Lecture Module 1: Back & Upper Extremity Flashcards
(146 cards)
1
Q
What are the back muscles?
A
- Extrinsic muscles
– superficial: limb to trunk, deep to skin and superficial fascia
— vertebral column to humerus: Latissimus dorsi
— vertebral column to scapula: Rhomboid minor/major, trapezius, and levator scapulae
– intermediate
— serratus posterior superior/inferior - Intrinsic muscles
– deep
— erector spinae: iliocostalis, longissimus, spinalis - Muscular triangles of the back: Auscultatory and lumbar
2
Q
What are the three groups of muscles of the back and what do they do?
A
- Extrinsic: superficially on structure, supplied by anterior rami of spinal nerves
1) Superficial group: movement of shoulder and upper limb & stabilize scapula
2) Intermediate group: attached to ribs & serve respiratory functions - Intrinsic: within/deeper in structure: true back muscles
3) Deep group: Movement vertebral column and head, supplied by posterior rami
3
Q
What comprises the skeleton?
A
- Axial skeleton (80 bones): skull bones, auditory ossicles, hyoid bone, ribs, sternum, vertebrae, & sacrum
- Appendicular skeleton (126): upper & lower extremities including pectoral & pelvic girdle
4
Q
What is the curvature of the adult spine?
A
- Cervical (7) and Lumbar (5): Convex/lordosis
- Thoracic (12) and Pelvic (5,4) : Concave. kyphosis
5
Q
What are the bony landmarks of the pectoral girdle and humorous?
A
- Acromion process
- Acromial end (clavicle)
- Head of the humerus
- Greater tubercle
- Lesser tubercle
- Intertubercle sulcus
- Deltoid tuberosity
*glenoid cavity**
6
Q
What are the regions of the scapula?
A
Anterior
- Supraglenoid tubercle
- Coracoid process
- Glenoid cavity
- Infraglenoid tubercle
- Subscapular fossa
- Lateral border
- Inferior angle
- Medial border
- Superior angle
- Superior border
- Scapular notch
Posterior
- Acromion
- Coracoid process
- Infraspinous fossa
- Spine
- Supraspinous fossa
7
Q
What are the movements of the scapula?
A
- Elevation/depression
- Adduction/abduction
- Upward/downward rotation
8
Q
What is the surface anatomy of the back?
A
- Deltoid: clavicular part (top when arm 90* abducted), middle part, spinal part
- Scapula: spine and medial border
- Trapezius: Descending, middle, and ascending parts
- Triangle of auscultation: lateral trapezius, medial scapula, superior border of latissimus dorsi (stethoscope for lungs)
- Rhomboids: deep to trapezius
- Latissimus dorsi: Superior & Lateral border
- Ilium: Iliac crest, posterior iliac spine
9
Q
Trapezius: regions, origin, insertion, action, innervation, injury
A
Regions:
- superior: descending fibers origin to insertion
- middle: horizontal fibers
- lower: inferior fibers, ascending to scapula
Origin: Occiput (bone & prominins) of skull, ligamentum nuchae, spinous processes C7-T12
Insertion: Clavicle, acromion, scapular spine
Action: move scapula
- superior: s. elevation & neck extension
- middle: s. adduction (retraction)
- lower: s. depression
Innervation: CN XI (Spinal Accessory Nerve)
Injury:
- strains: accident, exercise, overuse, nerve damage, poor posture (hunched)
- limited mobility, dec ROM, muscle weakness, neck/shoulder/between blades pain —> cramps/spasms
10
Q
The spinal accessory nerve pathway and injury
A
- Only motor
- Anterior gray horn of first 5 cervical segments
- Axons exit laterally through foramen magnum and jugular foramen with vagus and glossopharyngeal
- Injury: neck surgery trauma (lymph node biopsy), traction injury (whiplash) –> “winged” scapula, weakened trapezius and sternocleidomastoid
11
Q
Latissimus Dorsi: origin, insertion, action, innervation,
A
Origin: T6-12 spinous processes, iliac crest, thoracolumbar fascia, inferior 3 ribs
Insertion: near intertubercular sulcus of humorous (w/ teres maj) as common tendon
Action: Humerus/shoulder joint - shoulder extension, adduction, medial rotation, pulls truck upward & forward (arms overhead), flexion of lumbar and extension spine “swimmer’s muscle”
Innervation: thoracodorsal nerve
12
Q
Thoracodorsal nerve: origin and injury
A
- Off of brachial plexus (posterior cord), ventral rami from C6-8
- Injury: surgery at axillary region, paralysis latissimus dorsi - unable raise trunk w/ upper limbs (Breast cancer: surgery to axillary nodes)
13
Q
Levator Scapulae: origin, insertion, action, innervation
A
Origin: C1-C4 transverse processes (most covered Splenius capitis)
Insertion: scapula superior medial border
Action: scapula elevation
Innervation: dorsal scapular nerve (C5 only - also Rhomboids)
14
Q
Rhomboid Major: origin, insertion, action, innervation,
A
Origin: T2-5 spinous processes
Insertion: scapula medial border (b/w spine & inferior angle)
Innervation: Dorsal scapular nerve
Action: scapular retraction & downward rotation
15
Q
Rhomboid Minor: origin, insertion, action, innervation,
A
Origin: C7-T1 Spinous processes
Insertion: scapula medial border (@spine)
Innervation: Dorsal scapular nerve
Actions: Scapular adduction/retraction & downward rotation
16
Q
Intermediate group of back muscles: origin, insertion, action,
A
- Origin: vertebral column
- Insertion: ribs
- Action: rib movement for respiration
Serratus posterior superior (rib elevator)
Serratus posterior inferior (rib depressor) - Separated from deep by thoracolumbar fascia (fibrous tissue)
17
Q
Dorsal scapular nerve entrapment:
A
- Common body builders/heavy overhead lifting
- Compression of nerve
- Upper back & shoulder pain
- Possible winged scapula
- Weakness rhomboid and levator scapulae
18
Q
What are the general aspects of a vertebrae?
A
- Spinous process
- Lamina
- Superior/inferior articular process
- Transverse process
- Pedicle
- Body
- Vertebral arch: v. foramen
- Vertebral foramen: spinal cord
- Intervertebral foramen: for spinal nerves formed by superior and inferior vertebral notches
19
Q
What is the difference between a facet and a process/
A
- Facet: smooth surface where bones contact
- Process: extension (outgrowth) of bone
20
Q
What are the unique aspects of cervical vertebrae 1 and 2?
A
- Atlas (C1)
– no body or spinous process,
– large articular facets (w/ occipital condyles),
– atlanto-occipital joint “yes” - Axis (C2)
– Pivot rotating atlas & skull
– atlanto-axial joints (3) “no”
– Dens: large upright process
21
Q
What are the unique aspects of cervical vertebrae?
A
- Smallest, lightest vertebrae
- Short spinous process C2-6 may be bifid
- Transverse p. have foramina for vertebral arteries
- small bodies
- Uncovertebral joints: on each side of cervical disks for flexion and extension of the neck (limited lateral)
– by body & uncinate process in superior surface of vertebral body
22
Q
What are the unique aspects of the thoracic vertebrae?
A
- Articulate with ribs: costovertebral joint
– costal facets (rib heads): complete in 1, 10, 11, 12. 2-9 demifacets
– transverse costal facets (rib tubercles) - Heart-shaped body
- Long, thick, downward spinous process
- Sup/inf articular process –> facet/zygopophysial joint
23
Q
What are the unique aspects of the lumbar vertebrae?
A
- Large, thick bodies
- Heavy, rectangular spinous process
24
Q
What is unique about the sacrum and coccyx?
A
- Sacrum: fused mid-late adolescence, nerves through foramina
- Coccyx, fused, 1 coccygeal nerve
25
What are the aspects of the intervertebral disc?
- Outer: Annulus fibrosus
- Inner: nucleus pulposus
- Movement protection
- Spinal disc herniation: damage in annulus fibrosus allows nucleus pulposus to compress spinal nerves (numbness, tingling, muscle weakness/paralysis)
26
What is the ligamentum flava?
- connecting lamina
- stabilize spine
- preserve upright posture during flexion
- prevent hyperflexion
- pierced during spinal tap. Lumbar puncture (b/w L3/4 or L4/5) causing "pop" sound
27
What are the functions of the spinal cord?
- Send motor commands from brain to body
- Send sensory information from body to brain
- Coordinate reflexes
28
What are the meninges and associated spaces?
Meninges: connective tissue
- Epidural space (potential for brain bleed)
- Dura mater: superior, tough, inflexible
- Subdural space (potential for brain bleed)
- Arachnoid mater: middle with arachnoid villi for CSF transfer, villi protrude into dural venous sinus where can be reabsorbed to blood stream
- Subarachnoid space: CSF filled
- Pia Mater: innermost
- Denticulate ligament: pia extension anchoring spinal cord to dura mater
29
What are the segments and nerves of the spinal cord?
Segments: 31
- C8, T12, L5, S5, C1
- each with dorsal root entering and ventral root exiting
- 31 pairs spinal nerves with motor, sensory, autonomic fibers exiting through IV foramina
Enlargements
- Cervical: brachial plexus --> shoulders, arms, hands
- Lumbosacral: lower ab, pelvic, lower limbs
End
- Conus medularis:L1-2
- Filum terminale: pia mater extension
- Cauda Equina
30
What are the aspects of the cross-section of the spinal cord?
- Gray matter: neuronal soma & unmyelinated axons (interneurons)
-- Ventral and dorsal horns
- White matter: bundled myelinated axons aka tracts (sensory/motor)
-- Posterior median sulcus
-- Anterior median fissure
- Spinal nerve
-- dorsal root, dorsal root ganglion (afferent)
-- ventral root (efferent)
31
What is the denticulate ligament?
- Extension of pia mator anchoring spinal cord to dura mater
32
How do spinal nerves and vertebrae relate?
- C1 nerve above C1 vertebrae
- C2-7 nerves through IV foramina superior to corresponding vertebrae
- C8 nerve pass b/w C7 & T1
- T1-L5 nerves through IV foramina inferior to corresponding vertebrae
- Nerves S1-S4 through sacral foramina
33
What is a dermatome?
An area of skin receiving sensory innervation from a single spinal nerve
- C1: no dermatome
- C4: neck
- T4: nipples
- T10: belly button (TEN)
- L4: Nee
- S4: Anus
34
What do the true back muscles have in common?
- Action: maintain posture and produce movement of vertebral column
- Innervation: posterior rami of spinal nerves
35
What is the thoracolumbar fascia?
- aponeurotic and fascial layers
- separate deep (intrinsic) muscles of back from muscles of posterior abdominal wall
36
What are the superficial intrinsic back muscles?
Splenius capitis
- Origin: nuchal ligament and C7-T4 spinous processes
- Insertion mastoid process of temporal bone and occipital bone
Splenius cervicis
- Origin: T3-T6 spinous process
- Insertion: C1-C3 or 4 transverse processes
Action
- Unilaterally; flex & rotate toward active muscles
- Bilaterally: extend head and neck
37
What are the intermediate intrinsic back muscles?
Erector Spinae
Iliocostalis
- Origin: ribs & iliac crest
- Insertion: rib angles and C4-6 transverse processes
Longissimus
- Origin: C,T,L treansverse processes
- Insertion: mastoid process, C, T, L transverse processes
Spinalis
- Origin: nuchal ligament or spinous processes
Action
- Unilaterally: vertebral column flexion
- Bilaterally: vertebral column extensors
38
What are the deep intrinsic back muscles?
Transversospinalis: semispinalis, multifidus, rotatores
- Origin/insertion: gutter between transverse & spinous processes
- Action: upright posture, extend head/neck/spine, rotatores rotate spine
39
What is a bursa?
- fluid-filled sac
- reduces friction between moving parts
- Protects tendons of rotator cuff muscles
- Inflammation = bursitis
40
Look at radiology image of shoulder
Before exam
41
What is a synovial membrane?
- Connective tissue only
- Cavity with synovial fluid
42
What structures surround the AC joint?
- Bursa (outermost)
- Outer fibrous synovial membrane
- Synovial fluid
- Inner layer of synovial membrane
43
What are the movements of the scapular joint?
- Abduction/adduction (lateral/medial)
- Flexion/extension (anter/post)
- Lateral/medial rotation
44
What are the potential injuries of the shoulder?
- Subluxation of the head of the humerus
- Shoulder separation: injury to ligaments of clavicle: acromioclavicular, coracoclavicular ligaments
45
What are the shoulder muscles?
- Deltoid
- Teres major
Rotator cuff (SITS)
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
46
What is the origin, insertion, innervation, and action of the deltoid?
- Origin: lateral 3rd of clavicle, acromion and spine of scapula
- Insertion: deltoid tuberosity
- Innervation: axillary nerve
- Action:
-- Clavicular (anterior) part: flex & med rotate arm
-- Acromial (middle) part: abducts arm
-- Spinal (posterior) part: extends and laterally rotates arm
47
What is the origin, insertion, innervation, and action of the teres major?
- Origin: inferior angle of scapula
- Insertion: Medial lip of intertubercular sulcus
- Innervation: lower subscapular nerve
- Action: adducts & med rotate arm
48
What is the origin, insertion, innervation, and action of the supraspinatus?
- O: supraspinous fossa
- I: Greater tubercle of humorous
- I: Suprascapular nerve (upper trunk of brachial plexus, C5& 6, through superior transvers scapular ligament, under spine)
- A: Abduct arm (deltoid) & acts with rotator cuff muscles
49
What is the origin, insertion, innervation, and action of the infraspinatus?
- O: infraspinous fossa
- I: greater tubercle of humerus
- I: Suprascapular nerve (C5&6)
- A: laterally rotate arm & act with rotator cuff muscles
50
What is the origin, insertion, innervation, and action of the teres minor?
- O: Lateral border
- I: Greater tubercle
- I: Axillary nerve
- A: Laterally rotate arm
51
What is the origin, insertion, innervation, and action of the subscapularis?
- O: subscapular fossa
- I: lesser tubercle
- I: Upper & lower subscapular nerves (C5-7)
- A: Med rotate & adduct & hold head of humerus in glenoid cavity
52
Where are the spaces in the shoulder?
Finger trick:
- Humorous & triceps long head under teres minor, over teres major (lower)
- Triangular space (med), Quadrangular space (superior), triangular interval (inferior)
53
What comes through the quadrangular space?
(teres min/maj & long head triceps)
- Axillary nerve
- Posterior circumflex humeral artery & vein
54
What comes through the triangular space?
- teres min/maj, long head triceps
- Circumflex scapular a & v
55
What comes through the triangular interval?
(long head & lateral head of triceps & teres major)
- radial nerve
- profunda brachii artery
56
What are the surface anatomy aspects of the anterior shoulder and chest?
- Sternocleidomastoid
- Clavicle
- Clavicular part of deltoid
- Deltopectoral groove (for cephalic vein)
- Posterior axillary fold
- Anterior axillary fold
- digitations of serratus anterior
- Sternocostal head of pectoralis maj
- Axillary fossa
- Infraclavicular fossa (overlying clavipectoral triangle
- Descending (superior) part of trapezius
- Jugular notch
57
What is the venous drainage of the upper limb?
- Cephalic vein
- Basilic vein
(connected by Median cubital vein)
- cephalic vein in deltopectoral groove (maj) - diverge along clavicle --> deltopectoral triangle
58
What is the origin, insertion, innervation, and action of pectoralis major?
- O:
-- Clavicular head: anterior surface of medial half of clavicle
-- Sternocostal head: anterior surface of sternum, superior 6 costal cartilages, aponeurosis of external oblique muscle
- I: lateral lip of intertubercular sulcus of humerus
- I: lateral & medial pectoral nerves
- A: adduct & medially rotate humorous (+ other)
59
What is the origin, insertion, innervation, and action of pectoralis minor?
- O: 3-5 ribs near costal cartilage
- I: coracoid process
- I: medial pectoral nerve
- A: stabilize scapula, draw inferiorly & anteriorly against thoracic wall
60
What is the origin, insertion, innervation, and action of the serratus anterior?
- O: Lateral 1-8 rib
- I: medial border scapula (sup&inf angles)
- I: long thoracic nerve (C5-7)
- A: protract scapula & hold against thoracic wall (punch, reach, push-up)
61
What is the anatomy of mammary glands?
- **Glandular & supporting fibrous tissue embedded in fatty tissue**
-- mammary bed formed by pectoral fascia (overlying pectoralis major, pectoralis minor & serratus anterior muscles)
- Attached to dermis via **suspensory ligaments**
- **lactiferous ducts** give rise to **lobules of mammary glands**
- **areolae** contain **sebaceous glands** (enlarge pregnancy, oily substance lubricate areola & nipple)
62
What is the arterial supply and venous drainage of the breast?
Arterial supply
- Medial mammary branches of perforating branches & anterior intercostal **branches of the internal thoracic artery** off of subclavian artery
- **Lateral thoracic** and thoraco-acromial arteries, branches of axillary artery
- **Posterior intercostal arteries**
Venous drainage:
- Axillary vein
63
What is the lymphatic drainage of the breasts?
- (nipple, areola, lobules to) **subareolar lymphatic plexus**
- 75% to **axillary lymph nodes**
- then **subclavian lymphatic trunk
- rest **parasternal lymph nodes**
- **right** side drains into **right lymphatic duct**
- ** left** side to **thoracic duct**
64
What can cause winged scapula?
- Injury to long thoracic nerve
- Paralysis of serratus anterior
65
What are the aspects of rotator cuff injury?
- **instability of glenohumeral joint**
- overhead motions (painter, tennis)
- difficult hair care or reach behind back
- pain @ rest & night esp on shoulder, lift/lower arm (also weakness), crepitus
- treat: rest, ice, modify activities, NSAIDs, steroid injection, arthroscopy
66
What are the boundaries of the Axilla?
- Apex: clavicle, superior border of scapula, first rib
- Base: armpit skin and fascia
- Lateral: humerus
- Anterior: pectoralis major and minor and anterior axillary fold
- Posterior: scapula & subscapularis, teres major, latissimus dorsi, posterior axillary fold
- Medial: ribs
67
What is the axilla?
Contains
- Axillary vessels: axillary a + branches, & v. + tributaries
- Lymphatic vessels & axillary lymph nodes
- Large nerves -- cords & branches of brachial plexus
- Axillary fat
- Axillary sheath surrounding axillary artery & vain & brachial plexus
68
What are the first divisions of the arteries from the heart?
Ascending aorta
1) Right & left coronary arteries
2) Brachiocephalic artery --> a) right subclavian artery b) right common carotid artery
(Arch of aorta)
3) Left common carotid artery
4) Left subclavian artery
Descending aorta
69
What are the parts of the axillary artery?
Subclavian artery
- 1 branch lateral border 1st rib-medial border of pectoralis minor in axillary sheath
-- **superior thoracic artery**
- 2 branches posterior pectoralis minor
-- **Thoracoacromial & lateral thoracic arteries**
-- (T --> 4 branches: acromial, deltoid, pectoral, clavicular)
- 3 branches b/w lateral border pec min & inf border teres maj
-- **Subscapular artery, anterior & posterior circumflex humoral arteries**
-- s: circumflex scapular artery & thoracodorsal artery
70
What are the parts of the axillary vein?
- Formed by brachial veins and basilic vein
- @ lat border 1st rib becomes subclavian vein
(3 parts)
71
What are the aspects of the axillary lymph nodes?
Three streams from regions
1. Upper extremity (humeral)
2. Adjacent thoracic & upper abdominal wall & breast (pectoral)
3. The back (subscapular region)
72
What are the acronyms for the brachial plexus?
"Really Tired? Drink Coffee!"
- Roots: 5 - C5-T1
- Trunks: 3 Superior, Middle, Inferior
- Divisions: 3 (ea. trunk divides into A & P)
- Cords: 3 Lateral (A sup & A med), Posterior (all P cords), Medial (A inf)
- Terminal nerves: (creates M - M M & U)
-- Musculocutaneous: L (C5-C7)
-- Axillary: (P C5-C6)
-- Radial: P (C5-T1)
-- Median: L & M (C5-T1)
-- Ulnar: M (C7-T1)
(MARMU)
73
What are the roots of the brachial plexus?
- Five
- Union of the anterior rami from C5-T1
- Roots pass through scalene gap w/ subclavian artery
74
What is the brachial plexus nerve(s) and muscles innervated by the dorsal scapular nerve?
- C5 (off of root)
- rhomboids, levator scapulae
75
What is the brachial plexus nerve(s) and muscles innervated by the long thoracic nerve?
- C5-C7 (combined from roots)
- serratus anterior
76
What is the brachial plexus nerve(s) and muscles innervated by the suprascapular nerve?
- C5-C6 (second off superior trunk after subclavian)
- Supraspinatus & infraspinatus, glenohumeral joint
77
What is the brachial plexus nerve(s) and muscles innervated by the lateral pectoral nerve?
- C5-C7; side branch of lateral cord (in bridge with medial cord)
- pectoralis major
78
What is the brachial plexus nerve(s) and muscles innervated by the medial pectoral nerve?
- C8-T1; side branch of medial cord
- pectoralis minor & sternocostal part of pectoralis major
79
What is the brachial plexus nerve(s) and muscles innervated by the thoracodorsal nerve?
- middle subscapular from posterior cord
- latissimus dorsi
80
What is the brachial plexus nerve(s) and muscles innervated by the axillary nerve?
- C5-C6; terminal branch of posterior cord
- acromioclavicular & glenohumeral joints
- teres minor
- deltoid
81
What is the brachial plexus nerve(s) and muscles innervated by the radial nerve?
- C5-T1; terminal branch of the posterior cord
- all muscles of posterior compartment of arm (brachioradialis, anconeous, triceps brachii) and forearm (extensor)
- dorsum of hand lateral to axial line of digit 4
82
What is the brachial plexus nerve(s) and muscles innervated by the median nerve?
- C5-T1; terminal branches of lateral and medial cords
- Doesn't do anything in the arm
- muscles of anterior forearm compartment (except for flexor carpi ulnaris & ulnar part of flexor digitorum profundus)
- five intrinsic muscles of the half palm and palmer skin
83
What is the brachial plexus nerve(s) and muscles innervated by the ulnar nerve?
- C8-T1: larger terminal branch of medial cord
- Doesn't do anything in the arm
- Flexor carpi ulnaris & ulnar half of flexor digitorum profundus
- Intrinsic muscles of the hand
84
What is the brachial plexus nerve(s) and muscles innervated by the upper subscapular nerve?
- First from posterior cord
- Superior position of subscapularis
85
What is the brachial plexus nerve(s) and muscles innervated by the lower subscapular nerve?
- Last from posterior cord
- inferior portion of subscapularis
86
What are the potential injuries of the brachial plexus?
- Superior trunk: Erb-Duchenne palsy (C5-C6)
-- paralysis of muscles of shoulder and arm
-- waiter's tip hand: arm medial rotated, forearm pronated, elbow extended
-- land on shoulder (thrown from motorcycle), stretch neck during delivery
- Inferior trunk: Klumpke paralysis (palsy) (C8-T1)
-- Loss of function of intrinsic hand muscles
-- Claw hand deformity
-- Fall from tree, limb delivery
- Proximal humeral (surgical neck) fracture: elderly, osteoporosis, fall onto outstretch arm
- Glenohumeral joint dislocation (most often injured, axillary nerve)
87
What can cause an axillary nerve injury? What are the symptoms?
- Fracture of humerus (surgical neck)
- Pressure from casts or splints
- Improper use of crutches
Symptoms
- Weakness of deltoid muscle (abduction, flexion, extension shoulder joint)
- Weakness of teres minor muscle (lateral rotation of glenohumeral joint - may not be apparent b/c infraspinatus muscle action)
88
What is the arm? What movement does it allow? Muscular divisions? Muscles?
- Extends from the shoulder to the elbow
- Elbow movement: flexion-extension & pronation-supination
- Divisions: anterior & posterior muscle groups by humerus & lat & med intermuscular septae
- Anterior/flexor: biceps brachii, brachialis, coracobrachialis
- Posterior/extensor: triceps brachii
89
What is the origin, insertion, innervation, and action of the biceps brachii?
- O: (short head) coracoid process (long head) supraglenoid tubercle
- I: Tuberosity of radius (&fascia of forearm via) bicipital aponeurosis
- I: musculocutaneous nerve
- A: supinate forearm, flexes forearm (short resists shoulder dislocation)
90
What is aponeurosis?
Fibrous connective tissue that forms a sheath-like tendon
91
What is the origin, insertion, innervation, and action of the coracobrachialis?
- O: coracoid process of scapula
- I: middle third of medial surface of humerus
- I: Musculocutaneous nerve
- A: flex & adduct arm (resist dislocation of shoulder)
92
What is the origin, insertion, innervation, and action of the brachialis?
- O: Distal half of the anterior surface of the humerus
- I: Coronoid process & tuberosity of ulna
- I: Musculocutaneous nerve
- A: Flexes forearm
93
What is the origin, insertion, innervation, and action of the triceps brachii?
- O: (long head) infraglenoid tubercle (lat) posterior humerus (superior to radial groove) (med) posterior humerus (inf radial groove)
- I: proximal end of olecranon (& forearm fascia)
- I: radial nerve
- A: chief extensor (resist dislocation)
94
What is the origin, insertion, innervation, and action of the anconeus?
- O: lateral epicondyle
- I: lat surface of olecranon & superior posterior ulna
- I: radial nerve
- A: forearm extension (w/ triceps)
95
What are the arteries of the arm?
Brachial artery
- Continuation of axillary artery from lower border teres maj to cubital fossa
- Immediately branch into profunda brachii
- End branch into superior & inferior ulnar collateral arteries
96
What are the veins of the arm?
- Cephalic (lat) & basilic (med) vein
- Cephalic connects to basilic via median cubital vein: location for venipuncture
97
How do the terminal nerve branches of the brachial plexus relate to the arm?
- Musculocutaneous: branches to coracobrachialis, brachialis, biceps brachii
- Axillary: Teres minor & Deltoid
- Median: No branches to arm
- Ulnar: No branches to arm
- Radial: branches to long head and medial head of triceps brachii
98
What is the cubital fossa?
- A space that contains the median nerve, radial artery, and median cubital vein
- Superior border: transverse line between medial and lateral epicondyles of the humerus
- Lateral border: brachioradialis
- Medial border: pronator teres
- Location for venipuncture
- Bicipital myotatic reflex - C5 & C6
Anatonmists like potential spaces and like to describe what goes through the space
99
What is a reflex arc?
- A neural pathway that controls a reflex action
- Only synapse in spinal cord allows for quick response without brain processing
- Somatic - skeletal (autonomic - visceral)
- Sensory neuron (afferent) to interneuron to motor neuron (efferent)
- Pain or stretch reflex both end in contraction
*Biceps - C5-6, Triceps - C7, Patellar - L2-4, Achilles S1-2*
100
What is a fat pad sign?
- aka sail sign
- displacement of fat pad around elbow joint (slightly more anechoic)
- suggests and occult fracture
101
What is the brachial plexus nerves and muscles innervated by the musculocutaneous nerve?
- C5-C7 terminal branch of lateral cord
- coracobrachialis, biceps brachii, brachialis, skin of lateral aspect of forearm
- continues as lateral cutaneous nerve
102
What is in the radial groove of the humerus?
Radial nerve & profunda brachial artery
103
What are important orientators for the arm anatomy?
- Olecranon is posterior.
- If you can see the pisiform, it is anterior
- Medial epicondyle is larger
- Trochlea - Ulna "TU"
- Capitulum - Radius (cA, rA)
104
What are the carpals?
- Scaphoid
- Lunate
- Triquetrum
- Pisiform
- Hamate
- Capitate
- Trapezoid
- Trapezium
105
What is important about the elbow joint?
- There are multiple bursae between the tendons, ligaments, and muscles
- The bursae get inflamed often
(can get huge, palpably soft)
106
What is a common elbow problem?
- Nursemaid's elbow
- Lift child's weight by their arm
- Subluxation or dislocation of radius
107
What are the compartments of the forearm?
- Anterior: flexor-pronator compartment
- Posterior: extensor-supinator compartment
- 17 muscles cross elbow joint some act on elbow, others on wrist & fingers
108
What is the nerve supply of the forearm?
Flexors & pronators:
- all: median nerve by
-- anterior interosseus nerve
- *except* 1 1/2 by ulnar nerve: FCU & FDP
-- passes superficial to flexor retinaculum through small ulnar canal
-- palmar & dorsal cutaneous branches distally
- except brachioradialis is a flexor in the posterior comp. innervated by radial
Extensors & supinators:
- all: radial nerve
-- sensory & motor functions
-- superficial branch (sensory)
-- deep radial/posterior interosseous nerve (motor)
-- posterior cutaneous nerve (posterior compartment)
109
What are important general aspects of the forearm flexors-pronators?
- Tendons held in place by
-- palmar carpal ligament
-- flexor retinaculum
- Three groups
-- Superficial layer: pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris (hand trick, palm on medial epicondyle, 2- PT, 3-FCR, 4-PL, 5-FCU)
-- Intermediate: flexor digitorum superficialis
-- Deep layer: flexor digitorum profundus, flexor pollicis longus, pronator quadratus (group that does not cross elbow)
110
What is the origin, insertion, innervation, and action of the Pronator Teres?
- O: Ulnar head: coronoid process of ulna, Humeral head: medial epicondyle of humerus
- I: lateral surface of radius
- I: Median nerve
- A: pronates & flexes forearm
111
What is the origin, insertion, innervation, and action of the flexor carpi radialis?
- O: medial epicondyle of the humerus
- I: base of 2nd metacarpal
- I: median nerve
- A: Flexes & abducts hand (at wrist)
- Its tendon passes through canal in lateral part of flexor retinaculum in own **tendinous sheath**
112
What is the origin, insertion, innervation, and action of the palmaris longus?
- O: medial epicondyle of the humerus
- I: flexor retinaculum & palmar aponeurosis
- I: median nerve
- A: flexes hand and tenses palmar aponeurosis
- Absent in 14% people, deep & medial to median nerve @ wrist
113
What is the origin, insertion, innervation, and action of the flexor carpi ulnaris?
- O: Humeral head: medial epicondyle, ulnar head: olecranon & posterior border of ulna
- I: pisiform, hook of hamate, 5th metacarpal
- I: ulnar nerve
- A: flexes & adducts hand
114
What is the origin, insertion, innervation, and action of the flexor digitorum superficialis?
- O: humero-ulnar head: medial epicondyle, Radial head: superior half of anterior border of radius
- I: shafts of middle phalanges of medial 4 digits
- I: median nerve
- A: flexes middle phalanges @ proximal interphalangeal joints of digits 2-5
- flexes fingers independently
- 4 tendons pass deep to flexor retinaculum in synovial common flexor sheath
115
What is the origin, insertion, innervation, and action of the flexor digitorum profundus?
- O: proximal 3/4ths & anterior surfaces of ulna & interosseous membrane
- I: medial part distal phalanges 4& 5, lateral part distal phalanges 2&3
- I: medial part: ulnar nerve, lateral part: anterior interosseous nerve from median nerve
- A: medial part: flexes distal phalanges 4&5 @ DIP joints, lateral part: flexes distal phalanges 2 & 3 at DIP joints
- 4 tendons posterior to flexor retinaculum w/i common flexor sheath
116
What is the origin, insertion, innervation, and action of the flexor pollicis longus?
- O: anterior surface of radius & adjacent interosseous membrane
- I: distal phalanx of thumb
- I: anterior interosseous nerve from median nerve
- A: flexes phalanges of first digit
- Own synovial **tendinous sheath of the flexor pollicis longus**
(Deep to FDS)
(Superficial (small part) distally FCR
117
What is the origin, insertion, innervation, and action of the pronator quadratus?
- O: distal quarter of anterior surface of ulna
- I: distal quarter of anterior surface of radius
- I: anterior interosseous nerve from median nerve
- A: pronates forearm (bind radius & ulna tog)
- Prime mover for pronation
118
What are the arteries of the forearm and wrist?
**Brachial artery** splits into
- **ulnar artery** (main branches)
-- **anterior ulnar recurrent**
-- **posterior ulnar recurrent**
-- common interosseous --> anterior & posterior interosseous
-- dorsal & palmar carpal branches
-- **superficial palmar arch**
- **radial artery**
-- **radial recurrent artery**
-- **radial collateral artery**
-- palmar & dorsal carpal branches
-- **deep palmar arch**
119
What are the thenar muscles? What is their origin, insertion, innervation, and actions?
- Opponens pollicis (deep), abductor pollicis brevis (Lateral), flexor pollicis brevis (medial)
- O: flexor retinaculum, scaphoid, trapezium
- I: OP - 1st metacarpal, A&FBP - proximal phalanx of thumb
- I: recurrent branch of median nerve (except deep head of FPB & AP)
- A: OP - opposition of the thumb, APB: abducts thumb, FPB: flexes thumb
120
What are the muscles of the hypothenar? What is their origin, insertion, innervation, and action?
- Opponens digiti minimi (deep), flexor digiti minimi brevis (toward midline of hand), abductor digiti minimi (outside hand)
- O: ADM: pisiform, FDMB & OD - hook of hamate & flexor retinaculum
- A: ADM & FDMB - proximal phalanx of 5th digit, OD: 5th metacarpal
- I: deep branch of ulnar nerve
- A: ADM: abducts 5th digit, FDMB: flexes proximal phalanx of 5th digit, OD: opposes 5th with thumb
121
What are three groups of movements of the extensor muscles in the posterior compartment?
1. Extend & abduct/adduct hand at wrist: ECRL, ECRB, ECU
2. Extend medial four fingers: ED, EI, EDM
3. Extend or abduct thumb: APL, EPB, EPL
- **ALL innervated by the radial nerve**
122
What are the common aspects of the superficial extensor muscles?
- O: (most) common extensor tendon --> lateral epicondyle of the humerus
-- ECRB, ED, EDM, ECU, S
- O: (other two) supra-epicondylar ridge of the humerus & lateral intermuscular septum
-- B, ECRL
- Tendons held in place by extensor retinaculum through 6 osseofibrous tunnels
(Deep extensors: APL, EPL, EPB, EI)
123
What is the origin, insertion, action, and innervation of the brachioradialis?
- O: supra-epicondylar ridge of humerus
- I: distal radius (just proximal to styloid process)
- A: flexion of forearm (at the elbow)
- I: radial nerve
124
What is the origin, insertion, action, and innervation of the extensor carpi radialis longus?
- O: supra-epicondylar ridge of the humerus
- I: base of 2nd metacarpal
- I: radial nerve
- A: extends & abducts hand at wrist
125
What is the origin, insertion, action, and innervation of the extensor carpi radialis brevis?
- O: lateral epicondyle of humerus
- I: base 3rd metacarpal
- I: radial nerve
- A: extends & abducts hand at wrist
(same tendinous sheath as ECRL)
(Superficial, only deep proximally to B & ECRL, tendon distally APL, EPB, EPL)
(Posterior to ECRL)
(Anterior to ED)
126
What is the origin, insertion, action, and innervation of the extensor digiti minimi?
- O: lateral epicondyle of the humerus
- I: extensor expansion of the 5th digit
- I: radial nerve
- A: extend 5th digit @ metacarpophalangeal joint
127
What is the origin, insertion, action, and innervation of the extensor carpi ulnaris?
- O: lateral epicondyle of humerus
- I: bast of 5th metacarpal
- I: radial nerve
- A: extend & adduct hand @ wrist
128
What is the origin, insertion, action, and innervation of the extensor digitorum?
- O: lateral epicondyle of humerus
- I: extensor expansions (of medial four digits)
- A: extends medial 4 digits @ metacarpophalangeal joints
- I: radial nerve
129
What are the extensor expansion?
- Triangular **tendinous aponeurosis wrapping around dorsum & sides metacarpal & proximal phalanx** anchored on each side by **palmar ligament**
- Divides into **median band** (base of middle phalanx) & **2 lateral bands** (base of distal phalanx)
- A: med & lat: **facilitate finger extension** esp PIP & DIP & **stability** & proper motion of fingers during flexion/extension
130
What are the short muscles of the hand?
- Lumbricals
- Interossei
131
What is the origin, insertion, action, and innervation of the lumbricals?
- O: 1& 2: lat 2 tendons of FDP (unipennate)
3&4: med 3 tendons of FDP (dipennate)
- I: extensor expansions of 2-5 digits
- I: 1&2: median nerve, 3&4 deep branch of ulnar nerve
- A: flex metacarpophalangeal joints & extend interphalangeal joint of 2-5 digits
132
What is the origin, insertion, action, and innervation of the interossei?
- Dorsal interossei: b/w metacarpals
- Palmar interossei: palmar surface of metacarpals (interosseous compartment)
- I: ulnar nerve
- A: Dorsal- abduct 2,4,5 (DAP) Palmar - adduct 2,4,5, (PAD)
133
What is the origin, insertion, action, and innervation of the supinator?
- O: lateral epicondyle of humerus, radial collateral & anular ligaments, (supinator fossa, crest of) ulna
- I: (lat, post, & ant) proximal radius
- radial nerve
- A: supinates forearm
134
What are the anatomical snuff box muscle ligaments and what is their action?
- EPL tendon (dorsal), EPB tendon (palmar) + APL
- "outcropping muscles": cross over ECRB & ECRL
- base: scaphoid bone
135
What is the origin, insertion, action, and innervation of the abductor pollicis longus?
- O: (posterior proximal half) ulna, radius, & interosseous membrane
- I: base 1st metacarpal
- I: posterior interosseous nerve
- A: abducts thumb & extends it @ carpometacarpal joint
(Proximally Deep to ED, EDM, ECU)
(Lateral to EPL, EPB)
(Distally Superficial to B, ECRL, ECRB)
136
What is the origin, insertion, action, and innervation of the extensor pollicis longus?
- O: (post surface middle 1/3) ulna & interosseous membrane
- I: (dorsal aspect of base of) distal phalanx of thumb
- I: posterior interosseus nerve
- A: extends distal phalanx of thumb @ interphalangeal joint
137
What is the origin, insertion, action, and innervation of the extensor pollicis brevis?
- O: (post surface distal 1/3) radius & interosseus membrane
- I: (dorsal aspect) proximal phalanx of thumb
- I: posterior interosseous nerve
- A: extends proximal phalanx of thumb at metacarpophalangeal joint (extend carpometacarpal joint)
138
What are the arteries of the dorsal forearm and hand?
From the **ulnar artery**
- anterior interosseous artery, posterior division
- Posterior interosseous artery
- **Dorsal carpal branch of ulnar artery**
- **Dorsal carpal branch of radial artery**
139
What is the function of the radial nerve in the forearm and hand?
- Deep branch of radial nerve
--> **posterior interosseous nerve** --> muscles of posterior compartment of forearm
- **Posterior cutaneous nerve of forearm**
- **Superficial branch of radial nerve**: anterior base thumb, dorsal hand & 1-3 & 1/2 of 4 metacarpals
140
What is the sensory innervation of the hand and wrist?
- Ulnar nerve: digit 5 & 1/2 of digit 4, medial 1/2 wrist (C8-T1)
- Radial nerve: base thumb anterior, dorsal hand & 1-3 & 1/2 4 metacarpals (C6-C8)
- Medi**an** nerve: Most anterior hand, post 1-3 & 1/2 4 distal phalanges (C6-C8)
141
What is the anatomical course of the radial nerve?
- Continuation of posterior cord
- Along spiral groove
- Anterior to lateral epicondyle
- Posterior interosseous nerve
- Superficial sensory branch pierces fascia
142
What causes/results from injury to the radial nerve?
- Fracture humerus: proximal to motor branches to long & short extensors of wrist
-- Dropped wrist
- Injury to Deep Branch of Radial Nerve
-- Deep wound to posterior forearm
-- Muscles: ED, EI, EDM, APL, EPB, EPL (abductor pollicis longus)
-- Inability extend thumb & metacarpophalangeal joints
143
What are the symptoms of radial nerve injury?
- @ Axilla: weakness & tingling & numbness from back of arm to hand
- @ spiral groove: weaken brachioradialis, interfere bend @ wrist & straighten fingers
- Posterior interosseous nerve: weakness & X extend thumb & metacarpophalangeal joints other digits
- Loss of sensation may not occur b/c deep radial nerve only muscular
- Loose sensation if damage superficial radial nerve
144
What is the origin, insertion, action, and innervation of the extensor indicis?
- O: (post surface distal 1/3) ulna & interosseous membrane
- I: extensor expansion of 2nd digit
- I: posterior interosseous nerve
- A: extends 2nd digit
145
What is the brachial plexus nerves and areas innervated by the medial brachial cutaneous/medial cutaneous nerve of arm?
- (T1) from medial cord
- medial side of arm to medial epicondyle of humerus & olecranon of ulna
146
What is the brachial plexus nerves and areas innervated by the medial antebrachial cutaneous/medial cutaneous nerve of forearm?
- C8-T1 from medial cord
- medial side of forearm to wrist
