Muscles of the Head & Upper Limb Flashcards
The muscles of your head and some of the muscles of your neck are innervated by ___ ___
cranial nerves
___ (#) groups of facial muscles are traditionally identified by their innervation and function
3
All of the upper limb muscles are innervated by the brachial plexus, a combination of ventral rami from ___ to ___
C5 to T1
Upper limb muscles are grouped by ___
function
What are the groups of upper limb muscles
- movers of the scapula
- humeral shaft muscles
- rotator cuff muscles
- flexors of the elbow
- extensors of the elbow
- flexors of the wrist
- extensors of the wrist
Many of the muscles within each of the 7 groups of classification have a common ___ and/or common ___
common attachment and/or common function
muscles of the upper limb are innervated by the spinal nerves from
C5 to T1
The 5 ventral rami from C5 - T1 combine to form the __ ___
brachial plexus
what is the brachial plexus
a network of interchanges where neurons are regrouped on their way to their destination and as a result the nerves that lead to individual muscles of the limb will have innervation from several spinal nerves rather than just a single spinal nerve
Why is the arrangement of the brachial plexus beneficial?
it is beneficial in the case of localized nerve or spinal cord damage that could otherwise paralyze a muscle, but is aided by the fact that muscles are innervated by several spinal nerves
Why does a myocardial infarction (heart attack) result in pain in the shoulder and arm?
the sensory nerves from the heart converge upon the T1 spinal nerves and the dermatomes that include the arm and shoulder are also C5-T1; the spinal cord doesn’t distinguish between the pain from the shoulder and sensory information from the heart, so the brain perceives only shoulder pain
How is the brachial plexus protected
it is protected by passing through the space formed by the clavicle, ribs, and scapula; lymphatic vessels, the axillaryartery and the axillaryvein also utilize this protected space on their way to and from the upper limb
muscles are named according to their ___ ___ ___
ex. brachialis
shape, position or function
ex. brachialis is named bc of its position in the brachium, the upper arm
All muscles have ___ that may be drawn together during contraction
attachments
attachments are assigned an ___ and a __. Explain each
an origin and an insertion
origin - is the more stable and proximally located attachment
insertion - is the more mobile, distal attachment
The action of the muscle is determined by __
ex. brachialis
knowing the attachments of the muscle and the joint that exists between them
ex. the brachialis muscle will draw the ulnar tuberosity toward the humerus; since the humeroulnar joint is a hinge joint, the action will be flexion
Synergists vs antagonists
synergists - muscles that have the same or similar actions
antagonists - muscles that provide the opposite action
For muscles to have mechanical properties, they rely upon ___ __
connective tissues
Name the 4 connective tissue types discussed in manual
Tendon
Fascia
Aponeurosis
Retinaculum
Define a tendon
a continuation of the connective tissue of the muscle that connects it to a bone
Define a aponeurosis
a broad, flat tendon
Define a retinaculum
a specialized fascia that functions as a band to hold underlying tendons in place
Define a fascia
a catch all term for connective tissue that wraps around structures - muscles are divided into fascial compartments by intermuscularsepta
