Muscular System Flashcards
Muscles are formed from ______ which forms the bulk of the mesoderm.
Myoblasts of the Mesenchyme
The human body has more than _____muscles
600
Muscles are _____ of the body’s mass.
40-50%
_______shorten under neural control
Skeletal muscles of the head and neck
Skeletal muscles of the head and neck shorten under neural control causing
soft tissue and bony structures to move
When muscles move the resulting muscle movement is called the
action of the muscle
Each muscle is attached at both ends of these moving structures:
•Origin - the end of the muscle attached to the least movable structure
• Insertion - the end of the muscle attached to the more movable structure
What are origins of muscles?
the end of the muscle attached to the least movable structure
What is the insertion of a muscle?
the end of the muscle attached to the more movable structure
Muscles in the head and neck can be divided into what 6 main groups?
• Cervical muscles
• Muscles of facial expression
• Muscles of mastication
• Hyoid muscles
• Muscles of the tongue
• Muscles of the pharynx
Sternocleidomastoid muscle and the trapezius muscles are what kind of muscles?
Cervical muscles
The SCM and trapezius muscle is superficially or deeply located on the neck?
Superficially
Hold and stabilize the head
Position the head in relation to the
rest of the body
SCM and trapezius muscle
One of the largest and most superficial
muscles of the neck
Paired muscle
Thick
Primary muscular landmark of the neck during EO examination
SCM muscle
• Divides each side of the neck diagonally into an anterior and posterior cervical triangle
SCM muscle
Where is the origin of the SCM muscle?
medial part of the clavicle and sternum’s superior and lateral surfaces
Where is the insertion of the SCM muscle?
mastoid process of the temporal bone
What is the action of SCM muscle?
If one muscle contracts: the head and neck bend to the unilateral side, and the face and front of the neck rotate to the contralateral side
• If both muscles contract: the head flexes at the neck, and extend at the junction of the neck and skull
• This muscle assists in elevating the thorax during breathing
The SCM muscle is innervated by
Eleventh (XI) cranial nerve (accessory nerve)
the SCM is examined during an EO examination by
palpation
What is Palpation?
a physical examination technique that involves using the hands or fingers to feel the body in order to examine organs or body parts
When palpating the SCM muscle how should we position to the patient’s head to make their SCM more prominent?
turn their head to the contralateral side
Having the patient turn their head contra-laterally to palpate the SCM muscles increases accessibility for effective palpation of nearby
cervical lymph nodes
The insertion of the SCM into the mastoid process is just_____ to the external acoustic meatus
posterior and inferior