Respiratory Toxicity Flashcards
anatomy of upper respiratory tract contains:
nose
pharynx
larynx
nose is lined by _____ which do what?
epithelial cells that help with removal of bacteria and particles
olfactory epithelium helps with what?
sense of smell
sinuses help with what?
humidification and temperature regulation
pharynx extends from what?
the base of the skull to the esophagus
what is the function of the pharynx?
it prevents microbe from entering the body
Larynx is located where?
lies anterior to the laryngeal part of the pharynx
what does the larynx contain?
vocal cords
what does the larynx do?
moves up and down to prevent choking
anatomy of lower respiratory tract contains:
trachea bronchi bronchioles alveolar region lungs + plurea
trachea is made up of
multiple layers of tissue
bronchi contains the muscociliary elevator which does what?
moves particles up into the pharynx
alveolar region is highly sensitive to toxicants because of?
the large surface area
how thick is the alveolar membrane?
0.4 microns
what is the alveolar sacs made up of?
type 1 and type 2 epithelial cells
type 2 is the precursor cell
what are the muscle of respiration?
intercostal muscles and the diaphragm
the pulmonary interstitial is made up of
collagenous and elastic connective tissue and fibroblast
also contains macrophages, lymphocytes, plasma and mast cells
what three types of receptors are present in lymphatic drainage?
stretch
irritant
c - fibers
examples of air borne toxicants
fumes, dusts, mists, fog, smoke, haze, smog
examples of blood borne toxicants
paraquats, monocrotaline, bleomycin, cyclophosamide
coarse fraction particulate size
10-2.5 microns
coarse fraction examples
red blood cells, cells in general
fine particles size
2.5 -.1 micron
examples of fine particles
bacteria
ultrafine particles size is
less than 0.1 microns
ultrafine particles examples
viruses, molecules
the smaller the size of a particle the
more damage it can do
impaction is
the collision of a moving particle with a static structure
what size particles are involved with impaction?
coarse fractions
where does impaction occur?
pharyngeal and tracheobronchial regions
sedimentation occurs by
gravitational settling of particles
what size particles are involved with sedimentation
fine particles
where does sedimentation occur?
bronchioles and alveolar regions
diffusion is when particles reach airway surface by
random brownian movements
what size particles are involved with diffusion?
ultrafine particles
where does diffusion occur?
in terminal bronchioles and alveoli
interception is the predominant mechanism by which
fires are deposited in the airways
what toxicant enters via interception?
asbestos
the longer the length of the fiber
the more damage it can do
factors that determine the toxicity of gases and vapors
dose, solubitiliy, reactivity
dose of gases and vapors - low
sneezing, rhinitis, sore throat
dose of gases and vapors - moderate
persistent cough, bronchitis
dose of gases and vapors - high
laryngeal edema, ARDS, death
solubility - gases that have low solubility cause____ damage
more damage, because they travel further through the respiratory tract than gases with high solubility
reactivity of gases and vapors
formation of unstable conformations, generation of ROS, irritation of sensory nerves, stimulation of sensory receptors, bronchoconstriction
particle clearance defense mechanisms - 2 of them
mucociliary & macrophage
mucociliary is the predominant mechanism in
conducting airways
macrophage is the predominant clearance mechanism in
terminal respiratory
biological responses - initial response is
inflammation
acute irritant response all due to
inflammation
acute irritant response: upper respiratory tract
acute symptoms are due to inflammation
nasal: obstruction, runny nose, bleeding
throat: dry cough
laryngeal: hoarseness
acute irritant response: mid respiratory tract
bronchospasm
acute irritant response: lower respiratory tract
edema
chronic responses - three outcomes
- repair and restoration
- fibrosis
- emphysema
fibrosis
overproduction of growth factors
increased fibroblasts and collagen
causes lungs to become smaller
RESTRICTIVE
emphysema
imbalance between proteases and anti-proteases
elasticity of the lung is lost
OBSTRUCTIVE
spirometere
measures the amount and rate of air a person breaths in order to diagnose illness or determine progress
pulmonary diseases - asthma
IgE mediated immune response
asthma could be due to
household allergens and occupational allergens
how does asthma come about? 3 phases
sensitization phase - the primary exposure
activation phase - subsequent exposure
effector phase - causes bronchospasm/mucus secretion
pulmonary diseases - pneumoconiosis
an obstructive disease
pneumoconiosis casue
respirable dust
two type of pneumoconiosis - 1. nodular
silicosis, from mining/blasting
pathogenesis of nodular pneumoconiosis
related to intensity of exposure, macrophage activation, fibrogenic factor
pathology of nodular pneumoconiosis
greater in upper lobes, firm nodules 2-6mm diameter
symptoms of nodular pneumoconiosis
0-15 years have cough, infection, fibrosis, if removed from exposure things get better
two type of pneumoconiosis - 2. diffuse
caused asbestosis, often found in building materials 3 types: chrysotile, crocidolite, amosite
clinical features of diffuse pneumoconiosis
cough + shortness of breath
causative agents of diffuse pneumoconiosis
microbes, animal proteins, plants, chemicals, metals
phases of diffuse pneumoconiosis: acute phase
antigen binds IgG and activates macrophages which secrete chemokine to attract lymphocytes and monocytes
phases of diffuse pneumoconiosis: subacute phase
develop granulomas throughout the lung
phases of diffuse pneumoconiosis: chronic phase
inflammatory cells produce growth factors fibroblasts resulting in interstitial fibrosis
pulmonary diseases - COPD comes from…
cigarette smoke
causes of COPD
ciliatasis, inflammation, mucous hyper secretion, smooth muscle ell hypertrophy, fibrosis or emphysema
lunge cancer: major toxicants that cause it
cigarette smoke - 90% arsenic asbestos polycyclic aromatic hydrocarbons chromium nickel
major types of lung cancer:
squamous cell carcinoma
adenocarcinoma
small/large cell carcinoma
mesothelioma
