The “intercostal spaces” refer to the narrow gaps located between the ribs in the chest. These spaces contain muscles, nerves, and blood vessels that play roles in breathing and protecting internal organs. The 5th intercostal space holds particular significance due to its anatomical position and the structures it overlies.
Locating the 5th Intercostal Space
The term “intercostal” means “between the ribs.” There are 11 such spaces on each side of the chest, numbered according to the rib directly above. The 5th intercostal space is located directly beneath the 5th rib and above the 6th rib.
To locate this space, feel for the sternum, the flat bone in the center of the chest. Moving outwards, the ribs can be felt as bony arches, with the spaces between them being the intercostal spaces. In a female, this space is typically found along the mid-clavicular line, an imaginary line descending vertically from the middle of the collarbone. While general rib size may vary slightly between sexes, the anatomical reference points for locating the 5th intercostal space remain consistent.
Organs and Structures in the Area
The 5th intercostal space is a region containing important anatomical structures. Foremost among these is the heart’s apex, its pointed lower tip. The heart’s apical impulse, or apex beat (the pulsation felt as the heart contracts), is often most clearly palpable here at the mid-clavicular line.
The lungs also extend into this region, allowing breathing sounds to be heard. The diaphragm, the primary muscle of respiration, is situated just below this area, separating the chest cavity from the abdomen. In females, the presence of breast tissue overlies the rib cage and intercostal spaces, adding another layer of anatomical consideration and making it a unique aspect for assessment.
Common Symptoms and Conditions
Discomfort or symptoms in the 5th intercostal space can arise from various sources. Chest pain is a common symptom, which can stem from musculoskeletal issues like muscle strain or rib inflammation. This pain might worsen with movement or specific postures.
Pleuritic pain, which is sharp and often exacerbated by deep breaths or coughing, can also originate from irritation of the lung lining in this area. While less common, pain in this region could also relate to the heart, potentially indicating a cardiac concern. In females, any new lumps, tenderness, or changes in the breast overlying the 5th intercostal space should be evaluated by a healthcare professional.
Medical Assessment of the Area
Medical professionals routinely assess the 5th intercostal space as part of a physical examination. Palpation, or feeling the area, is used to detect tenderness, swelling, or unusual lumps, particularly relevant given the presence of breast tissue in females.
Auscultation, which involves listening with a stethoscope, is also performed here. The 5th intercostal space along the mid-clavicular line is the standard location to listen for the heart’s mitral valve sounds and to assess the apical impulse. Lung sounds are also evaluated to identify any abnormalities in breathing.