Muscles (Pt. 2) Flashcards
What is the platysma?
Single sheet-like muscle
What does the platysma cover?
Anterolateral neck
Where does the platysma originate from?
Originiates from the connective tissue covering of the chest muscles
Where does the platysma insert into?
The area around the mouth
What is the action of the platysma?
To pull the corners of the mouth inferiorly
What does the platysma produce at the mouth?
Produces downward sag of the mouth
What happens when both sternocledomastoid muscles contract together?
They flex your neck
What does the flex of the neck allow for? (Sternocleidomastoids)
Allows for bowing of the head
What are the sternocledomastoid muscles called?
Prayer muscles
What is the pectoralis major shaped like? What does it cover? (2)
- Large fan shaped muscle
- Covering upper part of chest
Where does the pectoralis major originate from? (2)
- Shoulder girdle
- First 6 ribs
Where do the internal intercostal muscles lay? What do the internal intercostal muscles do to help with exhalation? (2)
- Lie deep to the external intercostals
- Depress the rib cage to help with exhalation
What are the muscles of the abdominal girdle? (4)
- Rectus abdominis
- External oblique
- Internal oblique
- Transverses abdominis
What do the trapezius muscles extend?
Extend the head
What are the trapezius muscles to the sternocleidomastoids?
Antagonists
What can the trapezius muscles do to the scapula? (3)
- Elevate
- Depress
- Adduct
What are latissimus dorsi? What do they cover?
Large flat muscles that cover the lower back
What do the latissimus dorsi extend and adduct to?
Extend and adduct the humerus
What are latissimus dorsi important when? What actions benefit? (2)
- Important when the arm must be brought down
- As when swimming or sledge hammering
What action do the erector spinae group provide resistance and control to?
Provide resistance that controls the action of bending over at the waist
What happens when the erector spinae are injured? (2)
- Muscles go into spasms
- Common sourse of lower back pain
What are deltoid muscles? What do they form? (3)
- Fleshy
- Triangle-shaped muscles
- Form the rounded shape of shoulders
Why are deltoid muscles a good place for injection of small amounts of medication? What amount? (2)
- Because of the bulk size
- Less than 5 mL
What are the deltoid the prime movers of?
Prime movers of arm abduction
Where does the origin wind across from where to where? (3)
- Origin winds across the shoulder girdle
- From the spine of the scapula
- To the clavicle
Where do the deltoids insert into?
Inserts into the proximal humerus
