The Skeletal System: Bones, An Overview Chapter 5a **People who missed test need to make it up at lunch today. Get food and come in if you need**

Warm-Up 1. Name as many parts of the skeleton as you can think of. 2. Have you broken a bone or know someone who has? If so which one/s - any gnarly bone breaks you had or know of?

The Skeletal System Parts of the skeletal system Bones (skeleton) Joints Cartilages Ligaments Divided into two divisions Axial skeleton Appendicular skeleton Slide 5.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Axial Skeleton: The head and trunk

Appendicular Skeleton: makes motion possible

Quick Quiz 1 of 3 Where is the Axial Skeleton Located? What is the function of the Appendicular Skeleton? Name the 4 parts of the skeleton

Functions of Bones Support of the body Protection of soft organs Movement due to attached skeletal muscles Storage of minerals and fats Blood cell formation Slide 5.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Human Body The skeleton has 206 bones Two basic types of bone tissue Compact bone Homogeneous Spongy bone Small needle-like pieces of bone Many open spaces Figure 5.2b Slide 5.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Person with the best grades - tell your table 2 functions of the skeletal system

Classification of Bones Long bones Typically longer than wide Have a shaft with heads at both ends Contain mostly compact bone Ex: Femur, humerus Slide 5.4a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Classification of Bones Short bones Generally cube-shape Contain mostly spongy bone Ex: Carpals, tarsals Slide 5.4b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Classification of Bones Flat bones Thin and flattened Usually curved Thin layers of compact bone around a layer of spongy bone Ex: Skull, ribs, sternum Slide 5.5a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Classification of Bones Irregular bones Irregular shape Do not fit into other bone classification categories Ex: Vertebrae and hip Slide 5.5b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Classification of Bones on the Basis of Shape Figure 5.1 Slide 5.5c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz 2 of 3 What kind of bone can be found in the skull? Name a long bone.

Gross Anatomy of a Long Bone Diaphysis Shaft Composed of compact bone Epiphysis Ends of the bone Composed mostly of spongy bone Figure 5.2a Slide 5.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Structures of a Long Bone Periosteum Outside covering of the diaphysis Fibrous connective tissue membrane Sharpey’s fibers Secure periosteum to underlying bone Arteries Supply bone cells with nutrients Figure 5.2c Slide 5.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Challenge Problem 1. Identify 2 long bones 2. Identify 3 bones in the appendicular skeleton 3. Describe where the axial skeleton is. 4. Identify 3 flat bones 5. What type of bone is the pelvis?

Structures of a Long Bone Articular cartilage Covers the external surface of the epiphyses Made of hyaline cartilage Decreases friction at joint surfaces Figure 5.2a Slide 5.8a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Structures of a Long Bone Medullary cavity Cavity of the shaft Contains yellow marrow (mostly fat) in adults Contains red marrow (for blood cell formation) in infants Figure 5.2a Slide 5.8b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

People closest to the windows tell your table what we call the ends and shaft of long bones.

Turn in the worksheet from yesterday 1. In the medullary cavity, yellow marrow is mostly __ 2. If a person did not have red marrow, what would result? 3. Identify 3 bones in the appendicular skeleton 4. T/F- bones have arteries and veins inside them. 5. Check this out!

Bone Markings Surface features of bones Sites of attachments for muscles, tendons, and ligaments Passages for nerves and blood vessels Categories of bone markings Projections and processes – grow out from the bone surface Depressions or cavities – indentations Slide 5.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Microscopic Anatomy of Bone Osteon (Haversian System) A unit of bone Central (Haversian) canal Opening in the center of an osteon Carries blood vessels and nerves Perforating (Volkman’s) canal Canal perpendicular to the central canal Slide 5.10a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Microscopic Anatomy of Bone Figure 5.3 Slide 5.10b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Microscopic Anatomy of Bone Lacunae Cavities containing bone cells (osteocytes) Arranged in concentric rings Lamellae Rings around the central canal Sites of lacunae Figure 5.3 Slide 5.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Microscopic Anatomy of Bone Canaliculi Tiny canals Radiate from the central canal to lacunae Form a transport system Figure 5.3 Slide 5.11b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Person wearing school colors Tell your group members what happens when someone breaks a bone. Be as specific as possible. Pretend you are a doctor.

Changes in the Human Skeleton In embryos, the skeleton is primarily hyaline cartilage During development, much of this cartilage is replaced by bone Cartilage remains in isolated areas Bridge of the nose Parts of ribs Joints Slide 5.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bone Growth Bones are remodeled and lengthened until growth stops Bones change shape somewhat Bones grow in width Slide 5.13b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Long Bone Formation and Growth Figure 5.4a Slide 5.14a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Long Bone Formation and Growth Figure 5.4b Slide 5.14b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Bone Cells Osteocytes Osteoblasts Osteoclasts Mature bone cells Osteoblasts Bone-forming cells Osteoclasts Bone-destroying cells Break down bone matrix for remodeling and release of calcium Bone remodeling is a process by both osteoblasts and osteoclasts Slide 5.15 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Osteocyte

Quick Quiz 3 of 3 What is an Osteocyte? What two types of bone cells are responsible for re-forming and growth?

Challenge Problem 1. The vertebrae are part of which division of the skeleton? 2. ___________ break down too much bone in old people. 3. If someone went to the hospital and severe arm pain, what might the problem be? Be specific 4. If a basketball player smashed her patella, where is her injury? Specifically?

Questions for Verbal Skeleton Quiz You will need to be able to identify… Names of bones Divisions of the skeletal system Types of bones Example question: Point to and identify an irregular bone