Transcript
Skeletal System
Instructor: Sherwin Ramos Escurel
Skeletal System
• Consists of bone, cartilage, tendon, and ligaments
Bone
• A hard connective tissue that is consist of living cells and mineralized matrix.
• Support and protect other tissues and organs
• Example: Skull, ribs, vertebral column
Cartilage
• Composed of cartilage cells, located in the lacunae within an extensive matrix.
• Example: Hyaline Cartilage – most abundant type of cartilage– Covers the end of the bones– In joints, it forms smooth, resilient, surfaces that
can withstand compression
Tendon
• A tough connective tissue which connects a muscle to a bone
• Dense Collagenous Connective Tissue
Ligament
• A tough connective tissue which connects a bone to a bone
• Dense Collagenous Connective Tissue
Functions of Skeletal System
• Support
– Provides a structural framework for the body• Protection– Protects many internal organs from injury
• Assistance in movement– Provides skeletal muscle attachments
• Storage of Minerals– Bone tissue stores several minerals, especially
calcium and phosphorus
Functions of Skeletal System
• Blood cell production– Within certain bones a connective tissue called
red bone marrow produces red blood cells• Triglyceride storage– Yellow bone marrow consists mainly of adipose
cells, which store triglycerides
4 Categories of Bones, Based on their SHAPE
• Long Bones
• Short Bones
• Flat Bones
• Irregular Bones
Long Bones
• Longer than they are wide
• Examples: Humerus and Femur
Short Bones
• Broad as they are long
• Examples: Carpal Bones and Tarsal Bones
Flat Bones
• Relatively thin, flattened shape
• Examples: Scapula and Sternum
Irregular Bones
• have complex shapes and cannot be grouped into any of the previous categories
• Example: Vertebrae
Structure of a Long Bone
• Diaphysis• Epiphysis• Articular Cartilage• Ephiphyseal Plate• Medullary Cavity• Periosteum• Endosteum
• Diaphysis – central shaft
• Epiphysis – 2 ends of the bone • Articular Cartilage – covers the end of
epiphysis where the bone articulates with other bone
Epiphyseal Plate
• Composed of cartilage, between each diaphysis and epiphysis
• Where the bone grows in length
• When the bone growth stops, the cartilage of each epiphyseal plate is replaced by bone and become an epiphyseal line
Medullary Cavity
• A large cavity in the diaphysis
• Filled with marrow
• Types of Marrow:– Yellow Marrow – consists
mostly of adipose tissue– Red Marrow – consists of
blood forming cells and the only site of blood formation
Periosteum and Endosteum
• Periosteum - A dense connective tissue that covers the outer surface of of a bone which contains blood vessels and nerves
• Endosteum – A thinner connective tissue membrane which lined the surface of medullary cavity
• Osteoblast – function in the formation of bone
• Osteocytes – Bone cells
Appendicular and Axial Skeleton
• Axial Skeletons – composed of the skull, vertebral column and the thoracic cage
• Appendicular Skeletons – composed of the bones of the upper and lower limbs as well as the girdles.
Skull
Skull Cont’d
• Composed of Braincase and Facial Bones
• Maxilla – Upper Jaw• Mandible – Lower Jaw• Zygomatic Bone – Cheekbone• Nasal Bone – Bridge of the nose
Vertebral Column
• A central axis of the skeleton, extending from the base of the skull to slightly end of the pelvis
• Regions:– Cervical - 7– Thoracic – 12 – Lumbar - 5– Sacral - 1– Coccyx - 1
General Plan of the Vertebrae
Vertebral Column
• Body – weight bearing portion of the vertebra
• Intervertebral Disks – separates the vertebral body– Formed by fibrocartilage
• Vertebral Arch – surrounds the vertebral opening– Consist of 2 Pedicles and 2 Laminae
• Pedicle – extends from the body to the transverse process of the vertebra
• Laminae – Extend from the transverse process to the spinous process
Transverse Process
• Extends laterally from each side of the arch, between the pedicle and the lamina
Spinous Process
• Projects dorsally from where the 2 laminae meet
Articular Process
• Superior and Inferior Articular Process
• Where the vertebrae articulates with each other
Rib Cage
Rib Cage Cont’d
• Protects the vital organs within the thorax and prevent the collapse of the thorax during respiration
• Consist of Thoracic vertebrae, the ribs with their associated cartilages, and the sternum
Ribs
• 12 Pairs of Ribs
– 1 – 7 (True Ribs) – They are attached directly to the sternum by mean of costal cartilages
– 8 – 12 (False Ribs) – They are not attached directly to the sternum• Ribs 11 – 12 – (Floating Ribs) – Do not attach at all to
the sternum
Sternum
• Manubrium
• Body
• Xiphoid Process
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