Anatomy notes

? Week 1- Introduction & Nervous System pt.1 Anatomical position  Superior (cranial): toward the head end or upper part of a structure or the body; above o ex: the head is superior to the abdomen  Inferior (caudal) : away from the head end or toward the lower part of a structure or the body; below o ex: the navel is inferior to the chin  Anterior (ventral) : toward or at the front of the body; in front of o ex: the breastbone is anterior to the spine  Posterior (dorsal) : toward the back of the body; behind o ex: the heart is posterior to the breastbone  Medial: toward or at the midline of the body; on the inner side of o ex: the heart is medial to the arm  Lateral: away from the middle of the body; on the outer side of o ex: the arms are lateral to the chest  Proximal : closer to the origin of the body part or the point of attachment of a limb to the body trunk o ex: the elbow is proximal to the wrist  Distal: farther from the origin of a body part or the point of attachment of a limb to the body trunk o ex: the knee is distal to the thigh  Superficial: toward or at the body surface  Deep (internal): away from the body surface; more internal  Ipsilateral: on the same side  Contralateral: on opposite sides Planes of section through body  Sagittal (median): front middle  Frontal (coronal): side middle  Transverse: dividing upper and lower body Body movements  Flexion: decreasing the angle of a joint  extension: increasing the angle of a joint  Abduction: movement away from the midline  Adduction: movement toward the midline  Lateral/ medial rotation Division of the nervous system: Central nervous system peripheral nervous system sensory (afferent) division, motor (efferent) division Somatic nervous system Autonomic nervous system Sympathetic division, parasympathetic division What is a spinal nerve?  Part of the peripheral nervous system  Mixed nerve carrying motor and sensory information between the spinal cord and body

 31 pairs of spinal nerves Bony framework:  Vertebrae surround spinal cord  Spinal nerves exit between the vertebrae at the intervertebral foraman o Foraman between two vertebrae  During fetal growth the spinal column grows at a faster rate than the spinal cord Sections of the spine and number of vertebrae in each  cervical: 7  thoracic: 12  lumbar: 5  Sacral: 5  coccygeal: 1 Sections of the spinal cord and number of nerves in each  cervical: 8  thoracic: 12  lumbar: 5  Sacral: 5  Coccygeal: 1 How far does the spinal cord go  about to L1 then it is just nerves Where do nerves exit  cervical: EXIT ABOVE VERETBRAE  lumbar, thoracic, sacral: exit below Spinal cord to spinal nerve flow spinal cord - dorsal rootlets - dorsal root - spinal nerve - ventral rootlets - ventral root- spinal nerve divides into dorsal ramus and ventral ramus  ventral root and rootlets: MOTOR  dorsal root and rootlets: SENSORY  the motor nerves stop at muscle and then the sensory ones continue onto the skin Dermatomes  area of skin innervated by a single spinal nerve  Important for diagnosing spinal injuries and shingles (varicella-zoster virus) Motor function:  Each terminal branch applies a group of muscles within the upper limb Terminal branch Muscle group Muscle example musculocutaneous Arm flexors Biceps brachii median Forearm and hand flexors Flexor digitorum radialis ulnar Forearm and hand flexors Flexor digitorum ulnaris radial Arm and forearm extensors Triceps brachii axillary shoulder deltoid Brachial plexus

 network of nerves that supply the upper limb  begins at neck and ends at armpit, terminal branches continue down the length of arm  formed by the ventral ramus  brachial plexus terminal branches have mixed function (both sensory and motor)  multiple spinal levels compose muscles - therefore damage may just cause weakness but not total paralysis, however sensory region would be entirely knocked out Organization of the brachial plexus  roots, trunks, divisions, cords, branches o (really thirsty drink cold beer)  roots of brachial plexus: C5, C6, C7, C8, T1  trunks of brachial plexus: superior, middle, inferior  divisions of brachial plexus: 3 anterior and 3 posterior cords of brachial plexus: lateral, posterior, medial  branches of brachial plexus: musculocutaneous, axillary, radial, median, ulnar, musculocutaneous nerve  arm flexors - coracobrachialis, biceps brachii, brachialis  c5, c6, c7 o median nerve o forearm and hand flexors  c5,c6,c7,c8,t1 o ulnar nerve o forearm and hand flexors  c8, t1 o radial nerve o forearm and arm extensors  triceps o C5, C6, C7, C8, T1  axillary nerve  shoulder - deltoid and teres minor o c5 c6  pectoral girdle o scapula (posterior) and clavicle (anterior) ♀ Week 2- Shoulder & Arm The shoulder is not a true girdle - scapula do not meet in the back  function: attachment of upper limb to skeleton, movement and flexibility in various planes o this extra mobility results in a trade off of weakness and proneness to injury  Clavicle 2 ends o sternal end - attaches to manubrium of sternum

o acromial end - attaches to acromium process of scapula  function of clavicle o provides muscle attachment o acts as brace for the scapula and arms o transmits compression force  fracture of clavicle o occurs in center o side with the fracture will collapse medially and droop - very easy to see its "braceing" function Scapula  located on dorsal rib cage between ribs 2 and 7  3 borders and angles of scapula o superior, medial (next to spinal column) o lateral (ends in glenoid fossa where humerus connects)  lateral (glenoid fossa)  superior (superior and medial meet)  inferior (medial and lateral meet) Other features of scapula  subscapular fossa (front)  infraspinous fossa  supraspinous fossa  acromium  spine (on posterior)  coracoid process Prime mover  major action (agonist)  antagonist: muscle that opposes action  synergist: muscle that assists a prime mover Movements of the scapula  Elevation/Depression (shrugging)  Retraction/Protraction (punching)  Upward rotation/Downward rotation (arms overhead) Muscles of posterior thorax 1. trapezius 2. levator scapulae 3. rhomboids (major and minor) Trapezius  origin: medial third of superior nuchal line, nuchal ligament, occipital protuberance, spinal processes C7-T12  insertion: lateral third of clavicle, acromium, spine of scapula  action: elevate (superior fibers), retract (medial fibers), rotate scapula, inferior depress scapula  innervation - accessory nerve (CN XI) Levator scapulae  origin: transverse processes of vertebrae c1-c4  insertion: top of medial scapula  Action: elevate and rotate scapula inferiorly  innervation: dorsal scapular (c5) and cervical nerves (c3-c4) Rhomboids  origin:

o minor - nuchal ligament and spinous processes c7-T1 o major - spinous processes t2-t5  insertion: medial border of scapula  action: retract and rotate scapula, attaches scapula to thoracic wall  innervation - dorsal scapular nerve Muscles of anterior thorax: 1. pectoralis minor 2. serratus anterior 3. subclavius Pectoralis minor  origin: ribs 3-5  insertion: coracoid process of scapula  action: lifts scapula anteriorly and inferiorly  innervation: medial pectoral nerve Serratus anterior  Origin: fleshy slips from upper ribs  Insertion: bottom part of medial margin of the scapula  innervation: long thoracic nerve  Actions: protracts and stabilizes scapula, assists in upward rotation Subclavius  stabilizes and depresses pectoral girdle Rotator cuf 4 muscles that originate on scapula and CROSS SHOULDER JOINT to insert on humerus 1. subscapularis 2. supraspinatus 3. infraspinatus 4. teres minor Subscapularis  this guys on the front  Insertion: LESSER tubercle  Action: medial (internal rotation)  Innervation: subscapular nerve Supraspinatus  Action: abducts arm and prevents downward dislocation  Innervation: suprascapular nerve Infraspinatus  Action: lateral rotation  Innervation: suprascapular nerve Teres minor  Action: lateral rotation (outward)  Innervation: axillary nerve which muscles of rotator cuf rotate? 1. Subscapularis 2. Infraspinatus 3. teres minor which muscle of rotator cuf abducts? 1. supraspinatus Humerus