Human Skeleton

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Human Skeleton
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Skeleton?

• The skeleton is a supportive framework that
  maintains the shape of humans and protects our
  internal organs.
• It also plays a vital role in our ability to move
  around.

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Endoskeleton

• Humans have a bony endoskeleton made up of 206
  bones, although we are born with more than 300.
• The skeleton is divided into two parts axial and
  appendicular skeleton.

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Axial Skeleton

• Consists of the skull, backbone, and the ribcage.
• Forms the upright axis of the body.
• Protects the brain, spinal cord, and the organs
  in the chest.

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Axial Skeleton

• The axial skeleton makes up 80 of your 206 bones
  and can be broken down into three areas the
  skull (cranium), the backbone (spine), and the
  bony thorax (ribcage).

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The skull provides the framework for most of your
sensory organs and is considered as the most
important structure in your skeleton.
The bony thorax is basically your chest, made up
of your ribs and sternum. You have twelve ribs
that help protect your lungs and heart.
The backbone is actually a flexible structure
made up of 26 bones. It is approximately 28
inches long and separated into 5 regions.
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Appendicular Skeleton

• Consist of the upper and lower limbs, and the
  pectoral (shoulder) and pelvic (hip) girdles.
• Pelvis is adapted for an upright stance.
• Lower limbs support the upper body and enable
  walking.
• Upper limbs are used for manipulation.

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Three types of bone

• Periosteum A glistening double layered tissue
  that covers the hard bone.
• Compact bone Seems very hard to the naked eye,
  but is very hollow.
• Spongy bone Houses the red bone marrow and the
  yellow bone marrow

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What is the difference between red and yellow
bone marrow?

• Red bone marrow is what makes red blood cells.
  The majority of the red bone marrow for an adult
  is located in the head of the femur and the
  humerus.
• Yellow bone marrow is stored fat. This marrow
  can sometimes turn into red bone marrow when a
  person is very anemic.

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Lets look at the parts of a bone
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What are the five main functions of bones?
Protection
Support
Blood cell formation
Movement
Storage
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How many bones are in the human skull?

• 10?
• 15?
• 20?
• What is your guess????
• There are 22 bones in the
• human skull, not including the
  
• three in the inner ear

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What is the purpose of so many bones?

• Cranial bones surround and protect the brain.
• Facial bones provide attachment points for facial
  muscles, openings for eating and breathing,
  cavities for the sensory organs, and anchorage
  for the teeth.

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Names of all the bones

• Frontal bone
• Nasal bone
• Lacrimal bone (2)
• Ethmoid bone (2)
• Nasal spine
• Supraorbital ridge
• Glabella
• Parietal bone (2)

• Mandible
• Maxilla
• Vomer
• Mastoid process
• Zygomatic bone
• Occipital bone
• Temporal bone (2)
• Sphenoid bone (2)
• External auditory meatus

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Now lets look at where all those bones are
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Directionality

• Anterior view Lateral View
• Inferior view Interior view