Claw Hand

Block 1: Upper Limb and Back Lecture 1: Anatomic principles and the Pectoral Region • Anatomical position • Sagittal, coronal, transverse planes • Layers of the body o Skin: epidermis, dermis; NOT the same thickness all over the body  Functions of skin= protection, keeps insides in, temperature control, conveys info about the external environment o Fascia  Superficial and deep  Muscle  Bone Collectively, the skin, superficial and deep fascias, muscle and bone are components of the BODY WALL Lecture 2: Axilla • Breast o Prominent superficial structure of anterial thoracic wall o Overlying pectoral muscles • Mammary gland o Glandular tissue (modified sweat gland) o May extend to armpit • Ectodermal ridge o Axilla to groin (embryonic/developmental) • Congenital abnormalities o Polymastia= aberrant breast/accessory breast o Polythelia= residual/excess nipples o Gynecomastia= enlargement of the breast (associated with young men with Klinefelter syndrome XXY) o Amastia= no breast formation • Masectomy o Radical masectomy= Breast, pectoralis major, pectoralis minor taken out, axillary dissection o Modified radical masectomy= remove breast, leave pectoralis major/minor, o Care taken to preserve the LONG THORACIC nerve or you get winged scapula • Cooper’s ligaments- shortened in breast cancer  dimpled appearance • Apex of the armpit o Clavicle, scapula, first rib • Costocoracoid membrane penetrated by LATERAL PECTORAL NERVE, CEPHALIC VEIN, THORACOMIAL ARTERY (TLC) Lecture 3: Innervation of the trunk and limbs • Spinal nerves o Nerve impulses travel along NEURONS, nerve impulses transmit between nerves by way of SYNAPSES o Sensory/Afferent information= from body to CNS o Motor/Efferent information= from CNS to body o Somatic= body, Visceral= viscera/internal organs

Somatic components: 1 neuron system • Somatic afferent perceive pain, temp, touch, etc • Somatic efferent innervate skeletal muscle  Visceral components: 2 neuron system (preganglionic and postganglionic) • Visceral efferent innervates smooth muscle, cardiac muscle and glands • Preganglionic impulses originate in lateral horn of the spinal cord o Spinal cord level vs. vertebral level (remember that the nerve comes out above the vertebra) o Typical parts of a spinal nerve  Nerve roots: dorsal= sensory only, ventral= motor only  Spinal ganglia  Spinal nerve proper  Primary rami: dorsal= supplies back, ventral= supplies lateral/ventral trunk and limbs o Sympathetic nervous system (visceral efferent)  Sympathetic trunk  Communicating rami: white and gray Somatic sensory innervation= dermatomes Somatic motor innervation= myotomes 

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Lecture 4: The Brachial Plexus • Ventral primary rami participate in nerve plexus formation • Plexus  distribution of nerve fibers from different levels to each segment of the limb (formed by nerves C5-C8 and T1) • Major components o Roots, trunks, divisions, cords, terminal branches • Common injuries (compression, traction, penetrating wound) o Trauma  paralysis or anesthesia that may be complete or incomplete o Traction on the plexus  dorsal and ventral roots of the spinal nerves may be pulled out of the spinal cord  Upper trunk (C5, C6) traction (Duchenne paralysis)  excessive separation of shoulder and neck  Lower trunk (C8, T1) traction (Klumpke paralysis)  hyperabduction of upper limb o Presence of cervical rib  compression of the plexus (lower trunk) o Infraclavicular injuries  Example: poorly fitting crutches injures posterior cord (often only radial nerve)  wrist drop Lecture 5: Superfical Back and Shoulder Region • Skeletal components o Pectoral girdle= clavicle + scapula DYNAMIC SUPPORT o Functions: support base for limb motions, shock absorber, protects neurovascular structures passing to arm o Humerus held in articulation with the scapula ONLY by muscles o Humerus is weakest at the surgical neck, radial nerve follows spiral groove o Humeral head and the glenoid fossa of the scapula display poor congruence (do not fit together well) • Muscles: located dorsally on trunk, ALL are ventral primary rami innervated (branches of brachial plexus) o Trapezius  To test: shoulder shrugged against resistance

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 Injury  winged scapula (CN XI) o Latissimus dorsi  To test: arm abducted 90 degrees and then adducted against resistance o Levator scapulae o Rhomboids o Pectorals o Serratus Anterior  Paralysis (damage to LONG THORACIC NERVE)  winged scapula o Deltoid o Supraspinatus o Infraspinatus o Teres minor o Teres major o Subscapularis Scapula movement

Lecture 6: The Back- Functional and Morphological Correlates • The vertebrae o General features: body, pedicles, laminae, spinous processes, transverse processes, articular processes o Regional characteristics  Cervical vertebrae (atlas and axis) 7  Thoracic vertebrae (facets for rib articulation) 12  Lumbar vertebrae LARGE 5  Sacral vertebrae (fused) 5  Coccyx (fused) 3-4 o Epidural anesthesia- local anesthetic injected into sacral canal • Joints of the spinal column o Fibrous joints  Posterior longitudinal ligament  Anterior longitudinal ligament (prevents whiplash) o Interarticular synovial joints  Spondylolysis: weakness/bone defect  fracture  one bone slips over another  Spondylolithesis: body of L5 slips forward on the body of sacrum o Cartilaginous joints = intervertebral discs between the bodies of adjacent vertebrae  Nucleus pulposus (liquid= compression force transmitter)  Annulus fibrosis  Age related changes: water content reduces with age, degeneration affects annulus  Rupture of IV disc: nucleus pulposus protrudes  presses on spinal cord/nerves • Affected nerve is one spinal cord level higher than the vertebral that is located superior to the ruptured disk • Considerations of the spinal column o Kyphosis= humpback, exaggeration of the thoracic primary curvature o Lordosis= backward bending, exaggeration of the lumbar secondary curvature (COMMON in pregnant women) o Scoliosis= crookedness, may be congenital, myopathic, idiopathic o Sacralization and lumbarization of vertebrae o Lumbar puncture (spinal cord does not extend full length of vertebral column)

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Insert needle between adjacent lamina, last pop is ligamentum flavum

Lecture 7: Upper Extremity • Arm o Anterior compartment (flexors)= biceps, brachialis, coracobrachialis (supplied by musculocutaneous nerve) o Posterior compartment (extensors)= triceps o Patient with laceration:  Test ulnar nerve: check abduction and adduction of little finger  Test radial nerve: extension of fingers/wrist (look for wrist drop)  Test median nerve: check flexion of fingers/wrist (specifically index finger flexion) • Radial nerve runs along humerus: vulnerable spot!! Fracture  wrist drop • Ulnar nerve runs on posteromedial aspect of elbow right on the bone: vulnerable spot! Injury  parasthesia of ulnar nerve (affects little finger sensory/motor) • Elbow: radial and median nerves (cast too tight puts pressure on these nerves) • Radial and ulnar bursa: infection of thumb moves to little finger (communication= abscess near wrist which allows for radial bursa and ulnar bursa to connect) • Median nerve and brachial artery are buddies (run together) o Brachial artery is main supply to the arm (continuation of axillary artery) Lecture 8: Hand Anatomy • Needed for functional hand o Stability: bones and ligaments o Viability: vascular supply o Sensibility: nerves  Radial nerve: controls all extensors of the arm and forearm, NO intrinsic muscles of the hand  Median nerve: controls thumb muscles  Ulnar nerve: controls all of the intrinsic muscles of the hand (except thumb) o Mobility: functional joints and muscles Lecture 9: Upper Limb Innervation • Median nerve damage o Inability to flex digits 1,2,3 (hand of benediction) o Carpal tunnel  inability to flex thumb • Ulnar Nerve damage o Claw hand (deformity of digits 4,5) Lecture 10: Joints of the Upper Extremity: The Shoulder and Elbow • Synovial joints • Clavicle fractures • Shoulder tradeoff: mobility vs. stability • Rotator cuffs muscles: SITS (supraspinatus, infraspinatus, teres minor, subscapularis) • Radial head subluxation= radial head dislocated (Nursemaid’s elbow)