Exchange Surfaces Flashcards
State the equation for ventilation rate
Ventilation rate = tidal volume × breathing rate
Define the term tidal volume
V of air that moves in & out of lungs w/ each resting breath
Define the term vital capacity
V of air that can be breathed in when strongest possible exhalation is followed by deepest possible intake of breath
Define the term residual volume
V of air left in lungs when exhaled as hard as possible
Define the term inspiratory reserve volume
Max v of air you can breathe in over & above normal inhalation
Define the term expiratory reserve volume
Extra v of air you can force out of lungs over & above normal tidal v of air you can breathe out
Define the term total lung capacity
Sum of vital capacity & residual volume
How do you HAVE to write the units for breathing rate per minute
breath min ^-1
Explain how a spirometer works
-Subject breathes regularly through mouth in spirometer
-CO2 absorbed from exhaled air by soda lime because if builds up can cause respiratory disease
-As subject breathes , trace drawn on rotating drum
Explain why the mammalian gas exchange surface needs to be moist
-Reduce friction between walls of alveoli
-Prevents alveolar collapse
State the function of the alveoli
Gas exchange w/ blood (of O2 & CO2)
State 4 adaptations of alveoli and how this is achieved
-Thin layer -> 1 squamous epithelial cell thick
-Large SA -> Millions of alveoli
-Good ventilation -> Constant inhalation & exhalation of air
-Rich, constant blood supply
What structures are found in the nasal cavity?
-Ciliated epithelium
-Goblet cells
-Hair
What structures are found in the trachea?
-C shaped rings of cartilage
-Smooth muscle
-Goblet cells
-Ciliated epithelium
-Connective tissue has collagen & elastin
-Blood vessels
What structures are found in the bronchi?
-Cartilage
-Smooth muscle
-Ciliated epithelium
-Goblet cells
-Connective tissue w/ collagen & elastin
What structures are found in bronchioles?
-Smooth muscle
-NO cartilage
-Ciliated epithelium
-Connective tissue
-Blood vessels
What structures are found in the alveoli?
-Capillaries
-Squamous epithelium
-Elastin
Describe the process of gas exchange in the alveoli
-Inhaled air enters lungs & reaches alveoli
-Squamous epithelial cells in close contact w/ surrounding endothelium capillaries
-O2 diffuses quickly from alveoli to blood in capillaries
-CO2 diffuses from blood into alveoli -> exhaled
State the structures that make up the mammalian respiratory system
-Nasal cavity
-Oral cavity
-Trachea
-Lungs
-Bronchi
-Bronchioles
-Heart
-Rib cage
-Diaphragm
State the difference between respiration and breathing
-Breathing = Mechanical process of inhalation &exhalation
-Respiration = Chemical reaction in cells releasing E from gluc
State a limitation of using a spirometer and how this can be overcome
-O2 can run out
-Keep replenishing
Describe the process of inspiration
-Dome shaped diaphragm contracts -> flattens & lowers
-External intercostal muscles (EIM) contract, IIM relax -> rib up & out
-Thorax v increases -> thorax p decreases
-P = lower than atmospheric -> air drawn through nasal passages, trachea, bronchi, bronchioles, lungs
-Equalises P in & out of chest
Describe the process of expiration
-Diaphragm relaxes -> up into resting dome shape
-EIM & IIM relax -> ribs move down & in
-Thorax v decreases -> thorax p increases
-Thorax p > atmospheric -> air moves out of lungs until pressure in & out is =
Is inspiration an active or a passive process?
Active (E required)
Is expiration an active or a passive process?
Passive
Is forced exhalation an active or a passive process?
Active (E required)
Describe the process of forced exhalation
-Diaphragm relax
-IIM contract
-EIM relax
Explain why organisms need to exchange substances with their environment
-Take in reagants for chemical reactions
(e.g. O2 & gluc for aerobic resp)
-Excrete waste products from these reactions (e.g. CO2, urea) (if CO2 not excreted pH would decrease)
What is an exchange surface?
Area adapted for efficient exchange of molecules from 1 side of a surface to the other
Describe what happens to the surface area to volume ratio as the size of an organism increases
Decreases
(small animals = high SA:V)
(large animals = low SA:V)
Describe the impact an organism’s level of activity has on its requirements for exchange surfaces
-Higher activity -> higher metabolic demand -> higher metabolic activity -> more reagants needed -> more exchange surfaces required
State 1 adaptation large cells have to compensate for their small SA:V ratio
Microvilli
Define the term excretion
Removal of waste products
Explain why single-celled organisms do not need specialised exchange surfaces
-High SA:V
-Metabolic activity = low -> little O2 needed
-d between chemical reactions in cytoplasm & external environ = short -> can survive off of diffusion
What is the name of the gas exchange system of insects?
Tracheal system
