Please enable JavaScript.
Coggle requires JavaScript to display documents.
What is a Vertebrate (Characteristics of Chordates (Nerve Cord in Back (As…
What is a Vertebrate
Characteristics of Chordates
One of the earliest fish was the jaw-less fish.
Chordata is a phylum.
All members of this phylum are known as chordates.
Most chordates are vertebrate, but some are invertebrates.
Some examples are:
Fish
Amphibians
Frogs
Snakes
At one some point in a chordates life, it has a notochord.
A notochord is a nerve cord that goes down their back and slits in their throat area.
Notochord
The phylum chordata comes from the notochord.
A notochord is a flexible rod that supports the chordate's back.
Some chordates have notochords their whole life.
In vertebrates a notochord is replaced by a backbone.
Nerve Cord in Back
As well as chordates having a notochord, they also have a nerve cord going down their back.
Humans spinal cord is a nerve cord.
The nerve cord is a connection between the brain and the nerves where messages travel back and forth.
Other animals have nerve cords that do not run down their back.
Slits in Throat Area
Also at some point in their lives, chordates have a slit in their throat area.
This slit is called pharyngeal.
Some chordates such as fish, keep these slits as a part of their gills for their whole lives.
Other vertebrates including humans, pharyngeal slits disappear before birth.
Characteristics of Vertebrates.
Most chordates are vertebrates.
In addition to the other characteristics that chordates share, are that vertebrates have a backbone.
The backbone is a part of an internal skeleton.
The endoskeleton supports the body and allows it to move.
Backbone
Backbones are formed by many similar bones called vertebrae.
The vertebrae are lined up in a row, like beads on a string.
Joints and movable connections between the the vertebrae give the spine flexibility.
You are able to bend over a tie your shoe because of your backbone flexibility.
Each vertebra has a hole in it that lets the spinal cord pass through.
The spinal cord fits into the vertebrae like fingers fit into rings.
Internal Skeleton
The backbone of a vertebrate is part of its endoskeleton.
The endoskeleton protects the internal organs of the body, helps give the body shape and helps give muscles a place to attach.
A vertebrates endoskeleton includes the skull and ribs.
The skull protects the brain.
The ribs attach to the vertebrae and protect the heart, lungs and other internal organs.
Animals can adapt their arm and leg bones to movement.
An endoskeleton doesn't need to need to be replaced as the animal grows.
It forms an internal frame that supports the body against the downward pull of gravity.
This still allows easy movement.
Because of the characteristics vertebrates have, they can grow bigger than animals with exoskeletons, or no skeleton.
Keeping Conditions Stable
Vertebrates are different in the way they control their body temperatures.
The body temperature of most fish, amphibians, and reptiles is close to the temperature of their environments.
In contrast, birds and mammals have a temperature that is warmer than their environments.
Ectotherms
Some ectotherms are:
Fishes
Amphibians
Reptiles
An ectotherm is an animal whose body doesn't produce much internal heat.
Its body temperature changes based on the environment around them.
For example, when a turtle is lying on a sunny riverbank, it has a higher body temperature then when it is swimming in a cool river.
Ectotherms are sometimes called "coldblooded."
This term is misleading because their blood is usually very warm.
Endotherms
In contrast to a turtle, a beaver would have the same body temperature whether it was on cool water or on warm land.
An endotherm is an animal whose body regulates its own temperatures.
They do this by controlling the internal heat it produces.
Endotherms have adaptations such as sweat gland and fur or feathers.
Since endotherms are able to keep their body heat stable, they can live in a bigger variety of environments than ectotherms can.