gas exchange Flashcards
(115 cards)
gaseous exchange system
A gaseous exchange like this circulatory system with the atmosphere
the gaseous exchange system is adapted to
- clean and warm the air that enters during breathing
- maximize the surface area for diffusion of oxygen , carbon dioxide between the blood and atmosphere
- minimize the distance for this diffusion
- maintain the adequate gradients for this diffusion
gas exchange in single celled organisms
single-celled organisms, the oxygen simply diffuses from the fluid outside the cell, through the cell surface membrane and into the cytoplasm
oxygen and CO2 are
nonpolar molecules, and they can cross the phospholipid bilayer
gaseous exchange in multicellular organisms requires
a special gas exchange surface - example: alveoli in the human lungs
Alevoli collectively have a large/huge surface area , probably traveling around 20m^2 in adults- therefore gas exchange of oxygen and carbon dioxide.
greater the surface area, greater the rate of diffusion
lungs seen in
thoratic ( chest ) activity
lungs surrounded by
the plural membranes which enclose an airtight space
this space contains a small quantity of fluid ( plural fluid ) to allow friction-free movement as the lungs are ventilated by the movement of the diaphragm and ribs
air pathway
nostrils- nasal cavity - pharynx - larynx - bonchi - terminal bronchiole - respiratory bronchiole - alveolar duct- alveoli ( gas exchange occurs)
the beating of the cilia in the airways
carries mucus upwards towards the larynx at a speed of about 1cmmin^-1
what happens to air inside the nasal chamber?
the nasal chamber is lined with hairs, mucus glands and richly supplied with blood vessels, the air flowing through the nose is warmed to body temperature and moistened by evaporation from the lining, for protecting the delicate surface inside lungs from dessication( drying out), particles smaller than 5-10 micro metre are trapped by nose hairs
mucus lining the nasal cavity traps the germs and suspended matter in the air and moistens the air, in the trachea and bronchi, the mucus produced by the goblet cells
Mucus-
mucin - glycoprotein- golgi bodies
glycoprotein process happening in
golgi body
trachea position
comes anterior to the oesophagus
cross-section of trachea
the lining is compressed of ciliated epithelium which rests on a basement made up of protein fibers
in between the ciliated cells are goblet cells
beneath the epithelium is an area of loose tissue with blood vessels and mucous glands
the trachea as a whole is supported by 15-20 C- shaped in complete rings of cartilage ( completely posteriorly by the trachealis muscle )
structure and function of golgi bodies
produce mucus to trap dust and pathogens, mucus must contain mucin, which is a glycoprotein. therefore, the number of golgi bodies are so high in goblet cells
structure and function of mucous glands
produce mucus to trap dust and pathogens , mucuc contains mucin which is a glycoprotein
structure and function of elastic fibres
they stretch during respiration and recoil ( to push air out) during expiration
structure and function of cillia
beats to push mucus to the throat, so that it could be swallowed
structure and function of C-cartillage
keep the aiways open , thus lowring resistance to air. provides support and keeps the trachea from colla[somh due to changes in air pressure
structure and function of smooth muscle
airways widen when smooth muscle relaxes ( for example during exercise) when it contracts the airways constricts
structure and function of trachealis muscle
found in the posterior wall allows the trachea to contract and decrease its diameter
steps involved in the production of mucus from goblet cells
- transcription: production of mRNA
- transalation: protein chains produced
- lumen of E.R- enzymes modify the secondary folding
- transport vesicles formed
- binds with golgi body- glucose is added
- tertiary or quaternary folding, if necessary
- exocytosis
- mucin with water
bronchi singular
bronchus