Muscles and Mechanics of Respiration

This video from Bite Size Med covers the muscles involved in respiration, focusing on how the diaphragm, ribs, and sternum contribute to the breathing cycle. It explains the active process of inspiration and the passive process of expiration, detailing the roles of various muscles, including the diaphragm, intercostal muscles, and accessory muscles. The video also highlights the importance of the phrenic nerve in diaphragm function and concludes with a summary of the key points discussed.

What is the primary function of the thoracic cavity during respiration?

• To change its volume

• To filter air

• To store oxygen

• To produce sound

Which muscle is primarily responsible for increasing the vertical dimension of the thoracic cavity during inspiration?

• Serratus anterior

• Diaphragm

• Internal intercostals

• External intercostals

How do the upper ribs move during inspiration?

• By rotating in place

• By moving laterally

• With a pump handle movement

• With a bucket handle movement

Which muscles are primarily involved in regular inspiration?

• Internal intercostals

• Sternocleidomastoid

• External intercostals

• Abdominal muscles

What role do accessory muscles play in respiration?

• They are involved in quiet expiration

• They assist during respiratory distress

• They are used during regular breathing

• They depress the diaphragm

Which muscle is NOT considered an accessory muscle of inspiration?

• Rectus abdominis

• Scalene muscles

• Sternocleidomastoid

• Serratus anterior

What is the primary action of the internal intercostal muscles during expiration?

• Contract the diaphragm

• Expand the thoracic cavity

• Depress the ribs

• Elevate the ribs

Which abdominal muscle is NOT involved in forced expiration?

• Diaphragm

• External oblique

• Rectus abdominis

• Internal oblique

What is the consequence of damage to the phrenic nerve?

• Increased lung capacity

• Diaphragmatic palsy

• Improved breathing efficiency

• Enhanced rib movement

Which nerve supplies the diaphragm?

• Phrenic nerve

• Vagus nerve

• Accessory nerve

• Intercostal nerve