RESPIRATORY BACTERIA Flashcards
(20 cards)
What is pus made up of?
It is made up of mucus, pathogen, dead cells, cytokines, and white blood cells
What are the most common VIRAL pathogens that affect the RHINITIS (the nasal cavity)?
Rhinovirus
Influenza virus
Parainfluenza
Respiratory syncitial virus (RSV)
Adenovirus
How does the SENSORY AFFERENT PATHWAY WORK?
The MECHANO-RECEPTORS are irritated (cough receptors). They send sensory information to AFFERENT NERVES:
- RAPIDLY adapting stretch receptors (RARs)
- SLOWLY adapting stretch receptors (SARs)
- C-fibres
They go via the vagus nerve to the MEDULLA OBLONGADA
coughing, adaptation of the lungs and the upper RT
How do the lung parenchyma keep sterile?
How to keep bacteria away from the lungs?
- Physical mechanism (nose hair)
- Mucociliary clearance mechanism - (mucus production)
- Alveolar macrophages
- Coughing and sneezing
Think step by step. There are 5
Name the physical mechanisms and describe how their action for this role
Long hairs on nose - filtering large particles
Epithelial cells - intact barrier
Mucus - (GOBLET CELLS) coats the mucous membranes to trap pathogen
Surfactants - type SPA and SPD. Bacteriocidal and facilitate phagocytosis (opsinisation)
Angular structures of the resp system - can trap at branching point
What is the mucociliary clearance?
Both the GOBLET CELLS and MUCUS CELLS secrete mucus. It produces a layer:
- SOL layer - has biochem properties but we don’t know much of it
- GEL layer - traps particles
Cilia then BEAT the mucus (1300/min)
What two systems are involved in the alverolar immunity?
Innate and adaptive immunity
Name of the innate and adaptive immune cells
Innate - neutrophils (first responders), macrophages, NK cells, and SURFACTANT molecules
Adaptive - T and B cells. Cytokines and IgA
Why is coughing important?
It clears the airways of irritants by forcefully expelling air from the resp tract.
Think of the neurones involved when they burns their hand
What are the 3 pathways of the COUGH ARC?
The afferent, The central, and the efferent pathway
Explain the cough reflex arc
Mechano-receptors are stimulated, which send sensory signals to the afferent nerves, which via the vagus nerves, they travel up to the MEDUALLA OBLONGADA.
The vagus nerve then synapse with the motor neurones and the signal travels through the efferent nerves, which causes a response to the target tissues.
What are the 3 types of sensory nerve fibres involved in the Sensory afferent pathway?
- Rapidly Adapting Stretch Receptors (RARs)
- Slowly Adapting Stretch Receptors (SARs)
- C-fibres
think of tractors and solitaire
What area of the medulla do the sensory information travel to?
Nucleus tractus solitarus (NTS)
Neck, chest,top and centre of abdomen
What respiratory muscles contract during a cough?
Diaphragm - it flattens
Laryngeal muscles - contract to open vocal cords
External intercostal muscles - change the space available in the thoracic cavity
Rectus abdominis - depresses rib cage and decreases the space in the thoracic cavity
What is the benefit of the diaphragm flattening?
It increases the thracic cavity space (decreases pressure) so that air can fill in.
The larygeal muscles - contract to CLOSE the vocal cords
External Intercostal muscles - contract to change the space available in the thoracic cavity
What are the 3 phases of coughing? Describe them
When you cough, what happens to your body physically?
Inspiratory phase - cough receptors irritated, vocal cords open, air enters inside the lungs. EXTERNAL INTERCOSTAL MUSCLE and DIAGPHRAM contract causing expansion of the chest cavity. AIR ENTERS IN, increasing intra-thoracic
pressure.
COMPRESSION PHASE - The epiglottis and vocal cords CLOSE (larygeal muscles), trapping the air within the lungs. There is
expiration against the closed epiglottis, causing a further increase in intra thoracic pressure.
EXPIRATORY PHASE - The INTERNAL INTERCOSTAL MUSCLES and ABDOMINAL MUSCLES contract to decrease the thoracic cavity. The vocal cords RELAX, and the epiglottis OPENS. This releases the
pressure from the lungs and causes air and the irritant to be rapidly expelled
It’s involved in most things
What nerve is sent sensory information during coughing?
Vagus nerve
What nerve is involved in sneezing are… (also what is depressed?)
The trigeminal nerves
(The ULVA)
What are external factors that can cause a depression of the defence mechanisms?
- CHRONIC ALCOHOL is associated with an increase incidence of bacterial infections.
- CIGARETTE smoke and air pollutants is associated with an
increase incidence of chronic bronchitis and emphysema. - OCCUPATIONAL IRRITANTS is associated with and increased
incidence of hyperactive airways or interstitial pulmonary
fibrosis
