Skeletal System Functions 1 Supports body 2 Protects
Skeletal System Functions: 1) Supports body 2) Protects internal organs 3) Provides for movement 4) Stores mineral reserves 5) Provides a site for blood cell formation
Skeletal System ► Has 206 bones ► Divided 1) 2) into two sections: Axial: skull, vertebral column, ribs, and sternum Appendicular: all other bones
Structure of Bones ► Bones are living tissue!! ► Periosteum – tough layer of connective tissue surrounding bone ► Compact bone – beneath the periosteum (dense but not solid) ► Haversian canals– tubes that run through compact bone and contain blood vessels and nerves
Structure of Bones ► Spongy bone – inside outer layer of compact bone ► Osteocytes – digest away old bone ► Osteoclasts – maintain healthy bone ► Osteoblasts – make new bone
3 -D Section of Bone Tissue
Bone Homeostasis ► 1. Most of our skeleton is constantly being broken down, and built back up ► 2. Amount of bone built up = amount of bone broken down ► 3. This balance of breakdown and buildup is called bone homeostasis
► Bone marrow – soft tissue center of bone § Maintains the balance of minerals § Serves as a storage for minerals (Ca, P) § Two Types: 1) Yellow – made mostly of fats, aids in Red Blood Cell (RBC) production 2) Red – produces RBCs, white BC, and cells to help clotting
Skeletal Development ► The skeleton of the embryo is made of cartilage ► Bone begins to replace cartilage by 9 th week of development (known as ossification)
Joints – where two or more bones meet ► Most allow movement ► Some are fixed (no movement): skull ►
Pelvis, Sexual Dimorphism
Types of Joints ► Five types: 1) Ball and socket: allows rotational movements (shoulder, hip) Ball and Socket Movement
Types of Joints, Cont’d 2) Pivot: bones twist against each other (atlas and axis of your vertebrae) Pivot Joint in Arm
Types of Joints Cont’d 3) Hinge: back and forth movements much like a door (elbow, knee)
Types of Joints 4) Gliding: bones slide against each other (wrist) 5) Saddle: Freely moveable joint found only in the thumb
Joint support ► Ligaments: bands of tissue that connect bone to bone § Surrounds joints with wide range of motion and little skeletal support ► Cartilage: covers bone ends and allows for smooth movement. Can also be found in joint to provide cushion (meniscus) ► Bursa: sacs of fluid that act as shock absorbers ► Tendons: bands of tissue that connect muscle to bone (patella tendon, Achilles)
Problems with Skeletal System Breaks ► Complete/Incomplete (Greenstick) ► Displaced ► Simple/Compound (breaks skin) ► Impacted or Comminuted ► Spiral ► Hairline
Breaks - Complete & Displaced
Breaks - Incomplete/Greenstick
Breaks - Spiral
Breaks - Compound
Breaks - Comminuted
Breaks - Hairline
Osteoporosis
Problems with Skeletal System Rheumatoid arthritis ► Inflammation in joints ► Redness, warmth, swelling, pain, fatigue ► Occurs on both sides of body ► Genetic, environmental, hormonal factors; immune system attacks the joints and other organs
Rheumatoid arthritis
Problems with Skeletal System Dislocation Normal Dislocated
Dislocation Normal Dislocated
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