The Skeletal System Lesson 1: 23 The Skeletal System Lesson 1:

Lesson Objectives Upon completion of this lesson, students should be able to … Define and spell the terms to learn for this chapter. List the various types of bones in the body. Identify specific bones for each bone classification. Discuss the functions of the bones of the human skeleton.

Lesson Objectives Explain various types of joints and body movements. Describe the axial skeleton. Describe the appendicular skeleton.

Skeletal System Composed of 206 bones, cartilage, and ligaments Divided into two systems Axial skeleton Consists of 80 bones from the axis of the body Includes the skull and the vertebral system Appendicular skeleton Consists of 126 bones Includes the extremities 4

Anterior and Posterior Human Skeleton 5

Bone Classification Long bones Short bones Flat bones Irregular bones Sesamoid Sutural (wormian) Long bones are not necessarily large bones. Go by definition, not size. 6

Six Main Functions of Bones Provide shape, support, and the framework of the body Provide protection for the body’s internal organs Serve as a storage place for mineral salts, calcium, and phosphorus Play an important role in the formation of blood cells as hemopoiesis takes place in the bone marrow

Six Main Functions of Bones Provide an area for the attachment of skeletal muscle Help to make movement possible through articulation

Features Found in Bones Epiphysis – the ends of a developing bone Diaphysis – the shaft of the long bone Periosteum – membrane that forms the covering of bones, except at their articular surfaces Compact bone – the dense, hard layer of bone tissue 9

Features Found in Bones Medullary canal – the narrow space or cavity throughout the length of the diaphysis that contains yellow bone marrow, which is made of fat cells Endosteum – the tough, connective tissue membrane lining the medullary canal and containing the bone marrow Cancellous or spongy bone – the reticular tissue that makes up most of the volume of bone

Bone Markings Crest Line Epicondyle Spine Trochanter Tubercle Tuberosity 11

Joints The positioning of the bones at the joint determines the type of movement that the joint performs Joints are always classified according to the type of movement they provide A joint that produces no movement is called a synarthrotic joint An amphiarthrotic joint permits very slight movement A diarthrotic joint allows for free movement in a variety of directions

Body Movements Allowed by the Diarthrotic Joint Abduction – movement of a body part away from the midline Adduction – movement of a body part toward the midline Circumduction – the process of moving a body part in a circular motion Dorsiflexion – the process of bending a body part backward Eversion – the process of turning outward

Body Movements Allowed by the Diarthrotic Joint Extension – the process straightening a flexed limb Flexion – the process of bending (or curving) the spine Inversion – the process of turning inward Pronation – the process of lying prone or face down: The process of turning the hand so that the palm points downward Protraction – the process of moving a body part forward

Body Movements Allowed by the Diarthrotic Joint Retraction – the process of moving a body part backward Rotation – the process of moving a body part around a central axis Supination – the process of lying supine or face upward; also the process of turning the palm or foot upward

Bones of Axial the Skeleton Includes bones of the Skull Cranium Face Sternum Ribs Vertebrae Sacrum Coccyx 16

What are the names of the spinal curves? The Vertebral Column Divided into 5 regions: Cervical vertebrae Thoracic vertebrae Lumbar vertebrae Sacrum Coccyx Pop Quiz What are the names of the spinal curves? 17

The Rib Cage Formation of ribs acts to form a protective cage that houses the heart, lungs, and other vital components of the human body Consists of 12 pairs of ribs, which are divided into three categories; true ribs, false ribs, and floating ribs

Bones of the Appendicular Skeleton Include bones of the Upper extremities Lower extremities Pectoral girdle Pelvic girdle 19

Bones of the Upper Extremities Clavicle Scapula Humerus Ulna Radius Carpals Metacarpals Phalanges 20

Bones of the Lower Extremities Os coxae Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges 21

Critical Thinking Questions How can you remember the difference between the ulna and the radius? How can you remember the difference between the carpals and metacarpals?

Try It For Yourself! Don’t Use Your Book! Where are the following bones? frontal mandible ulna metatarsals tibia metacarpals tarsals skull face lower arm/upper extremity foot/ankle lower leg/lower extremity hand/wrist foot 23

Try It For Yourself! Don’t Use Your Book! Where are the following bones? mandible sphenoid sacrum radius ilium femur fibula face skull vertebral column lower arm/upper extremity pelvic girdle upper leg/lower extremity lower leg/lower extremity 24

Questions? 25