Final answer:
The sagittal axis is where the frontal and transverse planes meet in the human body. There are three major axes, aligning with the sagittal, coronal, and transverse planes.
Step-by-step explanation:
The axis where the frontal and transverse planes meet is known as the sagittal axis. A sagittal plane divides the body into right and left sides, and if this division is exactly in the middle, creating two equal halves, it is known as the midsagittal or median plane. On the other hand, the frontal plane, also called coronal plane, divides the body into an anterior (front) portion and a posterior (rear) portion. Lastly, the transverse plane divides the body horizontally into upper and lower portions, producing cross-sectional images.
Regarding the number of major axes in the human body, there are three. These correspond to the three planes mentioned above: sagittal, coronal (frontal), and transverse. Each plane aligns with a major axis that is perpendicular to it, allowing for the analysis and description of movement and location in three-dimensional space within the human body.