Cross-section of a portion of the ribcage showing the intercostal artery and vein running parallel to the ribs within the intercostal muscles.

Cross-section of a portion of the ribcage showing the intercostal artery and vein running parallel to the ribs within the intercostal muscles. Needle is penetrating the muscle to gain access to the chest cavity.

Technique for intramuscular injection in children, dorsogluteal site; illustration shows cross-section of pelvic region at injection site indicating location of desired muscle (maximus, medium, minimus gluteal mm. ).

Schematic of horizontal section of inguinal canal and testis. Drawing shows eight layers of abdominal wall and three evaginations: scrotum, coverings of spermatic cord, and constituents of the cord.

Cross section of medium sized artery showing layers