1. Skeletal system

2. Benefits of skeletons Skeletons provide for the bodySkeletons provide support for the body Muscles and bones work together for of the animalMuscles and bones work together for movement of the animal Some skeletons provide for the animalSome skeletons provide protection for the animal A turtle’s skeleton plates provides protection

3. Arthropods vs. Vertebrates Vertebrates have a backboneArthropods have an exoskeleton Page 704- 705

4. Exoskeleton An exoskeleton is a on the outside of the body that provides a framework for support and the epidermal cells. The waxy exterior protects against water loss in terrestrial (land) animals.An exoskeleton is a hard, waxy covering on the outside of the body that provides a framework for support and protects the epidermal cells. The waxy exterior protects against water loss in terrestrial (land) animals. Exoskeletons are composed of and (polysaccharide)Exoskeletons are composed of protein and chitin (polysaccharide) The exoskeleton is divided into soft flexible joints that allow for movementThe exoskeleton is divided into soft flexible joints that allow for movement Exoskeletons are often found on invertebrates, which are animals which doExoskeletons are often found on invertebrates, which are animals which do not have a backbone

5. Disadvantages of an exoskeleton An exoskeleton Since they are very heavy, land animals can not have a large exoskeleton.An exoskeleton limits the size. Since they are very heavy, land animals can not have a large exoskeleton. It of an animal especially if they are large heavy exoskeletonsIt limits the movement of an animal especially if they are large heavy exoskeletons in arthropods. Since it is hard its size can not be changed. The immature, growing animals have to molt their old ones and grow a new exoskeleton.Growth is also limited in arthropods. Since it is hard its size can not be changed. The immature, growing animals have to molt their old ones and grow a new exoskeleton. A crab molting Once molted it has less protection since the new shell is soft and they also can lose water quickly

6. Endoskeleton Unlike an exoskeleton which covers the animal in one continuous unit, the endoskeleton is divided into many specialized parts ()Unlike an exoskeleton which covers the animal in one continuous unit, the endoskeleton is divided into many specialized parts (bones) Some bones are used for (skull, ribs and breastbone, vertebrae)Some bones are used for protection (skull, ribs and breastbone, vertebrae) Bones also function in support. The long dense bones support the weight of the body and aid in strength and speed of the animalBones also function in support. The long dense bones support the weight of the body and aid in strength and speed of the animal Vertebrates are animals which have a backbone orVertebrates are animals which have a backbone or vertebrae

7. Endoskeleton Internal skeletons protect internal organs but provide very little protection for the outside. (except skull)Internal skeletons protect internal organs but provide very little protection for the outside. (except skull) Some animals have special parts that help with protection. Ex the turtle has a shell made of bony plates attached to the endoskeletonSome animals have special parts that help with protection. Ex the turtle has a shell made of bony plates attached to the endoskeleton

8. Bone development When we are very young, we don’t have any bones, only cartilage. The bone is slowly deposited until the most of our skeletal system is made of bones and we only find cartilage where we need flexibility (ex. tip of nose, ears, spaces between vertebrae and movable joints.)When we are very young, we don’t have any bones, only cartilage. The bone is slowly deposited until the most of our skeletal system is made of bones and we only find cartilage where we need flexibility (ex. tip of nose, ears, spaces between vertebrae and movable joints.)  --------- Cartilage  ----------- Bone (femur)

9. Bone Growth Bones grow in both length and diameter.Bones grow in both length and diameter. At the end of bones there is a line called the cartilage plate. This area is where new bone is laid and bones grow in lengthAt the end of bones there is a line called the cartilage plate. This area is where new bone is laid and bones grow in length Bones go in width at the in the outer surface of the bonesBones go in width at the in the outer surface of the bones

10. Types of Joints Joints are where bone and bone or bone cartilage comes together. All joints are not alike – some permit movement others do not. Ligaments are connective tissue that will hold the bones together and Cartilage is another connective tissue that is found at the end of bones and helps by not allowing the bones to tub together

11. Bone Marrow Bone marrow is in the center of the bones. There is 2 types of bone marrow- Red marrow and Yellow Marrow. Red bone marrow produces red blood cells, some white blood cells and platelets. Yellow bone marrow stores excess fat.Bone marrow is in the center of the bones. There is 2 types of bone marrow- Red marrow and Yellow Marrow. Red bone marrow produces red blood cells, some white blood cells and platelets. Yellow bone marrow stores excess fat.

12. Questions What are the benefits, drawbacks of each of the types of skeletonWhat are the benefits, drawbacks of each of the types of skeleton What type of skeleton would be best for animals that 1) live in the sea 2) are very big 3) are very small 4) flyWhat type of skeleton would be best for animals that 1) live in the sea 2) are very big 3) are very small 4) fly Further research: What are bone plates, when do they close in humans, what are they used forFurther research: What are bone plates, when do they close in humans, what are they used for Please write a 250-500 word report on a bone disease (Osteoporosis, Paget's disease, bone cancer, Osteonecrosis, Osteoarthritis, or other. )Please write a 250-500 word report on a bone disease (Osteoporosis, Paget's disease, bone cancer, Osteonecrosis, Osteoarthritis, or other. ) Please email your work to purdy@satitpatumwan.netPlease email your work to purdy@satitpatumwan.net