Basal metabolic rate be elevated in stress, illness, and diabetes. Menopause may also affect metabolism. Heart rate is determined by the medulla oblongata and part of the pons, two organs located inferior to the hypothalamus on the brain stem. Heart rate is important for basal metabolic rate and resting metabolic rate because it drives the blood supply, stimulating the Krebs cycle. During exercise that achieves the anaerobic threshold, it is possible to deliver substrates that are desired for optimal energy utilization. The anaerobic threshold is defined as the energy utilization level of heart rate exertion that occurs without oxygen during a standardized test
Neomammalian brain essential in regulating heart rate, body temperature and space orientation. For example, if a human holds their breath and carbon dioxide levels rise, the primitive brain initiates the lungs to start breathing to achieve a state of homeostasis. The Paleomammalian brain is known as the intermediate or ‘old mammalian’ brain. The Paleomammalian brain anatomically consists of the hypothalamus, amygdala and the hippocampus. It is responsible for subconscious emotions such as fear, joy, fighting and sexual behaviour. The old mammalian brain is found in a large percentage of mammals and is believed to have a strong intricate connection with the neocortex.