Spiders belong to the Phylum Arthropoda, invertebrates with segmented bodies and jointed limbs. Their bodies consist of two segments, the cephalothorax (prosoma) and the abdomen (opistosoma). The cephalothorax seperates them from insects where the head and thorax are seperate segments. The cephalothorax and the abdomen are connected by the pedicel.

• Blue nervous system
• Red circulatory system
• Purple reproductive system
• Pink respiratory system
• Yellow digestive system
• Dark Green glands (venom gland, digestive gland, silk glands)

More detailed information can be found here.

Original by John Henry Comstock; Credits; CC_BY_3.0

A: Photo by Justin Jacobs. CC_BY_4.0. B/C: Credits: Jin et al., 2023. CC_BY_4.0

A: Photograph of an adult male Hylyphantes graminicola. In yellow the cephalothorax that holds the brain (B)

B: Dissected brain of the spider Hylyphantes graminicola

C: Schematic diagram of the organization and major structure of the spider CNS in dorsal view.

• EL: eye laminae (red)
• CB: central body (blue)
• CL: corpus lamellosum (yellow)
• MB: mushroom body (green)
• PPN: pedipalpal neuropil
• WLN1-4: walking leg neuromere 1-4
• OPIN: opistosomal nerves