Skeletal System Life Science Notes

Skeletal System Life Science Objectives 2/25/11 Complete ‘Bag of Bones’ Activity and turn in. Begin notes on the skeletal system. Bell Work – Think about what you might already know about the skeletal system. List at least 3 things you already know.

Skeleton There are 206 bones in an adult skeleton. The skeleton is broken into two parts The axial skeleton The appendicular skeleton

The Axial Skeleton Skull and supporting bones such as vertebral column, ribs, and sternum.

The Appendicular Skeleton Arms, legs, and structures that are associated with them such as wrists, hips, and shoulders.

Bag of Bones Activity In front of you are all of the major human bones from the axial and appendicular skeleton. Cut out all the bones. Organize them into two piles: Axial bones, and appendicular bones. Which numbers of bones belong to the axial skeleton? – color them in when you are sure. Which numbers of bones belong to the appendicular skeleton? Try to assemble your skeleton and tape him down neatly to a separate piece of paper. You will be taking notes on this paper and handing it in so do a neat job!

How are bones held together? Any place where two or more bones meet is called a joint. The connective tissue that holds bones together are called ligaments. Would you expect more ligaments in the finger or in the wrist? Why? More movement means we need more ligaments.

How are bones held together? The thick connective tissues that attaches muscles to bone is called tendons. What is the name of the tendon behind your ankle?

Keeping your bones able to move: Bones that grind together can cause damage to the skeleton. To keep the bones from rubbing the body has cartilage which covers the ends of bones to allow for smooth movement. Your body also has bursae which are fluid filled sacks on the outside of a joint to decrease the friction.

Types of Joints in the Body Ball and Socket Joint Allows for movement in all directions. Found in hips and shoulders.

Types of Joints in the Body Pivot Joint Allows bones to twist around each other. Found lower arm.

Types of Joints in the Body Hinge Joint Allows back and forth movement. Found in elbows, knees, fingers, and toes.

Types of Joints in the Body Gliding Joint Allows bones to slide past each other. Wrists and ankles.

Participation Question Points How many bones are there in the human body? What are the two main divisions of the skeleton? Name several bones in the axial skeleton. Name several bones in the appendicular skeleton. A place where two or more bones meet. Connective tissue that holds bones together. Connective tissue that holds muscles to bones. This keeps bones from rubbing together. This water filled sack decreases the friction between bones. This type of joint allows for movement in all directions. This type of joint allows for back and forth movement. This type of joint allows for pivoting (rotating) movement. This type of joint allows bones to slide past each other.

Journal Question Describe the four types of joints, explain how they work, and describe where each one might be found. Remember 7 lines or more is mandatory.

Objectives 2/28/11 Complete Skeletal System Activity. Bell Work: Define Ligament. Define Tendon. Define Bursae. Define Cartilage.

Journal Question List the types of skeletal system joints from least complicated to most complicated and explain why you listed them that way. (hinge, sliding, ball and socket, pivot)

Injuries and Disease Sprain – An injury to a ligament. Strain – An injury to a tendon. Arthritis – an inflammation of the joints. Caused by infection, aging, or injury. Can cause spurs – which are growths of bones inside joints.

The Structure of Bones Bones are composed of two types of tissue. Compact Bone Spongy Bone

Bone Structure Compact Bone Runs the entire length and surrounds every bone. Made of tubular structures known as osteons. Living bone cells are called osteocytes. Oxygen and nutrients run through small blood vessels here and nerves are in the canals to send information to bone cells.

Bone Structure Spongy Bone Contains many holes and spaces. Made of trebeculae.

Formation of Bone The skeleton of an embryo is made of cartilage. By the ninth week of human development, bone begins to replace cartilage. Blood vessels penetrate the exterior and stimulate cells to become osteoblasts. These secrete collagen. The bloodstream deposits calcium salts and ions that harden into bone trapping the osteocytes.

Where are some places that cartilage remains as an adult? Nose tip, Ears, Disks between vertebrae, Moveable joint linings.

Journal Question Explain the structure of a bone. Do you think the osteons or trebeculae are responsible for new bone growth? 5 lines or more is mandatory.