vertebrates

vertebral column (backbone) is made up of

• repeating structures called vertebrae that extend from the head to tail along the dorsal side of body

function of vertebral column

• provides central support for the endoskeleton, organism to hold its shape

• protects the spinal cord

the structure and number of vertebrae

varies between different species

human backbone consists of

33 vertebrae

snake has

as many as 500

the vertebra is composed of 2 main regions

• centrum

• neural arch

centrum

solid, disc shaped section, provides most of the strenght of the backbone

neural arch

encloses the spinal cord, located dorsal to the centrum

species may have a number of

spines that extend from the main structure of the vertebra

all vertebrates are highly

cephalized- their nervous system is centralized with a brain located in a distinct head with sensory organs (complex eyes)

the head region of vertebrates

is more distinct than in invertebrates

the vertebrate brain is enclosed in a

cranium or skull, from which the vertebral column extends

vertebral column + skull

core of the endoskeleton

a vertebrate endoskeleton includes

• vertebral column

• cranium

• limbs/appendages

• limb girdles

vertebrate endoskeleton may be composed

entirely of cartilage or both cartilage and bone

exclusively cartilaginous endoskeleton is found in

several fish classes

majority of vertebrates have endoskeletons made

primarily of bone tissue

cartilage is

less dense, lighter and more flexible

cartilage doesnt have the strenght to

support large bodies pf many vertebrate species

bone tissue consists of

dense, extrecellular matrix containing a protein called collagen

collagen is a

fibrillar protein, forming long fibers that form the basis of the bone matrix and contribute to the strenght of the tissue

collagen is highly

mineralized- contains high levels of inorganic elements like calcium, magnesium, phosphate

bone cells called

osteocytes are distributed throughout the collagen

in embryos of bony vertebrates the endoskeleton is initially formed from

cartilage, that is later converted to bone during development

bone marrow is associated with

bone tissue in many vertebrates

bone marrow produces

many blood cells

almost all vertebrates have

• jaws equipped with teeth for chewing food, attacking prey

• al least one pair of limbs located laterally

vertebrates muscles are made up of repeating units called

myomeres

muscles are attached to

endoskeleton

movement happens through alternating

• contraction- muscle shortens

• relaxation- muscle extends

vertebrates have many other

complex organ systems, located within a well developed coelom or body cavity