Explain physiologic adaptations of the cardiorespiratory system of seals to deep diving.
- Point out differences between seal and human physiology related to deep dives.
- Evaluate respiratory and cardiac function.
- Measure oxygen consumption and calculate the total amount of oxygen needed for dives of various durations and compare to estimated stores in the lungs, blood and tissues.
Introduction:
Active cells require a constant supply of oxygen in order to produce energy to carry out cellular processes and release carbon dioxide as a waste product. The body must replenish this supply of oxygen and remove the build-up of carbon dioxide, as it is toxic to cells in high concentrations.
Our respiratory rate, or the number of breaths we take per minute, and the depth at which we respire with each breath is controlled by the respiratory center, located in the brainstem. It ensures that our respiratory effort matches the metabolic demands of our body.
In this lab you will head to a research lab in Antarctica to learn how seals have adapted to perform long, deep dives. How Weddell seals can dive up to 600 meters for 30 minutes is a bit of a mystery. In this simulation you will learn about oxygen stores, aerobic dive limit, aerobic and partially anaerobic ATP generation, and special cardio-respiratory adaptations that allow seals to perform deep, long dives that would be impossible for humans without scuba diving equipment. This will be a fun way to learn more about human cardiorespiratory physiology as well. Humans and seals have different amounts of oxygen available to them and store it at different proportions in lungs, blood, and muscle. Do seals and humans have the same factorial increase in oxygen consumption? Monitor 3 dives and collect data on oxygen and lactate to find out!
Assignment:
Part 1: Complete Labster “Cardio-respiratory Physiology: How can seals dive so deep for so long?”
As you complete the lab, have the lab report ready to record data. The theory section of the lab is a useful resource.
Part 2: Complete the lab report.
Respiratory Physiology Lab Report
- Compare the diving depths and oxygen stores and aerobic dive limits: (5 points)
| Weddell seal | Human | |
| Diving depth |
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| mL O2 in lungs |
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| mL O2 in blood |
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| mL O2 in muscle |
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| Total mL O2 in stores before dive | ||
| % of Oxygen in blood | ||
| % of Oxygen in muscle | ||
| % of Oxygen in lungs | ||
| Aerobic dive limit (mins) | Predicted if have the same factorial increase in oxygen usage as humans:
Actual: |
- What is the main difference between seals and humans regarding oxygen stores? (1 point)
- Where is the greatest proportion of oxygen stored in humans? (1 point)
- Do seals show approximately the same factorial increase in oxygen consumption as humans during diving? (1 point)
- How did the rate of oxygen consumption during diving change between a seal diving for 12 mins vs diving for 30 mins? (1 point)
- Explain why some lactate accumulated in the 30 min dive vs none in the 12 min dive. (2 points)
- How does the seal’s heart respond to diving? (1 point)
- What do the heart rate and consumption rate patterns suggest about seal diving? (1 point)
- You’ve learned so much about the physiology of diving, and major adaptations of seals that enhance their oxygen storage capacity and ability to dive. Which of the following is an INCORRECT statement regarding seal adaptations? (1 point)
- Seals have larger lungs than humans per body mass
- Seals have a higher content of hemoglobin and larger blood volume than humans
- Seals have a higher content of myoglobin in the muscle relative to humans.
- Seals have smaller lungs than humans per body mass.
- How does the respiratory system complement the circulatory system? (1 point)
Grading Rubric for Lab Report
| Activity | Deliverable | Points |
| Part 1 | Complete Labster | 15 |
| Part 2 | Complete lab report | 15 |
| Total | Complete all lab activities | 30 |
Respiratory Physiology Lab Report
- Compare the diving depths and oxygen stores and aerobic dive limits: (5 points) Weddell seal Human Diving depth
mL O2 in lungs
mL O2 in blood
mL O2 in muscle
Total mL O2 in stores before dive
% of Oxygen in blood
% of Oxygen in muscle
% of Oxygen in lungs
Aerobic dive limit (mins) Predicted if have the same factorial increase in oxygen usage as humans: Actual: - a. What is the main difference between seals and humans regarding oxygen stores? (1 point)
The main difference between seals and humans regarding oxygen stores is that seals have larger oxygen stores in their muscles compared to humans.
b. Where is the greatest proportion of oxygen stored in humans? (1 point)
The greatest proportion of oxygen is stored in the lungs of humans.
- Do seals show approximately the same factorial increase in oxygen consumption as humans during diving? (1 point)
No, seals do not show the same factorial increase in oxygen consumption as humans during diving.
- How did the rate of oxygen consumption during diving change between a seal diving for 12 mins vs diving for 30 mins? (1 point)
The rate of oxygen consumption during diving increased as the duration of the dive increased. In other words, the rate of oxygen consumption was higher during the 30-minute dive compared to the 12-minute dive.
- Explain why some lactate accumulated in the 30 min dive vs none in the 12 min dive. (2 points)
Lactate accumulated in the 30-minute dive because the prolonged duration of the dive resulted in a higher demand for energy. As a result, the seal’s body had to rely more on anaerobic metabolism, which produces lactate as a byproduct. In contrast, the shorter 12-minute dive did not require as much reliance on anaerobic metabolism, leading to the absence of lactate accumulation.
- How does the seal’s heart respond to diving? (1 point)
During diving, the seal’s heart rate decreases. This is known as bradycardia, and it is an adaptation that allows the seal to conserve oxygen and extend the duration of the dive.
- What do the heart rate and consumption rate patterns suggest about seal diving? (1 point)
The heart rate and consumption rate patterns suggest that seal diving is a highly efficient and well-adapted process. The decrease in heart rate helps to conserve oxygen, while the consumption rate patterns indicate that seals can adjust their metabolic rate to meet the demands of diving.
- You’ve learned so much about the physiology of diving and major adaptations of seals that enhance their oxygen storage capacity and ability to dive. Which of the following is an INCORRECT statement regarding seal adaptations? (1 point) a. Seals have larger lungs than humans per body mass b. Seals have a higher content of hemoglobin and larger blood volume than humans c. Seals have a higher content of myoglobin in the muscle relative to humans. d. Seals have smaller lungs than humans per body mass.
The incorrect statement regarding seal adaptations is d. Seals have smaller lungs than humans per body mass.
- How does the respiratory system complement the circulatory system? (1 point)
The respiratory system complements the circulatory system by providing oxygen to the blood and removing carbon dioxide. The respiratory system takes in oxygen from the environment and transfers it to the bloodstream, where it binds to hemoglobin in red blood cells. Simultaneously, carbon dioxide, a waste product, is released from the bloodstream into the lungs to be exhaled. This exchange of gases between the respiratory and circulatory systems ensures a constant supply of oxygen to the body’s tissues and the removal of waste gases.