Introduction to Vertebrates. Vertebrate Vocabulary Chapters 32 -35 Chordate vertebrate vertebra (712) agnathan (714) ectothermic (724) endothermic (724) primate (731) fish list the major characteristics of these animals amphibian list the major characteristics of these animals
the jawless fish: agnathans,
the cartilaginous fishes: Chondrichthyes,
and the bony fishes:
The first group of vertebrates to live on land were the amphibians,
which appeared about 370 million years ago.
1. Legs. Legs support the body’s weight as well as allow movement from place to place.
3. Heart. Land animals tend to have higher metabolic rates than aquatic animals. The structure of the vertebrate heart allows oxygen to be delivered to the body efficiently.
The right atrium receives impure blood with little oxygen from the body proper, and the left atrium receives purified blood from the lungs that has just been oxygenated, but these two types of blood are mixed partially in the single ventricle. Mixed blood is then sent, in part, to the skin, where further oxygenation can occur. The frog heart is the only organ contained within the coelom, which has its own protective covering. This is the pericardium.
Terrestrial amphibians and mammals excrete nitrogenous wastes in the form of urea because it is less toxic than ammonia and can be moderately concentrated to conserve water. Urea is produced in the liver by a process that requires more energy to produce than ammonia does.
The skull is flat, except for an expanded area that encases the small brain. Only nine vertebrae make up the frog\'s backbone, or vertebral column. The human backbone has 24 vertebrae. The frog has no ribs. The frog does not have a tail. Only a spike like bone, the urostyle, remains as evidence that primitive frogs probably had tails. The shoulders and front legs of the frog are somewhat similar to man\'s shoulders and arms. The frog has one "forearm" bone, the radio-ulna. Man has two forearm bones, the radius and the ulna. Both frog and man have one "upper arm" bone, the humerus. The hind legs of the frog are highly specialized for leaping. The single "shinbone" is the tibiofibula.
There is no external ear. Both eardrums, or tympanic membranes, are exposed. There is only one bone in the frog\'s middle ear. The human middle ear contains three bones (malleus, incus, and stapes in the ossicles). As in man, semicircular canals help to maintain body balance.
1. Legs. The evolution of legs was an important adaptation for living on land. Frogs, toads, salamanders, and newts have four legs. Caecilians lost their legs during the evolutionary course of adapting to a burrowing existence.
The heterophil is the second most numerous WBC in most birds. Heterophils are phagocytic and use their enzyme-containing granules to lyse ingested materials. Heterophils are motile and can leave blood vessels to engulf foreign materials.
. Placental mammals develop within their mother’s body and are nourished by an organ called the placenta.
1. Grasping hands and feet
2. Forward orientation of the eyes
6. What is the name of a jawless fish?
7. What is the first group of vertebrates to move on to land?
8. What does the word amphibian mean?
10. Why do birds need hollow bones?
11. Birds evolved from reptiles but have what, that makes them different? feathers
15. List the vertebrates that are ectotherms.
16. What does endotherm mean?
31. What structure in the fish helped the fish detect vibrations in the water?