Right before the race, Jim was quite stressed and was also feeling nervous; this made his heart rate and respiratory rate to increase. This is due to the breathing centre responses to nervous and chemical signals and changes the rate and depth of breathing to make changing of the body.
The activation of sympathetic division had a mutual relationship (corresponded) with arousal and energy generation causing the heart to beat faster, the liver convert glycogen to glucose, bronchi of the lungs dilate and support increased gas exchange, digestion inhibited and secretion of adrenaline from the adrenal medulla is accelerated.
The changes that happened in the digestive system and urinary system at this time, is the stimulation of the sympathetic division, this inhibits digestion and urination so that the internal fluid in Jim’s blood would be maintained. For this reason, Jim was sweating.
Jim blood glucose level became high because when he is stressed, hormone adrenalin is produced and acraadrenela is release by the ending of sympathetic neuron, this will then activate glycogenolysis to escalate the supply of glucose to the cell.
Jim’s mouth was dry because he was dehydrated. This is because the solute concentration in extracellular fluid increases that is tissue fluid becomes hypertonic to cells and the water goes from the cells. However, there is no replacement of the water loss.
One minute into the race, Jim needed quite a lot of energy for rowing at full speed. However to be able to increase Adenosine triphosphate (ATP), his respiratory rate has to increase because a lot of oxygen is needed in producing ATP so that ATP in the cell can be supplied.
Oxygen from haemoglobin is used for aerobic respiration to be able to generate ATP that will be used in the muscles concentration.
Lacteal accumulation in the muscles causes Jim’s muscle to start to cramp and fatigue (tiredness). Anaerobic respiration happened in his muscle during the active exercise when the oxygen level in the muscle limited due to the rate of consumption exceeding the rate of supply.
To make the conflict easier, Jim had to be well hydrated before the race, which resulted in him staying calm and laid back so that his respiratory and also his heart rate would go down. The temperature receptor in the skin will send the heat and sensory information to hypothalamus that Jim will be able to cool his body. Hypothalamus stimulates sweat glands in the skin, in order to make sweat. Sweating is the process of cooling down.

At the halfway mark of the race, he changes his mind from stressful mindset to a more positive thinking by staying calm and laid back. And this causes his respiratory and hate rate to decrease slightly. He did this so that he will be able to restore the energy for the race at the correct time. Jim is ready to sprint and he managed to increase the number of strokes from 34 strokes to 39 strokes
At the finish of the race, Jim has stopped rowing and his muscle are now at rest, his heart and breathing rates are still high because of the additional oxygen that has to be taken into the body after exercise in order to restore the whole system to its normal state.
He is now beginning to sweat more because when more sweat is produced, the water in the sweat evaporates which requires more energy and therefore carries away heat to be able to reduce the body temperature.
The muscles are caused by an increase in the blood flow to the muscles. For this reason, there is increase in activity in the muscles and there is also a reduction in the amount of blood glucose which is then converted to energy. Carbon dioxide level in the blood will also increase as it is made with the use of glucose. The pH of the blood will drop to acidic due to the formation of carbonic acid from carbon dioxide and hydrogen. The more lactic acid is accumulated in the body, the more heat is produced, and this causes the temperature to increase. The lactic acid level of the blood will also increase as the end product of glucose and glycogen metabolism.
Back at the dock Parasympathetic division activates digestion, urination and defecation. It also counteracts the effects of the sympathetic division by slowing down heart beat rate, lowering blood pressure and slowing the breathing rate. At this moment, Jim’s oxygen is beginning to reduce. On the other hand, in order to supply energy to Jim’s body, the fat had been burned. Besides, he was having excessive sweating causing a lot of water loss from his body. This will now make Jim’s body weight to decrease. When excessive water loss was experienced in Jim, his blood will become more concentrated in response to increase blood osmolality, the hypothalamus will produce ADH(arginine vasopressin, a hormone which is made by the hypothalamus in the brain and stored in the posterior pituitary gland) which is then released from the posterior pituitary. More water is reabsorbed into the blood, blood volume and blood pressure rise and less urine is formed. Jim only takes sips of water because he wants to avoid water intoxication. Water intoxication is because of excessive intake of pure water. The tissue fluid becomes hypertonic to the cells and water then enters the cells. This can then lead to the pulmonary edema and swelling in the brain. In extreme cases, it is fatal and dangerous to the health.