Skeletal System

1
Skeletal System
2
The Skull

• The skull is the bony section of the head.
• The skull
• Encases and protects the brain
• Houses the brain senses
• Provides attachments for muscles of the head
  and neck
• Helps to form the beginning of the respiratory
  and digestive tracts.

3
The Cranium

• The cranium is the bone that protects the brain.
• We often refer to the entire skull as the cranium.

4
Vertebrae

• The adult spine is made up of 33 bones called
  vertebrae stacked on top of each other from the
  bottom of the skull to the pelvis.
• Each vertebra is composed of several parts that
  act as a whole to surround and protect the spinal
  cord and nerves, provide structure to the body
  and enable fluid movement.

5
Axis

• The skull rests on the first vertebra, which is
  called the "Atlas".

6
Babys Skull

• A babys skull contains "soft spots.
• The bones in the baby's head harden and grow
  together until the bones meet and mesh like a
  jigsaw puzzle.

7
Skeletal Bones

• An adult human skeleton contains 206 bones.
• However, at birth the human skeleton contains 350
  bones.

8
The Longest and Shortest Bones

• The longest bone in the body is the femur.
• The smallest bone is the stirrup bone inside the
  inner ear.

9
Bones

• Bones are made mostly of calcium.
• They support the body and allow movement.

10
Bones are Alive

• Many people think bones are dead tissue.
• However, bones are very much alive.
• Bones have cells, nerves, blood vessels and pain
  receptors.

11
The Function of Bones

• Levers bones, with the help of muscles, pull and
  push the body.
• Calcium 97 of the bodys calcium is stored in
  bone.
• Protection
• Marrow Bone marrow produces the red blood cells
  that carry oxygen to the body tissues and the
  platelets that allow clotting when we have a cut
  or wound.

12
Cartilage

• Cartilage is a tough elastic tissue.
• At birth our skeleton is made up of flexible
  cartilage.
• Within a few weeks a process called ossification
  occurs that replaces most of the cartilage with
  calcium and collagen.
• Our skeletons do not complete ossification until
  we stop growing around age 20.

13
Joints

• With the exception of the hyoid bone,
• every bone in the body is connected to at
  least one other bone by a joint.

14
Joint Function

• Joints serve two functions
• They hold the skeletal bones together
• They allow the skeleton some flexibility for
  stiff movement.

15
Joint Flexibility

• Joints may be
• Immovable Synarthroses
• Slightly movable Amphiarthroses
• Freely movable Diarthroses

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Structural Classification

• Fibrous joints
• Cartilaginous joints
• Synovial joints

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Synovial Joints

• Plane or gliding joints
• Hinge joints
• Pivot joints

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Synovial Joints

• Saddle joints
• Ball and Socket joints

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Tendons

• Tendons are bands of fibrous tissues that connect
  muscles to bones.

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Ligaments

• Ligaments are fibrous bands or sheets of
  connective tissue linking two or more bones,
  cartilages, or structures together.
• One or more ligaments provide stability to a
  joint during rest and movement.

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Muscles

• http//www.nlm.nih.gov/medlineplus/tutorials/muscl
  es/htm/_no_25_no_0.htm

22

• http//cartage.org.lb/en/themes/Sciences/LifeScien
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  /Introductory.htm
• www.innerbody.com
• http//www.enchantedlearning.com/subjects/anatomy/
  skeleton/
• http//kidshealth.org/PageManager.jsp?dnfamilydoc
  torps204article_set22630cat_id20121lic44
• http//www.zoology.ubc.ca/biomania/tutorial/bonej
  t/intro.htm
• http//www.spineuniverse.com/displayarticle.php/ar
  ticle1268.html
• http//orthopedics.about.com/cs/sportsmedicine/g/t
  endon.htm
• http//www.nlm.nih.gov/medlineplus/tutorials/muscl
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