The Respiratory System [4] Flashcards
What is the function of the respiratory system?
Work with circulatory system to provide cells with oxygen and remove carbon dioxide
(regulate blood acid levels)
State the passage of an air particle during inspiration
Nasal cavity > pharynx > epiglottis > larynx > trachea > primary >secondary > tertiary bronchi > bronchioles > alveoli > blood
Describe the structure and function of the nasal cavity
Projections (hair and mucus) trap debris
Mucous membranes warm and humidify air
Smell receptors
Describe the structure and function of the pharynx
Aka throat
Muscular tube connecting nasal cavity to trachea
Transports air to epiglottis
Describe the structure and function of the epiglottis
Flap of flexible elastic cartilage connected to a muscle
Diverts air into larynx and food into oesophagus
Describe the structure and function of the larynx
Cartilage structure, contains mucous membranes
Joins pharynx and trachea
Mucus can vibrate as air passes over it
Describe the structure and function of the trachea
Aka windpipe
C-shaped cartilage rings that hold structure open
Lined with mucous membranes that produces mucus, and cilia
What are the three stages of bronchi and their function (not structure)
Primary bronchi - end of trachea, structure splits into two, taking air into each lung
Secondary bronchi - split from primary, takes air into each lobe of the lungs
Tertiary bronchi - split from secondary bronchi
What is the structure of bronchi
C - shaped cartilage rings, which spread out more as each bronchus gets smaller.
Smooth muscle and elastin forms more of the structure to allow greater control of air flow
Mucus and cilia present
Describe the structure and function of the bronchioles
Splits from tertiary bronchi, then splits into millions of terminal bronchioles
Elastin and smooth muscle, allowing air flow control (expands when more oxygen is needed
Cilia and mucus present
Describe the structure and function of the alveoli
Following terminal bronchioles, small air sacs, functioning unit of the respiratory system
Wall is 1 cell thick
Surrounded by a network of capillaries (also 1 cell thick)
O2 and CO2 diffuses through the thin walls
Describe the structure and function of the pleura and pleura fluid
Pleura: membrane covering surface of lungs (visceral) and inside of chest (parietal)
Pleural fluid: lubricant in between visceral and parietal pleura, so lungs can slide against chest wall
What is the space in the chest cavity that isn’t occupied by the heart
Mediastinum (heart and blood vessels)
How many lobes are in the lungs
Two on the left (space for heart) and three on the right
What is the diaphragm and its function
A muscle separating chest from abdomen
Contracts to increase volume of the lungs during inspiration
What are intercostal muscles and their function
Muscles between ribs
Moves ribcage up and outwards to increase lung volume during inspiration
What is the name for breathing
Ventilation
Describe the steps of inspiration and expiration
Intake of air into lungs
1) Muscles contract - diaphragm pulls on chest cavity, intercostals extend ribcage
2) Lung volume increases as pleura adheres to wall of chest cavity, so it expands with cavity
3) Increase in thoracic volume = decrease in pressure in lungs. Air flows from higher to lower pressure.
Expiration is the opposite process
State features of the lungs that are well suited for gas exchange (don’t explain)
Alveoli surface area 50-80 m²
Thin alveoli walls
Blood vessels surrounding alveoli
Lungs far from body surface to prevent fluid evaporation
What is the name of the artery that brings deoxygenated blood to the capillaries around the alveoli
Pulmonary arteries
How does gas exchange occur in the alveoli
Concentration gradient - higher concentration of CO2 in blood and O2 in alveoli, so they diffuse into each other.
Gases diffuse through the walls of capillaries and alveoli (each 1 cell thick)
How is O2 and CO2 transported in the blood
O2 is carried in haemoglobin
CO2 is transported in plasma
What causes emphysema
Cause: long term exposure to irritants (dust, cigarette smoke, pollution etc)
How does emphysema affect the respiratory system
Irritants cause alveoli to lose elasticity, replaced with fibrous tissue. Alveoli may break down, reducing internal SA of lungs
What do emphysema patients suffer from?
Lungs lack elasticity = lungs constantly inflated = voluntary expiration
Less internal SA = inadequate gas exchange = breathlessness
What causes lung cancer
Tobacco smoking, asbestos, air pollution, genetics, chemicals
How does lung cancer affect the respiratory system
Exposure to risk factors irritate mucous membranes in the air passages (usually bronchi)
Cells replicate rapidly and the accumulating mucus cannot be removed, leading to the rupture of alveoli and emphysema
Cancerous growths develop in air passages and may spread to othe body parts
What are the causes/triggers of asthma
Allergic / non allergic:
Infections, smoke, dust, mites, molds, pollen, animals
Exercise, cold weather, medication, emotions, food
How does asthma affect the respiratory system
During attack, muscles lining bronchioles spasm (involuntary contractions)
Excessive mucus also produced from irritants
What do asthma patients suffer from?
Constricted airways and mucus build up = less volume of air intake = less oxygenated blood
What causes pneumonia
Viruses, bacteria, fungi, other organisms that infect the lungs
How does pneumonia affect the respiratory system
Inflammation leads to secretion of mucus into alveoli
What do pneumonia patients suffer from
Mucus in alveoli = less air intake = breathlessness
What causes tuberculosis
Bacteria Mycobacterium Tuberculosis
What effect does tuberculosis have on patients and their respiratory system
Same as pneumonia - secretion of mucus into alveoli, less air capacity and intake, thus difficulty breathing
