1.1 Identify the characteristic features of the proximal end of the humerus
Head of the humerus, anatomical neck, surgical neck, greater tubercle, lesser tubercle, bicipital groove
1.1.1 Review which muscles are attached to the bicipital groove. What are their respective nerve supplies?
Lateral - pectoralis major ; lateral pectoral nerve and medial pectoral nerve
Floor- latisimmus dorsi; thorcadorsal nerve
Medial - teres major ; lower subscapular nerve
1.1.1.1. Where do these nerves originate and explain why two of them share the same brachial plexus cord origin?
Lateral pectoral nerve - C5-C7 (lateral cord)
Medial pectoral nerve - C8,T1 (medal cord)
Thoracodorsal nerve - C6-C8 (posterior cord)
Lower subscapular nerve - C5,C6 (posterior cord)
Both thoracodorsal nerve and lower subscapular nerve are mainly extensor muscles and had common functions so they share a common origin.
1.2. Identify the characteristic features of the humeral shaft including the deltoid tuberosity.
Features:
The deltoid tuberosity is a roughened surface on the lateral side for deltoid muscle attachment.
Spiral groove (radial sulcus) is an oblique groove which lies posteriorly in which the radial nerve and profunda brachii artery lie.
The humerus shaft is the site of attachment for various muscles.
Anteriorly – coracobrachialis, deltoid, brachialis, brachioradialis.
Posteriorly – medial and lateral heads of the triceps (the spiral groove demarcates their respective origins)
1.3 Identify the spiral groove of the humerus
Ans: radial groove, located at the lateral border of the humerus
What does it demarcate (set the boundaries or limit of)?
Lateral and medial head of triceps
Identify its contents?
Radial nerve and profunda brachii vessels
2. Muscles
2.1. What is Axilla?
Axilla is the pyramidal-shaped space deep to the skin, located between arm and thorax. It is the region where neurovascular structures like brachial plexus pass through to innervate muscles of the upper limb.
http://act.downstate.edu/courseware/haonline/labs/l05/ov0100.htm Perform a virtual dissection in 4 D Anatomy (http://4danatomy.com/modules ) to explore the Axilla: Left Shoulder (upper Lateral View)
2.2. Identify the boundaries of the axillary space (ANM Upperlimb Regions 09)
Base- skin and associated fascia of the armpit.
Apex - cervicoaxillary canal
4 walls :
anterior - pec major, minor
Posterior - subscapularis, latissimus dorsi, teres major, scapula
Lateral - the floor of the bicipital groove of humerus
Medial - upper ribs (2nd to 6th) and the serratus anterior muscle
http://act.downstate.edu/courseware/haonline/labs/l05/ov0200.htm
2.3. Identify the boundaries of the cervicoaxillary canal (apex of the axilla)
Medially: 1st rib
Anteriorly: Clavicle
Posteriorly: the Superior edge of the scapula
2.3.1. What structures pass through it?
Brachial plexus, axillary artery, vein, lymph nodes
Ans: Long thoracic nerve traverses this passageway in addition to axillary blood vessels and the brachial plexus
2.4. Identify the flexor compartment of the arm (ANM Upperlimb Dissection 14)
Prime mover: Pectoralis major(clavicular head); deltoid (clavicular and anterior acromial parts)
Synergist: Coracobrachialis (assisted by biceps brachii)
Ans: coracobrachialis, biceps, brachialis
Musculocutaneous
2.4.1. Identify its major muscles and its nerve.
Pectoralis Major: Lateral and medial pectoral nerve; clavicular head (C5&6), sternocostal head (C7, C8, T1)
Deltoid: Axillary nerve (C5, C6)
Ans: Surgical neck of humerus, long head of triceps, subscapularis (anteriorly)/ teres minor posteriorly, teres major
Axillary nerve, posterior circumflex humeral artery
2.4.2. Identify the 2 heads of the biceps and their attachment on the skeleton.
Origin:
Long head: supraglenoid tubercle of the scapula
Short head: coracoid process of the scapula
Attachment: Radial tuberosity and bicipital aponeurosis (ulna)
2.4.2.1. What is its action?
(a)Supinates forearm and, when it is supine
(b)Flexes forearm and elbow
(c)Short head resists dislocation of shoulder joint
2.4.3. Identify brachialis. and its attachments on the skeleton.
Origin - distal half of anterior surface of the humerus
Insertion- coronoid process and tuberosity of ulna
2.4.3.1. What is its action?
Elbow flexion
2.4.4. Identify coracobrachialis and its attachments
O - tip of coracoid process of scapula
I - midshaft of humerus medially
2.5. What is its action?
Shoulder flexion & adduction, resist shoulder dislocation
2.6. Identify 3 heads of the triceps and its insertion.
Proximal attachment:
Long head: infraglenoid tubercle of scapula
Lateral head: posterior surface of the humerus, superior to radial groove
Medial head: posterior surface of the humerus, inferior to radial groove
Insertion: Proximal end of olecranon of ulna and fascia of forearm
2.6.1. What is its action?
Chief extensor of the shoulder (long head) & elbow extension; long head resist dislocation of the humerus; especially important during adduction
2.7. Study the plastinated cross-section of the arm. Draw a labelled cross-section of the middle third of the arm showing the following :
2.7.1. Superficial and deep fascia and its extensions
2.7.2. The anterior and posterior compartments
2.7.3. Neurovascular structures
The surgical neck of humerus, long head of triceps, subscapularis (anteriorly)/ teres minor posteriorly, teres major
3. Vessels
3.1. Identify the subclavian, axillary and the brachial arteries.
3.2. Identify the landmarks indicating the junction of the subclavian and axillary arteries as well as where the axillary continues as the brachial artery.
3.2.1. At what level does the brachial artery end?
The neck of radius which branches into radial and ulnar arteries
3.3. Identify the axillary artery.
(ANM Upperlimb System 48)http://act.downstate.edu/courseware/haonline/labs/l05/060103.htm
3.3.1. Where does it become brachial?
At the inferior border of teres major
3.3.2. How are its 3 parts defined?
1st Part: Medial border of pectoralis minor, lateral border of the first rib
2nd Part: Posterior to the pectoralis minor
3rd Part: Lateral border of pectoralis minor, lower border of Teres Major
3.3.3. List the branches from each part
1st Part: Superior Thoracic
2nd Part: Lateral Thoracic, Thoraco-aromial
3rd Part: Subscapular (biggest), Anterior and posterior circumflex humeral
3.3.4. How is the scapular anastomosis formed and what is its clinical significance?
The transverse cervical artery from the subclavian, usually the first part, occasionally the third part, has a descending branch (the dorsal scapular artery) which accompanies the dorsal scapular nerve. It runs down the vertebral border of the scapula to its inferior angle. The suprascapular artery from the subclavian, usually the first part (thyrocervical trunk in common with the transverse cervical) but occasionally the third part, crosses over the transverse ligament of the scapular notch, passes through the supraspinous fossa, turns around the lateral border of the spine of the scapula and supplies the infraspinous fossa as far as the inferior angle. The subscapular artery, branching from the third part of the axillary, supplies the subscapularis muscle in the subscapular fossa as far as the inferior angle. Its circumflex scapular branch enters the infraspinous fossa on the dorsal surface of the bone. All the vessels anastomose, thus connecting the first part of the subclavian with the third part of the axillary artery. The companion veins form corresponding anastomoses.
Ans: all arteries except the circumflex humeral artery anastomose to connect the first part of the subclavian with the third part of the axillary artery.
Many arterial anastomoses (communications between arteries) occur around the scapula. Several arteries join to form networks on the anterior and posterior of the scapula: the dorsal scapular, suprascapular and subscapular (via the circumflex scapular branch). The importance of the collateral circulation made possible by theses anastomoses becomes apparent when ligation of a lacerated subclavian or axillary artery is necessary. For example, the axillary artery may have to be ligated between the 1st rib and subscapular artery: in other cases, vascular stenosis of the axillary artery may result from an atherosclerotic lesion that causes reduced blood flow. In either case, the direction of blood flow in the subscapular artery reversed, enabling blood to reach the third part of the axillary artery. Note that the subscapular artery receives blood through several anastomoses with the suprascapular artery, transverse cervical artery and intercostal arteries. Slow occlusion of an artery (resulting from a disease) often enables sufficient collateral circulation to develop, preventing ischemia. Sudden occlusion usually does not allow sufficient time for adequate collateral circulation to develop as a result, ischemia of the upper limb occurs. Abrupt surgical ligation of the axillary artery between the origins of the subscapular and the profunda bracii artery will cut off the blood supply to the arm because the collateral circulation is inadequate.
3.3.5. What is the major branch of the brachial artery in the arm?
Profunda brachii artery
It allows blood to flow past the joint in case of occlusion, damage, or pinching of the following scapular arteries: Transverse cervical artery.
3.4. Identify the suprascapular nerve & vessels and their origin.
Tyrocervical origin (a direct branch of 1st part pf subclavian artery)
Superior trunk from C5,6,4
.
3.4.1. What is the position & relations of suprascapular ligament?
Passes almost directly posteriorly to the suprascapular notch; passes through this under suprascapular ligament to supraspinatus & infraspinatus. Ligament converts notch into a foramen. The nerve goes under, the artery goes over. Veins have variablecourse.
3.5. Identify the cephalic vein in the shoulder. (ANM Upperlimb System 50)
3.5.1. At what location does this vein enter the axillary vein and how?
The deltopectoral triangle and it empties into the axillary vein
Ans: runs in the groove between pectoralis major & deltoid, penetrates the
clavipectoral fascia to enter the axillary vein
3.5.2. Identify the cephalic vein located in the arm
The surgical neck of humerus, long head of triceps, subscapularis (anteriorly(/teres minor
posteriorly, teres major
Axillary nerve, posterior circumflex humeral artery
3.5.3. Is it pre-axial or post-axial? Pre-axial
3.5.4. Where does it arise? The lateral end of the dorsal venous arch of the hand
3.6. Identify the deep veins of the arm
Brachial veins, radial veins, ulnar veins
Perforating veins- run between the deep and superficial veins of the upper limb, connecting the two systems
3.6.1. What are vena commitantes?
It refers to a vein that is usually paired, with both veins lying on the sides of an artery.
2 or 3 veins that wrap around a peripheral artery
3.6.2. What is their function?
They are found in close proximity to arteries so that the pulsations of the artery aid venous return
Heat exchange, increased flow due to arterial pulsation
3.7. Identify the brachial vein
3.7.1. Where does it pierce the deep fascia?
The brachial fascia above the medial epicondyle or sometimes as high as the mid-arm
3.7.2. What structural changes occur at this level in the arm?
Cross-section change of humeral shaft- upper cylindrical lower triangle
Insertion of coracobrachialis & deltoid
Upper attachments of medial & lateral IM septa
Brachial artery- medial to the front of the arm
Entry of radial nerve and profunda brachii to the spiral groove
Basilic vein pierces the deep fascia
MAB nerve- becomes subcutaneous
4. Nerves
4.1. With the aid of a labelled diagram, describe the formation of the brachial plexus. Using models/specimens/atlas:
4.1.1. Identify the roots, trunks, divisions and cords of the brachial plexus.
http://act.downstate.edu/courseware/haonline/labs/l0 5/020203.htm
4.1.2. Name & identify the branches of the brachial plexus and give their root values.
(ANM Upperlimb System 42) (ANM Upperlimb Region 11) Do a virtual dissection in
4 D Anatomy (http://4danatomy.com/modules ) to explore the brachial plexus after
removal of the clavicle: Left Shoulder (upper Lateral View)
4.2. Identify the Serratus anterior and its nerve supply – the long thoracic nerve
Serratus anterior has a proximal attachment of external surfaces of the lateral parts of the 1st rib to 8th ribs, and its distal attachment is the anterior surface of the medial border of the scapula.
Long thoracic nerve originates in the posterior aspect of anterior rami of C5, C6 and C7. It passes through cervico-axillary canal descending posterior to C8 and T1 roots of plexus; runs inferiorly on the superficial surface of serratus anterior.
http://act.downstate.edu/courseware/haonline/labs/l05/090102.ht m
4.3. Identify the axillary nerve & describe its origin, root value & distribution. http://act.downstate.edu/courseware/haonline/labs/l05/08 0103.htm
4.3.1. From what cord does it originate? (ANM Upperlimb System 46)
The posterior cord of the brachial plexus.
4.3.2. What muscles does this nerve supply?
Teres minor and deltoid muscles.
4.3.3. Explain the relevance of Hilton’s law
Hilton’s Law: the nerve supplying the muscles extending directly across and acting at a given joint not only supplies the muscle, but also innervate the joint and the skin overlying the muscle. Axillary nerve not only innervates the teres minor and deltoid muscle but also the shoulder joint (glenohumeral joint) and the skin of superolateral arm (over inferior part of deltoid).
Defined as the regimental badge area or the small area around insertion. The axillary
the nerve must supply the shoulder joint
4.4. Identify the musculocutaneous nerve. (ANM Upperlimb System 43)
4.4.1. Describe its pathway.
Piercing the coracobrachialis when exiting the axilla; descends between biceps brachii and brachialis. Supplying both; continues as the lateral cutaneous nerve of forearm
Continuation of lateral cord passing through coracobrachialis to biceps & brachialis, finishing lateral to biceps as the lateral cutaneous nerve of forearm
4.4.2. From what nerve roots does it arise? C5, C6, C7
4.4.3. How will you test this nerve?
Tests on the sensory of the lateral aspect of the forearm, elbow flexion
4.5. Identify the Radial nerve. (ANM Upperlimb System 47)
4.5.1. From what nerve roots does it arise? C5,6,7,8 and T1
5. VISCERAL/BREAST
5.1. Breast
5.1.1. Identify the structures of the Breast
5.1.2. What is the arterial supply of the breast?
Lateral thoracic artery, internal thoracic artery (via medial mammary brs of, perforating brs and ant. Intercoastal brs), posterior intercoastal artery (branch of thoracic aorta in the 2nd, 3rd and 4th intercoastal spaces), thoracoacromial artery
Medial aspect: internal thoracic artery (a branch of the subclavian artery)
Lateral part:-
Lateral thoracic, thoracoacromial branches, superior thoracic and subscapular
(axillary artery)
Lateral mammary branches (posterior intercostal arteries from the aorta)
Mammary branch- anterior intercostal artery
Veins correspond with arteries - drain into axillary and internal thoracic veins
5.1.2.1. Which branches are encountered in the axillary dissection of a radical
mastectomy?
Long thoracic nerve, Axillary artery and vein, brachial plexus, thoracodorsal artery, vein and nerve, subscapular artery
5.2.Breast Development :
5.2.1. How does the breast develop?
5.2.2. What is the embryological explanation of accessory nipples (polythelia)?
Accessory nipples develop while a human embryo is developing in the womb.
During the fourth week of pregnancy, the embryo’s two milk lines, which are made of ridged ectoderm tissue, thicken.
Normally, the milk line tissue stays thick and forms your nipples while the rest of the thickened skin softens up again. But in some cases, parts of the milk line ridges don’t become regular ectoderm tissue again. When this happens, supernumerary nipples can appear where the milk tissue stayed thick and ridged after birth and development into adulthood.
5.3. SPREAD OF BREAST CANCER
5.3.1. How may Cooper’s ligaments involvement be evident in breast carcinoma?
Breast Dimpling: Cooper ligaments shorten
Fixity of lump: due to suspensory Cooper’s ligament
5.3.2. How may the carcinoma spread:
5.3.2.1. via lymphatics?
When cancer cells break away from a tumour, they can travel to other areas of the body through the lymph system. Then they must move through the vessel wallto flow with the lymph to a new organ or lymph node.
Lymphatic vessels carry cancer cells from the breast to the lymph nodes,
chiefly those in the axilla. The cells lodge in the nodes, producing nests of tumourcells (metastases). Abundant communications among llymphatic pathwaysand among axillary, cervical and parasternal nodes may also ccause metastasesfrom the breast or the abdomen. Because most of the lymphatic drainage of the breast is to the axillary lymph nodes, they are the most common site of metastasis from a breast cancer.
5.3.2.2. via veins?
The cancer cell must move through the wall of the capillary and into the tissue of the organ close by.
Spread from the breast through the posterior intercostal veins that drain into the azygos/ Hemi-azygos system of veins alongside the bodies of the vertebra and communicate with the internal vertebral venous plexus surrounding the spinal cord. Then, it spread to the cranium and brain.
5.3.2.3. Directly?
some cells from primary cancer must break away, travel to another part of the body and start growing there. Cancer cells don't stick together as well as normal cells do. They may also produce substances that stimulate them to move. Can spread contiguity (invasion of adjacent tissue). When breast cancer cells invade the retromammary space, attach to or invade the pectoral fascia overlying the pectoralis major, or metastasize to the interpectoral nodes, the breast elevates when the muscle contracts.
6. CLINICAL ANATOMY
Palpate and demonstrate on your willing and consenting peers the following:
6.1. Axillary lymph nodes
6.2. Anterior & posterior axillary folds
6.2.1.1. What constitutes the Ant Axillary and the Post Axillary folds?
Post: Latissimus dorsi, teres major muscle and subscapularis
Ant: lateral border of pectoralis major and minor muscle
6.3. With the arm by the side, forearm supported and pectoral muscles relaxed, palpate the axilla for:
6.3.1. Medial wall (ribs/serratus anterior)
6.3.2. Lateral wall (coracobrachialis/biceps brachii)
6.3.3. Head of the humerus
6.3.4. Axillary artery
6.4. How may an axillary nerve get damaged?
Fracture of the humeral neck or dislocation
6.4.1.1. How would you assess this clinically?
The weakness of shoulder abduction (15-90 degrees), wasting of the deltoid, regimental badge anaesthesia over the deltoid muscle
6.5. Regarding the features of humeral shaft
6.5.1. Identify the common site of its fracture explain the types of fracture and their injury mechanism.
Midshaft of humerus
Transverse (direct trauma- hit by a car), spiral (indirect twisting- wrestling), oblique (direct & indirect), comminuted (shotgun, osteoporosis)
6.5.1.1. What neurovascular structures may be injured and what is the clinical importance? Radial (most common)/ulnar/median nerve damage, up to 90% of patients with a closed humeral fracture with radial nerve injury will have a resolution of neuropraxia within three to four months following the injury.
Radial nerve, profunda brachii artery & vein
Large haematoma, muscle necrosis, compartment syndrome, peripheral ischaemia due to swelling, radial nerve palsy (wrist drop & sensory loss)
6.6. Regarding the biceps.
6.6.1.1. Why is it commonly injured?
Involved in many actions Crosses 2 joints (compare to hamstrings in the thigh)
6.6.1.2. Name 2 clinical conditions of biceps.
Proximal biceps tendinitis (tendonitis): Repeated use of the biceps or problems in the shoulder can irritate the proximal biceps tendon. Pain in the shoulder and biceps is the main symptom.
Biceps contracture: The biceps becomes permanently contracted, with the elbow bent. Biceps contracture may occur after a severe stroke.
Degenerative disease around shoulder joint- long head becomes frayed and weak - dislocated or torn
Torn muscle belly
6.7. Regarding the triceps .
6.7.1. Why its weakness and paralysis not of much clinical significance?
Because gravity will extend the elbow passively in most positions that the arm
assumes
6.7.2. Which group of patients will be most affected by its paralysis / weakness?
Those using crutches
6.8. What is compartment syndrome?
Compartment syndrome is a painful condition that occurs when the pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells. Compartment syndrome can be either acute or chronic.
6.8.1. What is the order in which key structures within the compartment are affected?
Compartment syndrome develops when swelling or bleeding occurs within a compartment.
Because the fascia does not stretch, this can cause increased pressure on the capillaries, nerves, and muscles in the compartment.
Blood flow to muscle and nerve cells is disrupted.
Without a steady supply of oxygen and nutrients, nerve and muscle cells can be damaged and necrosis occur.
6.8.2. What is their clinical significance?
Acute compartment syndrome is a medical emergency.
Can cause Volkmann’s contracture in affected limbs. Rhabdomyolysis (skeletal
muscle break down rapidly) and renal failure can occur.
6.9. Why is the suprascapular nerve liable to be injured.
The suprascapular nerve is particularly prone to injury at the suprascapular and spinoglenoid notches as the nerve is anatomically constrained at several points along its course, such as Distal to the suprascapular foramen, a posterior triangle of the neck and the supraclavicular region. Other reasons include the fractures of the superior lateral angle of the scapula,
with entrapment etc.
The nerve is held at both ends, has a long straight course & goes to a mobile structure
6.10. What is the clinical significance of the point where cephalic vein enter the axillary vein in the shoulder
Many patients who are critically unwell have lost blood or fluid, which requires replacement. Access to the peripheral vein is necessary to replace the fluid. The typical sites for venous access are the cephalic vein in the hand or veins that lie within the superficial tissue of the cubital fossa.
Can be readily exposed for emergency venous access
6.11. What are the two common types of brachial plexus injury and their causes?
Blunt trauma producing nerve avulsions and disruptions
Spinal cord injuries in the cervical region and direct pulling injuries affect the roots while severe trauma to the first rib usually affects the trunks. The division and cords of the brachial plexus can be injured by dislocation of the glenohumeral joint
Upper C5/6- erb’s palsy (shoulder dystocia in delivery, motorcycle injury, violent fall on head and shoulder
Lower C8/T1- Klumpke’s palsy (fall from a tree: grasping limb, motorbike injury)
6.11.1. What are the general effects of each injury type?
Upper- Mainly affects shoulder muscles
Lower- Affects hand muscles
6.11.2. What is the clinical appearance in an Erb-Duchenne paralysis?
6.11.2.1. Explain how this limb position is attained
Waiter’s tip: paralysis of deltoid and short muscle, arm limp by side, paralysis of
biceps and brachialis- the absence of flexion and supination of elbow
6.11.3. Briefly explain how to obtain brachial plexus nerve block?
Because the axillary sheath encloses the axillary vessels and the brachial plexus, a
brachial plexus nerve block can easily be obtained. The distal part of the sheath is closed
with finger pressure, and a syringe needle is inserted into the proximal part of the sheath.
The anesthetic solution is then injected into the sheath, and the solution is massaged
along the sheath to produce the nerve block. The position of the sheath can be verified by
feeling the pulsations of the 3rd part of the axillary artery.
6.12. Explain the following effects of AXILLARY NERVE involvement:
6.12.1. Loss of weakness of shoulder abduction between 15o -90o
Deltoid paralysed but supraspinatus which initiates abduction is intact
6.12.2. Loss of rounded contour of the shoulder
6.12.3. ‘Regimental badge’ sensory loss
6.13. Explain the physical appearance of a patient with LONG THORACIC NERVE INJURY
6.14. Explain the following effects of SUPRASCAPULAR NERVE entrapment
6.14.1. Typical dull posterior and lateral shoulder pain
6.14.2. Tenderness 2.5cm lateral to the midpoint of the scapular spine
Site of suprascapular notch
6.14.3. Weakness of shoulder abduction and external rotation
Involvement of supraspinatus and infraspinatus
6.15. The RADIAL NERVE can commonly be affected by injury (1)of the nerve roots of the brachial plexus (2) in the radial groove.
6.15.1. How will you distinguish this condition from lesions affecting the nerve roots of the
brachial plexus?
Loss of triceps function reflects an injury at the brachial plexus
If the brachioradialis or extensor carpi radialis longus are not functional, then the injury is
most likely at the level of humeral shaft
6.16. Explain the following motor effects of a high lesion of the radial nerve at the axilla (crutch
paralysis)
Loss of extension of supinated elbow
Loss of extension of wrist (wrist drop)
Motor deficit:- paralysis of triceps and extensors of forearm
Wrist drop, loss of wrist and finger extension. Radial nerve injuries result in a decrease in power grip and pinch related to loss of wrist extension. Paralysis of extensors wrist and unopposed action of flexors of wrist
6.17. Map the sensory loss produced in a Radial N. injury at the axilla
Loss of pin prick and light touch over post surface of lower arm and narrow strip over back of forearm, dorsum of 1st, 2nd and 3rd metacarpals and corresponding proximal and middle phalanges
6.17.1. What is a “Saturday night palsy” ?
This neuropathy is produced by compression of the radial nerve as it spirals around the humerus.
Palsy resulting from pressure after sleeping with arm over chair or hard object
6.18. Explain how one is able to extend his elbow in a lesion of the Radial N. in the radial groove (Saturday night paralysis).
Long and medial head of triceps (the chief extensors of the elbow) are supplied by radial nerve in the axilla
6.19. How would the effects of injury to the deep branch of the Radial N (post. Interosseous N.) be different from that of injury in the radial groove? .
The effects are the same as in the injury at the radial groove except that no or little wrist drop occurs due to sparing of the brachioradialis and wrist extensors.
7. RADIOLOGY
7.1. Describe a normal mammogram
Normal breast tissue contains fats as well as with glandular and fibrous tissue. The more fibroglandular tissue present in the breast, the denser the breasts are. Even though the breasts are dense, it doesn’t mean it is a positive chance of malignancy.
E.g of what still a normal breast looks like
The description for each image orderly, almost entirely fatty scattered areas of fibroglandular density heterogeneously dense extremely dense
1
No abnormalities were detected.
2
Results may be negative for cancer, but will be used for comparison for future mammograms.
3
Findings are probably benign. You may need a follow-up mammogram in 6 months.
4
An abnormality was found, but doesn’t appear cancerous. You may need a biopsy.
Study the following :
7.2. Humerus : AP and Lateral views (ANM Upper Limb Radiology 48)
AP(anteroposterior)
AP view of the humerus is part of the humerus series and is usually taken in standing position. However, it can also be obtained in a supine position.
Lateral view
7.3. Fracture shaft of humerus
Can be open or close (open more prone to infection)
occur as a result of a direct blow to the upper arm (transverse fractures). Indirect trauma from a fall or a twisting action (e.g. arm wrestling) are also encountered and usually result in spiral or oblique fractures
7.4. Fracture upper end of humerus
Surgical neck fracture
Intercondylar fracture of humerus
Avulsion of greater tubercle
7.5. Arteriogram of the Axillary artery and its branches
6.5.1.1. What neurovascular structures may be injured and what is the clinical importance? Radial (most common)/ulnar/median nerve damage, up to 90% of patients with a closed humeral fracture with radial nerve injury will have a resolution of neuropraxia within three to four months following the injury.
Radial nerve, profunda brachii artery & vein
Large haematoma, muscle necrosis, compartment syndrome, peripheral ischaemia due to swelling, radial nerve palsy (wrist drop & sensory loss)
6.6. Regarding the biceps.
6.6.1.1. Why is it commonly injured?
Involved in many actions Crosses 2 joints (compare to hamstrings in the thigh)
6.6.1.2. Name 2 clinical conditions of biceps.
Proximal biceps tendinitis (tendonitis): Repeated use of the biceps or problems in the shoulder can irritate the proximal biceps tendon. Pain in the shoulder and biceps is the main symptom.
Biceps contracture: The biceps becomes permanently contracted, with the elbow bent. Biceps contracture may occur after a severe stroke.
Degenerative disease around shoulder joint- long head becomes frayed and weak - dislocated or torn
Torn muscle belly
6.7. Regarding the triceps .
6.7.1. Why its weakness and paralysis not of much clinical significance?
Because gravity will extend the elbow passively in most positions that the arm
assumes
6.7.2. Which group of patients will be most affected by its paralysis / weakness?
Those using crutches
6.8. What is compartment syndrome?
Compartment syndrome is a painful condition that occurs when the pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells. Compartment syndrome can be either acute or chronic.
6.8.1. What is the order in which key structures within the compartment are affected?
Compartment syndrome develops when swelling or bleeding occurs within a compartment.
Because the fascia does not stretch, this can cause increased pressure on the capillaries, nerves, and muscles in the compartment.
Blood flow to muscle and nerve cells is disrupted.
Without a steady supply of oxygen and nutrients, nerve and muscle cells can be damaged and necrosis occur.
6.8.2. What is their clinical significance?
Acute compartment syndrome is a medical emergency.
Can cause Volkmann’s contracture in affected limbs. Rhabdomyolysis (skeletal
muscle break down rapidly) and renal failure can occur.
6.9. Why is the suprascapular nerve liable to be injured.
The suprascapular nerve is particularly prone to injury at the suprascapular and spinoglenoid notches as the nerve is anatomically constrained at several points along its course, such as Distal to the suprascapular foramen, a posterior triangle of the neck and the supraclavicular region. Other reasons include the fractures of the superior lateral angle of the scapula,
with entrapment etc.
The nerve is held at both ends, has a long straight course & goes to a mobile structure
6.10. What is the clinical significance of the point where cephalic vein enter the axillary vein in the shoulder
Many patients who are critically unwell have lost blood or fluid, which requires replacement. Access to the peripheral vein is necessary to replace the fluid. The typical sites for venous access are the cephalic vein in the hand or veins that lie within the superficial tissue of the cubital fossa.
Can be readily exposed for emergency venous access
6.11. What are the two common types of brachial plexus injury and their causes?
Blunt trauma producing nerve avulsions and disruptions
Spinal cord injuries in the cervical region and direct pulling injuries affect the roots while severe trauma to the first rib usually affects the trunks. The division and cords of the brachial plexus can be injured by dislocation of the glenohumeral joint
Upper C5/6- erb’s palsy (shoulder dystocia in delivery, motorcycle injury, violent fall on head and shoulder
Lower C8/T1- Klumpke’s palsy (fall from a tree: grasping limb, motorbike injury)
6.11.1. What are the general effects of each injury type?
Upper- Mainly affects shoulder muscles
Lower- Affects hand muscles
6.11.2. What is the clinical appearance in an Erb-Duchenne paralysis?
6.11.2.1. Explain how this limb position is attained
Waiter’s tip: paralysis of deltoid and short muscle, arm limp by side, paralysis of
biceps and brachialis- the absence of flexion and supination of elbow
6.11.3. Briefly explain how to obtain brachial plexus nerve block?
Because the axillary sheath encloses the axillary vessels and the brachial plexus, a
brachial plexus nerve block can easily be obtained. The distal part of the sheath is closed
with finger pressure, and a syringe needle is inserted into the proximal part of the sheath.
The anesthetic solution is then injected into the sheath, and the solution is massaged
along the sheath to produce the nerve block. The position of the sheath can be verified by
feeling the pulsations of the 3rd part of the axillary artery.
6.12. Explain the following effects of AXILLARY NERVE involvement:
6.12.1. Loss of weakness of shoulder abduction between 15o -90o
Deltoid paralysed but supraspinatus which initiates abduction is intact
6.12.2. Loss of rounded contour of the shoulder
6.12.3. ‘Regimental badge’ sensory loss
6.13. Explain the physical appearance of a patient with LONG THORACIC NERVE INJURY
6.14. Explain the following effects of SUPRASCAPULAR NERVE entrapment
6.14.1. Typical dull posterior and lateral shoulder pain
6.14.2. Tenderness 2.5cm lateral to the midpoint of the scapular spine
Site of suprascapular notch
6.14.3. Weakness of shoulder abduction and external rotation
Involvement of supraspinatus and infraspinatus
6.15. The RADIAL NERVE can commonly be affected by injury (1)of the nerve roots of the brachial plexus (2) in the radial groove.
6.15.1. How will you distinguish this condition from lesions affecting the nerve roots of the
brachial plexus?
Loss of triceps function reflects an injury at the brachial plexus
If the brachioradialis or extensor carpi radialis longus are not functional, then the injury is
most likely at the level of humeral shaft
6.16. Explain the following motor effects of a high lesion of the radial nerve at the axilla (crutch
paralysis)
Loss of extension of supinated elbow
Loss of extension of wrist (wrist drop)
Motor deficit:- paralysis of triceps and extensors of forearm
Wrist drop, loss of wrist and finger extension. Radial nerve injuries result in a decrease in power grip and pinch related to loss of wrist extension. Paralysis of extensors wrist and unopposed action of flexors of wrist
6.17. Map the sensory loss produced in a Radial N. injury at the axilla
Loss of pin prick and light touch over post surface of lower arm and narrow strip over back of forearm, dorsum of 1st, 2nd and 3rd metacarpals and corresponding proximal and middle phalanges
6.17.1. What is a “Saturday night palsy” ?
This neuropathy is produced by compression of the radial nerve as it spirals around the humerus.
Palsy resulting from pressure after sleeping with arm over chair or hard object
6.18. Explain how one is able to extend his elbow in a lesion of the Radial N. in the radial groove (Saturday night paralysis).
Long and medial head of triceps (the chief extensors of the elbow) are supplied by radial nerve in the axilla
6.19. How would the effects of injury to the deep branch of the Radial N (post. Interosseous N.) be different from that of injury in the radial groove? .
The effects are the same as in the injury at the radial groove except that no or little wrist drop occurs due to sparing of the brachioradialis and wrist extensors.
7. RADIOLOGY
7.1. Describe a normal mammogram
Normal breast tissue contains fats as well as with glandular and fibrous tissue. The more fibroglandular tissue present in the breast, the denser the breasts are. Even though the breasts are dense, it doesn’t mean it is a positive chance of malignancy.
E.g of what still a normal breast looks like
The description for each image orderly, almost entirely fatty scattered areas of fibroglandular density heterogeneously dense extremely dense
1
No abnormalities were detected.
2
Results may be negative for cancer, but will be used for comparison for future mammograms.
3
Findings are probably benign. You may need a follow-up mammogram in 6 months.
4
An abnormality was found, but doesn’t appear cancerous. You may need a biopsy.
Study the following :
7.2. Humerus : AP and Lateral views (ANM Upper Limb Radiology 48)
AP(anteroposterior)
AP view of the humerus is part of the humerus series and is usually taken in standing position. However, it can also be obtained in a supine position.
Lateral view
7.3. Fracture shaft of humerus
Can be open or close (open more prone to infection)
occur as a result of a direct blow to the upper arm (transverse fractures). Indirect trauma from a fall or a twisting action (e.g. arm wrestling) are also encountered and usually result in spiral or oblique fractures
7.4. Fracture upper end of humerus
Surgical neck fracture
Intercondylar fracture of humerus
Avulsion of greater tubercle
7.5. Arteriogram of the Axillary artery and its branches
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