Fever, leukocytosis, CRP/ESR

7. Healing phases

8. Primary vs secondary intention

9. Complications: infection, ulcer, dehiscence, keloid, adhesions

10. Burn depth and burn shock

11. RA autoimmune pathogenesis

12. Pannus → erosion → fibrosis → ankylosis

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