BIO 1500 chapter 22
1. For exchange, requirements include and en-
tering cytoplasm
Waste products like must exit the cell by crossing plasma mem-
brane: oxygen, nutrients, CO2
2. Complexity of respiratory system correlated with of organism. As
increases, diffusion increase
Direct diffusion feasible only for or small multicellular or high-
ly-flattened (ex flatworms): size, distances, unicellular
3. Small molecules can move between cells and surroundings by diffusion
Diffusion only efficient over distances because time it takes to dif-
,fuse is proportional to the square of the distance: small
4. In most animals, cells exchange materials with the environment via a
- circulatory system: fluid-filled
5. • Some animals (cnidarians and flatworms) lack a system.
• Have cavity: for both digestion and distribution of sub-
stances
• This cavity is enclosed in only -cells thick body wall
• This cavity and the flat shape of flatworms increases
of contact with exterior, minimizing , ensuring
each cell has access to O2 by diffusion: circulatory, gastrovascular, two, surface
area, distances, direct
,6. Earthworms and amphibians use (integument) as a respiratory
organ. Below skin, a dense network of facilitates gas exchange
between exterior and circulatory system. Surface must be for gases
to dissolve and diffuse: skin, capillaries, moist
7. - Aquatic organisms obtain O2 from
- Fish have to take up dissolved O2 -> thin tissue filaments, highly
branched and (large surface area). O2 rapidly diffuses across gills
, into bloodstream. Circulatory system then carry oxygenated blood to body
parts: water, gills, folded
8. Blood with low O2 circulates through the .
Concentration of O2 in water is than that in gills.
O2 molecules diffuse from water to
Similarly, CO2 in the blood diffuse from the blood (high concentration) to
(low concentration): gills, higher, blood, water
9. Tracheal systems
- In insects, respiration is of circulatory system.
- A highly specialized tracheal system, network of small tubes carries O2 to
entire body
1. For exchange, requirements include and en-
tering cytoplasm
Waste products like must exit the cell by crossing plasma mem-
brane: oxygen, nutrients, CO2
2. Complexity of respiratory system correlated with of organism. As
increases, diffusion increase
Direct diffusion feasible only for or small multicellular or high-
ly-flattened (ex flatworms): size, distances, unicellular
3. Small molecules can move between cells and surroundings by diffusion
Diffusion only efficient over distances because time it takes to dif-
,fuse is proportional to the square of the distance: small
4. In most animals, cells exchange materials with the environment via a
- circulatory system: fluid-filled
5. • Some animals (cnidarians and flatworms) lack a system.
• Have cavity: for both digestion and distribution of sub-
stances
• This cavity is enclosed in only -cells thick body wall
• This cavity and the flat shape of flatworms increases
of contact with exterior, minimizing , ensuring
each cell has access to O2 by diffusion: circulatory, gastrovascular, two, surface
area, distances, direct
,6. Earthworms and amphibians use (integument) as a respiratory
organ. Below skin, a dense network of facilitates gas exchange
between exterior and circulatory system. Surface must be for gases
to dissolve and diffuse: skin, capillaries, moist
7. - Aquatic organisms obtain O2 from
- Fish have to take up dissolved O2 -> thin tissue filaments, highly
branched and (large surface area). O2 rapidly diffuses across gills
, into bloodstream. Circulatory system then carry oxygenated blood to body
parts: water, gills, folded
8. Blood with low O2 circulates through the .
Concentration of O2 in water is than that in gills.
O2 molecules diffuse from water to
Similarly, CO2 in the blood diffuse from the blood (high concentration) to
(low concentration): gills, higher, blood, water
9. Tracheal systems
- In insects, respiration is of circulatory system.
- A highly specialized tracheal system, network of small tubes carries O2 to
entire body
