Respiratory Flashcards
What is the primary function of the respiratory system?
To obtain oxygen (O2) for use by the body’s cells and to eliminate carbon dioxide (CO2) produced by cells
What are the two main types of respiration?
Internal (cellular) respiration
External respiration
Draw and label a diagram showing how blood becomes oxygenated
See lecture notes
What are the non-respiratory functions of the respiratory system?
Route for water loss and heat elimination
Enhances venous return
Contributes to the maintenance of blood pH
Enables speech, singing and other vocalisation
Defends against inhaled foreign matter
Can act as a filter for blood returning to the peripheries
The nose serves as an organ of smells
What are the two key zones within external respiration?
The conducting zone:
Respiratory passageways
The respiratory zone:
The site of gaseous exchange
What structures come under the conducting zone:
The nose
The nasal cavity
The pharynx
The larynx
The trachea
The bronchi
What is the structure of the nose
Bone and cartilage
What is the function of the nose
Provides an airway for respiration
Moistens and warms entering air
Filters inspired air
Serves as a responding chamber for speech
Houses the olfactory receptors
What is the structure of the pharynx?
Funnel shaped, connects the nasal cavity and the mouth to the larynx and oesophagus
What is the function of the pharynx?
Serves as a common pathway for food and air
Commonly called the throat
What is the larynx?
Also termed the voice box because it houses the vocal cords
What is the structure of the pharynx?
Bone and cartilage
What is the function of the larynx?
To provide an open airway
Act as a witching mechanism to route air and food into the proper channels
Voice production
What is the trachea commonly termed?
The windpipe
What is the structure of the trachea?
Supported by hyaline cartilage rings
The trachea consists of three main layers:
Mucosa: contain cilia for the removal of mucus
Submucosa: connective tissue layer containing glands that produce mucus
Adventitia: outermost layer supported by ‘c’ shaped hyaline cartilage rings fixed together with trachealis muscle
What is the structure of the bronchi?
The trachea split into two, forming two distinct bronchi
These bronchi lead into the actual lung and then divide again into the secondary bronchi
The bronchi continue to sub-divide until termination, approximately 23 orders of branching
What does the respiratory zone consist of?
Bronchioles
Alveolar ducts
Alveolar sacs
What is the respiratory membrane
Walls of the alveoli are composed of squamous epithelial type I cells
The external surface of the alveoli are covered with a complex network of pulmonary capillaries
Together, the alveoli and the network of pulmonary capillaries form the respiratory membrane
Scattered amongst the type I cells are cuboidal type II cells, which secrete a fluid containing surfactant
Describe the gross anatomy of the lungs
The lungs are located in the thoracic cavity, occupying the same anatomical regions as the heart and the great blood vessels
Each lung is suspended in its own pleural cavity
The left lung consists of two lobes and is smaller than the right due to the positioning of the heart
The right lung consists of three lobes and is bigger than the left
How is blood supplied to the lungs?
Pulmonary arteries deliver deoxygenated blood to the lungs (arteries take blood away from the heart)
Pulmonary veins take oxygenated blood away from the lungs and back to the heart for systemic distribution
What is the pleura?
A thin, double layered steroids (a membrane that secretes serous fluid)
The partial pleura lines the thoracic wall and the superior aspects of the diaphragm
The visceral pleura covers the external lung surface
The pleurae produce pleural fluid, a lubricating serous secretion that fills the pleural cavity
This allows the lungs to slide freely over the thorax
Explain the difference between external and inter Earl respiration
Internal:
Internal respiration refers to the gas exchange across the respiratory membrane in the metabolising tissues
Oxygen diffuses out form the blood into tissue
Carbon dioxide diffuses into the blood from the tissue
Internal environment only
External:
External respiration refers to gaseous exchange across the respiratory membrane of the lungs
Oxygen diffuses from alveolar air into the blood
Carbon dioxide diffuses out of the blood into the alveolar air
Internal environment and external environment
Outline the non-respiratory functions of the mammalian respiratory system
See lecture notes
Describe the two main external respiratory zones
See lecture notes