1. No category

The Skeletal System:
I.
Purpose:
The main organs of the skeletal system are the _bones___. Bones work with muscles to _move____,
_protect____, and __support____ sensitive internal organs.
II.
Evolution of the Skeletal/Muscular Systems:
Skeleton
Hydrostatic
Type of support
Have muscles surrounding a fluidfilled cavity. When contracted, they
push against the fluid and cause the
body to change shape.
Exoskeleton
A hard external skeleton,
made of chitin and is
continually shed as the
organism grows - molting
Endoskeleton
Have a well developed
Endoskeleton or
internal skeleton
made of calcified plates.
Picture of
system
Examples
III.
Annelids (worms) and Jellyfish
Arthropods (Insects) and
Crustaceans
mammals, birds, reptiles,
fish, amphibians
Characteristics and Structures:
a. Bones are attached to other bones with special connective tissues known as _ligaments__.
b. A place where one bone attaches to another is called a _joints___.
c. Bones are a living part of your body that contain _nervous____ tissue to send and receive
information, as well as blood vessels to bring the nutrients___ and _oxygen___ gas that is
necessary for the bones’ health and growth.
d. Bone is composed of _____2_____ types of tissue:
i. _Spongy___: soft, interior layer of bone tissue.
1. Site of _red blood cell__ production.
2. Less dense
3. Contains ___bone marrow____
ii. __Compact__ :outer layer of tissue surrounding bone
1. Stores minerals – ___calcium____
2. Extremely dense and strong
e. Bone marrow_______ is found inside of bones. This tissue is responsible for creating new
__blood___ cells in animals. These cells are a vital part of the _Circulatory______ system.
V.
Organization of Life: Skeletal System
VI.
Skeletal Body System Interactions:
a. ___Circulatory System___: bones help produce new blood cells in addition to storing
minerals transported by the circulatory system.
b. __Muscular System____: bones and muscles work together to enable body movement and
provide support.
c. ___Nervous___: bones protect many vital organs of the nervous system – Skull (brain),
Vertebrae (spinal cord).