Respiration Flashcards
What is the purpose of gas exchange?
To gain oxygen and remove carbon dioxide from the body
What is the composition of air?
Oxygen=21%, Nitrogen=78%, CO2=0.04%
By what process do gasses move?
Diffusion
What is diffusion?
Ions of molecules move from an area of higher concentration to an area of lower concentration across a semipermeable membrane
What is Flick’s Law?
R=DxA(difference between)p/d
The rate of diffusion = diffusion constant X area diffusion takes place times difference in partial pressure over the distance across which diffusion takes place
What leads to an increase in diffusion?
Large surface area, small distance travelled and high concentration gradient
Gas exchange needs a _____ surface
Moist
Which is a better respiratory medium, air or water? Why?
Air as it has higher O2 concentration and is easier to ventilate
In water, as temperature increases, the oxygen content _______
Decreases
How are small animals able to exchange gases at the body surface?
Due to a large surface area to volume ratio
What does the structure of gas exchange surfaces depend on?
Size of the organism, habitat (water/land), metabolic demands of the organism (high/moderate/low)
How does respiration occur in flatworms?
Diffusion through body surface, due to small size
In gastropods, what is the respiratory protein that transports O2?
Hemocyanin, hemoglobin in a few species
How does respiration occur in cephalopods?
Water is drawn into the cavity behind the mantle where it reaches the gills; excess water pushed out by siphon
How does respiration occur in annelid worms?
Diffusion through skin, or gill filaments in some aquatic species
In annelids, what respiratory proteins transport O2?
Hemoglobin or chlorocruorin
What type of breathing apparatus does a spider have?
Book lung, bringing air in to mix with haemolymph from circulatory system, and trachea
How does respiration occur in insects?
Air travels through spiracles (holes on body surface) to give O2 to cells directly
How does respiration occur in crustaceans?
Internal gills attached to basal segments of legs
How do mosquito larvae get air?
Via a posterior siphon that comes out of the water surface, gaining contact with air
What are biological gills? What animals are they found in?
Tracheated cuticular extensions from the body, seen in mayfly nymphs
What are rectal tracheated gills? What animals are they found in?
Opening into the rectal area with internal gills alog the walls, seen in dragonfly nymphs
What are physical gills? What animals are they seen in?
Animal keeps an air bubble to allow diffusion to take place between the bubble and water, seen in aquatic beetles and bugs
What is the oxygen transport protein in vertebrates?
Haemoglobin
What phases are involved in fish respiration?
Suction pump phase - mouth opens and buccal cavity expands letting in water; Pressure pump phase - mouth closes and buccal cavity contracts pushing water out past the gills
In fish, what do gill arches do?
Support the primary lamellae (gill filaments)
In fish, what does ram ventilation consist of?
The mouth is kept slightly open while the fish swims, continually pushing water passed the gills
How does the structure in elasmobranch gills differ from other fish?
They have septa
Where can gas exchange in an amphibian lung take place?
On the outer surface only
How do amphibians minimise the mixing of oxygenated and deoxygenated air?
Inhaled air is kept in the buccal cavity while air is exhaled; the inhaled air is then able to enter lung
In amphibians, low oxygen levels leads to an increase in _________
Skin surface area
How does respiration occur in amphibian larvae?
Gills
How does a snake’s respiratory system differ from other reptiles?
Usually only use one lung (right); the left is not present or reduced
How do reptile and mammal alvioli differ?
Reptilian alvioli are larger and fewer in number
Turtles are unable to move their ribs. How to they push air out of the lungs?
Use their forelimbs and pectoral girdle
What is teh hepatic piston method of ventilation used by crocodilians?
The liver is pulled back using muscles, pulling the lungs back and expanding
What is characteristic of bird respiratory systems?
The presence of air sacs
