Certainly! Here are the answers to the questions provided:
1. Burning Sensation in Muscles (Question 6a):
When Jim feels a burning sensation in his muscles while running, it is due to the buildup of lactic acid. Lactic acid is produced as a byproduct of anaerobic respiration when the body cannot supply enough oxygen to the muscles during intense exercise. This buildup of lactic acid leads to the sensation of burning in the muscles.
2. Breathing while Running (Question 6b):
Even after Jim slows down, his breathing remains deep and fast because his body needs to continue supplying oxygen to the muscles to help break down the accumulated lactic acid and meet the increased oxygen demand from the muscles. The deep and fast breathing helps deliver oxygen to the muscles and remove carbon dioxide efficiently.
3. Isotonic vs. Isometric Contractions (Question 7):
- Isotonic Contractions: Isotonic contractions occur when the muscle length changes as it contracts. This type of contraction is further divided into concentric and eccentric contractions. In concentric contractions, the muscle shortens while generating force (e.g., bicep curl). In eccentric contractions, the muscle lengthens while under tension (e.g., lowering a weight).
- Isometric Contractions: Isometric contractions occur when the muscle generates force without changing its length. This type of contraction is seen in activities like planks or holding a weight in a fixed position where the muscle contracts but does not change in length.
I hope this helps you understand the concepts better! Let me know if you need further clarification or have any more questions.
