1. Human Anatomy, Larry M. Frolich, Ph.D. BASIC BODY PLAN From a two-layered sheet to a segmented tube within a tube

2. Human Anatomy, Larry M. Frolich, Ph.D. Sagittal view of “generic” vertebrate embryo/body plan Draw gut tube within “outer” tube Mouth, anus Cut across middle to see cross (or transverse) section

3. Human Anatomy, Larry M. Frolich, Ph.D. Outer(“somatic”) tube --striated muscle --somatic motor nerves Inner (“visceral”) tube --smooth muscle --visceral motor nerves Celom or Body Cavity --empty space between tubes

4. Human Anatomy, Larry M. Frolich, Ph.D. Celom and diaphragm in sagittal section view

5. Human Anatomy, Larry M. Frolich, Ph.D. THE INNER TUBE Gut Serous lining (peritoneum) Mesenteries Celom/Body Cavity/ Peritoneal Cavity

6. Human Anatomy, Larry M. Frolich, Ph.D. THE OUTER TUBE Neural tube—brain, spinal cord (Dorsal Hollow Nerve Tube) Notocord Vertebra Muscle, Nerve, Skin, Bone LIMBS!! SEROUS MEMBRANES Peritoneum --visceral --parietal/somatic Pleura --visceral --parietal/somatic Mesentery

7. Human Anatomy, Larry M. Frolich, Ph.D. SEGMENTATION Brain and spinal cord Notocord Vertebrae and Ribs Segmented Spinal Nerves Sensory Areas (dermatomes) Muscle Segments (myotomes)