Question

What bones make up the rib cage? What are the functions of the rib cage? (page 241 )

Short answer

The rib cage consists of 12 pairs of ribs, the sternum, and 12 thoracic vertebrae. The ribs are categorized into true ribs (1st to 7th), false ribs (8th to 10th), and floating ribs (11th and 12th). The primary functions of the rib cage are to protect vital organs, aid in respiration, provide structural support, and serve as anchorage points for muscles.

Step-by-step solution

Identify the bones that make up the rib cage

The rib cage is primarily composed of the following bones: 1. Ribs: There are 12 pairs of ribs, numbered from 1 to 12. The ribs are divided into three categories: a. True ribs (1st to 7th ribs): These ribs attach directly to the sternum via costal cartilage. b. False ribs (8th to 10th ribs): These ribs do not attach directly to the sternum but connect to the cartilage of the rib above. c. Floating ribs (11th and 12th ribs): These ribs do not connect to the sternum or another rib, and only attach to the vertebrae at the back. 2. Sternum: A flat bone located in the center of the chest, also known as the breastbone. The sternum consists of three parts: a. Manubrium: The upper part of the sternum that articulates with the clavicle and the first rib. b. Body: The middle part of the sternum that articulates with the second to seventh ribs. c. Xiphoid process: The lower part of the sternum which is a small, cartilaginous structure that may ossify in later life. 3. Thoracic vertebrae: There are 12 thoracic vertebrae (T1 to T12) that form the posterior part of the rib cage, articulating with the ribs on either side.

Describe the functions of the rib cage

The rib cage has several important functions, including: 1. Protection: The rib cage forms a protective enclosure for vital organs such as the heart, lungs, and liver, preventing injury from external forces. 2. Respiration: The ribs play a crucial role in the process of breathing by assisting in the expansion and contraction of the thoracic cavity. This allows the lungs to expand and fill with air during inhalation and contract to expel air during exhalation. 3. Structural support: The rib cage provides a stable framework that supports the bones and muscles of the shoulder and upper limbs, allowing for a wide range of movement and functional stability. 4. Anchorage for muscles: The ribs, sternum, and thoracic vertebrae serve as attachment points for several muscles involved in respiration, body movements, and stabilization of the spine.