PLTW HBS Lymphatic and Immune System

what causes jungle rot

prolonged moisture exposure, bacterial/fungal infection in tropical conditions

what kind of treatment(s) are used

keeping feet dry, antifungal medication, antibiotics if bacterial, regular cleaning

what would happen if treatment was not received

can progress to severe infection, tissue damage, potentially requiring amputation in extreme cases

what is a pathogen

infectious agents capable of causing disease

prions

description: misfolded proteins - cause normal proteins to fold, are transmissible and nonliving

treatments: no treatments

prevention: avoid consuming infected tissues, proper sterilization of medical equipment

found: extremely rare, consuming game meat

viruses

description: nonliving infectious agents containing genetic material that attack host cells

treatments: antiviral medication, supportive care

prevention: vaccines, hygiene practices, avoiding exposure

found: insect bites, contaminated water, other people

bacteria

description: single-celled microorganisms that reproduce independently

treatments: antibiotics, draining abscesses

prevention: hygiene, vaccination, food safety

found: contaminated water, food, soil, cuts/wounds exposure

protists

description: single-celled eukaryotes, infect through contaminated food/water/vectors

treatments: antiprotozoal medications

prevention: clean water, food safety, vector control

found: contaminated water sources, insect vectors

helminths

description: parasitic worms that infect through ingestion, skin penetration

treatments: antihelminthic medication

prevention: proper sanitation, cooking food thoroughly, wearing shoes

found: contaminated soil/water, undercooked meat, insect vectors

fungi

description: eukaryotic organisms that reproduce via spores; infect through contact, inhalation

treatments: antifungal medication, topical treatments

prevention: hygiene, keeping skin dry, avoiding contaminated environments

found: moist environments, soil, decaying vegetation

what items would you pack for your expedition to help prevent or treat an infection from one of these agents

first aid kit with antiseptic, hand sanitizer/soap, water purification methods, insect repellent, appropriate footwear/clothing, basic antibiotics, antifungal cream

what is a parasite

an organism that lives in or on another organism and benefits at the host’s expense

epidermis

protective barrier; stratum correum (dead cells), stratumlicidum (clear cells), stratumgranulosum (granular cells), stratum spinosum (spire cells), stratum basale (dividing cells)

dermis

strength, elasticity, contain blood vessels and nerve endings; papillary layer (connective tissue), reticular layer (dense irregular connective tissue), contains hair follicles, sweat glands, sebaceous glands

subcutaneous fatty tissue (hypodermis)

insulation, energy storage, shock absorption; adipose tissue, loose connective tissue, blood vessels

why is the skin important

physical barrier against pathogens, prevents water loss, temperature regulation, sensation, vitamin d synthesis, physical protection

how do the skin cells protect from invaders

continuous renewal through basal cell division pushes cells upward, creating constant replacement of the protective barrier and removal of potential pathogens

what is the role of mucus

traps microorganisms and foreign particls, contains antimicrobial enzymes, prevents pathogens from reaching cell surfaces

how would a second degree burn impact skin function

compromises barrier function, increases infection risk, impairs temperature regulation, causes fluid loss, damages nerve endings affecting sensation

what is sepsis

a life-threatening condition caused by the body’s extreme response to infection

sepsis

systemic inflammatory response to infection with elevated heart rate, respiratory rate, abnormal temperature, elevated white blood cell count

severe sepsis

sepsis plus organ dysfunction, such as difficulty breathing, abnormal heart function, reduced urine output

septic shock

severe sepsis with dangerously low blood pressure that doesnt respond to fluid replacement

sepsis TIME acronym

t - temperature: fever or chills

i - infection: signs of infection - redness, swelling, pain, or discharge

m - mental decline: confusion, drowsiness, difficulty waking up

e - extremely ill: severe pain, difficulty breathing, high heart rate

prevention of sepsis from cuts

1 - clean wounds properly with antiseptic

2 - cover wounds with clean, sterile dressings

3 - monitor for signs of infection (redness, warmth, swelling)

lymphatic system

returns fluid to bloodstream, transports fats from digestive system, filters lymph through lymph nodes, supports immune function

immune system

identifies pathogens, neutralizes/destroys foreign substances, creates immunological memory, distinguishes self from non-self

compare and contrast lymphatic to cardiovascular system

lymphatic - one-way system (toward heart), no pump, intermittent flow, moves via skeletal muscle contractions, valves prevent backflow

cardiovascular - closed circular system, heart pumps blood, continuous flow, higher pressure

how is lymph fluid propelled around the body

skeletal muscle contractions, one-way valves preventing backflow, respiratory movements, peristalsis of lymphatic vessels

what do lymph nodes do

filte4r lymph fluid, trap pathogens, house immune cells that destroy pathogens, initiate immune response

what happens to lymph fluid after it travels through the lymph nodes

returns to bloodstream via the thoracic duct and right lymphatic duct, which empty into the subclavian veins near the heart

why are swollen lymph nodes an indication of infection

indicate immune system activation; nodes enlarge as immune cells multiply to fight infection

why does regular movement help eliminate excessive fluid

regular movement activates muscle pumps, enhancing lymph flow against gravity, helping to reduce edema in lower extremities

how do different systems respond to cuts

lymphatic system - carries pathogens to lymph nodes, inflammation occurs

cardiovascular - increases blood flow to area, deliver immune cells

immune - neutrophils attack bacteria, inflammation begins, adaptive immunity activates

is skin a part of the immune system

yes, the skin is a part of the immune system because it promotes a physical barrier against pathogens, hosts immune cells, and initiates inflammatory response

what steps can you take to avoid catching a disease

wash hands frequently, use hand sanitizer, stay current on vaccinations, drink clean water, avoid raw/undercooked foods, use insect repellent

what do you do if a person in a group gets sick

isolate sick person, encourage masks, maintain hand hygiene, disinfect shared surfaces, monitor symptoms, ensure adequate rest and hydration

platelets

cell fragments that initiate blood clotting to prevent excessive bleeding

red blood cells

transport oxygen from lungs to tissues and carbon dioxide from tissues back to lungs

white blood cells

defend the body against infection and disease as a part of the immune system

prokaryotic cells

lack a nucleus and membrane-bound organelles, ex. bacteria

eukaryotic cells

contain a nucleus and specialized organelles, ex. white blood cells

innate (nonspecific) immunity

first-line defense present at birth including physical barriers (skin, mucous membranes), chemical barriers (stomach acid, enzyme), inflammatory response, and cells (neutrophils, macrophages, natural killer cells, dendritic cells)

acquired (specific) immunity

develops throughout life from exposure to pathogens or vaccines. involves B cells (antibody production), T cells (cell-mediated response), and memory cells for future protection

example of a nonspecific response to a skin injury

when skin is breached, blood vessels dilate causing redness and warmth. vessels become more permeable, allowing plasma and white blood cells to enter tissues. platelets form a clot. neutrophils and macrophages remove debris and pathogens. inflammation develops. damaged cells release histamine and cytokines cto attract more immune cells.

benefits of inflammation

benefits: inflammation increases blood flow to deliver immune cells, creates a barrier to prevent spread and facilitate tissue repair. fever creates an unfavorable environment for pathogens, accelerates immune responses, inhibits pathogen replication

antigen

any substance that triggers an immune response, typically pathogens

antibody

y-shaped proteins produced by b cells that bind to specific antigens to neutralize/mark for destruction

example of a specific response to a skin injury

after antigen presentaton by dendritic cells or macrophages, helper T-cells activate. they stimulate B-cells to produce antibodies and activate cytotoxic T-cells. memory B and T-cells develop for faster future responses. includes complement system activation and cytokine signaling for cell recruitment and communication

autoimmune disease

conditions where the immune system mistakenly attacks healthy body tissue due to loss of self-tolerance

what are prodromal symptoms

early warning signs before full disease onset, like fatigue, mild fever, or slight sore throat

how does the rhinovirus spread

primarily through respiratory droplets and contaminated surfaces

which part of the respiratory system is most susceptible to the common cold

upper respiratory tract, especially nasal passages and sinuses

what are signs and symptoms of the common cold

runny/stuffy nose, sneezing, sore throat, cough, mild headache, low-grade fever, fatigue

what causes thick mucus in the respiratory system

dehydration, inflammatory response, increased mucus production from irritated membranes

what are risk factors of developing colds

weakened immune system, seasons, crowded environments, poor hygiene, smoking, stress, lack of sleep

how long does a cold typically last

7-10 days

how might mucus help fight off a sickness

traps pathogens, contains antibodies and enzymes, prevent further infection

what is the common cold caused by

VIRUS not bacteria

humoral (antibody mediated) response

B cells activated by helper T cells differentiate into plasma cells that produce antibodies. these antibodies circulate in blood and lymph, binding to pathogens to neutralize them, mark for phagocytosis, or activate complement

cell mediated response

cytotoxic T cells directly kill infected or abnormal cells. helper T cells coordinate the response and release cytokines. macrophages present antigens and engulf pathogens

explain the difference between b and t cells

both lymphocytes, but B cells produce antibodies and respond to free antigens, while T cells respond to presented antigens and directly kill infected cells

response to bacterial vs viral infections

differences - bacterial infections trigger stronger responses adn can be cured with antibiotics. viral infections are unaffected by antibiotics

similarities - inflammation, fever, activation of innate immunity

why cant the body respond the same ways to pathogens

pathogens have different structures, life cycles and evasion mechanisms requires specialized responses. some hide inside cells, others have thick cell walls, some rapidly mutate

primary vs secondary responses

differences - secondary are stronger, faster, and long-lasting due to memory cells. primary take days to respond fully

similarities - both involve antigen recognition, cellular attraction and both humoral and cell mediated responses

virus structure

genetic material (DNA or RNA), capside (protein coat), envelope (not all)

viruses are NOT living and are NOT cells

virus size

microscopic - 100 times smaller than a red blood cell

viral replication

1. virus binds to host cell

2. virus enters the cell or releases genetic material into it

3. viruses uses host cell machinery to produce viral RNA or integrates genome with the host genome

4. newly created virus parts are assembled inside of the cell

5. viruses are released through lysis or budding

lytic cycle

virus releases dna into a host cell and to create more viruses and escapes the cell by killing it

lysogenic cycle

viral dna enters the cell and integrates into the host cells genome before being created

retrovirus

retroviruses use an enzyme called reverse transcriptase to make viral DNA from the viral RNA which can then be incorporated into the host cell’s DNA

mRNA vaccine

mrna with instructions for making the virus’ spike protein is injected into a human cell and is used to create antibodies