Behind the significators sits the doctrine of temperament, which is the framework the whole classical account of the body runs on, and it is worth setting out, because a modern reader will otherwise miss what these entries are doing.
The scheme is humoral. Four qualities, hot, cold, moist and dry, combine into four temperaments: choleric, hot and dry; sanguine, hot and moist; melancholic, cold and dry; phlegmatic, cold and moist. Every planet, sign and house carries a combination of the qualities, and a chart is read by weighing them against one another. Ptolemy devotes a chapter of the third book to bodily form and temperament and another to bodily injuries and diseases, and both proceed by that arithmetic.
Astrology and medicine were a single subject for most of the period this material comes from. The physician cast a chart for the onset of an illness, timed treatment by the Moon, and read the patient's constitution from the nativity, and the technical vocabulary of the two disciplines is one vocabulary. Culpeper's herbal, which this atlas also draws on, is written entirely inside that assumption.
The humoral physiology has been superseded, and the atlas states that plainly. What survives as description is the tradition's account of how a body was reasoned about, which is worth recording accurately. Nothing under this entry is medical advice or a substitute for it.