L02 Respiratory System Flashcards
What is the Larynx?
It connects the back of the nose and the trachea. Also known as the voice box because it contains muscles and ligaments that form vocal chords
Why is the nasal cavity lined with hairs?
Traps dust, pathogens & pollen
What do goblet cells do?
Produce mucus which traps unwanted substances. The mucus also moistens the air inhaled.
Role of the epiglottis
It is a flap of cartilage behind the tongue which prevents food from entering the trachea
What is the pharynx
Connects the nasal cavity to the trachea
Structure and function of the trachea
Made up of C-shaped cartilage (this is so food can still pass in the oesophagus). It supports the trachea structurally to prevent collapse.
Has ciliated epithelium to trap unwanted substances
connects the pharynx to the lungs
Structure and function of Bronchi
smaller in diameter than trachea
c-shaped cartilage
branch from trachea to bronchioles
contain mucus
Structure of bronchioles
smaller in diameter compared to bronchi.
connects bronchi to alveoli
Structure and function of alveoli
Air sacs at the bottom of bronchioles
they have a large surface area
they are moist
they have thin walls (1 cell thick)
excellent blood supply
elastic fibres to withstand pressure
where gas exchange occurs
Role of diaphragm
Muscle that separates the chest from abdomen. Contracts and relaxes to push lungs up and down/ in and out
What are the 3 main processes in the respiratory system
Pulmonary ventilation
Gaseous exchange
Cellular respiration
What is pulmonary ventilation
breathing air into and out of the lungs
What is gaseous exchange
The diffusion of oxygen and carbon dioxide into and out of the blood stream
What is cellular respiration
the process where oxygen and glucose make energy/ATP in cells
Explain what happens in the respiratory system during inspiration
Diaphragm: Contracts + flattens
Lungs: Inflate, volume increases, pressure decreases
External intercostal muscles: contract
Internal muscles: relax
Rib cage: Upwards and outwards
Explain what happens in the respiratory system during expiration
Diaphragm: relaxes
Lungs: deflate, volume decreases, pressure increases
External intercostal muscles: relax
Internal intercostal muscles: contract
Rib cage: Moves downwards and inwards
What is the pleural membrane
two layers of thin membrane.
moist and slippery
contain pleural fluid
prevents friction as the lungs move
If the space between the membranes is punctured the lung on that side will not inflate
What is the role of the pleural fluid
Lubricates the surface of the lungs allowing the layers of membrane to slide over each other.
Allows the lungs to move easily within the chest cavity
How are the alveoli adapted for gaseous exchange
walls are 1 cell thick = short diffusion pathway
surrounded by capillaries = provides concentration gradient
large surface area = large amount of gaseous exchange can take place
Moist = allows oxygen to dissolve before diffusing through alveoli and capillary walls
What is meant by diffusion gradients?
Diffusion: movement of molecules from an area of high concentration to an area of low concentration
particles diffuse down a concentration gradient
capillaries: lower concentration of oxygen than alveoli
so oxygen diffuses from high concentration (alveoli) to low concentrations (blood stream)