Skeletal System.pptx

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