3.3.1 exchange surfaces. Flashcards
what does the trachea look like
C shaped ring of cartilage
smooth muscle only between cartilidge ends
biggest
Has ciliated colomnar epithelium
What does a bronchus look like
a full ring of smooth bronchial muscle
has cartilage plates
has ciliated columnar epithelium
medium size
What do the bronchioles look like
Lumen is star shaped
branches of pulmonary vessels are parralel
smallest
what is tidal volume
volume of air breathed in and out at rest
what is vital capacity
the volume of breathed in and out during exercise so the greatest volume of air that can be taken in by the lungs
what is residual volume
the minimum amount of air always within the lungs to prevent collapse
Chemoreceptors that change breathing patterns detect what?
CO2 ———-hydrogencarbonate ions
Where are these chemoreceptors of breathing found
brain stem/medulla or aortic bodies
what part of the body controls the breathing rate
brain stem/medulla
Describe inspiration
External intercostal muscles contract internal intercostal muscles relax rib cage come up and out diaphragm contracts volume increases in the thorax air enters due to pressure being less inside
Why do organisms need respiratory surfaces
so they can absorb enough oxygen and get rid of enough co2 to support the amount of metabolic activity.
features of a good exchange surface
moist- dissolve oxygen within it
good blood supply/ventillation- to keep conc gradient
thin- short diffusion distance
how are mammals respiratory systems adapted
millions of alveoli so large S/A lined with squamous epithelial tissue which is really thin surrounded by dense capillary network moist so can dissolve oxygen elastic so can adapt to ventillation
How are insects respiratory systems adapted
insects carry out ventilation movements to maintain concentration gradient as they dont use vessels like mammals
have millions of tracheoles so increased surface area
how are fishes respiratory systems adapted
Gills have filaments and lamellae which allow for large s/a
counter current flow maintains conc gradient
efficient ventilation so conc gradient is maintained with oxygen rich water
large blood supple and capillary network for conc gradient
gill filaments have thin walls
how do fish ventilate
the mouth lowers water enters buccal cavity raised up increases pressure forces water into operculum operculum moves outwards water flows over gills
what is counter current flow
blood flows in the opposite direction to the flow of water to the conc gradient is always at the max
why are ciliated epithelial and goblet cells needed
goblets produce mucus
traps dust or pathogens
cilia use hair like projections to waft mucus to top of the throat
defence against infection and keep airways clean
why is cartililage needed in the airways
keeps trachea and bronchus open during stages of ventilation
allows food to pass through the oesophagas
provides attachment for smooth muscle in trachea
Ring cartillage in the tracheo allows in to be flexible and bend
why is smooth muscle needed in the airways
allows bronchi to constrict or dilate for air flow adjustment
allows the bronchioles to recoil and push every bit of air out
closure of air pipes eg asthma
what is surfactant
it lines the alveoli and is used for oxygen to be dissolved and so that the alveoli dont collapse during low pressure conditions
reduces surface tension
how is the alveoli adapted to ventilation movements
contains elastic fibres which allow for dimension changes during ventillation
elastic recoil helps expel air out
how are paticles of dust removed from the alveoli
macrophages engulf them and the lysomal actions breaks them down
how are alveoli adapted
thin- 1 cell thick elastic- expel air squamous epithelial surfactant to prevent collapse conc gradient maintained
why do mammals need a transport system
low s/a to volume
cells deep within get nout
the metalbolism too fast so to get enough 02 and get rid enoiugh co2
