2A Gas exchange Flashcards
Nasal cavity
this is the main route by which air enters the gas exchange system
mouth
air can enter the respiratory system here, but misses out on the cleaning, warming and moistening effects of the nasal rout
epiglottis
- a flap of tissue that closes over the glottis in a reflex action when food is swallowed
- this prevents food form entering the gas exchange system
larynx
the voice box, which uses the flow of air across it to produce sounds
trachea
- the major airway to the bronchi, lined with cells including mucus-secreting goblet cells
- cilia on the surface of the trachea move mucus and any trapped microorganisms and dust away form the lungs
incomplete rings of cartilage
these prevent the trachea and bronchi form collapsing but allow food to be swallowed and moved down the oesophagus
left and right bronchi
- these tubes lead to the lungs and are similar in structure to the trachea but narrower
- they divide to form bronchioles
bronchioles
- small tubes that spread through the lungs and end in alveoli
- their main function is still as an airway, but some gas exchange may occur
alveoli
the main site of gas exchange in the lungs
ribs
protective bony cage around the gas exchange system
intercostal muscles
found between the ribs and important in breathing, which moves air into and out of the lungs to maintain a steep concentration gradient for rapid gas exchange
pleural membranes
surround the lungs and line the chest cavity forming a sterile, sealed unit
pleural cavity
space between the pleural membranes, usually filled with a thin layer of lubricating fluid that allows the membranes to slide easily with breathing movements
diaphragm
broad sheet of tissues made of tendon and muscle that forms the floor of the chest cavity, also important in breathing movements
inhalation
breathing in
exhalation
breathing out
breathing in
inhalation
breathing out
exhalation
pathogens
microorganisms that cause disease
breathing
the process in which physical movements of the chest change the pressure so that air is moved in or out
lung surfactant
a special phospholipid that coats the alveoli and prevents them from collapsing
factors that affect the rate of diffusion across a membrane
- surface area; large surface area increases rate of diffusion
- concentration gradient ; the higher the faster
- thickness of the exchange surfaces; the shorter the diffusion distance the faster diffusion takes place
what is the principle called, which is used to calculate the rate at which substances of a given size will diffuse at a known temperature?
Fick’s law of diffusion
Fick’s law of diffusion
what does an effective gas exchange system include?
- large surface area
- thin layers for short diffusion distance
- rich blood supply
- moist surfaces (diffusion takes places with gases in solutions)
- permeable surfaces
what function do the hairs and the mucus in the passages of the nasal cavity have?
filter out and remove much of dust, small particles and pathogens such as bacteria that you breath in
what is an alveolus made of?
a single layer of flattened epithelial cells
what is found between the alveoli and capillaries?
a layer of elastic connective tissue holding everything together
elastic recoil of the lungs
elastic tissue helps to force air out of the lungs, which stretch when you breath in
what coats the alveoli?
lung surfactant
