BFM 10 Axilla and Brachial Plexus 2024 PDF

Axilla and brachial plexus Body Movement and Function Dr Sara Sulaiman [email protected] Learning outcomes By the end of this lecture, you should be able to: Describe the structure and function of the muscles of the pectoral girdle Describe the structure and function of the muscles of the back...

Axilla and brachial plexus Body Movement and Function Dr Sara Sulaiman [email protected] Learning outcomes By the end of this lecture, you should be able to: Describe the structure and function of the muscles of the pectoral girdle Describe the structure and function of the muscles of the back Identify the axilla and its contents, including the artery and vein Discuss the structure and function of the brachial plexus and its branches Demonstrate clinically relevant anatomical landmarks on clinical or radiographic examination Identify the structure and function of the breast and the underlying muscles and fascia. Describe the changes that occur within the breast with gender, age or disease. Discuss the vascular and lymphatic components of the breast, how these relate to ageing and disease. Recommended reading Abrahams, Peter H. et al. McMinn & Abrahams’ Clinical Atlas of Human Anatomy. Seventh edition. Maryland Heights, Missouri: Elsevier Mosby, 2013. Print Drake, Richard L. Gray’s Anatomy For Students. 4th. ed. Philadelphia: Elsevier, Inc., 2020. Print. Moore, Keith L., Arthur F. Dalley, and A. M. R. Agur. Essential Clinical Anatomy. 4th ed. Philadelphia, Pa.; London: Lippincott Williams & Wilkins, 2011. Print. Netter, Frank H. (Frank Henry). Atlas of Human Anatomy. 5th ed. Philadelphia, Pa.; London: Saunders, 2010. Print. Smith, C., Dilley, A., Mitchell, B. and Drake, R.L., 2017. Gray’s Surface Anatomy and Ultrasound: Gray’s Surface Anatomy and Ultrasound E-Book. Elsevier Health Sciences. Spratt, J., Salkowski, L.R., Loukas, M., Turmezei, T., Weir, J. and Abrahams, P.H., 2020. Weir & Abrahams' Imaging Atlas of Human Anatomy. Elsevier Health Sciences.  Axillary process Breast Mammary glands are modified sweat glands Subcutaneous fat: gives the contour and volume of the breasts. Rib 1 Except during pregnancy: mammary glands enlarge, and new glandular tissue forms. Rib 2 The circular base of the female breast extends: Rib 3 Transversely: from the lateral border of Pectoralis major the sternum to the anterior axillary line muscle Subcutaneous fat Rib 4 Vertically: from the 2nd to 6th ribs. A small piece extends to the inferolateral Rib 5 edge of the pectoralis major muscle toward Gland lobules the axillary fossa, forming an axillary process or tail. The retro-mammary space Rib 6 (bursa): between the breast and the deep pectoral fascia  Suspensory ligaments (of cooper): connects the mammary glands to the dermis Suspensory ligaments (of cooper) The areola: circular pigmented area Nipple: prominence of the breast Nipple Areola The breast contains 15 to 20 lobules of glandular tissue. Each lobule is drained by a lactiferous duct-opens independently on the nipple. Lactiferous duct Each duct has a dilated portion, the lactiferous sinus Lactiferous sinus  Internal thoracic Internal thoracic Thoracoacromial trunk a. vein Arteries: Lateral thoracic Medial mammary branches Axillary vein From internal thoracic artery Lateral mammary branches From lateral thoracic and Medial mammary a. posterior intercostal Lateral mammary a. arteries Branches from Post. Intercostal a. thoracoacromial Apical lymph nodes Lymphatics: Central lymph nodes Most lymph (75%) will drain Pectoral/ anterior lymph Para-sternal nodes to axillary lymph nodes nodes Some drain to parasternal Humeral/ lateral lymph nodes lymph nodes Some drain to the abdominal lymph nodes subscapular/ posterior lymph To abdominal lymph nodes nodes  Male breasts and pre-pubertal female breasts are much the same Changes in Glands are rudimentary the breast At puberty, fat deposition and branching of the lactiferous ducts occurs. This continues throughout the menstrual cycle and during pregnancy. During pregnancy, oestrogen and progesterone stimulate the breast tissue to proliferate. In multiparous women (those who have given birth two or more times), the breasts often increase in size and are pendulous. Post-menopausal breasts are usually small because of the decrease in fat and atrophy of glandular tissue. Carcinoma of the breast Breast cancer can spread via lymphatics and veins as well as by direct invasion. Men can get breast cancer too-less common but with a poorer prognosis EVERYONE should be regularly self-checking Axilla Gateway to the upper limb Irregular pyramid with: Four sides An inlet A floor  Inlet Axilla Rib 1, clavicle, coracoid process and scapula Anterior wall Pectoralis major and minor, subclavius and clavipectoral fascia Lateral wall Clavipectoral Intertubercular sulcus fascia of the humerus Floor Fascia and a dome of skin Pectoralis minor  Pulls tip of shoulder down  Medial pectoral nerves Pectoralis major  Flexion, adduction, medial rotation of arm. o Clavicular head: flexion of extended arm o Sternocostal head: extension of flexed arm  Medial and lateral pectoral nerves Lateral pectoral nerve Thoraco-acromial artery (and its branches) Cephalic vein Clavipectoral fascia  Axilla-Posterior and medial wall Long thoracic nerve Subscapularis  Medial rotation of the arm Teres major  Upper and lower  Extension and subscapular nerve Serratus anterior medial rotation of the arm Latissimus dorsi  Protraction and rotation  Lower subscapular of the scapula nerve  Long thoracic nerve  Adduction, extension and medial rotation of the arm  Thoracodorsal nerve Posterior wall Medial wall Subscapularis, teres major, Upper thoracic wall and latissimus dorsi and long head serratus anterior of triceps brachii  Winged scapula When the serratus anterior is paralysed because of injury to the long thoracic nerve (C5-7), the medial border of the scapula moves laterally and posteriorly away from the thoracic wall. Appearance of a wing Think: 5,6,7-raises your arm up to heaven  Inferior margin of the  subscapularis​ The surgical neck of the Gateways in  humerus​ Superior margin of the teres the posterior wall major​  The lateral margin of the long head of the triceps brachii​ Suprascapular foramen Quadrangular  Medial margin of the long head of the triceps brachii​ space  Superior margin of the teres major​ Triangular space  Inferior margin of the  Lateral margin of the long head of the teres minor.​ Triangular triceps brachii​  Shaft of the interval humerus​  Inferior margin of the teres major ​ You must know Anterior view what passes into each space Axilla-Content Apical Passing through: Central Proximal parts of biceps brachii and Humeral coracobrachialis Axillary artery and vein Subscapular Brachial plexus Lymphatics Five groups of lymph nodes: Anterior/pectoral Posterior/subscapular Lateral/humeral Pectoral Central Apical Continuation of subclavian artery- Axillary artery starts at the inferior margin of rib 1 to inferior margin of teres major Separated into three parts by pectoralis minor 1 2 3 Continuation of subclavian artery- starts at the inferior margin of rib Axillary artery 1 to inferior margin of teres major Separated into three parts by pectoralis minor Superior thoracic artery First part: Anterior circumflex Superior thoracic artery 1 artery 2 Second part: Thoraco-acromial 3 Lateral thoracic Third part: Posterior circumflex artery Subscapular Anterior circumflex Posterior circumflex Thoraco-acromial Subscapular artery Lateral thoracic artery artery  Think: Red Trucks Drive Cats Nuts Brachial plexus Formed by the anterior rami of C5- 5 Roo ts C8 and T1 n ks C5 Tr u Five roots 3 & ns 3 C6 r o Pass into the posterior triangle between n t erio ivisi 3 a rior d r io r anterior and middle scalene muscles te e pos Sup C7 Three trunks o rds A nt dle 3c Mid C8 Pass lateral to over rib 1 A nt l ral s r Six divisions na Po erio Pos m i s at e In f T1 Ter nche L Pos Three cords bra s st er i o r eou Po A nt Named after their position l ocu t a n u y around the axillary artery u sc x i llar ial M A Med Five terminal branches R a dia l n e dia (nerves) M r na Ul Roots Phrenic nerve ts 5 Roo Originate from the roots: Dorsal scapular nerve C5 Dorsal scapular nerve (C5) C6 Innervates rhomboid major and minor C7 Long thoracic nerve (C5,6,7) C8 Innervates serratus anterior muscle T1 C5 contribute to the phrenic nerve Long thoracic nerve Innervates the diaphragm  Lateral cord Lateral pectoral nerve: innervates pectoralis major Lateral root of the median nerve Mucocutaneous nerve Cords Anterior compartment of the arm ts Lateral pectoral 5 Roo Cutaneous: Lateral side of the forearm nerve C5 unks Medial cord 3 & ns 3 Tr C6 r Medial pectoral nerve t e ri visio o n i 3 a rior d r Innervates pectoralis major and te e r io pos Sup C7 minor o rds Medial cutaneous nerve of the arm 3c A nt Mid dle C8 A nt Medial cutaneous nerve of the s ral Po rior Pos e forearm L at e In f T1 Pos Medial root of the median nerve er io r o us st ne Po A nt Ulnar nerve ta l root ul ocu sc One and a half muscles in the Mu Latera ial anterior forearm, most of the M ed t Medial roo muscles in the hand n Sensory to the skin of the hand e dia Medial pectoral M nerve (medial 1 and half) l nar Medial cutaneous nerve of U Medial cutaneous nerve the forearm of the arm  Posterior cord Superior/upper subscapular nerve: Innervates subscapularis Cords Inferior/lower subscapular nerve: ts innervates subscapularis and teres 5 Roo major C5 Thoracodorsal nerve: innervates r unks 3 3 T Latissimus dorsi r & ns ri visio o C6 t e i Axillary nerve: n 3 a rior d r te e r io Motor: deltoid and teres minor pos Sup C7 o rds Cutaneous: regimental patch (lateral 3c A nt Mid dle C8 upper arm) A nt ral s rior Radial nerve Po Pos e L at e In f T1 Motor: posterior compartment of the r Pos st er io arm and forearm Po A nt Cutaneous: skin on posterior arm, ry ial forearm, dorsal lateral hand illa M ed Ax l dia Ra Upper subscapular nerve Lower subscapular Thoracodorsal nerve nerve Cutaneous innervation of the upper limb-general Axillary nerve As we discuss the upper limb we will discuss the specific Radial nerve Intercostalbrachial nerve (T2) branches of nerves that innervate these Medial cutaneous nerve of the arm areas Terms: Musculocutaneous nerve (Lateral cutaneous nerve of the Medial cutaneous nerve of the forearm) Brachial=arm forearm Antebrachial=forearm Radial nerve Costal=related to ribs Ulnar nerve Ulnar nerve Median nerve Injuries to the brachial plexus Injuries to the brachial plexus affect movements (muscle paralysis) and cutaneous sensations (anaesthesia) in the upper limb. Klumpke palsy Injury to inferior parts of the brachial plexus (C8-T1 roots and thus inferior trunk branches) Typically results in hand paralysis (affects muscles in the forearm and hand that are supplied by C8 and T1 fibers-ulnar, median, and radial). Claw hand and wasting of hand intrinsic muscles Supinated forearm Diminished sensation from the medial arm and forearm Erb-Duchenne palsy Injury to superior parts of the brachial plexus (C5-C6, it can sometimes involve C7) Affects components that carry axons from the C5-C6 (axillary, suprascapular, subscapular (lower and upper), musculocutaneous and radial nerves) “waiter’s tip position,” which is characterized by: An adducted and internally rotated arm Extended elbow Pronated forearm A flexed wrist. Diminished sensation from the lateral aspect of the upper limb  Superficial muscles Rotator cuff muscles (they all function to stabilise the shoulder joint) Trapezius  From spinous processes of Supraspinatus C7-T12 and ligamentum  Supraspinous fossa to greater nuchae to scapular spine, tubercle acromion and clavicle  Abduction of arm at 15˚  Elevates, retracts,  Suprascapular nerve depresses and rotates scapula.  Accessory nerve Infraspinatus  Infraspinous fossa to greater tubercle  Lateral rotator  Suprascapular nerve Deltoid Teres minor  Scapular spine, acromion and  Posterior surface of the clavicle to deltoid tuberosity.  scapula to greater tubercle Abducts arm beyond 15˚,  Lateral rotator flexes and extends the arm.  Axillary nerve  Axillary nerve Subscapularis (not shown)  Subscapular fossa to lesser tubercle  Medial rotator  Upper and lower subscapular nerves  Musculocutaneous: C5-C7 Axillary: C5-C6 Radial: C5-T1 Median: C5-T1 Ulnar: C8-T1 Thank you