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 SystemThe Skeletal System

Slide 5.1Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Parts of the skeletal system

Bones (skeleton)

Joints

Cartilages

Ligaments

Divided into two divisions

Axial skeleton

Appendicular skeleton

Axial Skeleton: The head and trunk

Appendicular Skeleton: makes motion possible

Quick Quiz 1 of 3

1. Where is the Axial Skeleton Located?

2. What is the function of the Appendicular Skeleton?

3. Name the 4 parts of the skeleton

Functions of BonesFunctions of Bones

Slide 5.2Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Support of the body

Protection of soft organs

Movement due to attached skeletal muscles

Storage of minerals and fats

Blood cell formation

Bones of the Human BodyBones of the Human Body

Slide 5.3Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The skeleton has 206 bones

Two basic types of bone tissue

Compact bone

Homogeneous

Spongy bone

Small needle-like pieces of bone

Many open spacesFigure 5.2b

Person with the best grades

- tell your table 2 functions of the skeletal system

Classification of BonesClassification of Bones

Slide 5.4aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Long bones

Typically longer than wide

Have a shaft with heads at both ends

Contain mostly compact bone

• Ex: Femur, humerus

Classification of BonesClassification of Bones

Slide 5.4bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Short bones

Generally cube-shape

Contain mostly spongy bone

Ex: Carpals, tarsals

Classification of BonesClassification of Bones

Slide 5.5aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Flat bones

Thin and flattened

Usually curved

Thin layers of compact bone around a layer of spongy bone

Ex: Skull, ribs, sternum

Classification of BonesClassification of Bones

Slide 5.5bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Irregular bones

Irregular shape

Do not fit into other bone classification categories

Ex: Vertebrae and hip

Classification of Bones on the Basis Classification of Bones on the Basis of Shapeof Shape

Slide 5.5cCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.1

Quick Quiz 2 of 3

1. What kind of bone can be found in the skull?

2. Name a long bone.

Gross Anatomy of a Long BoneGross Anatomy of a Long Bone

Slide 5.6Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Diaphysis

Shaft

Composed of compact bone

Epiphysis

Ends of the bone

Composed mostly of spongy bone

Figure 5.2a

Structures of a Long BoneStructures of a Long Bone

Slide 5.7Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Periosteum Outside covering of

the diaphysis

Fibrous connective tissue membrane

Sharpey’s fibers Secure periosteum to

underlying bone

Arteries Supply bone cells

with nutrientsFigure 5.2c

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 BoneStructures of a Long Bone

Slide 5.8aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Articular cartilage

Covers the external surface of the epiphyses

Made of hyaline cartilage

Decreases friction at joint surfaces Figure 5.2a

Structures of a Long BoneStructures of a Long Bone

Slide 5.8bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

People closest to the windows

tell your table what we call the ends and shaft of long bones.

Turn in the worksheet from yesterday1. 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 MarkingsBone Markings

Slide 5.9Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

Microscopic Anatomy of BoneMicroscopic Anatomy of Bone

Slide 5.10aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

Carries blood vessels and nerves

Microscopic Anatomy of BoneMicroscopic Anatomy of Bone

Slide 5.10bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.3

Microscopic Anatomy of BoneMicroscopic Anatomy of Bone

Slide 5.11aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lacunae Cavities containing

bone cells (osteocytes)

Arranged in concentric rings

Lamellae Rings around the

central canal

Sites of lacunae Figure 5.3

Microscopic Anatomy of BoneMicroscopic Anatomy of Bone

Slide 5.11bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Canaliculi

Tiny canals

Radiate from the central canal to lacunae

Form a transport system

Figure 5.3

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 SkeletonChanges in the Human Skeleton

Slide 5.12Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

Bone GrowthBone Growth

Slide 5.13bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones are remodeled and lengthened until growth stops

Bones change shape somewhat

Bones grow in width

Long Bone Formation and GrowthLong Bone Formation and Growth

Slide 5.14aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.4a

Long Bone Formation and GrowthLong Bone Formation and Growth

Slide 5.14bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.4b

Types of Bone CellsTypes of Bone Cells

Slide 5.15Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Osteocytes 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

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