Question

1. Use Boyle’s law and the anatomy of a mammal to explain how inhalation and exhalation occurs.

2. What is the difference between external gills and internal gills? What are the advantages/disadvantages of each?

3. Structure determines function: what features are common in different respiratory organs, and how do these features help with gas exchange?

4. What challenges to gas exchange do aquatic animals face? Terrestrial?

5. What is a “countercurrent exchange system”? Explain its role in fish gills.

6.Amphibians use 2 methods for respiration. What are they, and explain each. Why do

amphibians use both methods?

7. Describe the five factors discussed in class affecting gas exchange. Apply these

factors to the efficiency of a tracheal system, gills, lungs in mammals, lungs in birds.

8.Be able to identify a smoker’s lung versus a non-smoker’s lung.

Answer 1

During the process of inhalation, the lung volume expands as a result of the contraction of the diaphragm and intercostal muscles (the muscles that are connected to the rib cage), thus expanding the thoracic cavity. Due to this increase in volume, the pressure is decreased, based on the principles of Boyle's Law.

Boyle's law important in breathing when considering the changes in volume of the lungs upon inhaling and exhaling?

We can breathe air in and out of our lungs because of Boyle's law. According toBoyle's law, if a given amount of gas has a constant temperature, increasing itsvolume decreases its pressure, and vice-versa. When you inhale, muscles increase the size of your thoracic (chest) cavity and expand your lungs

Internal gills- A gill consists essentially of a membrane or outgrowth from the body, with a large surface area and a plentiful blood supply, through which diffusion of oxygen and carbon dioxide between the water and blood occurs. Fishes have internal gills, formed as outgrowths from the pharynx wall and contained within gill slits.

External gills- External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside the pharynx and covered by gill slits, as they are in most fishes. Instead, the respiratory organs are set on a frill of stalks protruding from the sides of an animals head.

internal gills advantages

Advantages. An aquatic lifestyle ensures that the gas exchange surface (gills) remain moist. Lamellae (primary and secondary) give the gill a large surface area increasing the rte of diffusion and therefore gas exchange. ... This is essential for an aquatic lifestyle as water has a much lower oxygen content than air.

External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside the pharynx and covered by gill slits, as they are in most fishes. Instead, the respiratory organs are set on a frill of stalks protruding from the sides of an animals head.

Respiration in Animals

• Through Plasma Membrane. In unicellular animals, such as amoeba, exchange of gases takes place through cell surface. ...

• Through Body Wall or Skin. Tapeworms, earthworms, and leeches use their skin for the exchange of gases. ...
• Through Tracheal System. ...

• Through Gills. ...
• Through lungs.

• 1. Through Plasma Membrane

  In unicellular animals, such as amoeba, exchange of gases takes place through cell surface. They absorb oxygen from the surrounding air or water and give out carbon dioxide through plasma membrane by diffusion.

  2. Through Body Wall or Skin

  Tapeworms, earthworms, and leeches use their skin for the exchange of gases. The skin of Earthworms is very thin and moistened. Many blood cells are spread on this skin. These blood cells are known as capillaries. The exchange of gases occurs at capillaries. They die of suffocation if their skin is dried up.

  Amphibians such as frogs use more than one organ of respiration during their life. They breathe through gills while they are tadpoles. Mature frogs breathe mainly with lungs and also exchange gas with the environment through skin

  3. Through Tracheal System

  In insects like cockroaches, grasshopper, transportation of gas or gaseous exchange take place by a special type of fine tubes is called tracheae.

  Air containing oxygen enters through spiracles into the tracheal tubes. It then diffuses into the body tissue and reaches every cell in the body. Carbon dioxide released from the cells goes into the tracheal tubes and comes out through spiracles.

  4. Through Gills

  A majority of aquatic animals like fish and prawns breathe through special organs called gills. Gilla are projections of the skin that help in using oxygen dissolved in water. Gills contain blood vessels which help in exchange of gases.

  Fish live in water. To get oxygen dissolved in water, fish gulp water through the mouth and pump it over the gills. Water passes into the gill chamber through gill slits. In each chamber, the water passes over the filaments. They absorb oxygen from the water and replace it with carbon dioxide formed. The water then passes out through the gill opening and this process is repeated again and again.

  5. Through lungs

  Amphibians, mammals, and birds exchange gases through special respiratory organs called lungs. Lungs are air-filled sac-like structures in the chest cavity. They are connected to the outside by a series of tubes and small opening.

  The challenges aquatic animals face against terrestrial organism is the amount of dissolved oxygen is less as compared to atmospheric oxygen which is much more efficient as compared to aquatic animals