What bones compose the shoulder joint?
Scapula, clavicle, and humorous
What are the 4 joints of the shoulder
glenohumeral, sternoclavicular, acromioclavicular, and scapulothoracic
How many muscles are involved with the shoulder
14
What is the purpose of studying anatomy
1.physical exams 2. therapeutics (joint injections) 3. chart notes
What structures are present on day 34 of fetal development
eye, ear, arm bud, leg bud
What structures are present on day 28 of fetal development
heart, brachial arches
How long does a fertilized egg remain an embryo
9 weeks
What happens in week 3 of development
embryonic cells flatten into a trilaminar disc
What are the germ layers of the trilaminar disc
Endoderm, mesoderm, ectoderm
What tissues are formed by the endoderm
Inner lining of the digestive and respiratory tracts, and glands such as the liver and pancreas
What tissues are formed by the mesoderm
Muscles, bones, circulatory system, dermis, and connective tissue
What tissues are formed by the ectoderm
Brain and nervous system, and the epidermis (skin, hair, nails etc)
What significant event happens in week 4 of development
The paraxial mesoderm thickens and divides into paired masses on both sides of the notochord. The masses are made of mesenchymal cells and are called somites
Why are somites clinically significant
Because they are ultimately the cause of the segmentation of the spinal chord
What are the three parts of a somite
Dermatome, myotome, sclerotome
What tissue does the dermatome form
the dermis
What tissue does the myotome form
The muscles of the back, thorax, and limbs
What tissue does the sclerotome form
The vertebrae and ribs
What type(s) of germ layer are in limb buds
Mesoderm (lateral somite) and ectoderm (Apical ectodermal ridge)
What happens to limb development if the apical ectodermal ridge is removed?
The limb ceases to grow.
How do the cells in the developing limb know which is superior and which is inferior
The secretion of ZPA creates a concentration gradient
What are dermatomes
Dermatomes are segments of the body that refer to different sections on the spine
how are limbs innervated?
Spinal nerves migrate with the myotome cells as they migrate into the limb bud.
By what week do the cartilage models of the arm bones form
by 6 weeks
What significant event begins in week 9
enchondral ossification
Which 2 shoulder bursae are clinically important
Subacromial and subdeltoid bursae
What are the extracapular ligaments of the glenohumeral joint
Transverse humeral lig. and coracoacromial lig.
What is the function of the transverse humeral ligament?
It spans the bicipital groove thus holding the bicipital tendon in place
What is the function of the coracoacromial ligament
It limits superior movement thus strengthening the roof of the shoulder
What permits the great mobility of the shoulder joint
The shallow glenoid cavity and a lax capsule
What gives the shoulder joint stability
The rotator cuff muscles
What are the ligaments of the sternoclavicular joint
interclavicular lig. and costoclavicular lig. and articular disc
What is the function of the interclavicular ligament
limits shoulder depressions
What is the function of the costoclavicular ligament
limits shoulder elevation
What is the anatomical neck of the humerus
The narrow ring between the head and the tubercles
What is the surgical neck of the humerus
Empirically designated region below the tubercles that is subject to fractures
