gas exchange and transport

• Gases tend to move from areas of higher concentration to lower concentration due to differences in partial pressure.
• What is the challenge during gas exchange?

  As the organism becomes bigger, SA:V decreases and diffusion distance increases
• What are the adaptations for having a high diffusion rate?


  Permeability: The cell membrane allows for non-charged particles to move across it. Large surface area. Steep concentration gradient. Moisture: When gases inside solutions can pass through the membrane. Thin tissue layer.
• What does a shallow concentration gradient mean?

  Low diffusion rate?
• How do you keep a steep concentration gradient?

  A dense network of blood vessels to increase surface area. Ventilation: Mechanical process for lungs to inflate and deflate to excrete waste products. Continous blood flow.
• Explain how breathing in/inhalation works?

  ERDVPA
• Explain how breathing out/exhalation work?

  ERDVPA
• What are the adaptation in mammals?

  Bronchioles are surrounded by smooth muscle to alter the diamater of bronchiole tubes. Surfactant lowers surface tension in alveoli. Capillaries surround alveoli to even out blood flow. There is a high number of alveoli to increase surface area.
• What are the adaptations for plants?

  Waxy cuticle prevents water loss from the epidermis. The upper epidermis has the same function. The palisade mesophyll maximizes energy production during photosynthesis. The spongy layer/mesophyll keeps the concentration gradient. The air spaces increase surface area. Guard cells control with gas exchange. Lower epidermis contains lower temperatures and the stomata (open and close depending on gas exchange). Xylem vessels help during photosynthesis and transpiration.
• How much concentration of oxygen is there in the air?

  21%
• How much concentration of nitrogen is in the air?

  78%
• How much concentration of carbon dioxide is in the air?

  47%
• What effect does the diffusion distance have on the rate of diffusion of oxygen?

  Inverse
• What effect does the concentration difference have on the rate of diffusion of oxygen?

  Direct
• What is concentration difference?

  The process by which matter is transported from one part of a system to another as a result of random molecular motions
• What effect does the surface area have on the rate of diffusion of oxygen??

  Direct
• Which substances need facilitated diffusion to move through the membrane?

  Charged ions and hydrophilic substances
• What is the concentration gradient?

  Occurs when the concentration of particles is higher in one area than another.
• What are the adaptations of capillaries?

  A single layer of endothelial cells. Fenestrations between endothelial cells that promote leak out of oxygen, CO2, and glucose. Small lumen diameter which forces blood flow to be slower.
• What are the adaptations for arteries?

  An endothelial layer which is smooth to prevent friction. Smooth muscle and elastic tissues to withstand high pressures. Collaged and elastic fibers to prevent rupture due to overstretching.
• What are adaptations of veins?

  Valves to prevent backflow. Wide lumen for carrying a high blood volume. Thin middle layer. Low pressure. Flexible walls which facilitate blood flow to the heart.
• What type of blood to veins carry
• What type of blood do arteries carry
• How are the vascular systems in plants?

  Xylen transports water, phloem transport food/nutrients. Cell walls between connected cells degrade and the inside contents are broken down. Walls are strenghtened with lignin to prevent collapse. pits between vessels.
• How does emphysema happen?

  Destruction of alveoli and breakdown of elastic fibers by PROTEASES, which are chemicals secreted by immune cells
• What does alveolar macrophage do?

  Phagocytosis
• What is the cause of emphysema?

  imbalance between the antiprotease and protease activity
• What happens if there is more protease activity?

  more damage
• What happens if the number of neutrophils increases?

  They will release more proteases, especially elastase, which will break down the elastic fibers.
• What is "air trapping" during emphysema?

  Hyperinflation and the inability to deflate completely. Destruction of elastic fibers that unable a recoil system.
• Hoe do blood clots form?

  Coagulation, or trauma to the arteries/injury called atherosclerosis
• Describe de structure of the alveoli and the function?


  Alveoli are tiny, sac-like structures in the lungs where gas exchange occurs. They have thin walls surrounded by a network of capillaries, allowing for an efficient exchange of oxygen and carbon dioxide between the air and the blood.
• Outline the air's path during inhalation?

  nose cavity, trachea, bronchi, lungs, bronchioles, alveoli