12.10a Gas exchange Flashcards
What is ficks law?
Surface area x concentration gradient / diffusion distance
What is a good exchange surface?
Large surface area
Large concentration gradient
Large SA:V ratio
Small diffusion distance
Gas exchange in insects
O2 enters spiracles into trachea
Spiracles close
O2 diffuses down trachea into tracheoles
O2 delivered to respiring tissues
CO2 produced leaves when spiracles open
How do insects get oxygen during flight?
The insect may momentarily respire anaerobically, producing lactate
Water builds up in the tracheoles
The lactate lower the water potential so water passes from the tracheoles to muscles
Draws oxygen into cell
How does oxygen diffuse into insects?
The tissues respire, producing oxygen
Increases oxygen conc in tissues
Oxygen moves down conc gradient from trachea to tissues
Lowers conc grad in trachea so oxygen moves in via spiracles
How does carbon dioxide diffuse out of insects?
Tissues respire, using carbon dioxide
Increases conc grad in tissues
CO2 moves down conc grad into trachea
CO2 diffuses out of spiracles
Does oxygen move in or out of an amoeba and how?
Diffuses in by simple diffusion
Do amino acids move in or out of amoeba and how?
In by simple diffusion
Does glucose move in or out of amoeba and how?
Glucose diffuses in by facilitated diffusion
Does CO2 move in or out of amoeba and how?
CO2 diffuses out by simple diffusion
Does ammonia move in or out of amoeba and how?
Ammonia diffuses out by simple diffusion
How does respiration in an amoeba work?
Produces carbon dioxide and uses up oxygen
Tracheoles definition
Small tubes with thin walls to diffuse gases through the body of an insect
What is counter current flow?
Counter current means the water and blood flow in opposite directions
Maintains a concentration gradient along the whole length of a gill
Equilibrium never reached
How do gills increase gas exchange?
Increase surface area
How do gills increase oxygen in the fish?
Water carrying oxygen enters the fish mouth, passes through the lamellae where most of the oxygen is removed
How do lamellae increase gas exchange?
Increases gills surface area even more
Has capillaries - rich blood supply
Thin epithelium for short diffusion distance
Adaptations of a plant for good gas exchange
Rolled leaves
Hairs
Needles
Sunken stomata
Waxy cuticle
How does oxygen diffuse in plants?
Mesophyll produces oxygen from photosynthesis
Oxygen diffuses into air spaces
Increases the conc of O2 in plant
Oxygen diffuses out to maintain conc gradient via stomata
Trachea structure
Tube like structure carrying air from the mouth to lungs
C rings of cartilage for movement and prevent collapsing
Bronchi structure
Splits trachea into 2 lungs
Splits into bronchioles
Brochioles structure
Further divides bronchi into small branches
Supply alveoli with air
Reason for good diffusion in the lungs
Moist - gases dissolve better in a permeable solution
Rich blood supply - large capillary network
Thin - short diffusion distance
Large SA - ficks law
Permeable - gases exchanged easily in and out of lungs
Alveoli structure
Small sacs at the end of bronchioles
Barrier between lungs and blood
How is deoxygenated blood brought to the lungs and oxygenated?
Via the pulmonary artery
Gases diffuse through the squamous epithelium membrane of the alveoli and endothelium wall of capillary
Ventilation definition
Mechanism of breathing
Breathing definition
Result of the pressure difference between the lungs and atmospheric pressure
Inhalation method
External ICM contract
Diaphragm moves down
Thoracic capacity increases
Pressure in lungs less than outside
Air moves down conc grad into lungs
Exhalation method
Internal ICM contract
Diaphragm moves up and out
Thoracic capacity decreases
Pressure in lungs more than outside
Air moves down conc grad out
Makeup of deoxygenated blood
Low in oxygen
High in carbon dioxide
What does the oxygen diffuse across to get from the alveoli to blood?
5 membranes
Squamous epithelium membrane of alveoli
Endothelial wall of capillary
How do oxygen and carbon dioxide get from the alveoli in to blood?
Via simple diffusion
Tidal volume definition
Natural breathing volume at rest
Inspiratory/expiratory reserve definition
Extra volume needed for a deep breath
Residual volume
Air that remains in lungs to prevent collapse of alveoli
Vital capacity
Maximum volume of air a person can expel from the lungs
