What type of vertebrate assists in breathing alongside with the ribs?

Analyze the question: It asks which type of vertebra works together with the ribs in breathing (ventilation of the lungs).

Explain the concept: The mammalian vertebral column has five regions:

• Cervical (neck): 7 vertebrae, support the skull (atlas and axis)
• Thoracic (chest): 12 vertebrae, articulate with the ribs
• Lumbar (lower back): 5 vertebrae, large and strong, bear body weight and allow movement
• Sacral (hip): 5 fused vertebrae, attach to the pelvic girdle
• Caudal (tail): small vertebrae forming the tail (coccyx in humans)

Step-by-step solution:

1. Breathing in involves the ribs moving upward and outward (with the intercostal muscles) while the diaphragm flattens. This enlarges the thoracic cavity.
2. Ribs attach at the back to the thoracic vertebrae, and at the front to the sternum. Together they form the rib cage.
3. Only the thoracic vertebrae carry the ribs, so they are the ones that assist in breathing by providing the pivot point for rib movement.
4. Sacral and caudal vertebrae are in the hip and tail regions, and lumbar vertebrae carry no ribs, so none of these help in breathing.

Answer: C. Thoracic

Exam tip: Remember "Thoracic = Thorax = Chest = Ribs." Whenever a question links ribs to vertebrae, think thoracic. A handy mnemonic for the number of vertebrae in each region (cervical, thoracic, lumbar) is 7, 12, 5.