Week 3-4 Anat slides Flashcards
What is Newtons first law
An object in motion will remain in motion and an object at rest will remain at rest unless acted upon by a force. The more mass an object has, the greater its inertia and the more force it takes to change the state of motion.
What is Newton second law
When a force acts on an object, it will cause the object to accelerate. The larger the mass of the object, the greater the force will need to be to cause it to accelerate. This law may be written as force = mass x acceleration.
What is Newtons third law
For every action, there is an equal and opposite reaction. What this means is that pushing on an object causes that object to push back against you, the exact same amount of force, but in the opposite direction.
What is considered an external force
Name three examples of external forces
Push or pull on the body that arise from outside of the body
Gravity is a human’s constant force and thus always needs to be considered first when looking at human movement (on earth!)
Friction
Ground Reaction Force (GRF)
What is an internal force?
Internal
These forces act on the body but come from within the body: muscles, ligaments and bones
What to joints do?
Joints provide articulating points within our skeleton to allow movement.
What do muscles do?
Muscles contract to provide the force necessary to move the joints.
What do spinal muscles do?
Spinal muscles surround and support spinal column.
What is agonist and antagonist muscles?
Agonist and antagonist muscles act simultaneously.
What is co contraction?
Agonist and antagonist muscles acting simultaneously.
Exerts force in different directions to stabilize
Acts as synergists for movement
What is friction?
Friction is the force produced between two surfaces when they interact against one another.
What is:
Kinetic friction
Static friction
Define kinetic friction
Kinetic friction – the force produced when one object moves against another.
Static friction occurs between two surfaces that are at rest.
Kinetic friction occurs in the opposite direction to the movement of the object (Newton’s third law)
Name 2 factors that effect friction
Relative roughness of the sliding surfaces
Weight of the object
Define core (trunk)
Central scaffold for maintaining or transitioning to various positions
Body’s core region
Back, abdomen, thorax (chest), and pelvis
Define vertebral (spinal) column
All of the vertebrae that form the spine
Define co contraction
Simultaneous activation of agonist and antagonist muscles
Contributes to static and dynamic stability for occupational performance
Define axial skeleton
Vertebral column
Ribs
Sternum
Skull
Attachment sites for large muscles
What positions are made possible in the vertebral column and what is the range of motion limited by?
flexion, extension, lateral flexion and rotation
The range of movement of the vertebral column is limited by the thickness, elasticity, and compressibility of the vertebrae discs.
Name the 5 regions of the spine.
How many vertebrae are in each
5 regions:
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Cervical (7)
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Thoracic (12)
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Lumbar (5)
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Sacral (5)
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Coccygeal (4)
What is lordosis and where does it occur in the spine?
Anterior curvature of spine
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Cervical vertebrae
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Lumbar vertebrae
Define kyphosis and where does it occur
Posterior curvature of the
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Thoracic vertebrae
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Sacral vertebrae
What is the function of the vertebral body?
Main portion of vertebrae
Cancellous (spongy) bone
Absorbs compressive forces
What is the vertebral arch?
Formed by pedicles and laminae
Bony base for processes
What is the vertebral foramen
Opening posterior to vertebral body
Bony canal for spinal cord
What is the Intervertebral foramen?
Opening between adjacent vertebrae
Passage for spinal nerves
What is the intervertebral disc?
Between vertebral bodies
Stabilizes and absorbs shock
What is the annulus fibrosus in the vertebral column?
Fibrous outer ring
What is the nucleus pulposus?
Gel-like inner core
Where is the spinous process?
Projects dorsally and inferiorly
Where is the transverse processes located?
Extend laterally from each side
What is the sternum?
Also known as breastbone
Flat vertical bone
Aligned with vertebral column
Anterior support for rib cage
Articular surfaces for ribs (sternocostal joints)
List all ribs and what they connect too
Formed by 12 pairs of ribs
Held to skeleton by vertebrae and sternum
True ribs:
First 7 ribs
Direct links to sternum with costal cartilage
False ribs:
ribs 8-10 connect to other costal cartilage
Ribs 8–12
Floating ribs 11-12
No bony connection to sternum
What are the function of the diaphragm
Muscular seal to inferior rib cage
Controls volume of thoracic cavity for respiration and speech
Contraction causes chest cavity to expand
Function of the lumbar spine
5 vertebrae
Largest and least mobile
Thicker anteriorly
Lumbar lordosis
What is the sacrum
Sacrum:
Triangular bone
Beneath 5th lumbar vertebra
Forms posterior pelvic wall
What is the coccyx
Tailbone
Formed by 3–5 small vertebrae