Respiratory System Flashcards
What does the respiratory system contain? What do the structures do?
Nose, nasal cavity, pharynx, larynx, trachea, bronchii, lungs. The structures other than lungs assist in filtering and transporting air to the lungs. The lungs are where the exchange of oxygen and removal of carbon dioxide occurs.
When do we use our nose and mouth to breathe?
During rest, ventilation of air occurs at 5-6 liters per minute, hence only using nose as primary instrument for inspiration. During exercise, ventilation can increase to 20-30 liters per minute thus requiring our mouth to become the primary instrument.
How does air travel in the respiratory system? (From nose/mouth to the lungs)
From the nose/mouth, air travels down to the larynx and into the trachea, where it branches out into two primary bronchii (Right and left), which then branches put into secondary bronchii for each lobe of the lungs (About 3 lobes). It then branches out again into tertiary bronchii and then again into bronchioles. The bronchioles branch out into terminal bronchioles, further into respiratory bronchioles and finally tiny air sacs of alveoli where gas exchange occurs. The lungs have about 300 million alveoli and diffusion of air can occur in a surface area as large as a tennis court!
What occurs during inspiration? (State the muscles involved, the contents, and how it moves)
During inspiration, the diaphragm(which is the only skeletal muscle essential for life and the muscle of inspiration), contracts and pulls downwards, allowing the abdominal contents to also push downwards and forwards. During this time, the external intercostals of the ribs pulls the ribs outwards allowing it to expand. This expansion reduces the pressure of the membrane surrounding the lungs and allows the lungs to expand outwards, allowing airflow into the lungs.
During exercise, what happens to inspiration?
Accessory muscles are recruited to assist in inspiration as ventilation has increased (About 20-30 liters per minute now). The assisting muscles include, the sternocleidomastoid, scalenes and pectoralis minor. These muscles assist in increasing the volume of the thorax for the lungs to expand even more.
During exercise, what occurs to expiration?
Expiration becomes active, and important muscles of expiration become activated, these include, the serratus posterior, internal intercostals, internal obliques, and rectus abdominus. These muscles pull the ribcage downwards and force air out of the lungs by pushing abdominal contents upwards against the diaphragm
Why does exercising improve endurance?
The oxidative capacity of respiratory muscles (Those involved in inspiration and expiration) increases thus increasing the endurance of those respiratory muscles. This further improves exercise performances at various intensities
