The Skeletal System

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The Skeletal System
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Skeletal System

• Bones of the skeleton
• Specialized tissues that connect them
• Cartilage
• ligaments
• Other connective tissue

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Functions of the Skeletal System

• Support
• Protection
• Storage
• Blood cell production

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Bone

• Osseous Tissue
• Cells within solid ECM
• osteocytes
• collagen
• calcium deposits

ECM extracellular matrix
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Bone Shapes

• Long
• Flat
• Short
• Irregular

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Long Bone Structure

• Gross structure
• Head
• Shaft

typo
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Long Bone Structure

• Internal
• Bone
• periosteum
• endosteum
• Marrow

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Long Bone Structure

• External Surface
• Articular Cartilage
• Periosteum

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Bone Cells

• Osteocytes
• mature bone cells
• Osteoblasts
• bone matrix-forming cells
• Osteoclasts
• bone remodeling cells

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Bone Types

• Compact
• Spongy

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Skeletal Development

• Cartilaginous skeleton
• Endochondral Ossification

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Bone Remodeling

• Allows adaptation
• Osteoclasts work in concert with osteoblasts
• Osteoporosis results when clasts blasts

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Divisions of Skeletal System

• Axial skeleton
• Appendicular skeleton

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Axial Skeleton

• Support and protection of organs and organ
  systems
• Includes bones of
• Skull
• Vertebrae
• Thoracic Cage

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Skull

• Protects brain
• 22 bones
• Cranium (8)
• Face (14)

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Cranium

• Bones are held together by sutures (immovable
  joints)
• Parietal
• Temporal
• Frontal
• Occipital

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Vertebral Column

• 4 regions
• Cervical (C1 to C7)
• Thoracic (T1 to T12)
• Lumbar (L1 to L5)
• Sacral (5 fused)
• Coccyx

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Vertebrae

• Spinous process
• Transverse process
• Vertebral foramen
• Body

sp
tp
vf
body
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Thoracic Cage (Rib Cage)

• Sternum and ribs
• Sternum contains
• manubrium
• body
• xiphoid process

Figure 7-10
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Ribs-12 pairs

• 1-7 True Ribs
• connected directly to sternum by costal cartilage
• 8-12 False ribs
• 11-12 floating ribs

• Males and females have same number of ribs

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Apendicular Skeleton

• Movement
• Includes bones of
• Pectoral girdle
• Arm, wrist and hand
• Pelvic girdle
• Leg, ankle and foot

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Pectoral Girdle

• Clavicle
• Scapula
• Humerus

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Upper Limb

• Humerus
• Radius (thumb side)
• Ulna (elbow)
• Carpal (wrist) (8 bones
• Metacarpals (hand) (5)
• Phalanges (fingers) (3/finger, 2/pollex)

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Pelvic Girdle

• Coxa
• Ilium
• Ishium
• Pubis
• Femur

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Lower Limb

• Femur
• Tibia
• Fibula
• Patella
• Tarsal (ankle) (8)
• Metatarsals (foot) (5)
• Phalanges toes (3/toes, 2/hallux

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Joints

• Wherever two bones meet
• movable
• immovable (sutures)

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Structural Types of joints

• Fibrous
• Fibrous joints connect bones without allowing any
  movement. The bones of your skull and pelvis are
  held together by fibrous joints. The union of the
  spinous processes and vertebrae are fibrous
  joints.
• Cartilaginous
• Cartilaginous joints are joints in which the
  bones are attached by cartilage. These joints
  allow for only a little movement, such as in the
  spine or ribs.
• Synovial

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Synovial

• Synovial joints allow for much more movement than
  cartilaginous joints.
• Articular cartilage covers bone ends
• Contains
• capsule of dense CT
• meniscal cartilage
• fat pads
• bursa sacs
• Cavities between bones in synovial joints are
  filled with synovial fluid.
• This fluid helps lubricate and protect the bones.
  

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Bio 111-73
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Synovial Joints

• Hinge A hinge joint allows extension and
  retraction of an apendage.
• Saddle A saddle joint allows movement back and
  forth and up and down, bot does not allow for
  rotation like a ball and socket joint.
• Ball and Socket A ball and socket joint allows
  for radial movment in almost any direction. They
  are found in the hips and shoulders.
• Ellipsoid
• Ellipsoid joints are similar to a ball and
  socket joint. They allow the same type of movment
  to a lesser magnitude. The wrist is an ellipsoid
  joint.
• Pivot
• Pivot joints allow rotation arround an axis. The
  neck and forearms have pivot joints. In the neck
  the occipital bone spins over the top of the
  axis. In the forearms the radius and ulna twist
  arround each other.
• Gliding In a gliding or plane joint bones slide
  past each other. Midcarpal and midtarsal joints
  are gliding joints

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Types of Movement

• Gliding
• Flexion and Extension
• Abduction and adduction
• Circumduction
• Rotation pronation and supination
• Inversion and eversion
• Dorsiflexion and plantar flexion