Human Locomotion

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Chapter 14

• Human Locomotion

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In humans, locomotion involves the interaction
of

• 1. Bones
• 2. Cartilage
• 3. Muscles
• 4. Tendons
• 5. Ligaments

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(I) Bones

• Composed mainly of calcium
• Made up of living bone cells and connective fiber
  tissue

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Bones provide

• Support and protection of body organs
• Anchorage for muscles
• Leverage for muscles
• Bone marrow for the production of blood cells

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Bone Marrow

• Found in hollow cavities of bone
• These hollow cavities are known as the Haversian
  canals
• Produce
• red blood cells
• white blood cells
• platelets

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Joints

• Where bone meets bone in an organism

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Types of Joints

1. Immovable joint
2. Ball-and-socket joint
3. Hinge joint
4. Gliding joint

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Immovable Joint

• Bones that are tightly fitted together

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Ball-and-Socket Joint

• Can move in all directions

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Hinge Joint

• Permits back and forth motion

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Gliding Joint

• Provides limited flexibility in all directions

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(II) Cartilage

• Unlike bone, cartilage is flexible and elastic
• Found at joints, nose, and ear
• Absorbs shock

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Ossification

• The process by which cartilage gradually changes
  into bone
• Ex In humans, the skeleton of an embryo
  is made up of mostly cartilage. By adulthood,
  most of this cartilage changes into bone by the
  process of ossification

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(III) Muscles

• Three types of muscle
• Skeletal muscle
• Smooth muscle
• Cardiac muscle

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Skeletal Muscle

• Voluntary (can be controlled)
• Involved in locomotion
• Attached to bone
• Striated in appearance (striped)
• Function as antagonistic pairs

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Antagonistic Pairs

• Muscles work as opposites
• Ex
• 1. Bicep contracts then triceps relaxes
• 2. Triceps contracts then the bicep relaxes

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Summary

• When the bicep contracts, the arm bends upward
  (flexes) and therefore the bicep is known as a
  flexor
• When the triceps contracts, the arm extends
  outward and therefore the triceps is known as an
  extensor

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Smooth Muscle

• Smooth and not striated in appearance
• Involuntary (cannot move)
• Found in
• -walls of digestive organs
• -walls of arteries and veins
• -walls of internal organs

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Cardiac Muscle

• Found only in the heart
• Striated in appearance
• Involuntary

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(IV) Attachments

1. Ligaments- connect bone to bone
2. Tendons- connect muscle to bone

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(V) Disorders of Locomotion

1. Arthritis- inflammation of the joints
2. Tendonitis- inflammation of a tendon, usually
   where it is attached to the bone