Biology: Vertebrates Characteristics

Characteristics of Vertebrates

• Possess a vertebral column (backbone) made up of vertebrae
• Have a central nervous system (brain and spinal cord) enclosed in the vertebral column
• Possess a cranium (skull) that encloses and protects the brain
• Have a defined head and tail region
• Possess a dorsal hollow nerve cord (spinal cord)
• Have pharyngeal slits (gill arches) during embryonic development

Classification of Vertebrates

• Classes:
  1. Mammalia (mammals): warm-blooded, hair, produce milk for young
  2. Aves (birds): warm-blooded, feathers, lay eggs
  3. Reptilia (reptiles): cold-blooded, scales, lay eggs
  4. Amphibia (amphibians): cold-blooded, moist skin, lay eggs
  5. Pisces (fish): cold-blooded, gills, lay eggs

Vertebrate Skeleton

• Axial skeleton: vertebral column, skull, ribs, and sternum
• Appendicular skeleton: limbs, pelvis, and shoulder girdle
• Endoskeleton: internal skeleton made up of bone and cartilage
• Vertebrae: individual bones that make up the vertebral column

Muscular System of Vertebrates

• Skeletal muscles: voluntary muscles that attach to bones and help move the body
• Smooth muscles: involuntary muscles that help move substances through the body (e.g., digestive system)
• Cardiac muscles: involuntary muscles that make up the heart and help pump blood
• Muscle fibers: bundles of muscle cells that contract and relax to produce movement