Lab 6 and Chapter 8: Musculoskeletal System 1 Flashcards
Define the following: agonist (prime mover), antagonist, synergist, and fixator.
Agonist (Prime Mover): Any specific muscle that provides the major force of the movement.
Antagonist: any muscle that would oppose the prime mover’s movements
Synergist: a muscle that is not the prime mover but enhances or aids the prime mover’s movement
Fixator: a muscle that will immobilize a muscle’s origin or “fix” the bone to keep it from moving
Define the following: origin and insertion
Origin: the muscle attachment to the immovable (or less moveable) bone
Insertion: the muscle attachment to the movable bone
During contraction, the movemement usually results in the insertion moving toward the origin.
What are the primary movements for each of the muscles on the head / neck?
Sternocleidomastoid: flexion of the head and neck
Trapezius: extension of the head and neck
Frontalis: wrinkles forehead, lifts eyebrows
Occipitalism: antagonist to frontals
Obicularis Oculi: squinting; winking
Zygomaticus: smiling (pull corners of mouth up)
Risorious: pulls angle of mouth laterally; synergist to zygomaticus (fake smile)
Obicularis oris: pucker lips ass for kissing or whistling
Temporalis and massester: elevation of mandible (chewing)
Buccinator: compresses cheeks; sucking (in nursing infants); assists in chewing by directing food between molars
Mentalis: protudes lower lip as in pouting; wrinkles chin
Levator labii superioris: elevates upper lip
Depressor labii inferioris: pulls lower lip down as in pouting
Genioglossis: protudes tongue; moves tongue side to side
What are the primary movements for each of the given muscles of the trunk?
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Review the following chart.
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Define the following: axial skeleton and appendicular skeleton.
Axial skeleton: the region of the skeleton that forms the central supporting axis of the body. It includes the skull, auditory ossicles, hyoid bone, vertebral column, and thoracic cage.
Appendicular skeleton: the region of the skeleton that includes the bones of the upper limb and pectoral girdle and the bones of the lower limb and the pelvic girdle.
Review the following chart on bone names.
Where are the paranasal sinuses and what do they do?
- These are paired cavities in the ethmoid, sphenoid, frontal, and maxillary
- Lined with mucous membranes
- They open into the nasal cavity
- Resonanting chambers for voice
- Lighten the skull
What are the fontanels of the skull at birth and what is their purpose?
- dense connective tissue membrane-filled spaces (soft spots)
- Unossified at birth but close early in a child’s life
- 2 purposes:
- allow fetal skull to pass through birth canal
- allow rapid growth of the brain during infancy
- bone can’t keep up with brain growth initially
- Skull reaches adult size by 8-9 years old
What are intervertebral discs?
- discs between the vertebrae that absorb shock
- permit movements of the vertebral column
- made of ring of fibrocartilage with a pulpy center
What is a herniated disc?
- most commonly seen in the lumbar region
- can occur anywhere
- pressure on spinal nerves causes pain
What are the normal curves of the vertebral column?
- Primary curves
- thoracic and sacral curves are formed during fetal development
- Secondary curves
- cervical curve forms when infant raises head at 4 months
- lumbar curve forms when infant sits up and begins to walk
- We are born with 1 basic curve which is retained in the thorax and sacrum of our adult spines
What are the types of abnormal spine curves and their associated issues?
- kyphosis
- exaggerated thoracic curve
- usually from: osteoperosis, osteomalacia, spinal tuberculosis, wrestling/weight lifting in young boys
- lordosis
- exaggerated lumbar curve
- caused by obesity or pregnancy
- scoliosis
- lateral bending of the column
- most common, especially in adolescent girls
- fixed like braces on teeth–break down some bone, move bone over and build new border around it
- some bones form wrong (e.g. scapula) but may remodel with correction
