The breathing process is primarily controlled by:
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Diaphragm: The diaphragm is the main muscle involved in respiration. When it contracts, it expands the chest cavity and allows air to be drawn into the lungs.
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Rib muscles: The muscles between the ribs, known as intercostal muscles, assist in expanding and contracting the thoracic cavity during breathing.
The other options are less directly involved in the control of the breathing process:
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Pharynx: While the pharynx is part of the respiratory tract and plays a role in directing air to the lungs, it does not control the process of breathing.
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Blood vessels: Blood vessels are involved in the transport of oxygen and carbon dioxide but do not control the breathing process itself.
So, the correct selections are:
- Diaphragm
- Rib muscles