Please explain step by step in precise detail how the Nervous system and Respiratory system work together to help an individual smell?

Please explain step by step in precise detail how the Nervous system and Respiratory system work together to help an individual smell?
Please explain step by step in precise detail how the Nervous system and Respiratory system work together to help someone who has respiratory failure?
Please explain step by step in precise detail how the nervous system and cardiovascular system work together to help a person breathe?
Please explain step by step in precise detail how the Nervous system and immune system work together to help someone who just contracted a cold from another person?