Lecture 25: Upper Limb Compartments Flashcards
What do the muscles in the anterior and posterior group of the axial skeleton to the pectoral girdle originate from and insert onto?
Originate from the axial skeleton and insert onto the scapula
What is the function of the anterior muscles in the axial to pectoral girdle?
To protract the scapula and shoulders
What is the function of the posterior muscles in the axial to pectoral girdle?
To pull the scapula backwards (retracting the shoulders)
What is the function of the muscles connecting the axial skeleton to the arm
- Moves the humerus
What muscles are in the anterior compartment connecting the axial skeleton to the arm. What is their origin and insertion and function?
- Pectoralis major
- Originates from the axial skeleton
- Inserts on lateral side of the midline of the proximal humerous
- Functions in adduction
- Medially rotates the arm and shoulder
- Helps flex the arm and shoulder
What muscle is in the posterior compartment connecting the axial skeleton to the arm. What is their origin and insertion and function?
- Porsticimus dorci
- Originates from axial skeleton
- Inserts on the midline of the groove on anterior side of humerus
- Extends the arm and shoulder joint when contracted
- Medially rotates the arm
- Helps the pectoralis in adducting
What muscle connects the pectoral girdle to the humerus
The deltoid
What is the function of the deltoid
Anterior part assists with flexing the arm and shoulder
Medially rotates arm
Posterior fibres help with lateral rotation and flexion
Anterior fibres help with flexing
PRImary function if abducting
Where does the deltoid originate and insert upon
Originates from the clavicle - in 3 different spots
Inserts onto lateral side of humerus about halfway down
What muscle is in the anterior compartment of the muscles of the arm?
The biceps brachii
What muscle is in the posterior compartment of the muscles of the arm?
The triceps brachii
What compartment of the forearm flexes the forearm
The anterior compartment
What compartment of the forearm extenses the forearm?
The posterior compartment
Describe the structure and origin and insertion of the biceps brachii
- Has two heads, long and short head
- The long head originates from scapula
- Short head originates from corocoid process
- Inserts onto the anterior middle surface of the proximal radius
Describe the structure, origination, and function of the triceps brachii
- 3 heads
- Long head originates from scapula
- Lateral head originates from the proximal portion of the humerus
- Medial head originates from posterior surface of humerus
- Fuse together to form triceps
- ## Extends the forearm when contracts
What is the anterior compartment of the muscle of the forearm responsible for?
Flexing
What is the posterior compartment of the muscle of the forearm responsible for?
Extending
How many muscles are in the posterior compartment in the forearm. Where do they originate from? Where do they insert onto? What is their function?
6 extensor muscles
- originates from the lateral epichondial
- Inserts on the meticarples an phalanges
- Extends hand at wrist and extends fingers
Sources of nerves for all the upper limb compartments are innervated by what?
The brachial plexus
How many terminal branches does the brachial plexus have? What are they?
- Median nerve
- Ulnar nerve
- Radial nerve
- Axillary nerve
- Musculocuaneous
What nerve innervated the deltoid?
The axillary nerve
What nerve innervates the biceps brachii
The musculocaneous nerve
What nerve innervates the triceps?
The radial nerve
What nerves innervate the anterior of the forearm?
The median nerve and the ulnar nerve
