Brachial Plexus Quiz

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brachial plexus is formed by
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Terms in this set (142)
when does the subclavian artery become the axillary artery?when the subclavian passes the first ribthe 5 ventral nerve rami (roots) unite into 3 trunks of the neck:superior middle inferiorsuperior trunkC5, C6middle trunkC7inferior trunkC8, T1each trunk divides intoanterior and posterior divisionsanterior divisions supply theflexor (anterior) compartment of the upper limbposterior divisions supply theextensor (posterior) compartment of the upper limbthree cords are formed behind thepectoralis minorlateral cord formed byanterior division of superior and middle trunksmedial cord formed byanterior division of inferior trunkparalysisloss of motor functionpareisisweakness of motor functionparasthesianumbness and tinglingwhat does the axillary sheath surround?the nerves and vessels (neurovascular bundle) of the upper limbwhat is the location of the axilla?space inferior to the GH joint and superior to the axillary fascia/ skin of the axillary fossa at the junction of the arm and thoraxwhat forms the anterior axillary fold?inferior border of the pectoralis majorwhat forms the posterior axillary fold?latissimus dorsi and teres majorthe axilla contains... which are embedded in a matrix of axillary fat.blood vessels lymphatic vessels groups of axillary lymph nodesthe axillary sheath enclosesaxillary artery axillary vein three cords of brachial plexusroots of the brachial plexusanterior rami of spinal nerves C5-C8, plus T1brachial plexuslarge nerve network that extends from the neck to the upper limb via the cervico-axillary canal to provide innervation to the upper limb and shoulder regionbrachial plexus is formed by theanterior rami of the C5-C8 nerves and the greater part of the anterior ramus of T1 nervethe brachial plexus gives rise to ___ terminal branched17terminal branches are locateddistal to the pectoralis minor musclethe terminal branches are divided intosupraclavicular and infraclavicularhow many supraclavicular branches are there?4what are the supraclavicular branches?dorsal scapular (posterior to the roots) nerve to subclavius (anterior to the roots) long thoracic nerve (posterior to the roots) suprascapular nervedorsal scapular nerveC5nerve to subclaviusC5-C6long thoracic nerveC5, C6, C7suprascapular nerveC5-C6How many infraclavicular branches are there?13what are the 3 infraclavicular branches from the lateral cord?lateral pectoral nerve musculocutaneous nerve lateral head of the median nervelateral pectoral nerveC5, C6, C7musculocutaneous nerveC5, C6, C7lateral head of the median nerveC5, C6, C7what are the 5 infraclavicular branches from the medial cord?medial pectoral nerve medial head of the median nerve ulnar nerve medial cutaneous nerve of the arm medial cutaneous nerve of the forearmmedial pectoral nerveC8-T1medial head of the median nerveC8-T1ulnar nerveC7, C8, T1medial cutaneous nerve of the armC8-T1medial cutaneous nerve of the forearmC8-T1what are the 5 infraclavicular branches of the posterior cord?upper subscapular nerve thoracodorsal nerve lower subscapular nerve axillary nerve radial nerveupper and lower subscapular nerveC5-C6thoracodorsal nerveC6-C8axillary nerveC5-C6radial nerveC5-T1ventral root ismotor (efferent)dorsal root issensory (afferent)the vental root and the dorsal root join to form aspinal (mixed) nervethe spinal nerve divides intoventral (anterior primary) ramus and dorsal (posterior primary) ramusventral ramussupplies muscles and skin of the anterior 3/4 of the body walldorsal ramussupplies muscles on the spinal column and the overlying skinaxillary artery begins and ends at thelateral border of the 1st rib as the continuation of the subclavian artery and ends at the inferior border of the teres majorwhen the axillary artery passes posterior to the pectoralis minor into the arm it becomes the___ when it passes the inferior border of the teres majorbrachial arteryfirst part of the axillary arterylocated between the lateral border of the 1st rib and the medial border of the pectoralis minor; enclosed in the axillary sheathbranch of the first part of the axillary arterysuperior thoracic arterysecond part of axillary arteryLies posterior to pectoralis minor and has two branchesbranches of second part of axillary arterythoracoacromial (passes medial) and lateral thoracic arteries (passes lateral)third part of the axillary arteryextends from the lateral border of the pectoralis minor to the inferior border of the teres majorbranches of the third part of the axillary arterysubscapular artery, anterior and posterior circumflex humerallargest branch of the axillary arterysubscapular arteryaxillary veinlies initially (distally) on the anteromedially side of the axillary arteryaxillary vein is formed byunion of the brachial and basilic vein at the inferior border of the teres majorthe axillary vein ends at the? and becomeslateral border of the 1st rib and becomes the subclavian veinorigin of dorsal scapular nervePosterior aspect of anterior ramus of C5 with a frequent contribution from C4dorsal scapular nerve innervatesrhomboids, levator scapulaeorigin of long thoracic nervePosterior aspect of anterior rami of C5, C6, C7long thoracic nerve innervatesserratus anteriororigin of suprascapular nerveSuperior trunk, receiving fibers from C5, C6, and often C4suprascapular nerve innervatessupraspinatus and infraspinatus muscles; GH jointorigin of subclavian nerveSuperior trunk, receiving fibers from C5, C6, and often C4subclavian nerve innervatesSubclavius and sternoclavicular jointorigin of lateral pectoral nerveSide branch of lateral cord, receiving fibers from C5, C6, C7lateral pectoral nerve innervatespectoralis majororigin of musculocutaneous nerveTerminal branch of lateral cord, receiving fibers from C5-C7musculocutaneous nerve innervatesflexor compartment of the arm; coracobrachialis, biceps brachii, brachialisorigin of median nervelateral and median root are terminal branch of lateral (C6-7) and median (C8-T1) nerve, respectivelymedian nerve innervatesflexors of the forearm and parts of the hand (five intrinsic muscle in thenar half of the palm and palmar skin)origin of radial nerveLarger terminal branch of posterior cord (largest branch of plexus), receiving fibers from C5-T1radial nerve innervatesextensors of upper limb; all muscles of posterior compartments of arm and forearm; skin of posterior and inferolateral arm, posterior forearm, and dorsum of hand lateral to axial line of digit 4origin of axillary nerveTerminal branch of posterior cord, receiving fibers from C5, C6axillary nerve innervatesmuscles around the shoulder; AC and GH joints, teres minor and deltoid muscles; skin of superolateral armorigin of thoracodorsal nerveSide branch of posterior cord, receiving fibers from C6, C7, C8thoracodorsal nerve innervateslatissimus dorsiorigin of ulnar nerveLarger terminal branch of medial cord, receiving fibers from C8, T1, and often C7ulnar nerve innervatesintrinsic muscles of the hand; flexor carpi ulnaris and half of flexor digitorum profundusprefixed brachial plexuswhen the superior most root (anterior ramus) of the plexus is C4 and the inferiormost root is C8postfixed brachial plexusSuperior root is C6 and inferior root is T2what happens when the brachial plexus is injured?affects movements and cutaneous sensations in the upper limbinjuries to the brachial plexus result inparalysis and anesthesiacomplete paralysisno movement is detectableincomplete paralysisnot all muscles are paralyzed; person can move but the movements are weak compared to normalwhat tests the degree of anesthesia?determining the ability of the person to feel paininjuries to superior parts of the brachial plexus (C5 and C6) results fromexcessive increase in the angle between the neck and shoulderhow can someone injure their superior brachial plexus?if you are thrown from a motorcycle/horse and land on shoulder in way that separates the neck and shoulder with the shoulder stopping and the head and trunk continuing to move it stretched/ruptrues superior parts of the brachial plexus/tears the roots from the spinal cordcharacteristic position of an injury to the superior trunk of the plexuswaiter's tip position limb hangs by the side in medial rotationhow can upper brachial plexus injures occur?in a neonate when excessive stretching of the neck occurs during deliveryinjury to the superior parts of the brachial plexus causes ___ of what musclesparalysis deltoid, biceps, and brachialisappearance of paralysis due to superior parts of plexus being injured?upper limb with adducted shoulder, medially rotated arm, and extended elbow; lateral aspect of forearm experiences some loss of sensationchronic microtrauma to the superior trunk of the brachial plexus from carrying a heavy backpack can produce motor and sensory deficits in the distribution of themusculocutaneous and radial nerveswhat injury may produce muscle spasms and sever disability in hikers (backpacker's palsy) who carry heavy backpacks for long periodssuperior brachial plexus injuryacute brachial plexus neuritis (brachial plexus neuropathy)neurological disorder of unknown cause that is characterized by the sudden onset of sever pain, usually around the shoulderwhat can cause inflammation of the brachial plexus?upper respiratory infection, vaccination, or nonspecific traumacompression of cords of the brachial plexus may result fromprolonged hyperabduction of the arm during performance of manual tasks over the head (ex. painting a ceiling)what happens to the cords when they are compressed?impinged or compressed between the coracoid process of the scapula and the pectoralis minor tendonsymptoms when cords are compressedpain radiating down the arm, numbness, parasthesia (tingling), erythema, and weakness of handscompression of axillary artery and vein causesischemia of the upper limb and distension of the superficial veinssigns and symptoms of hyperabduction syndrome result fromcompression of the axillary vessels and nervesinjuries to inferior parts of the brachial plexus (klumpke paralysis) may occur whenthe upper limb is suddenly pulled superiorly; less commonwhen a person grasps something to break a fall or a baby's upper limb is pulled excessively during delivery is an example ofinjuries to the inferior parts of the brachial plexclaw hand can result frominjuries to the inferior parts of the brachial plexuswinged scapulaparalysis of serratus anterior and injury to long thoracic nerve; medial border of the scapula moves laterally and posteriorly away from the thoracic walldeltopectoral triangle is formed bypectoralis major, deltoid, and claviclewhat vein runs through the deltopectoral triangle?cephalic veinwhen is the long thoracic nerve the most vulnerable?when the limbs are elevatedbullets to the thorax and a mastectomy surgery make what nerve vulnerable?long thoracic nervetriangle of auscultationsuperior horizontal border of latissimus dorsi, medial border of the scapula, and the inferolateral border of the trapeziusplace where examining posterior segment of the lungs with a stethoscope?triangle of auscultationwhen does the triangle of auscultation enlarge?When the scapulae are drawn anteriorly by folding the arms across the thorax and the trunk is flexedhow does injury to the spinal accessory nerve present?"dropped" shoulder; ipsilateral weakness when the shoulders are elevated against resistancewhat injury occurs as a result of a traction injury such as whiplash, tumor, or cervical lymph node biopsy/surgical procedure at the posterior triangle.injury to the spinal accessory nervesurgery to the inferior part of the axilla, mastectomies when axillary tail of the breast is removed, and during surgery on scapular lymph nodes puts what nerve at risk?thoracodorsal nerve (C6-C8)why is the thoracodorsal nerve vulnerable during surgery on scapular lymph nodes?its terminal part lies anterior to them and the subscapular arterywhat happens with paralysis of the latissimus dorsi?unable to raise the trunk with the upper limbs, cannot use an axillary crutch because the shoulder is pushed superiorly by itif the rhomboids on one side are paralyzed due the scapula on that affected side is locatedfarther from the midline than that on the normal sideinjury to the dorsal nerve affects what muscles?rhomoids and levator scapulaethe deltoid and teres minor atrophy when?the axillary nerve (C5 and C6) are severely damagedwhat is usually injured during fracture of the surgical neck of the humerus or humeral head?axillary nerveanterior dislocation of the GH joint and compression from the incorrect use of crutches can injure..axillary nerveflattening/atrophy of the deltoid along with loss of sensation may occur over the lateral side of the proximal part of the arm which is the area supplied by thesuperior lateral cutaneous nerve of the arm (cutaneous branch of the axillary nerve)