The Respiratory System Flashcards
What are the functions of the respiratory system?
- Gas Exchanger (alveoli only)
- Filters
- Influences speech
- Assists in control of body’s acid bace balance
- Makes sense of smell possible
How does the respiratory system function as a gas exchanger?
a) Air must first exchange gases with blood (O2 breathed in, CO2 out)
b) Blood must circulate
c) Finally blood and cells much exchange gases
Why does the respiratory system function as a gas exchanger?
So that O2 can be supplied to, and CO2 can be removed from body’s cells.
How does the respiratory system function as a filter?
- Cleanses the air we breathe
- Warms the air we breathe
- Humidifies the air we breathe
How does the respiratory system influence speech?
Sound production
How does the respiratory system assist in control of body’s acid base balance?
- Lower or decreased CO2 = more alkaline
- Higher or increased CO2 = more acidic
How does the respiratory system make sense of smell possible?
Olfactory receptors in nasal mucosa.
What does the respiratory system consist of?
- The upper respiratory tract
- The lower respiratory tract
- Accessory structures
What are the parts of the upper respiratory tract?
- Nose
- Pharynx
- Sinuses
- Larynx (voice box)
What are the parts of the lower respiratory tract?
- Trachea
- Bronchial Tree
- Lungs
What are the accessory structures of the respiratory system?
- Oral cavity - mouth
- Rib cage
- Diaphragm
What is the main function of the nose?
Passageway for air going to and from the lungs.
Air entering through the nose is?
- Filtered of impurities
- Warmed (mucus and blood)
- Moistened (and lacrimal fluid)
Hollow paranasal sinuses serve as what?
Resonating chambers for speech
What is another name for the pharynx?
Throat
What are the three parts of the pharynx?
- Nasal pharynx
- Oropharynx
- Laryngeal pharynx
What is the function of the pharynx?
Hallway for respiratory and digestive tracts, since both food and air pass through this structure before reaching appropriate tubes.
What is the pharynx’ role in speech?
By pharynx changing shape, different vowel sounds can be formed.
What does the pharynx take part in?
- Eating
- Breathing
- Talking
What is another name for the larynx?
Voice box
What does the larynx consist of?
9 cartilages
What do the mucous membranes of the larynx do?
- Helps remove dust particles
- Warms air
- Humidifies air
What does the epiglottis do?
Protects airway against entrance of solids or liquids during swallowing.
How does the larynx assist in voice production?
Muscles change vocal cord length and tension and regulate shape of larynx inlet to change voice.
Vocal cords are set into vibration by the flow of air from the lungs.
What lines the sinuses?
Mucous membranes
What do mucous membranes in the sinuses do?
Supply mucous to the nasal cavity
What is another name for the trachea?
Wind pipe
What does cartilage in the trachea prevent?
Tends to prevent the collapse and shutting off of airway.
What is the trachea a part of the passageway for?
For air to reach lungs from outside.
What kind of lining does the trachea have?
Ciliated membrane lining?
What are cilia?
Tiny hairs attached to a cell. They drive impurities toward throat to be eliminated.
What does the trachea divide into?
2 primary bronchi
What do the bronchi do?
- Distribute air to lungs interior.
2. Alveoli surrounded by capillaries accomplish the lungs vital function, that of gas exchanger between air and blood.
What can block passage of air through bronchioles or alveoli?
Certain diseases such as pneumonia.
The walls of the alveoli consist of what?
A single layer of epithelial tissue.
What shape are lungs?
Cone shaped.
What are the functions of the lungs?
- Air distribution to the alveoli
- Gas exchanger - between blood and alveoli an enormous surface area, where thin walled alveoli and thin walled capillaries come into contact so large amounts of O2 can quickly load into blood while CO2 is rapidly unloaded from blood.
What is the region between the lungs and what does it contain?
The mediastinum Contains: - Heart - Blood vessels - Esophagus - Trachea - Lymph nodes
What is each lung covered by?
A continuous double sac known as the pleura.
What is the portion of the pleura attached to the chest cavity wall called?
The parietal pleura
What is the portion of the pleura attached to the surface of the lung called?
The visceral pleura
Each closed sac (pleura) completely surrounds the lungs with what exceptions?
The place where the bronchus and blood vessels enter the lung.
What is the pleural space and what does it contain?
Between the two layers of pleura is the pleural space that has enough pleural fluid for lubricant of membranes.
What is the technical term for breathing?
Pulmonary ventilation.
What are the two phases of breathing?
- Inspiration - moves air into the lungs (inhalation)
2. Expiration - moves air out of lungs (exhalation)
Explain the mechanism of breathing.
- Air moves in and out of lungs for the same reason that any liquid or gas moves from one place to another, because pressure in one place is different from that in another place.
- Fluid and gas always moves from an area of high pressure to an area of lower pressure.
- When atmospheric pressure is greater than pressure within the lung, air moves from the atmosphere into lungs (inhalation) trying to achieve homeostasis of pressure (reverse)
- When pressure in the lungs becomes greater than that of the atmospheric pressure, air moves out of the lungs and into the atmosphere (exhalation).
What are differences in pressure established by?
Changes in the size of the chest (thoracic) cavity
The change in size of the chest cavity is produced by what?
By the contraction and relaxation of respiratory muscles (diaphragm and external intercostals).
Expansion of the chest cavity (increase in volume) results in what?
In decreased pressure within the chest cavity.
Explain inhalation.
Contraction of diaphragm alone, or of diaphragm and external intercostal muscles produces quiet inhalation. As the diaphragm contracts it decends. Contraction of external intercostal muscles pulls the anterior end of each rib up and out.
Explain exhalation.
Quiet exhalation is ordinarily a passive process. Inspiratory muscles relax, causing decreased size of thorax and increased thoracic pressure. As pressure increases in alveoli, over atmospheric pressure, expiration occurs. When it comes to forced exhalation, contraction of internal intercostal muscles can increase interalveolar pressure greatly.
What are the respiratory centres in the brain?
- Medulla - main one basic pattern
2. Pons - modifies basic pattern
Respiratory centres are controlled by?
- High blood CO2 stimulates expiration
- Low blood O2 stimulates inspiration
- Increased pressure in the alveoli inhibits inspiration
- Voluntary control (within limits) is provided by cerebrum of brain
Why is breathing regulated?
So that CO2 and O2 and acid balance are kept within normal limits.
What is normal respiratory rate for an adult?
12 to 20 breaths per minute.
