Act 12: General Morphology of Animals

• Five grades of organization:

  • Protoplasmic
  • Cellular
  • Cell-tissue
  • Tissue-organ
  • Organ system
• The simplest animal is a sponge with a cellular level of organization.
• Symmetry is the balance in proportion in size and shape of animals.
• Radial symmetry has multiple planes.
• Bilateral symmetry has only 2 complete halves.
• Cephalization is where the nervous tissues and sense organ are concentrated in the head.
• Sponges do not show symmetry, they are asymmetrical.
• Segmentation is when body is organized into definite regions or segments.
• Metameres is when segments are similar with each other.
• Tagmata is when there is no similar segments.
• Invertebrates are animals without vertebra or spinal column.
• Vertebrates are animals with backbone or spinal column.
• 5 classes of vertebrates are fish, amphibians, reptiles, birds and mammals.
• Oral - located near or toward the mouth.
• Aboral - opposite the mouth.
• Central - middle portion of body.
• Peripheral - away from the middle portion of the body.
• Anterior - head end
• Posterior - tail end
• Dorsal - back/ upper surface
• Ventral - belly or the lower surface
• Lateral - toward the side
• Medial - toward the middle
• Proximal - toward the central part
• Distal - away from the center
• Peripheral - near the surface of the body (near skin)
• Pectoral - chest region
• Pelvic - hip region
• Cephalic - toward the heart
• Caudal - toward the tail
• frontal plane - divides body into dorsal and ventral halves
• transverse plane - divides body into anterior and posterior portions
• saggital plane - divides body into right or left
• midsaggital - divides body down the middle
• Sponge - phylum porifera
• Ostia - pores where water is drawn
• Osculum - another opening for exit of water
• Choandrocytes - flagella for filtration of plankton
• Starfish - phylum echinodermata
• Central disc- very distinct region location of mouth and anus