Chapter 30 Biology Quiz 152

Oxygen

Oxygen

• is necessary for aerobic respiration

• final electron acceptor in electron transport chain

• Respiratory Gas

Carbon Dioxide

• produced as a result of the breakdown of food

• Respiratory Gas

Respiratory Gases

• Oxygen and Carbon Dioxide

• Move via diffusion and bulk flow

Diffusion

• Use over small distances (cell to cell)

• Governed by Fick’s Law

• VERY quick cell to cell (0.1µs)

Bulk Flow

• Necessary for large distances (organ to organ)

Fick’s Law

• the rate of diffusion of a gas across a segment of membrane depend upon the concentration of the gas on both sides of the membrane (C1 and C2), and the distance the molecule have to travel (L)

• Rate is proportional to C1-C2/L

True

True or False? all animals need to obtain oxygen from, and release carbon dioxide to, their environment.

Gas Exchange Membrane

a thin layer of epithelial tissue through which the respiration gases move between the external environment and the animals respiratory system

• How animals obtain oxygen and expel carbon dioxide

• Held in respiratory organs

True

True or False? Human lungs have a surface area of over 120m2

Lungs and Gills

Two types of respiratory organs

Gills

• are respiratory organs in which the gas exchange membrane is folded outwardly (evadignated) and is surrounded by the external environment (i.e. water)

• Can be external or internal

• Ventilation is unidirectional, water moves in one direction over the gills

External Gills

Direct contact with the environment

Internal Gills

Held in a protective cavity

Lungs

• respiratory organs in which the gas exchange membrane is folded inwardly (invaginated) and the external medium (air) is drawn into the lung via tidal ventilation

• Ventilation is tidal, air flow into the lungs, and once the oxygen has been obtained, it flows out the same way it entered

Ventilation

• the movement of the environmental medium (Water or air) into or through the gas exchange membrane

• the moving air and out

True

True or False? Water have about 1/20 of the oxygen as air (at the same temperature)

True

True or False? Respiration in water requires ten times the energy as air, water is more viscous than air

True

True or False? Solubility of oxygen in water decreases with increasing temperature and increasing salinity

Counter - Current Gas Exchange

• Respiration in fishes involves unidirectional ventilation over the gills

• blood in the gill filaments flows in a direction opposite to the flow of water through the gill chamber

• Oxygen concentration of water is always higher than the blood so oxygen will always diffuse into the blood

True

True or False? Respiration in most terrestrial vertebrates involves tidal ventilation into sac-like lungs.

Interior Surface of Terrestrial Vertebrates

• have a lot of surface area and are coated with surfactants to ease the diffusion of oxygen into the blood stream.

Positive Pressure

• used by amphibians

• Pushes air into the lungs, after gulping air the mouth and nostrils are sealed and the air pushed into the lungs

Suction

• In reptiles and mammals, the lungs expand, and the air rushes into the lungs

Bird respiratory organs

• highly efficient

• due to flight requiring a lot of energy avian respiratory system provides a lot of oxygen via unique adaptations

  • Arrangement of Parabronchi and air sacs

Insects

• Use a set of tubes (tracheae) that open directly to the air through their exoskeleton (spiracles) to deliver oxygen directly to their cells

Tracheae

• tubes in insect respiration

• become more narrow as they extend through the body

Spiracles

• opening in insect exoskeleton to allow respiration

True

True or False? some animals do not have gills or lungs or any other respiratory tissues. They are able to allow respiratory gases to diffuse through their skin.

Respiration in Humans

• Like all mammals, have a high metabolism and require a lot of oxygen to meet their metabolic needs

• Can extract oxygen from air with high efficiency

  • direct result of extensive surface area provided by the branching airways and close connections with the circulatory system

• Ventilation by musculature (diaphragm and intercostal muscle)

Mechanics of Breathing

• air flows from high to low pressure

• When chest expands pressure inside is lower than pressure outside

‘Tidal Volume’ of Humans

• Approx 10% of our capacity

True

True or False? Humans breathe via involuntary control

False

True or False? ALL marine species breathe via involuntary control.

Neurological Control of Breathing

• sensory receptions sense H+ (pH)

• As CO2 is generated H+ is produced

• CO2 is produced by cellular respiration

Respiratory Rate

• Increased H+ causes motor centers to in the brainstem to increase the rate and depth of breathing

• Increased respiration eliminated more CO2, which decreases H+

Three Ways of Transport of CO2 in Blood

• Dissolved in Blood: 5%

• Bound to Hemoglobin: 10%

• Bicarbonate Ions (HCO3-): 85%