Joints & Muscles Flashcards
What is Abduction?
movement away from the midline, or the fanning movement of fingers or toes when they are spread out.
What is Adduction?
opposite of abduction is the movement towards the midline or drawing the fingers or toes together.
What is Circumduction? part 1/2
occurs as a result of a continuous sequence of flexion, abduction, extension, and adduction, usually ball and socket joints.
What is Circumduction? part 2/2
Circumduction refers to movement of the distal end of a part of the body in a circle, while the proximal part remains stationary.
Rotation refers to…
a bone revolving around its own longitudinal axis: Turning the head from side to side as when you shake your head “no”Occurs in ball and socket joints and movement of the atlas around the dens of the axis.
What is Pronation?
movement of the forearm so that the palm is turned downward.The distal end of the radius moves across the ulna so that the bones form an X .
What is Supination?
movement of the forearm so that the palm is turned upward (anatomical position). The radius and ulna are parallel during supination.
What is Opposition?
movement of our magnificent opposable thumb across the palm to touch the tips of the fingers on the same hand.
What is Inversion?
movement of the foot that turns the sole of the foot medially.
What is Eversion?
movement that turns the sole of the foot laterally.
What is Dorsiflexion?
bending of the foot at the ankle in an upward direction.
What is Plantar Flexion?
bending the foot at the ankle in a downward direction, as if standing on one’s toes or pointing the toes.
What is Elevation?
upward movement of a body part. i.e…closing the mouth
What is Depression?
downward movement of a body part. i.e…opening of the mouth
What is Protraction?
movement of a body part anteriorly, while retraction is movement back to normal. i.e..Thrusting the mandible outward
Origin (usually proximal):
attachment of a muscle tendon to the stationary bone
Insertion (usually distal):
attachment of the muscle’s other tendon to the movable bone, or the skin in case of muscles of facial expression
Action/s:
main movements that occur when the muscle contracts
Prime mover (agonist)
major responsibility for a certain movement
Antagonist:
opposes or reverses a movement
Synergist:
helps the prime mover
–By adding extra force
–By reducing undesirable movements
–Fixator: type of synergist that holds a bone firmly in place
Biceps:
Origin: Scapula
Insertion: Radius
Action: pronate and flex the arm
Triceps:
ORIGIN:Scapula near shoulder joint Upper lateral and posterior sites of humerus Posterior surface of humerus INSERTION: Back of olecranon process of ulna
ACTION: Straighten (extend) the arm
Fixator muscles
type of synergist muscle that are used to steady the proximal joints of a prime mover.
Ex: Shoulder stabilizers for the forearm flexors
Circular –fascicles
arranged in concentric rings
–Surround external body openings
–Sphincter: general name for a circular muscle–Examples: Orbicularis orisand orbicularis oculi
Frontalis
- Draws scalp forwardRaises eyebrowsWrinkles forehead
- Origin: from the epicranialaponeurosis
- Insertion: skin of eyebrowsand root of nose.
Occipitalis
- Draws scalp backward Posteriorly.
- Origin: occipital bone
- Insertion: epicranialaponeurosis.
Orbicularis oculi
Closes the eye, and blinking. It is a tripartite sphincter muscle. Origins: Frontal and maxillary bones. Inserted in the tissue of eyelid. *Blink your eyes, wink, brings eyebrows inferiorly, You are contracting orbicularis oculi
Orbicularis oris
–Action: Closes and protrudes lips for kissing and whistling
–Origin: Surrounding the opening of the mouth
–Insertion: The skin at the corner angles of the mouth
*Close your lips and pucker up. This requires contraction of Orbicularis Oris..
Zygomaticus major
- Draws angle of mouth up= Smile
* Inserted at skin and muscle at corner of mouth
Platysma:
•Unpaired sheet like superficial muscle, tenses the skin of the neck and depresses mandible, pulls lower lip back.
muscles of mastication
Muscles that move the mandible (lower jaw)
Four main pairs of muscles involved in mastication:
-Innervated by mandibular division of the trigeminal nerve (cranial nerve V)
•Masseter and temporalis
~Prime movers of jaw closure
•Pterygoid muscles
~Side-to-side movement
•Buccinator muscles
~Compression of cheeksMasseter
Covers lateral aspects of mandibular ramus, can be palpated on forcible closure of jaws.
–Origin: Maxilla and zygomatic arch
–Insertion: Mandible ramus and angle
–Action: Prime Mover of Jaw. Closes the mouth, by elevating the Mandible.
–Clench your teeth and palpate the angle of the jaw.
Temporalis
-Fan shape muscle lies over parts of frontal, parietal, and temporal bones
- Elevates Mandible
- Origin: Temporal fossa
- Insertion: Mandible
- Place your hands on your temples and clench your teeth.
Buccinator
-Principal muscle of cheek. Runs horizontally deep to the masseter.
- Compresses cheek
- Cave in like suckling straw
- Origin: maxilla and Mandible
- Insertion: Orbicularis Oris
Sternocleidomastoid
Muscles of the Neck and Vertebral Column •Head movement: —most prominent neck muscle –Sternal head –Clavicular head
Deep to the sternocleidomastoid
–Common carotid artery
–Internal jugular vein
The sternocleidomastoid muscles divide the neck:
–Anterior triangle
–Posterior triangle
Sternocleidomastoid (commonly abbreviated as SCM)
two headed muscle
–Origin: Clavicle and Manubrium of the sternum
–Insertion: Mastoid process of temporal bone
–Action: Contraction of both muscles Flexes the cervical vertebrae Acting independently rotate the head toward shoulder on opposite site
Pectoralis major prime mover of flexion, adduction and medially rotation.
–Origin: Clavicle and sternum
–Insertion: Proximal humerus
–Action: Adducts and medially rotates the arm at the shoulder joint
Pectoralis minor beneath the Pectoralis major.
–Origin: Ribs 3–5
–Insertion: Coracoid process of the scapula
–Action: Internally rotates the shoulder
