general pathology lecture 5 inflammation & repair
TRANSCRIPT
INFLAMMATION AND REPAIR
Lecture 5
INFLAMMATION AND REPAIR
Lecture 5
INFLAMMATORY CELLSINFLAMMATORY CELLS
SIGNS OF INFLAMMATION• RUBOR- REDNESS DUE TO INCREASED BLOOD BLOW AND VASODILATION• CALOR- OR HEAT DUE TO INCREASE BLOOD FLOW TO THE PERIPHERY• TUMOR- SWELLING FROM INFLAMMATORY EDEMA• DOLOR-PAIN FROM SWELLING AND PRESENCE OF INFLAMMATORY
MEDIATORS• FUNCTIO LAESA-LOSS OF FUNCTION DUE
TO MAIN AND STRUCTURAL NECROSIS
Question
• Pain associated with acute inflammation is thought to be caused by
A. pressure effects of exudate fluid
B. histamine
C. serotonin
D. kinins
E. all of the above
Acute Inflammation• What is it?
– Series of reactions of
vascularized tissuevascularized tissue to injury
• What is its purpose?– Defend against foreign
substances (infection)
– Dispose of dead / dying
tissue
– Immobilize injured area
– Compartmentalize area
Acute Inflammation
• Events in Acute Inflammation– Neurologic events– Hemodynamic events– Cellular events
• Events Overlap and are related• Events are the same regardless of cause of
inflammation– Magnitude of events depends on:
• severity of injury• immune status• temperature
Acute Inflammation – Neurologic events
• Initial Vasoconstriction– Transatory & reflexive
– usually lasts up to 30 seconds
• Gradual Vasodilation– Relaxation of reflexive spasm
– Causes “bleeding” to start
Acute Inflammation – Hemodynamic Events
• Vasodilation– From relaxation of reflex & chemical mediators
• Slowing of bloodflow– Relationship of flow to diameter
• Margination of Leukocytes– ???? Nobel prize for Medicine
• Hemostasis• Permeability Changes
Acute Inflammation – Hemodynamic Events
• Permeability Changes– Mostly from inflammatory chemicals– Occurs in capillaries & small venules– Junctions between epithelial cells loosen– Fluid leaks (transudate exudate)– Leads to hemoconcentration– Makes margination easier
ACUTE INFLAMMATIONACUTE INFLAMMATION
Events in Acute Inflammation
• The order of the events in acute inflammation are
1. vascular dilatation 2. increased vascular permeability 3. local hemoconcentration and slowing of blood 4. margination of white blood cells 5. emigration of leukocytes
Acute Inflammation – Cellular Events• Circulating Leukocytes
– Marginated cells emmigrate from vasculature (diapedesis) – smaller first, larger later
– Basophils – release anti-coagulants– Neutrophils – vicious phagocytes
• Release many chemical mediators – chemotaxis• Primary job is to phagocytize bacteria• Magnifies inflammation above required level in musculoskeletal
injury
– Monocytes Macrophages• Arrive ~ 5h post-injury• Remove dead tissue debris (clean up the mess)
Acute Inflammation – Chemical events
• Over 180 different chemicals involved in acute inflammation
• Sources = damaged cells, inflammatory cells, platelets, plasma, etc.
• Histamine – 1st chemical, strong vasodilator & increases permeability
• Bradykinins – increases permeability & pain (especially with prostaglandins)
• Prostaglandins – made from released phospholipids (arachadonic acid cascade)– Target of NSAIDS & steroidal anti-inflammatories
Acute Inflammation – big picture
• First few seconds– Immediate vasoconstriction
• First Hour– Gradual vasodilation
– Hemostasis begins
– Mast Cell degranulation
– Margination of WBC’s
– Large scale neutrophil response begins
• After the first hour?– Hemoconcentration
from edema– Ischemia– Growing interaction of
chemical mediators– Emmigration of larger
WBC’s– Complement System
Question
• Of the following events that are part of the acute inflammatory response, which would occur THIRD in correct sequence?
A. vascular dilatation
B. local hemoconcentration and slowing
of blood
C. margination of WBC’s
D. emigration of WBC’s
E. increased vascular permeability
TYPES OF INFLAMMATION BASED ON SITE AFFECTED
• ABSCESS
• ULCER
• CELLULITIS or PHLEGMON
• PSEUDOMEMBRANOUS INFLAMMATION
Chronic Inflammation
• Immunologists define as period when macrophages predominate
• Clinicians define as recurrent inflammation prior to completion of repair or resolution
• Cellular Aspects– Leukocytes during early post-acute phase
• CD8+ (T- killer) & CD4+ (delayed hypersensitivity)
CHRONIC OSTEOMYELITIS-BRODIE’S ABSCESS
CHRONIC OSTEOMYELITIS-BRODIE’S ABSCESS
Chronic Inflammation
• Easy to re-start inflammation– Clinically, must control activity level & protect
injury site
• Leads to hypertrophic scarring– Additional infiltration of fibroblasts– Abundance of stimulating chemicals
Question
• The features, monocytes, giant cells, fibroblasts and lymphocytes, are characteristics of
A. acute inflammation
B. granulation tissue
C. wound healing
D. chronic inflammation
E. suppuration
ABSCESS-HEARTABSCESS-HEART
Question Which of the following inflammation commonly
is characterized by collections of dead and dying polymorphs, dead and dying bacteria, and necrosis of tissue, all of which form a turbid or thick fluid in tissues?
A. catarrhal inflammation
B. phlegmonous inflammation
C. cellulitis
D. abscess formation
E. granulomatous inflammation
ULCER-GASTRIC MUCOSAULCER-GASTRIC MUCOSA
PEPTIC ULCERPEPTIC ULCER
CELLULITISCELLULITIS
PSEUDOMEMBRANOUS INFLAMMATION - DIPTHERIA
PSEUDOMEMBRANOUS INFLAMMATION - DIPTHERIA
TYPES OF INFLAMMATION BASED ON THE NATURE OF EXUDATES
• SEROUS INFLAMMATION
• MUCOUS INFLAMMATION
• FIBRINOUS INFLAMMATION
• CATARRHAL INFLAMMATION
• HEMORRHAGIC INFLAMMATION
• PURULENT OR SUPPURATIVE
FIBRINOUS INFLAMMATION-PERICARDIUM
FIBRINOUS INFLAMMATION-PERICARDIUM
HEMMORRHAGIC INFLAMMATION-RIGHTHEMMORRHAGIC INFLAMMATION-RIGHT
GRANULOMATOUS INFLAMMATION
• Granulomatous inflammation occurs after the acute-phase response and consists of epithelioid and giant cells.
• Two types of granuloma:
1. Foreign Body granuloma-formed in response to indigestible materials
2. Allergic granuloma-formed in delayed hypersensitivity reactions
Question
Which of the following findings is an invariably histologic feature of granulomatous inflammation?
A. caseous necrosis
B. multinucleated giant cells
C. positive acid-fast staining of causative
organism
D. surrounding cuff of lymphocytes
E. epithelioid cells
GRANULOMATOUS INFLAMMATION-LUNGSTHYROIDITIS WITH GRANULOMA
GRANULOMATOUS INFLAMMATION-LUNGSTHYROIDITIS WITH GRANULOMA
GRANULOMATOUS INFLAMMATION WITH SPHERULES
GRANULOMATOUS INFLAMMATION WITH SPHERULES
LANGHAN’S GIANT CELLS FOREIGN BODY GIANT CELL- IN SUTURE LINELANGHAN’S GIANT CELLS FOREIGN BODY GIANT CELL- IN SUTURE LINE
SYNCYTHIAL GIANT CELLSSYNCYTHIAL GIANT CELLS
REED-STERNBERG GIANT CELLREED-STERNBERG GIANT CELL
TOUTON GIANT CELLWARTHIN-FINKELDEY GIANT CELL
TOUTON GIANT CELLWARTHIN-FINKELDEY GIANT CELL
PRIMARY SKIN LESIONSPRIMARY SKIN LESIONS
PRIMARY SKIN LESIONS
MACULE
• MACULE IS A CIRCUMSCRIBED FLAT AREA LESS THAN 1 CM OF DISCOLORATION WITHOUT ELEVATION OR DEPRESSION OF SURFACE RELATIVE TO SURROUNDING SKIN
MACULEMACULE
PAPULE
• PAPULE IS A CIRCUMSCRIBED, ELEVATED, SOLID LESION LESS THAN 1 CM IN DIAMETER, SUCH AS THE LESIONS OF LICHEN PLANUS AND NONPUSTULAR ACNE
PAPULEPAPULE
PATCH AND BULLA
• PATCH IS A CIRCUMSCRIBED AREA OF DISCOLORATION, GREATER THAN 1CM WHICH IS NEITHER ELEVATED OR DEPRESSED RELATIVE TO THE SURROUNDING SKIN
• BULLAE ARE RAISED, CIRCUMSCRIBED LESION GREATER THAN 0.5 CM THAT CONTAIN SEROUS FLUID
PATCH and BULLAEPATCH and BULLAE
PLAQUE AND PUSTULE
• PLAQUE IS A WELL-CIRCUMCRIBED, ELEVATED, SUPERFICIAL, SOLID LESION, GREATER THAN 1 CM IN DIAMETER
• PUSTULE IS A SMALL (1CM IN DIAMETER) CIRCUMSCRIBED SUPERFICIAL ELEVATION OF THE SKIN THAT IS FILLED WITH PURULENT MATERIAL
PLAQUE and PUSTULEPLAQUE and PUSTULE
TUMOR and VESICLE
• TUMOR – is a solid, firm lesion about 1 cm in diameter that can be above, level with or beneath the skin surface. It is also called a mass.
• VESICLE – is a small , superficial elevation of the skin, less than 0.5 cm, that contains serous fluid.
TUMOR and VESICLETUMOR and VESICLE
WHEAL OR PLAQUES ARE TRANSIENT,
CIRCUMSCRIBED, ELEVATED
PAPULES OFTEN WITH
ERYTHEMATOUS BORDERS AND PALE CENTERS
WHEAL OR PLAQUES ARE TRANSIENT,
CIRCUMSCRIBED, ELEVATED
PAPULES OFTEN WITH
ERYTHEMATOUS BORDERS AND PALE CENTERS
REPAIR, REGENERATION AND FIBROSIS
• Cell types and regenerative ability: 1. Labile cells- cells with short life span that
constantly proliferate. Excellent regeneration. (Ex. skin, gut, hemopoietic cells)
2. Stable cells-normally with little proliferation but remain capable of more raid cell division following injury. Good regeneration. (Ex. liver, renal PCT)
3. Permanent cell- are not capable of proliferation. No regeneration. Healed by scarring (Ex. Brain, heart)
Tissue Repair
• Fibroplasia – fibrous repair– Formulation of Granulation tissue
• Capillary budding results from mitogens– PDGF most important, hypoxia contributes
• Forms meshlike framework for scar development
– Infiltration of fibroblasts– Collagen laid down in random pattern
• Structure can be manipulated!!!!!
– Scar tissues excessive if inflammation re-initiated
Tissue Repair
• Maturation & Remodeling– Initial scar formation takes weeks– Scar matures
• Longest part of inflammation (over 1 yr)• Re-absorb temporary vasculature
– Scar shrinks (contraction) & changes color
– Scar remodels• Collagen fibers re-align with stress (SAID)• Less tensile strength than tissue it replaces
GRANULATION TISSUE IN HEALED SCAR
GRANULATION TISSUE IN HEALED SCAR
SURGICAL WOUNDS
• HEALING BY PRIMARY INTENTION – is letting a surgical wound heal without a big scar, where the wound hasneatly apposed edges
• HEALING BY SECONDARY INTENTION- is letting a surgical wound heal and leave a big scar, called granulation tissue that is formed from the bottom up, with the edges not neatly apposed.
GRANULATION TISSUE IN MYOCARDIAL INFARCT
GRANULATION TISSUE IN MYOCARDIAL INFARCT
KELOIDSKELOIDS