Gen Path Chapter 2 Flashcards
(193 cards)
1
Q
List the Antibiotic Super Bugs
A
- Methicillin-Resistant Staphylococcus Aureus (MRSA)
- Multi-drug Resistant: Mycobacterium tuberculosis
- Vancomycin-resistant enterococci
- Fluoroquinolone-Resistant Clostridium Difficile
2
Q
Infection
A
Some bacteria, all viruses and all parasites cause illness via infection
3
Q
Bacteria Examples
A
Salmonella spp, listeria monocytogenes, Campylobacter, jejuni, Vibri parahaemolyticus, and Yersinia enterocolitica
4
Q
Virus Examples
A
- Hepatits A
- Norovirus
- Rotavirus
5
Q
Parasites
A
- Trichinella Spiralis
2. Giardia Duodenalis
6
Q
Intoxication
A
Results when a person eats food containing toxins that cause illness
Produced by harmful microorganisms, the result of chemical contamination or a natural part of a plant or seafood. Some bacteria cause an intoxication.
7
Q
Viruses and Parasites do not cause food borne intoxication T/F?
A
True
8
Q
Intoxicating Bacteria
A
- Clostridium Botulinum
- Staphylococcus Aureus
- Clostridium Perfringens
- Bacillus Cereus
9
Q
Signs and symptoms of disease
A
Systemic (fever) or Local (Pus)
10
Q
What do the symptoms of a disease depend on?
A
Etiologic Agent - Type and virulence
- System affected
- Health of the individual
11
Q
Common Systemic S&S
A
- Fever
- Chills
- Sweat
- Malaise
- Nausea
- Vomiting
- Change in
- Leukocyte type and/or Number
- Enlarged lymph nodes
- Possible cognitive changes in elderly
12
Q
What is a pyrogen?
A
A substance that typically causes fever
- Bacteria
- Cytokines
Raises ‘set point’ in the hypothalamus resulting in increased temperature
13
Q
Fevers that are not infectious are usually caused by
A
- Inflammatory Diseases
- Abnormalities of the hypothalamus
- Dehydration
- Toxic Substances - medications
- Neoplastic Diseases
- Immunologically - mediated diseases
- Pulmonary embolism
14
Q
Normal Body temperature of a child and an adult
A
Child: 96.6-99f (36-37.2 C)
Adult: 98.6 F (37c)
15
Q
Temperature of low grade fever
A
Up to 102 F (39C)
16
Q
Temperature of high fever
A
101f or over for babies
over 102f
104f (40c) - Seek medical attention
17
Q
Effects of Prolonged High Fever
A
- Seizures
- Delirium
- Disorientation
- Hallucinations
18
Q
Describe inflammations caused by infections
A
- Local or systemic
Abscess - pus formed from leukocytes
19
Q
Infectious Diseases Caused by abscesses:
A
Infectious GI diseases (Diverticulitis)
P.I.D (Pelvic Inflammatory Disease)
20
Q
Rashes with Fevers can result from:
A
Infection caused by microbe that has successfully penetrated the layers of the skin and multiplied locally
Infection elsewhere in the body unrelated to local skin disease (eg Scarlet Fever from streptococci)
21
Q
Common Rashes Caused by Infections:
A
- Maculopapular Eruptions
- Nodular Lesions
- Diffuse Erythema
- Vesiculobullous eruptions
- Petechial purpuric eruptions
22
Q
What are red streaks and what are they caused by?
A
Local infection that is spreading into the lymphatic system (Lymphangitis, moves toward local lymph Node)
23
Q
What can inflamed lymph nodes be associated with?
A
Many infectious diseases, not just sepsis
24
Q
What regions are the lymph nodes palpated
A
- Cervical
- Inguinal
- Axillary
25
Causes of inflamed lymph nodes
1. Cancer
2. Rheumatoid Arthritis
3. medications
26
Characteristics of acute swollen nodes (bacterial)
1. Palpable
2. Tender
3. Enlarged
4. Fluctuant
If red and hot with fever send to Dr.
27
Characteristics of Chronic swollen Nodes (Infection)
1. Palpable
2. Tender
3. Enlarged
Not usually red/warm
28
Characteristics of Metastatic Cancer
1. Supraclavicular & Inguinal are common areas
| 2. Hard, fixed, non-tender and may be rubbery
29
What is Sepsis caused by normally?
Secondary to infection:
1. Hemolytic Streptococcus and/or staphylococcus
30
What lymph Nodes are the most often affected by sepsis?
1. Submandibular
2. Cervical
3. Inguinal
4. Axillary
31
What causes Joint effusion and what can it be a sign of?
```
Another sign of infection
Result of:
1. Bacterial
2. Mycobacterial
3. Fungal
4. or Viral
Usually through the blood stream, but could be innoculated as a consequence of surgery or trauma
```
32
Signs and Symptoms of joint effusion
Usually one joint
Associated with infectious Arthritis
and Suppurative infectious arthritis
33
Define infectious arthritis
arthritis resulting from infection of synovial tissue with pyrogenic bacteria or other agents
34
Define Suppurative infectious arthritis
Suppuration (pyrogenic): the formation or discharge of pus
35
Symptoms of Infectious Arthritis
1. Acute Pain
2. Stiffness
3. Most common in knee
4. Also in shoulder, wrist, fingers, hips, elbows
5. Fever and Chills
6. Heat
7. Tenderness w Palp
36
Define Immunosenescence
Changes in immune system as we age
37
Effects of aging
Immunosenescence
Decreased circulation and poor wound healing
Decreased function of natural barriers
Decreased cough/gag reflexes
(decrease ability to clear secretions)
Decreased bronchiolar elasticity and mucociliary activity (increased risk of phenumonia
38
What causes a decrease in t-cells but an increase in memory cells?
Aging...
Slower to respond/require a strong stimulus
Increased likelihood of reactivation of dormant infections (Tb, Shingles)
39
effects of comorbidities
chronic disease rises with age
40
Medications and aging
Can mask signs and symptoms of other problems related to aging
41
Fever symptoms in an aging person
Serious infection with little to no fever due to impaired thermoregulatory system
or masking effects of drugs
42
1st symptoms of infection in elderly may be:
1. Confusion
2. Memory Loss
3. Delirium
43
Define Infectious Diseases
Organism establishes parasitic relationship with host causing an invasion + Multiplication = an immune response
Thus causing damage to the host
either by microorganisms toxins, replication, or indirectly by competing for nutrients.
Or even our own immune system
44
Define Carriers
Someone infected with microorganisms with 0 symptoms. Can still transmit to other people and be infectious (non-symptomatic)
45
List the 3 Processes of infection
1. Transmission
2. Incubation
3. Infection
46
Define Transmission in regards to process of infection
Depends on pathogen, ideal factors for transmission as well as state of host.
MUST have -
1. Portal of entry
2. Mode of transportation
3. Portal of exit
47
Define Chain transmission and list the 6 steps
Infection begin with transmission
1. A pathogenic agent
2. reservoir
3. Portal of exit
4. Mode of transmission
5. Portal of entry
6. Susceptible host
This is known as the chain of transmission
48
define pathogen
| and how the infection is caused
```
organism elicits a pathologic response in host
Depends on:
1. Site of invasion
2. Number of pathogens and virulence
3. How well they disseminate in host
4. Immune status of host.
```
49
Define Principal Pathogens
Cause disease in people with intact immune systems
50
Define Opportunistic Pathogens
Pathogens that don't cause disease in people with intact immune systems, but can cause devastating disease in hospitalized or immunocompromised people
51
Define Pathogenicity
Ability of organism to induce disease
52
Define Virulence
Refer to potency of pathogen in producing sever disease and is measure in case fatality rate
53
Define Nosocomial infections
Originates or takes place in hospital, acquired in hospital esp, in reference to an infection
HAI - hospital acquired infection
54
List the most common nosocomial infection HAI
UTI from catheters or urologic procedures, blood infections from IV catheters or surgical wounds and GI infections.
55
Define Reservoir
Environment in which organism can live and multiply
(Animals, Plants, Soil, Food, Organic Substances)
Humans an animal reservoirs can be symptomatic or asymptomatic
56
What is a portal of exit?
Where the organism leaves the reservoir and corresponds to the entry point on the next host
1. Respiratory Droplets
2. Blood
3. Vaginal Secretions
4. Semen
5. Tears
Urine and Feces as well as Open lesions and Pus
57
List how the organism gets from an infected host to a new host:
1. Contact (Direct or Indirect)
2. Aiborne - floating through air
3. Droplet - diff then airborne bc drops 3ft
4. Vehicle - common source Salmonella or contaminated food
5. Vector - Involves insects and animals that act as intermediaries between 2 or more hosts
58
Define Portal of entry and list examples
Where the pathogen leaves/enters
1. Ingestion
2. Inhalation
3. Bites
4. Contact with mucous membranes
5. Percutaneous
6. Transplacental
59
List the factors of host susceptibility
1. Age, sex ethnicity
2. Health & Nutrition
3. hormonal balance
4. Co-morbidities
5. Living Conditions
6. Personal Behaviours (drug use, hygiene, diet, sexual practices)
7. Medications
8. Environment
9. Use of invasive equipment - Catheters iv lines and chest tubes
10. Stress
11. Underlying medical disorders that specifically decrease t-cell and b-cell medicated immunity
60
List and explain the Process of an infection
1. Incubation
- Time between entering the host, and 'infection'
- Hours (GI Bugs) to months (lyme DZ)
- Symptoms = end of incubation
- 'Latency = Dormant
2. Infection
- Clinical Symptoms
- Host-parasite interaction causes injury
- Mild -> Fatal
- Communicability: Ability to spread to another host
61
List the Lines of defense
1st line of defense - external barriers/secretions and microbial antagonism
2nd line of defense - inflammation
3rd Line of defense - Immune response
62
List the types of Organisms
1. Viruses
2. Mycoplasmas
3. Bacteria
4. Rickettsiae
5. Chalmydiae
6. Protozoa
7. Fungi (Yeast/Mold)
8. Helminths (worms)
9. Mycobacteria
10. Prions
63
How are organisms characterized?
Size, shape structure chemical composition, antigenic make up, growth requirements, produce toxins, viability under diff circumstances (sun, o2, heat, acid, etc..)
64
List the characteristics of Cell Walls
1. Rigid Thick
2. Outermost layer, surrounds cell membrane when present. Occurs in plants, bacterium and fungi
3. Made of peptidoglycan in bacteria and chitin in fungi
4. Metabolically inactive and non-living
5. Determines cell shape and offers protection
65
Characteristics of cell membrane
1. delicate, thin
2. Outermost layer in animal cells, semipermeable
3. made of lipids, proteins and carbs.
4. Metabolically active and living
5. protects the protoplasm and maintains homeostasis in a cell
66
Define Viruses
Smallest RNA or DNA covered with proteins
- antibiotics do not help
- antiviral meds only moderately effective
Entirely dependent on host
(Acyclovir decreases DNA replication)
67
Define mycoplasma
very small self-replicating bacteria with no cell wall, dependent on host for nutrition
68
Define bacteria
Single celled organisms with cell wall; independent
Replicates by growing and diving in half, they can do this in any tissue.
Classified by shapes
69
List the shapes that bacteria can be classified as:
Spherical-cocci, Rod-shaped - bacilli, spiral - shaped - spirochetes) Staining (gram positive/negative) motility, spores, 02, NonO2
70
Ex of Anaerobic bacteria
Normal gut flora
71
Ex of Aerobic bacteria
Staphlococcus Aureus (lungs, skin)
72
Compare Gram + and Gram -
Effects susceptibility to antibiotics and detergents
Gram + Destroyed by penicillin
Gram - Much more resistant
73
Define Rickettsiae
Small obligate intracellular parasites that are non-motile gram negative bacteria
Primarily animal pathogens that produce disease inhumans and are commonly transmitted by insect bites (tick, flea, louse, Mite)
Require host for replication
i.e. Q Fever (Coxiella); "Trench fever" Carried by lice (rochalimaea)
74
Define Chlamydiae
Smaller than bacteria but larger than viruses
- Obligate Intracellular - Dependent on host for replication
1. Always contains both RNA and DNA (Unlike Viruses)
2. Susceptible to antibiotics - curative
3. Most common STD
- Leading cause of P.I.D.
- Leading cause of preventable blindness in neonates
75
Define protozoa
1. SIngle cells or group of cells
2. Motile, free living in moist environments
3. Cell membrane, no cell wall
4. Divide similar to bacteria
Ex. Giardia
76
Fungi
1. Unicellular organism that produces hyphae (filamentous outgrowths)
2. Contains Nuclei (eukaryotic)
3. Cell Walls
4. Yeasts or molds
5. Reproduces by budding off
6. Candida Albicans is an example
77
Define Helminths
Large multicellular organisms that are generally visible to naked eye in adult stages.
Can be either free-living or parasitic in nature.
In adult form helminths are unable to multiply in humans
78
List the 3 groups of helminths
1. Flatworms (platyhelminths) Trematodes (flukes) and cestodes (tape worms)
2. Thorny headed worms (acanthocephalins)
3. Roundworms (nematodes) - adult form of these worms can reside in gastrointestinal tract, blood, lymphatic system or subcutaneous tissue.
79
Define Staphylococcus
BACTERIAL INFECTION
most common bacterial pathogen on skin
S. Aureus most virulent
Leading cause of nosocomial and community acquired infections
13% of all hospital infections .. 2 million per year and can effect all ages.
Effects blood, skin, lung, soft tissues, joints and bones and is a gram +
80
Define S. Aureus
BACTERIAL INFECTION
Transmission:
1. Direct Contact - nasal passages most common; also skin, axilla, perineum, vagina, oropharynx
Risks:
1. Insulin-dependent Diabetics; HIV+ Hemodialysis; IV Drugs, Chronic Skin lesions; corticosteroid use; surgery, burns
Pathogenesis:
1. Secretes membrane-damaging enzymes & Toxins
2. Stimulates a strong host immune response
81
Causes of S.Aureus
BACTERIAL INFECTION
Consumption of toxins in food.. Poisoning
Clinical manifestation (pus, and abscess formation)
Respiratory tract infection: Osteomyelitis, infections of burns and surgical wounds, septicimia, toxic shock syndrome, bacterial arthritis, Bacterial endocarditis, impetigo
82
How is S.Aureus Diagnosed?
BACTERIAL INFECTION
Culture from infected site, blood or other fluids & must be tested for antibiotic resistance..
Prognosis is good with tx unless MRSA - Endocarditis
83
Define Streptococcus
BACTERIAL INFECTION
Anaerobic Gram + bacteria...
Grp A (S.Pyogenes)
- Most common bacteral pathogens of humans
Causes:
Skin infections, Pharyngitis (strep) Rheumatic fever
Suppurative - invasion of site with necrosis and pus -> acute inflammation
Non Suppurative - away from site of invasion immune related and triggered by prev. infection.
Symptoms: fever, chills, sore throat, enlarged lymph nodes, skin inflammation
Usually transmitted via respiratory droplets
84
Ex. of group A streptococcus
BACTERIAL INFECTION
- Strep Throat
- Scarlet Fever
- Necrotizing Fasciitis
85
Streptococcal Pharyngitis (Strep)
```
BACTERIAL INFECTION
Most common in kids (5-10 yrs)
Incubation 1-5 days
Clinical manifestation:
1. Sore throat
2. Beefy red pharynx
3. Tonsillar exudates
4. Swollen tonsils and uvula
5. swollen regional lymph nodes
6. Malaise and weakness
7. Anorexia
```
Can also colonize with no symptoms
Complications: otitis media, sinusitis, or rarely arthritis, endocarditis, meningitis can also colonize w no symptoms
86
Define Scarlet Fever
BACTERIAL INFECTION
Usually follows untreated strep throat (pyogenic exotoxin released)
Kids ages (2-10)
Clinical Manifestations:
1. Sore Throat,
2. Fever,
3. Strawberry Tongue
4. Rash which starts on upper chest. spares palms/soles
5. Desquamation of palms and soles later on
87
Define necrotizing fasciitis
BACTERIAL INFECTION
Serious infection that progresses rapidly along fascial planes usually found in legs...
Causes severe tissue damage
Used to be known as streptococcal gangrene
Symptoms: edema, tenderness, pain, fever
88
Define group B strep (Streptococcus Algalactiae)
BACTERIAL INFECTION
Most common cause of neonatal pneumonia, meningitis, sepsis.. Fatal in 3-4% of neonates
Normal vaginal flora in 30% females
- May be passed on to baby as it passes through birth canal
- only 1% of these babies develop infection
- Infection in baby: Hypotension, pneumonia, bacteremia, meningitis
- this is the reason moms are put on antibiotics just before delivery due date.
89
Streptococcus pneumoniae
BACTERIAL INFECTION
important gram + organism bc of major cause of bacterial pneumonia and meningitis in adults and otitis media in children
Risk: Post-influenza or viral URTI, chronic disease, immunosuppresion, alcohol abuse
Clinical features:
Acute fever, chills
pleuritis w pleuritic chest pain
dyspnea
Productive cough or purulent sputum - blood streaked
90
Define Clostridium
BACTERIAL INFECTION
Clost- Perfringes Gram+
Severe trauma, wartime injury, septic abortion
Pathogenesis: Death of tissue with loss of vasculature , bacterial invasion, fermentation -> Gas and putrefaction (decomposition)
Clinical features: <3 days after injury -> sudden severe pain -> discharge w foul odour
Prognosis: Amp, extremities better than visceral or trunk
91
Define corynebacterium diptheria
BACTERIAL INFECTION
Gram +
Spread through aerosol or skin shedding
asymptomatic to life threatening syndrome that includes pharngitis and toxic mediated damage to heart, nerves, and other organs
92
Pseudomonas
BACTERIAL INFECTION
Aerobic gram negative
Opportunistic pathogen spread by contact, most common nosocomial pathogen, uncommon in health people. Thrives in pools, tubs, moist) Pneumonia, wound infection, esp burn... sepsis UTI, osteochondritis)
Inherently antibiotic-resistant
93
Neisserial Infection
BACTERIAL INFECTION
Gram- coffee bean-shapred diplococci aerobic bacteria
Neisseria gonorrhoeae responsible for STI Gonorrhea
Neisseria meningitides (meningococcus) - Significant cause of bacterial meningitis
94
Yersinia pestis
| bubonic plague
BACTERIAL INFECTION
Gram- rod shaped coccobaciullus, facultative anaerobic bacterium can infect humans and animals
caues deadly disease named plague.
95
Bloodborne viral infections include:
Hep b, c, and hiv
(5 types viral hep: - A -> E
B & C spread through sex blood or placenta (vaccine available)
C - Spread through blood no vaccine available
HIV: Retrovirus causes immunodeficiency syndrome Infects CD4 +T cells (Body fluid transfer
96
Define herpesviruses (HSV)
VIRAL INFECTION
Mucosal Contact = initial transmission
After first outbreak, becomes latent in sensory ganglia
Periodic lifetime outbreaks with certain triggers (a bad cold, high stress, decreased immune function etc)
97
List the Herpes Simplex Virus Types
VIRAL INFECTION
HHV1 - Simplex 1Cold Sores
HHV2 - Simplex 2Genital Herpes
HHV3 - Varicella Zoster 1. Form (Varicella) Chicken pox 2. form (zoster) Shingles
HHV4 EBV - Infectious mononucleosis, fever, rash, fatigue, lymphadenopathy, spleen enlargement
HHV5 - cytomegaly - Asymptomatic 80% carriers, immunocompromised exp: fever, splenomegaly, hepatitis, blindness, and peripheral neuropathy
HHV6 & 7 B-cell and T Cell Viruses - Roseola or 6th Disease Rash, Fever, runny nose
HHV8 - Kaposi sarcoma in aids - vascular tumor
98
Influenza
Respiratory Virus:
Outbreaks common in winter and spring,
Lrg droplet transmission or contact
Symptoms: High fever, chills malaise, myalgia, HA, sore throat, congestion, nonproductive cough
99
Respiratory Syncitial Virus (RSV)
Respiratory Virus
- Leading cause of lower resp. infections in children worldwide.
- Mild in older children / adults - common cold
100
Human Papilloma virus
Dna virus
| Many strains some cause cervical cancer and genital warts
101
Poliovirus
Almost eradicated - rarely causes poliomyelitis
102
Lyme Disease
Bacteria: Borelia Burgadorferi
- Vector - deer, bear, or black legged tick
Stage 1 1st 2 weeks; localized; bulls eye rash flu-like sx
stage 2 - early disseminated, rash resolved, lyme arthritis unilateral swelling of large joints, fatigue, loss of appetite
stage 3: 50% untreated intermittent arthritis, profound fatigue, chronic neuropathy, bone erosion
tx prevention and antibiotics
103
STI's
sex, sharing needle, birth
HPV - cause of 99% cervical cancer; also genital warts common in men
Chlamydia - most common sti - can lead to neonatal blindness and P.I.D.
Syphilis - 3 stages
- Painless chancre
- Warty lesion
- Very pad complications (granulomas, CVD, neuropathologies, CNS, infection, insanity
Gonorrhea - painful urination; pus d/c from urethra, P.I.D. in female partner, sterility/ectopic pregnancy - cured w antibiotic, but serious antibiotic resistance now
104
Ringworm
```
Fungal infection
(Tinea Corporis) Forms a ring shape with a red raised border. expands and raised red border represents areas of active inflammation with a healing center
```
105
Tinea Versicolor
Superficial fungal infection which leads to hypopigmented or skin hyperpigmented patches on the skin
106
Candidiasis
Fungal infection that can infect mouth, groin or vagina, also opportunistic infection
107
Pneumocystis Carnii
Opportunistic fungal infection causing pneumonia
108
Define the lymphatic system
Developed embryologically from venous system
Main job: Take extra fluid
Physiological function:
maintain fluid level
fight infections
remove cellular waste/debris from extracelluar spaces
109
What is the lymphatic system made up of
Network of tissues and organs, it is made by
Lymph - fluid that contains white blood cells that defend against germs
Lymph Vessels - vessels that carry lymph throughout your body. They are different from blood vessels
Lymph Nodes - glands found throughout the lymph vessels. Along w your spleen, these nodes are where white blood cells fight infection
110
List the pathway of lymph Flow
1. Interstitial Fluid
2. Initial lymphatic vessels
3. Larger collecting lymph Vessels
4. Trunks
5. Subclavian Veins
111
How is the lymphatic system apart of circulation
Takes up capillary filtrate (blood plasma-proteins)
-90% returned by venous sys; 10% by lymphatics
Lymph System - superficial and deep lymph vessels + nodes
Lymph 'pumping'
-Superficial -> oncotic/hydrostatic pressure; muscle contraction; arterial pulsation; skin movement
- Deep -> Lymph Vessels w smooth mm walls and valves like veins
- Regional lymph system
112
List the disorders of the lymphatic system
Lymphangitis - inflammation of lymph vessel
Lymphadenitis - inflammation of one or more lymph nodes
lymphedema - increased lymph fluid in tissues
Lymphadenopathy - enlargement of the lymph nodes
113
Define Lymphangitis
acute inflammation of subcutaneous lymphatic channels - often d/t hemolytic staphylococcus and/or streptococcus entering the lymph system through an abrasion/cut
Wound, trauma, or invasive infection (E.g cellulitis)
Can manifest as a red streak under the skin
Pose also general systemic signs of infection -> fever, malaise, chills, anorexia
114
Define lymphadenitis
Lymphnode inflamed due to infection
```
Invading pathogens (viral, bacterial, fungal, parasitic)
Injuries or immunosuppression
```
115
Define lymphedema
Abnormal accumulation of protein-rich fluid in interstitial space (extracellular) due to lymphatic transport malfunction
Mechanisms: Decreased lymph capacity and/or
Increased lymphatic load
116
List the different kinds of lymphedema
1. idiopathic w unknown etiology
approx 15% at birth
approx 75% onset b/t adolescence and mid life in a 4:1 ration of female:male
Tine % = genetic (milroy's or meige's disease)
Aplastic, hypoplastic, hyperstatic
Type 2 lymphedema
Acquired
secondary to damage of the vessels and /or nodes
MC cause = filariasis (parasitic infection - tropical climates)
MC cause in non-tropical areas = procedures in the dx and tx of cancer
LN Dissection;radiation tx; reconstructive surgery
Other causes.... bacterial or viral infections
multiple abdominal surgeries
any trauma including surgeries.. repeated pregnancies
paralysis, and certain medications (tamoxifen)
117
Stages of lymphedema
0. Latent: Impaired transport but no obvious clinical signs
Sx's: Heaviness, aching, and/or Fatigue in limb
1. Soft - Pitting reverses w elevation fibrosis begins
2. no pitting - no reversal w elevation. Clinical fibrosis, skin changes, chronic inflammation, recurrent bacterial and fungal infections
3. lymphostatic elephantitis - severe, not pitting, Fibrosis, atrophic skin
118
Define pathogenesis lymphedema
Acummulation of lymphatic fluid in tissue -> chronic inflammation and progressive tissue fibrosis.. Decrease tissue oxygenation and increased risk of infection (decreased activity of macrophages)
- exacerbated by further infection (cellulitis or lymphangitis, or inlammation)
Sequelae - delayed wound healing, possible necrosis
119
Clinical manifestations of lymphedema:
Swelling, pain, paraesthesia (tingling) decrease ROM loss of function
Stemmers sign - thick skin fold over 2nd toe
120
Define lymphadenopathy
Inflammation of one set of localized lymph nodes or numerous regional lymph nodes
Due to inflammation or neoplasm
generally enlarged may be warm,. may be tender, fluctuant or fixed depending on cause
121
List the causes of inflammation:
Chemical Agents
Physical Force
Microbes
Any other stimuli that disturbs normal steady state
122
What type of organism does inflammation occur in?
Only in Multicellular organisms and living tissues
- Must be able to mount a neurovascular and cellular response
Protective and USUALLY beneficial
123
Four Cardinal signs of inflammation:
```
Heat (Calor)
Redness (rubor)
Swelling (Tumor)
Pain (dolor)
Loss of function (function Laesa - added later in 1990)
```
124
Five classic signs of inflammation:
```
SHARP
Swelling
Heat
Altered Function/immobility
Redness
Pain
```
125
Inflammation complex includes
1. Changes in circulation of blood
2. Changes in vessel wall permeability
3. White Blood Cell Response
4. Release of soluble mediators
126
Circulatory changes - first response to injury
1. Vasoconstriction of arterioles - lasts only seconds
2. Vasodilation
- a mechanical stimulus stimulates nerves to relax the smooth muscle cells on precapillary arterioles -> Blood rushes into capillaries -> redness, swelling, warm tissue
- Hyperemia
3. Edema - Fluid leaks out of blood vessels
4. Pain
- Direct Trauma, pressure from edema, chemical mediators, swelling of nerve endings
127
Vessel Wall Changes
Changes in permeability of capillary and post capillary venule walls occur because of:
1. Increased pressure inside congested blood vessels
2. Slowing of circulation -> reduces oxygen and nutrient supply
3. Adhesion of platelets -> release of soluble mediators of inflammation
4. Adhesions of leukocytes (white blood cells) to endothelial cells - Pavementing
128
White blood cell response:
1. Margination of leukocytes
2. Attach to endothelium - pavementing
- protrusions from cytoplasm stick to endothelial cells. Especially post capillary venules.
3. Adhesion molecules help with pavementing
- selectins and integrins
- ACtivated by cytokines (soluble mediators of inflammation) released by endothelial cells, leukocytes, platelets and macrophages
- Eg. Interleukins and Tumor Necrosis Factor
4. Emmegration (AKA Transmigration)
- Move through the blood vessel wall to inflammed tissue
-phagocytosis -> Swelling and pain
Increased permeability allows for transudation
-Emigration leads to exudate
-within first 48 hours of inflammation
- exudate contains a high concentration of PMN's, monocytes, eosinophils
The lifespan is only 2-4 days.
129
Define Transudation
Leaking of fluid from vessels into interstitial spaces -> protein rich edema (Transudate)
130
Define Exudate
Fluid containing more protein than transudate and also polymophonuclear leukocytes or polymophonuclear neutrophils (PMNs)
131
Describe phagocytosis role in inflammation
Once WBC's reach source of inflammation (microbes, destroyed tissue) they lose their mobility and become scavengers
132
Define Phagocytosis
To eat microbes or cellular debris
- > PMN cytoplasm surrounds the foreign particle -> invagination
- Foreign particle is internalized into phagocytic vacuole -> fuses with lyosomes
Lysosomal enzymes digest the foreign particle
Many leukocytes die during this time -> pus
Purulent or suppurative - inflammation dominated by pus
133
List the 4 Chemical mediators of inflammation
1. Histimine
2. Bradykinin
3. Leukotrienes
4. Complement system
5. Arachidonic acid
134
Describe the chemical mediator known as histamine
Released by mast cells and platelets
1. Causes contraction of endothelial cells of venules -> Gaps -> Increased blood vessel permeability
- > Vasodilator and bronchoconstrictor
- > Lasts less than 30 minutes
135
Define Bradykinin chemical mediator
Plasma protein formed by hageman factor (coagulation factor XII)
It has the same effects as histamine but at a slower pace and causes pain
136
What is the complement system?
Several proteins that are activated in a cascade acting on one another
137
List the 3 Pathways that activate the complement cascade
1. Classical Pathway - Activated by antigen-antibody complexes
2. Alternative pathway - activated by bacterial endotoxins, fungi, snake venom
3. Lectin Pathway - activated by binding of lectin to bacteria
138
In the complement cascade complex what pathways converge to form
All pathways converge to form the MAC Membrane attack complex
-Bores holes into membranes of microbes or body's own cells
Fills with fluid -> cell Death
139
What other complementary complexes and fragments are also biologically active?
1. Phagocytosis
2. Release of histamine causing vasodilation
3. Attract and activate WBCs (Chemotaxis) -> leukotriene production & Propagation of inflammation
140
Define Chemotaxis
Movement of PMNs to area of inflammation
141
What is an Arachidonic Acid Derivative?
Derived from phospholipids of cell membranes
Forms Leukotrienes and prostaglandins
Polyunsaturated fatty-acid found in brain, muscle, and liver
142
Define Leukotrienes
Increased vascular permeability and promotes chemotaxis
- Formed through the LOX pathway (Lipoxygenase Pathway)
- Bronchospasm - Contract smooth muscles in Borchi
- Anaphylactic shock
143
Define prostaglandins
Stimulates vasodilation, increases vascular permeability
-Formed through the cox pathway (cyclooxygenase pathway)
Pain and fever
144
List the different types of White Blood Cells
1. Neutrophils
2. Eosinophils
3. Basophils -> Mast cells
4. Monocytes -> Macrophages
5. Lymphocytes -> plasma cells
145
Describe polymorphonuclear Neutrophils (Leukocytes)
```
Most numerous WBCs in blood (60-70%)
First Cells to appear in acute inflammation
Features:
Mobility
Phagocytosis
Bactericidal Activity - Kill bacteria
Cytokine production - release mediators of inflammation
1. Promotes inflammation
2. Recruits new leukocytes
3. Cause Symptoms of inflammation
```
146
Describe Eosinophils
2-3% of circulating WBCs
Appear 2-3 Days after pmns in area of inflammation
1. Longer lifespan - chronic inflammation
Like PMNs they are mobile, phagocytic, and bactericidal
Interacts with basophils
Allergic Reactions: Hay Fever, Asthma
Responds to parasitic Infection
147
Define Basophil
less than 1% of circulating WBC's
Most prominent in allergic reactions (IgE)
Cytoplasmic granules contain histamine
Precursors to mast cells
Basically basophils outside of the blood vessel
148
Define Macrophages
```
Derived from monocytes in blood
Large
Appear at site of inflammation 3-4 days after onset of infection or injury
Long lived (chronic inflammation)
Phagocytosis and release of cytokines
```
Two main phagocytic cells = monocytes/Macrophages and Neutrophils
149
Define Platelets
Released from megakaryocytes in bone marrow
-No Nucleus
-Cytoplasm contains vacuoles and granules
- Histamine, coagulation proteins, cytokines, growth factors
Release histamine in early stages of inflammation
150
Define lymphocytes and plasma cells
Chronic inflammation
151
Summary of events of inflammation
1. Vasodilation
2. Altered Permeability
3. Activation of Inflammatory Cells
4. Chemotaxis
5. Cytotoxicity
6. Degradation of tissue
7. Pain and fever
152
What are the classification of inflammation?
Acute: sudden onset and can last hours to days
(Common Cold, Ankle Sprain )
Chronic:
-Weeks to months to years
May be result of: Recurrent acute inflammation
-Prolonged healing of acute inflammation
-Persistence of causes of inflammation
Due to prolonged duration it produces more extensive tissue destruction, heals less readily, and is associate with more functional deficiencies.
Etiology - What caused the inflammation?:
Infectious
- Bacterial, Viral, protozoal, fungal, helminthic
Chemical - organic or inorganic
Physical
- Heat, Trauma, Foreign body
Immune - To be discussed shortly
Location
Localized or systemic
Boil - Local vs sepsis - systemic
153
What are the cells required for wound healing?
Most important: Leukocytes, Macrophages, connective tissue cells, epithelial cells
Myofibroblasts, Angioblasts, Fibroblasts
154
Define Myofibroblasts
Properties of smooth muscle cells and fibroblasts
Contract like muscle cells and secrete cell matrix substances like fibroblasts
Holds edges of damaged tissue together
155
Define Angioblasts
Precursors of blood vessels
Proliferate from small blood vessels at the edges of damaged tissue
Appear 2-3 Days after injury. By day 6 New blood vessels are formed
- Provides a route for scavenger cells to remove tissue debris and scabs
-Allow oxygen and nutrients to flow to injured site
156
Define fibroblasts
Produces extracellular Matrix.
Fibronectin - provides the glue to hold cells together in wound healing
Collagen - From fibrils in interstitial spaces
157
What is granulation tissue?
Vascularized tissue filled with macrophages, myofibroblasts, angioblasts, fibroblasts, and turns into a scar
158
what does Wound healing depend on?
```
Site of wound
Mechanical factors
size of wound
Presence or absence of infection
Circulation Issues
Nutritional and metabolic factors
Age
```
159
What is deficient scar formation
Poor formation of granulation tissue
| - Inadequate collagen production can lead to wound dehiscence
160
What is excess scar formation
Keloid scar - hypertrophic scars
| Can lead to disfigurement and loss of function
161
what are the two types of immune responses?
Innate Immunity
- Nonspecific, protective
- No Memory
Acquired immunity
- Specific
- Has memory
162
Describe innate immunity
Inherited and operating at birth
First line of defense
Non specific - Each time an antigen is encountered the SAME response occurs
Do NOT rely on previous exposure to foreign substances
Includes:
Mechanical Barriers:
- Epidermis, Ciliated cells of nasal mucosa, or bronchus, hair, pH, Phagocytic Cells - Neutrophils and Macrophages
- Natural Killer Cells (NK)
Protective proteins found in tissue and plasma - complement lysozome
Inflammation
Cells of inflammation
163
Explain the line of defense in relation to innate immunity
1st Line of Defense: Physiological barriers
| 2nd line of Defense: NK cells, Phagocytes, inflammation
164
Describe the characteristics of 1st line of defense
1. Physical Barriers - Exterior Defenses
Skin - best defense we have, shown when significant burns occur - infection is a major problem
Mucosa - Body openings have their own defenses
Tears - Lysozomes protect the eyes wash away foreign substances
Ears - Ciliated, ear wax
Stomach and duodenal - Low pH values (Acidic)
Vagina - acidic
Urine - acidic
165
Describe the characteristics of 2nd line of defense
```
Cells and inflammation:
Phagocytes
-Neutrophils
-Monocytes
-Macrophages
Cells that release inflammatory mediators
-Basophils
-Eosinophils
-Mast cells
-Complement system
```
Natural killer cells
interferons
166
What are natural killer cells?
Granular lymphocytes that are neither T or B lymphocytes
Function is to kill viruses, infected cells, and tumor cells
Bind to potential target cells - release cytotoxic granules and cytokines
Natural killer cells burst forth from the tonsils, lymph nodes and spleen, and destroy infected cancerous cells while the immune system's T and B cells are still mobilizing.
Without natural killer cells, threatening conditions can get a strong foothold before the adaptive immune response kicks in
167
What are interferons?
They act as messengers, within the immune system and between the immune system and other systems of the body.
Produced by virally infected cells early in infection to limit the spread of infection by protecting surrounding (noninfected) cells
Once a cell is infected by a virus, certain genes are turned on in the cell that will produce interferons that coat the surrounding cells to make them viral resistant
they also inhibit tumor growth
168
Describe acquired immunity
Based on specific responses elicited by antigens
Antigen - Any chemical substance that can induce a specific immune response
Specific
Antigen Specific - Remembers the Antigens to an immune response can be mounted faster and more effectively
Has memory
Our bodies create immunologic memory to distinguish self from non-self
Immunocompetence - ability to mount an appropriate immune reaction
169
What is the basic terminology of immunity?
Antigens, Antibodies, and Major Histocompatibility complex.
170
Define antigens
Any substance that does not have the characteristic cell surface markers of that individual and is capable of elicitng an immune response
- Bacteria
- Virus
- Fungus
- Parasites
- Foreign Tissue
- Own cells/tissues (autoimmunity)
171
Define Antibodies
Protein molecules that fit specifically to an antigen like a lock and key
172
Major histocompatibility complex
Cell markers on the surface of all of our bodys cells that are unique to each of us, and tell our immune system that these cells are "self" like fingerprints
173
Epitopes
The part of the antigen that elicits the immune response - the part that binds to the antibody.
ie. A single bacterium contains hundreds of epitopes.
Confers "antigency' of a substance
The greater the number of epitopes (can be hundreds on each molecule of a foreign substance, ie a bacterium) the more places for an antibody to bind. The greater the immune response
174
Describe the major histocompatibility complex (MHC)
It is based on immunity depending on the immune cells ability to distinguish self from non-self
Originally discovered on leukocytes (white blood cells)
First called human leukocyte antigens (HLAs)
Functions: Essential for immune function
In addiction to telling the immune system which antigens are self and non-self they can also determine how strongly the system responds
And allows the immune system cells to communicate with one another
175
What diseases are HLA's more susceptible to?
Rheumatoid Arthritis, Graves Disease, Psoriasis
and most HLAs are inherited
176
What are the 3 basic rules to Acquired immunity?
Antigens and antibodies bind
"presents" the antigen to the immune system
and then the immune system mounts a response
177
What are the two ways to acquire immunity?
Active immunity:
Immunity acquired by introduction of an antigen into the host
- Environmental exposure
- Vaccination
Passive Immunity
- Immunity acquired when antibodies produced by one person are transferred to another.
- Trans placental transfer, Breast milk, antibody inoculation
- Does not form from memory cells; therefore it is only temporary immunity (lasting a few weeks to months)
178
Where do the cells of the acquired immune system originate from?
All originate from bone marrow stem cells
179
Define lymphocytes
Small cells, round nucleus, very little cytoplasm
Derived from bone marrow stem cells and turn into one of two different lineages
- Bone marrow stem cells -> migrate to the thymus -> T Lymphocytes
- Bone Marrow stem Cells -> remain and mature in bone marrow -> Colonize lymphoid tissues as B lymphocytes
Primary lymphoid organs - bone marrow and thymus
180
What do T and B lymphocytes do?
Enter blood circulation and colonize secondary lymphoid organs
- lymph nodes
- spleen
181
What do T and B lymphocytes form?
MALT - Mucoca-Associated lymphoid tissue
- found in the gastrointestinal tract
- Bronchial mucosa
182
Facts about T lymphocytes
Matures in thymus, part of the cell-mediated immunity
2/3rds of all lymphocytes in the blood, lymph nodes, and spleen
-all express protein CD3 on their membrane
-Linked to T-cell receptor
Used to recognize antigens
183
What are the sub types of lymphocytes?
T Helper Cells
T Suppressor Cells
Cytotoxic Cells
184
What do T suppressor Cells do?
Suppress activation of the immune system and prevent pathologic self-reactivity (Auto-immune disease)
185
What are cytotoxic T Cells?
Express CD8 Antigen on their surface
| Mediate the killing of virus infected cells or tumor cells
186
What clinical conditions affect Tcells?
```
HIV
Stress, Malnourishment
Cancer, Diabetes,
Surgery,
Immunosuppressing drugs - corticosteroids
Age - 65+ Produce less T cells
```
187
Describe the characteristics of B Lymphocytes
Differentiate into immunoglobulin producing plasma cells or memory B-Cells
Part of humoral immunity
Memory B-Cells
-Circulate among the blood, lymphoid system, and tissues for 1 year or longer
-Responsible for more rapid and sustained immune response that occurs with repeated exposure to the same antigen
188
What are Plasma Cells?
Full differentiated B lymphocytes
Produce Immunoglobulins (antibodies) (lg)
Surface of plasma cell is coated with ig
-5 types of antibodies are produced
189
What are the different types of Immunoglobulin antibodies?
IgG:
- Major anti-bacterial and anti-viral antibody
- Most abundunt type in blood
- Only antibody to cross placenta
- Responsible for the protection of the newborn for the first 6 months of life
igM
- Primary or initial immune response
- Largest antibody
- Stays in blood vessels
```
igA
-Defends external body surface
-Found on mucous membranes
-Found in secretions:
Saliva
Breast Milk
Urine
Seminal Fluid
Tears
and Nasal Fluid
```
igD
Controls lymphocyte activation or suppression
Found exclusively on B-cells
igE
- Primary factor in eliminating parasitic infections
- Functions during allergic reactions
- Activates mast cells to release histamine
- Associated with anaphylaxis, hives, allergen-induced asthma
190
What are the two types of acquired immunity?
Humoral - B lymphocytes (B Cells)
-Protects against extracellular microbes and their toxins (e.g. Bacteria)
Cell Mediated - T Lymphocytes (T Cells)
Defense against intracellular microbes (EG. Viruses)
Both types work together and bother are needed to mount an immune response
191
Describe humoral acquired immunity
Mediated by antibodies (Ab) Present in body fluids or secretions.
-Humoral = body fluids
->Blood, lymph, interstitial Fluid
A.K.A Antibody-Mediated Immunity
B-lymphocytes
-Formed in bone marrow
-Mature in bone marrow
-Differentiate into Memory B-Cells or Plasma Cells
Plasma cells secrete immunoglobulins (antibodies) to mount an immune response
Bind antigen to display it for destruction
Memory B-cells
-Remember antigen after first exposure
192
Described Cell mediated acquired immunity
All viruses and some bacteria hide inside cells where antibodies cannot reach them
T-Lymphocytes can recognize these hidden organisms and destroy the cells.
-Also implicated in transplant rejection, hypersensitivity reactions, and some autoimmune diseases
```
Intereaction with antigen -> activates T-Lymphocyte to produce specialized T-Cells (or sensitized T-cells)
Helper t cells (75% of all T-cells)
Cytotoxic T-cells
Suppressor T-cells
Memory Cells
```
193
Line of Defense
1st line of defense - Skin, Mucosal Hair, pH Barriers, innate
2nd line of defense - inflammation
innate
3rd line of defense - immune system cells
acquired
