The Respiratory System Flashcards
Upper Respiratory Tract URT
- includes the functioning organs in the head and neck
Lower Respiratory Tract LRT
- includes the chest cavity
Respiratory Mucosa + Mucus
- Most of the respiratory system is lined with mucus
- Cleans the air before it enters the lungs
- Moistens the air that we breath
Ciliary Escalator
- Mucus is cleared from the respiratory tract via the ciliary escalator
- cilia move contaminants ever-upward, toward the throat through coughing or swallowing
Order of Functions: URT
- breathe through the nose, air passes through the nares (nostrils) and into the nasal cavities and paranasal sinuses which warm, moisten and clean air before it proceeds further
- inhaled air passes into the pharynx (throat)
- inhaled air passes through the larynx
Structures of the Pharynx: Nasopharynx, Oropharynx and Laryngopharynx
- N = most superior (nares)
- O = in the oral cavity
- L = inferiorly-located and has two potential pathways, determined by the epiglottis (trap door for food and air)
Larynx
- is composed of cartilage
- rigid structure of which helps to keep it open for the passage of air, regardless of the air pressure
Rhinitis + Sinusitis
- R = inflammation of the nasal mucosa, which can be caused by viral infections or allergies
- S = often more severe, from a bacterial infection of the paranasal sinuses
Larynigitis
- Inflammation of the mucosa of the larynx
- caused by an infection, allergies, smoke, and acid reflux
Laryngeal Cancer
- common in men over the age of 50, and regular users of tobacco and alcohol are at the greatest risk
- can be treated by surgical removal of larynx
Pharyngitis
- “sore throat,”
- painful and red throat that can be accompanied by difficulty in swallowing.
- caused by bacterial infection like strep
Order of Functions: LRT
- the trachea (‘wind pipe’), forming the base and trunk of the inverted tree
- From the trachea, branches off into the bronchial tree, first into the left and right primary bronchi
- further subdivide into secondary bronchi within each lung
- further branch into bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
Alveoli
- are surrounded by blood capillaries
- the air-filled interior of each alveoli is separated from those capillaries by an extremely thin layer of cells called the respiratory membrane
- this thin layer that gas exchange occurs by diffusion
- mucus is less sticky because of the production of surfactant to reduce surface tension
Pleura
- each lung and the cavity is covered by pleura which is a slippery substance that allows for the lungs to expand
- limits friction between lungs
Pleurisy
- Inflammation of the pleura, caused by tumours or bacterial or viral infections
Atelectasis and Collapsed Lung
- a collapsed lung due to ANY cause
- A collapsed lung is one that is unable to expand, due to pressure on the outside of the lung
Pneumothorax
- a puncture to the visceral pleura or the chest wall
- fills with air; rendering the lung unable to fully ‘inflate.’
Hemothorax
- injury/disease that causes blood to fill the pleural space - The lung ‘collapses’ due to the pressure of blood on the outside of the lung
Bronchitis
- acute inflammation of the bronchi
- due to infection
Pneumonia
- an acute inflammation wherein alveoli become congested with fluids.
Tuberculosis (TB)
- chronic lung infection due to the bacillus Mycobacterium tuberculosis
- affects people living in impoverished and crowded conditions
Restrictive Pulmonary Disorders
- affect one’s ability to inspire (to breathe in), due to the loss of flexibility of lung tissue
Obstructive Pulmonary Disorders
- restrict both inspiration and expiration
- damage to lung tissue or airway obstruction
Chronic Obstructive Pulmonary Disease = COPD
- umbrella term for 3 types of COPD
1. Chronic Bronchitis
2. Emphysema
3. Asthma
Chronic Bronchitis
- swelling of lung tissues and excessive production of mucus that blocks the air passages and impedes exhalation,
- associated with a severe, ‘rattling’ cough
- due to air pollution and cigarette smoke
Emphysema
- swelling and rupture of alveoli, leading to a dramatic loss in the area available for gas exchange
- breathlessness and the need for supplementary oxygen
Asthma
- spastic contractions of smooth muscle in the lungs, narrowing airways and making breathing difficult.
- stressful events, exercise, lung infections, or inhalation of pollutants
Lung Cancer
- loss of lung capacity
- metastasized by the time it’s discovered, so prognosis of the disease is poor.
- smoking and vaping
Mechanisms of Breathing
- Air moves in and out of our lungs always from high to low pressure.
Process of Inhalation
- must decrease the air pressure in our lungs, allowing the higher air pressure outside of our lungs to flow in to equalize the pressure
- the chest cavity expands
- diaphragm flattens, increasing the up-down volume of the chest cavity, and the external intercostal muscles contract to move the rib cage up and out
Process of Exhalation
Two different things can happen:
- Passive (‘quiet/resting’) expiration: is the diaphragm and exterior intercostal muscles returning to their relaxed state, which reduces the volume of the chest cavity, increasing air pressure in the lungs
- Forceful expiration: if we need to increase the volume of air moving in and out of our lungs, expiratory muscles (interior intercostal muscles and abdominal muscles) contract, making the ribcage smaller, while the diaphragm is pushed further upward.