In this Grade 7 Life Science lesson from Chapter 17, students learn how the skeletal system provides support and protection by exploring two types of bone tissue — compact bone and spongy bone — and how marrow produces red blood cells. Students also examine how the human skeleton is organized into the axial skeleton and appendicular skeleton, and investigate how bones function as levers to enable movement. The lesson is part of a unit on body systems, tissues, and organs in the McDougal Littell Life Science textbook.
Section 1
Bones Build Living Framework for Body Support
Bones consist of two types of living tissue: hard compact bone for support and lightweight spongy bone containing marrow. The skeletal system protects organs and provides structure for movement.
Section 2
Skeletons Divide Into Two Major Sections
The axial skeleton forms the body's central axis, protecting vital organs. The appendicular skeleton attaches to it, including limbs and shoulders, primarily enabling movement through various joints.
Section 3
Joints Connect Bones to Enable Movement
Joints where bones meet come in three types: immovable (like skull), slightly movable (like ribs), and freely movable (like elbows). Different joint shapes create various movements—hinging, rotating, and gliding.
Section 4
Bones Transform Throughout Human Development
Bones continuously change from infancy through adulthood. Growth plates determine bone shape during childhood and adolescence. In adults, bone density decreases with age as breakdown exceeds formation.
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Section 1
Bones Build Living Framework for Body Support
Bones consist of two types of living tissue: hard compact bone for support and lightweight spongy bone containing marrow. The skeletal system protects organs and provides structure for movement.
Section 2
Skeletons Divide Into Two Major Sections
The axial skeleton forms the body's central axis, protecting vital organs. The appendicular skeleton attaches to it, including limbs and shoulders, primarily enabling movement through various joints.
Section 3
Joints Connect Bones to Enable Movement
Joints where bones meet come in three types: immovable (like skull), slightly movable (like ribs), and freely movable (like elbows). Different joint shapes create various movements—hinging, rotating, and gliding.
Section 4
Bones Transform Throughout Human Development
Bones continuously change from infancy through adulthood. Growth plates determine bone shape during childhood and adolescence. In adults, bone density decreases with age as breakdown exceeds formation.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter