Exam 2

Inflammation occurs…

With infection (it cannot be an infection until you get a diagnostic test), _______ always occurs first.

It is general

microbe

• microscopic organism that can be single celled or form a colony of cells

• also can be non-cellular viruses that can enter the cells

• bacteria, virus, fungi, protozoa

infectivity

amount of pathogens needed to infect measured by 50% of a population; ability for pathogen to enter a host

virulence

how harmful a pathogen is by looking at the number of cases of a disease in a population and comparing it with the number of people exposed to the mircoorganism

infection

• occurs when a pathogen or microorganism causes disease

• Process that happen for an infection to occur:

1. invade the body/exposure

2. replicate/adhesion

3. cause disease/invasion

4. affect the host/infection

pathogen

microorganisms capable of causing disease

Mechanism of disease

1. direct destruction of host cell by pathogen

2. interference with the host cell’s metabolic function (anaerobic or aerobic)

3. exposure of toxins produced by pathogen (which increases in inflammatory mediated responses

Where the influenza virus attaches

binds to sialic acid cell receptor in the respiratory tract and hijacks and takes over additional cells (it can also attach to nasal passages)

HIV

enters the CD4 helper cell, deactivates it, and disables the cell from protecting the host; so when a microorganism enters, the body cannot fight off the infection

pathogenicity

qualities that promote the production of disease; potency, invasiveness, production of toxins, adherence to human host cells, and tissue damage is elicited

pathogenic defense mechanisms

Are the ways that a pathogen can avoid destruction by the host cell

Example: pathogen develops a thick protective capsule that can prevent phagocytosis

coinfection

The simultaneous occurrence of hosting two or more pathogens. Certain pathogens, such as those that cause chlamydia and gonorrhea, are more likely to be transmitted and to coexist in the host. Presents a greater challenge to the immune system.

• ex: Lyme disease, rocky mountain spotted fever

superinfection

An infection that arises in addition to one that is already present. Often results from compromised host defenses and over proliferation of resident flora

• immunocompromised, transplant patients, HIV, cancer, RA are all at risk

• overuse or abuse of antibiotics can cause this

opportunistic infections

occur in patients who are immunocompromised

bacteria

• gram-positive cocci: require oxygen for growth (aerobic), single-celled

• gram-negative cocci: release endotoxins (pyogenic/fever causing), can cause sepsis (bacterial infection of the blood) and septic shock (ex: E.coli, klebsiella)

virus

• Obligate intracellular parasite, need a host cell to survive

• Ex: HIV, COVID, flu

• Binds to specific receptors on the host cell and then moves into the host cell. Once inside, it utilizes the host’s cellular mechanisms to replicate.

• Have the ability to either directly kill the cell or modify certain cellular functions, such as protein synthesis.

• Can cause cells to proliferate rapidly and randomly, causing tumors to form in the body.

endotoxin

A complex of phospholipid–polysaccharide molecules that form the structural component of the Gram-negative cell wall. Causes inflammatory mediators to be released, leading to a massive inflammatory response. Gram-negative bacteria releases the most damaging of these. 

exotoxins

Secreted by both Gram-positive and Gram-negative bacteria into the surrounding environment to directly damage host cells or interfere with cell functions.

systemic manifestations of inflammation (SIR’s)

• fever

• tachycardia, tachypnea

• aches

• malaise

• increase in WBC (greater than 12000), shift to the left

• increase in metabolic demand

Local manifestations of inflammation

redness, heat, pain, swelling, loss of function

septic shock

A process of systemic vasodilation due to severe infection, often with Gram-negative bacteria (the endotoxin component). Massive vasodilation leads to poor perfusion of vital organs.

manifestations of septic shock

Fever, tachycardia, tachypnea, hypotension despite fluid resuscitation, decreased strength of peripheral pulses, cool extremities to touch

Pan culture

• blood, urine

• helps locate the source of infection/origin

viral receptor for COVID

angiotensin converting enzymes (ACE)

cartilage

• avascular (lacks direct blood supply); no blood supply=lacking nutrients and things needed for repair

• does not get the benefits of innate immune response so it takes longer to heal (2-3 months)

osteoblast

bone forming cells; forms bone matrix; non-dividing

osteocytes

mature osteoblasts

osteoclast

resorption and degradation of existing bone

osteoblast formation

=osteoclast resorption to retain bone density

metaphysis

region between epiphyseal bone plate and diaphysis

epiphysis

growth plate (increases bone length)

diaphysis

shaft of long bone

synovial/diarthrodial joints

• move freely

• knees, wrists, hands, fingers, and feet, are highly mobile and common targets for inflammation.

non-synovial joints

• do not move freely

• Skull sutures, Intervertebral discs, Pubic symphysis, Growth plates, and Tibiofibular joint. 

joints

connection between 2 or more bones; provide stability and mobility

tetany

impaired nerve firing; involuntary muscle spasm

chvostek’s

an abnormal muscle spasm of the facial muscles that occurs when the facial nerve is tapped (impaired nerve firing)

dislocation

complete displacement/separation; severe injury of ligamentous structures

subluxation

partial or incomplete displacement of joint surface

Fracture healing process

1. hematoma formation and inflammation= blood clotting

2. granulation tissue/cell proliferation=restore blood supply

3. callous formation= osteoblast formation

4. ossification-consoldiation= osteoclast resorption (takes away anything not becoming bone)

5. remodeling= osteoclasts resorb excess callous bone, returns pre-injury strength

6. healing time

open/compound fracture

bone breaks through skin or is visible through wound (increase risk for infection)

spiral fracture

bone breaks in a twisting pattern; sign of abuse

transverse fracture

caused by trauma; clean break that runs horizontal

stress fracture

happens frequently to those with osteoporosis; small crack

greenstick fracture

occurs in kids; incomplete break in bone (bone cracks on one side but does not go all the way through)

oblique fracture

diagonal break

calcium levels

8.6-10.3 mg/dL

parathyroid hormone

regulates calcium in the body

increase in calcium means

issue with the parathyroid gland, cancer, or dysrhythmia

parathyroid gland

• 4 little glands on top of the thyroid

• promotes bone resorption, preserves calcium in kidneys, enhances intestinal absorption through activation of vitamin D, reduces serum phosphate levels

vitamin D

a steroid hormone unless its converted in the kidney to the active form

calcitonin (produced by the thyroid)

decreases calcium production through stopping osteoclasts (which release calcium) and reducing calcium reabsorption in the kidneys

malunion

deformity from fractures that are not set; heals in an incorrect position

delayed union

failure of fracture to unite; takes longer than expected

angulation

deviation from normal alignment (forms an angle instead of being straight)

nonunion

fracture fails to heal properly and remains separated

manifestations of fractures

• edema, swelling

• pain and tenderness

• muscle spasm

• deformity

• ecchymosis/bruising

• loss of function

• crepitation (bone crunching)

compartment syndrome

pressure/swelling inside the fascia that builds up and cuts of circulation

6 P’s of compartment syndrome

paresthesia (tingling/pins & needles), pain (not relieved with meds), pressure, pallor, paralysis, pulselessness

osteomyelitis

• bone infection caused by Staph. aureous

• Local manifestations: pain, redness, edema, warmth, disability

• Systemic manifestations: fever, night sweats, chills, restlessness, increase in WBC, increase in bands

intracapsular hip fracture (complex)

break at the ball

trochanteric hip fracture

below ball/trochanter region

diagnostic tests for fractures

X-ray, MRI (magnet, safety concerns)

hip fractures

• 90% occur in the elderly

• post-menopausal women, smokers, poor diet, white and asian women are at risk

• caused by osteoporosis

function of the lungs

exchange of oxygen and carbon dioxide between the environment and the blood; ventilation and diffusion

ventilation

involves both acquiring oxygen (inspiration) and removing carbon dioxide (expiration) from the blood; the process of moving air into and out of the trachea, bronchi, and lungs.

perfusion

supplying oxygen to the blood, lungs, organs, via blood vessels

respiration

a process in which cells throughout the body use oxygen aerobically to make energy

diffusion

the process of moving and exchanging the oxygen acquired during ventilation with carbon dioxide waste across the alveolar–capillary membrane; gas exchange between alveoli and capillary

ventilation (V) to  perfusion (Q) ratio

0.8:1.2 (if the ratio is mismatched, something is wrong)

upper respiratory tract

warms and humidifies the air and filters out small particles; tubinates (inside of nose) increase surface area of the nasal mucosa which warms and moistens air; helps move air in and out of lungs

Includes conducting airways:
 Nasal cavity
 Pharynx
 Nasopharynx
 Oropharynx
 laryngopharynx

Trachea

• A cylindric tube is supported by U-shaped cartilages that keep it open but allow the
  adjacent esophagus to expand during swallowing.

• Bifurcates into the right and the left mainstem bronchi at the point called the carina.

carina

• Located at the level of the manubriosternal junction, also called Angle of Louis.

• Is extremely sensitive and touching it during suctioning causes vigorous coughing

• Once the air passes this, that is the start of the lower respiratory tract

epiglottis

• A small flap located behind the tongue that closes over the larynx during the swallowing.

• This prevents solids and liquids from entering the lungs

Lower respiratory system

Consists of the bronchi, bronchioles, and alveolar ducts, and alveoli

Why aspiration is more likely to occur in the right lung

The right mainstem bronchus is shorter, wider and straighter than the left mainstem bronchus

mucociliary clearance system

Protects the respiratory system by trapping and expelling inhaled particles, toxicants, and pathogens from the airways using a wave-like motion of cilia and mucus.

How does the role in inflammation and the release of biochemical mediators impact intinsic protection of the lungs

When the airway is exposed to harmful stimuli — such as pathogens, allergens, or smoke — inflammatory responses are triggered:

• Epithelial cells, macrophages, and mast cells release biochemical mediators (like histamine, cytokines, and prostaglandins).

• These mediators cause vasodilation, increased capillary permeability, and recruitment of immune cells (neutrophils, macrophages) to fight infection or remove debris.

• This response also stimulates more mucus production and can alter ciliary activity.

Together, these processes form part of the intrinsic (innate) defense system of the lungs — the natural, non-specific protection against pathogens and irritants.

Protective benefits:

• Helps remove pathogens and debris before they reach the delicate alveoli.

• Prevents colonization of bacteria and viruses in the lower respiratory tract.

• Supports tissue repair after injury.

How the bronchioles react with infection, irritation, and irritants

• Bronchoconstriction: Smooth muscle in the bronchiole walls constricts → narrowing of the airways.

• Mucosal edema: Inflammation causes swelling of the mucous membranes.

• Increased mucus production: Goblet cells and submucosal glands produce excess mucus to trap and remove irritants.

• Inflammatory cell infiltration: Neutrophils, macrophages, and eosinophils migrate in response to infection/allergens.

➡ These changes collectively impair airflow and gas exchange, leading to respiratory symptoms.

Manifestations when bronchioles become full of mucous, pus, or respond to an allergen/antigen/foreign environmental substance like cigarette smoke?

• Cough (productive if mucus or pus present)

• Wheezing (from narrowed airways)

• Dyspnea (shortness of breath)

• Tachypnea (rapid breathing)

• Use of accessory muscles to breathe

• Decreased breath sounds or crackles/rhonchi on auscultation

• Hypoxemia (low O₂ saturation if obstruction is severe)

• In infection → fever, malaise, sputum production

Examples:

• Asthma (bronchoconstriction + mucus)

• Chronic bronchitis/COPD (chronic mucus hypersecretion)

• Pneumonia (inflammatory exudate filling distal airways/alveoli)

where gas exchange begins

When the sub-segmental bronchioles become respiratory bronchioles

Type 2 alveolar cells

secrete surfactant

surfactant

A lipoprotein that coats inner surface and facilitates expansion during inspiration; a lipoprotein that coats the inner surface of the alveolus and facilitates its expansion during
inspiration, lowers alveolar surface tension at end – expiration, and thereby prevents the lung from collapsing

humidify the oxygen

when administering O2 in the hospital…

right lung

has three lobes (upper, middle, lower)

layers of the bronchiole wall

epithelial lining, smooth muscle, connective tissue

epithelial lining of the bronchial wall

• contains single-celled exocrine glands= mucus secreting goblet cells and ciliated cells.

• the ciliated epithelial cells rhythmically beat mucous toward the trachea and pharynx where it can be swallowed or expectorated by coughing

smooth muscle layer of the bronchial wall

Biochemical mediators released during inflammation play a role in antibody-mediated hypersensitivity reactions like asthma (smooth muscle will constrict)

type 1 alveolar cells

provide structure and air exchange

Results in decreased velocity or airflow into the gas- exchange portion of the lung and
allows for optimal gas diffusion

Because the airways are spreading out into many tiny passages, the airflow slows down by the time it reaches the gas-exchange region (the alveoli).

This slower air movement is actually good — it gives oxygen and carbon dioxide more time to diffuse (move) across the thin walls of the alveoli and capillaries.

pulmonary artery

carries deoxygenated blood to the lungs

pulmonary vein

carries oxygenated blood from lungs to the heart

visceral pleura

membrane covering the lungs

parietal pleura

lining of the thoracic cavity

pleural fluid

lubricates pleural surface, allowing 2 layers to slide over each other without separating

pleural effusion

fluid in the lungs

functions of the pulmonary systems

ventilate alveoli, diffuse gases in and out of blood, perfuse lungs so organs and tissues receive oxygen rich blood.

why breathing is involuntary

Homeostatic changes in ventilatory rate and volume are adjusted automatically by nervous system to maintain normal gas exchange

brainstem, medulla oblongata

• the respiratory center is located in the…

• the basic rhythm is set by nerve cells in the…

• the _____ sends impulses from peripheral chemoreceptors in the carotid and aortic to detect PaCO2 and PaO2

increased work of breathing

• patients can’t speak, nasal flaring is present, use of accessory muscles, tachypnea, tachycardia

• can result in a marked increase in oxygen consumption and metabolic demand, which can cause significant morbidity in individuals with severe lung disease.

• Can occur with spinal deformities, obesity, pulmonary edema (lung compliance is decreased), and when airways are obstructed by bronchospasm or mucous plugging asthma or bronchitis.