Back & Shoulder Region Ernest F. Talarico, Jr., Ph.D. Associate Director of Medical Education Associate Professor of Anatomy & Cell Biology Course Director, Human Gross Anatomy & Embryology Indiana University School of Medicine – Northwest Gary, Indiana AY14-15 Human Gross Anatomy

IUSM-NW AY Objectives  Identify all structures in this region  Understand anatomical relationships in this region  To be able to comprehend and discuss the structure of the nervous system  To apply this knowledge to clinical situations and radiography

The Back Human Gross Anatomy

IUSM-NW AY Vertebral Column (Spine) 33 vertebrae –7 cervical (C) –12 thoracic (T) –5 lumbar (L) –5 sacral (S) –4 coccygeal (C 0 ) cervical thoracic lumbar sacral coccygeal Intervertebral disc

IUSM-NW AY Vertebrae (vertebra = singular)

IUSM-NW AY Vertebrae (vertebra = singular)

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IUSM-NW AY Nervous System Somatic Motor –general somatic efferent (GSE) –single target organ –no synapse –fast - myelin Visceral Motor –general visceral efferent –2 to 3 target organs –2 neuron relay from CNS –slow - myelin

IUSM-NW AY Spinal Nerves (31 pairs) all are mixed nerves (sensory and motor) 4 fiber components –Sensory GSA: general somatic afferent GVA: general visceral afferent –Motor GSE: skeletal GVE: visceral

IUSM-NW AY Typical Thoracic Spinal Nerve 31 pairs of spinal nerves: 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal

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IUSM-NW AY Muscles of the Back Superficial Group Intermediate Group Deep Group trapezius m. latissiumus dorsi m. rhomboideus major m. rhomboideus minor m. levator scapulae m. serratus posterior superior m. serratus posterior inferior m. Splenius (capitius; cervicis) Semispinalis m. Erector Spinae iliocostalis m. longissimus m. spinalis m. anchor the upper limb to the axial skeleton function in respirationintrinsic muscles of the dorsum (supplied by dorsal nerve rami)

IUSM-NW AY Muscles of the Back Superficial Group trapezius m. latissiumus dorsi m. rhomboideus major m. rhomboideus minor m. levator scapulae m.

IUSM-NW AY Muscles of the Back Intermediate Group serratus posterior superior m. serratus posterior inferior m.

IUSM-NW AY Muscles of the Back Deep Group Splenius (capitius; cervicis) Semispinalis m. (5, 13) Erector Spinae iliocostalis m. (11) longissimus m. (10) spinalis m. (18)

IUSM-NW AY Muscles of the Back Deep Group – Other intrinsic muscles Rotatores m. (14) Intertransverse mm. (16) [note: levators costarum mm.; 13)

IUSM-NW AY Spinal Cord Meninges –Pia mater denticulate ligaments filum terminale –Arachnoid mater (9) subarachnoid space with CSF Lumbar cistern (L1 – S2) –Dura mater (8) Epidural space Subdural space Table #1 sacral region Table #2lower cervical Table #3U - thoracic region Table #4L - thoracic region Table #5lumbar region Table #6 sacral region

IUSM-NW AY L1/L2 (adult) L2/L3 (child)

IUSM-NW AY CSF & DIAGNOSIS OF NEUROLOGICAL DISORERS lumbar puncture (L3/L4; L4/L5) myelography and intrathecal route for medications need prior CT Scan to rule out  ICP  Sample Collection (7 – 8 ml)

IUSM-NW AY  Diagnostic Analysis Cell CountWBCs or RBCs make CSF turbid bacterial meningitis (mostly neutrophils) meningeal syphilis & fungal infections (lymphocytes) RBCs  subarachnoid hemorrhage or AV malformation traumatic tap vs. subarachnoid hemorrhage ictus  xanthochromia (faint yellow color)  Differential Protein 200 mg/100 ml  gives CSF a yellow-orange color  protein is due to  vascular endothelial cell permeability (BBB breakdown) pathological conditions (hemorrhage, syphilis, meningitis, MS, Guillian-Barré Syndrome, diabetic neuropathy)

IUSM-NW AY  Differential Glucose Glucose concentration is  in bacterial infections  Microorganisms  CSF Pressure decreased  dehydration; CSF leaks spinal subarachnoid block increased  brain edema; intracranial mass acute stroke; infections, etc.

IUSM-NW AY Suboccipital Region Reflect trapezius; splenius and semispinalis Identify –Rectus capitis minor m. (16) –Rectus capitis major m. (18) –Superior oblique m. (17) –Inferior oblique m. (19) Identify –Greater occipital n. (C2; 6) –Suboccipital n. (C1; 5) –Occipital artery (2) –Vertebral artery

The Shoulder Human Gross Anatomy

IUSM-NW AY Muscles of the Shoulder Region Deltoid (axillary n.) Suprapinatus (suprascapular n.) Infraspinatus (suprascapular n.) Subscapularis (upper & lower subscapular nn.) Teres major (lower subscapular n.) Teres minor (axillary n. Latissimus dorsi (thoracodorsal n.)

IUSM-NW AY Quadrangular space –Boundaries Teres minor (4) & subcapularis Teres major (6) Long head of triceps surgical neck of humerus (laterally) –Contents (9) Axillary nerve Posterior humeral circumflex artery

IUSM-NW AY Triangular space –Boundaries Teres major (6) Long head of triceps (10) Teres minor (4) –Contents Circumflex scapular artery & vein (5)

IUSM-NW AY Triangular Interval –Boundaries Teres major (6) Long head of triceps (10) Medial head of triceps (or humerus) –Contents Radial nerve (21) Profunda brachii artery (20)

IUSM-NW AY Triangle of Auscultation –Boundaries Trapezius m. Latissimus dorsi m. Scapula

IUSM-NW AY NervesArteries Suprascapular n. (C5 – C6) Dorsal scapular n. Suprascapular a. Dorsal scapular a. Anastomoses around the scapula

IUSM-NW AY The Shoulder Joint 1)Cut and reflect the coracobrachialis m., the short head of biceps brachii m., and the long head of triceps brachii 2)Clean the insertion of subscapularis 3)Identify the fibrous capsule and remove the posterior portion 4)Attempt opening up the joint (removal of the head of the humerus may be necessary