Midterm 3: Dorsal Regions - Superior (Dustin) Flashcards Preview

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Flashcards in Midterm 3: Dorsal Regions - Superior (Dustin) Deck (43):

Nuchal region borders?

Superior: from external occipital protuberance to mastoid process

Inferior: vertebra prominens (C7)

Medial: midline btwn superior and inferior points

Lateral: the lateral borders of trapezius from mastoid process until the inferior boundary



Nuchal region: layers from outer to inner?

6 things

1. skin

2. subcutaneous with fat and nerves

3. superficial cervical fascia

4. three superficial nuchal muscles (detailed later)

5. deep cervical fascia

6. deep nuchal muscles with suboccipital triangle


what are the 3 superficial nuchal muscles, from outer to inner?

what nerves innervate them?

1. trapezius (from CN XI)

2. splenius capitis

3. semispinalis capitis


#2 and 3 innervated by suboccipital nerve


what are the borders of the suboccipital triangle?


what are the contents?

base: posterior atlanto-occipital membrane

medially: rectus capitis posterior major

supero-laterally: oblique capitis superior

infero-laterally: oblique capitis inferior


contents: vertebral artery, suboccipital nerve


What two arteries and three nerves can be found in the nuchal region?


  1. Occipital artery (from ext carotid)
  2. Vertebral artery (from subclavian)


  1. suboccipital nerve (motor innervation for suboccipital muscles)
  2. greater occipital nerve (sensory)
  3. third occipital nerve (sensory)




Scapular region: boundaries

Superior: horizontal line between acromion and T1 spinous process

Inferior: horizontal line between inferior scapular angle and posterior axillary fold

Medial: midline

Lateral: obliquely, line between acromion and lateral end of the posterior axillary fold


What are the 2 superficial muscles of the scapular region?


What nerve innervates them?

Trapezius (CN XI)

Deltoid: spinous part (axillary n)


What are 6 layers of the scapular region, starting from the skin and going deeper?

  1. skin
  2. subcutaneous tissue / fat
  3. fascia of superficial muscles
  4. superficial muscles (trapezius, deltoid)
  5. supraspinal and infraspinal fascia
  6. deeper muscles (supraspinatus, teres min/maj, etc.)


What are the important relationships of vessels/nerves around the suprascapular notch?

The suprascapular nerve goes through the notch. The notch is covered by the transverse ligament, and above this ligament is the suprascapular artery


What anastomoses does the suprascapular artery form, and with what other arteries?

Together with the circumflex scapular artery and the dorsal scapular artery, form the arterial network of the scapula: rete of the scapula


What is the content of the medial axillary hiatus?


also called medial triangular space

circumflex scapular artery


what is the content of the lateral axillary hiatus?


also called the quadrangular space

posterior circumflex humeral artery

axillary nerve


What muscles do the suprascapular nerve innervate?


From which trunk of the brachial plexus does it originate?




comes from superior trunk


What nerve innervates the rhomboids and levator scapulae?


from which trunk does it originate?

Dorsal Scapular Nerve


from Superior Trunk


What muscles do the subscapular and thoracodorsal nerves innervate?


From which cord of the brachial plexus do they originate?

Subscapular: Subscapularis and Teres Major

Thoracodorsal: Latissimus Dorsi


Originate in the posterior cord


What nerve invervates teres minor?


From which cord of the brachial plexus does this nerve originate?

Axillary nerve (also innervates deltoid)


from Posterior Cord


Posterior brachial region: borders

Proximal: posterior axillary fold level

Distal: 3 fingers above the olecranon

medial: medial bicipital groove

lateral: lateral bicipital groove


4 layers of posterior brachial region

  1. skin
  2. subcutaneous tissue/fat, with subcutaneous nerves
  3. brachial fascia
  4. triceps brachii muscle


What can be found between the lateral and medial heads of the triceps brachii muscle?

radial nerve

deep brachial artery


Which septa divide the posterior brachial and anterior brachial regions?

Lateral and Medial Intermuscular Septa


What nerve innervates triceps brachii?


From which cord of the brachial plexus does this nerve originate?

Radial nerve


from Posterior Cord (makes sense because it goes to posterior muscles)


label 17, 18, 19, 20

17 Long head of triceps brachii muscle
18 Lateral head of triceps brachii muscle
19 Medial head of triceps brachii muscle
20 Medial intermuscular septum


Which two nerves supply most of the cutaneous innervation to the posterior brachial region?


From what nerve do they originate?

Posterior cutaneous brachial

Posterior cutaneous antebrachial


Both from radial nerve


Posterior cubital region: borders

proximally and distally: three finers above and below olecranon

medially and laterally: medial/lateral epicondyles of humerus


What nerve supplies the sensory innervation of the posterior cubital region?


from which nerve does it originate?

Posterior Cutaneous Antebrachial Nerve


from Radial Nerve


What arterial anastomoses occurs on the posterior cubital region?

Which arteries contribute?


Rete Olecrani

from the collateral and recurrent arteries


(collaterals from brachial and deep brachial, recurrent from ulnar artery)


What important nerve passes on the medial side of the posterior cubital region?


What cord of the brachial plexus is it from?

Ulnar nerve (in ulnar groove)


from Medial Cord


Posterior antebrachial region: borders

Proximally: 3 fingers below olecranon

Distally: ulnar head

Laterally: lateral epicondyle -> styloid process of ulna

Medially: medial epicondyle -> styloid process of radius


Posterior antebrachial region: 5 layers, starting at skin

  1. skin
  2. subcutaneous tissue/fat/nerves/veins
  3. posterior antebrachial fascia
  4. extensor muscles of forearm
  5. interosseus membrane, with ulna and radius


What nerve innervates all of the extensor muscles in the posterior forearm?


What canal does it travel through to get there?


From what cord of the brachial plexus does it originate?

Deep Radial Nerve


Travels through Supinator Canal


From Posterior Cord


What 3 nerves provide most of the cutaneous innervation of the posterior antebrachial region?

  1. Medial cutaneous antebrachial (from medial cord)
  2. Lateral cutaneous antebrachial (from musculocutaneous {lateral cord})
  3. Posterior cutaneous antebrachial (from radial {posterior cord})


What 3 muscles make up the superficial radial extensor group? 

(posterior antebrachial region)


Extensor carpi radialis longus

Extensor carpi radialis brevis


What 3 muscles make up the superficial ulnar extensor group?

(posterior antebrachial region)

Extensor digitorum

Extensor digiti minimi

Extensor carpi ulnaris


What 5 muscles make up the deep extensor group of forearm?

hint: 3 extensors, 2 others

(posterior antebrachial region)


Abductor pollicis longus

Extensor pollicis brevis

Extensor pollicis longus

Extensor Indicis


Posterior carpal region: borders


(this one is pretty useless)

Proximal: head of ulna

Distal: base of metacarpals

Ulna and radius as lateral borders


Posterior carpal region: layers

6 things from skin

  1. skin
  2. subcutaneous tissue/fat
  3. fascia of forearm
  4. extensor retinaculum (by the dorsal carpal ligament)
  5. tendons of extensor muscles
  6. carpal bones


What 2 superficial important veins travel over the posterior carpal region?




What are the tendons passing through the 6 extensor compartments in the extensor retinaculum?


(for the posterior carpal region)

Pattern: 221211

  1. Abductor pollicis longus and extensor pollicis brevis (2)
  2. extensor carpi radialis longus and brevis (2)
  3. extensor pollicis longus (1)
  4. extensor digitorum and extensor indicis (2)
  5. extensor digiti minimi (1)
  6. extensor carpi ulnaris (1)


Dorsum of the hand: borders

proximal: basis of the metacarpals

distal: heads of the metacarpals

lateral margins based on the ulnar & radius


What tendons make up the anatomical snuff box (foveola radialis)?


What important artery, vein, and nerve are in this area?

Extensor compartment 1 (abductor pol. longus/ ext. pol. brev)

+ Extensor compartment 3 (ext pol. longus)



Radial artery

Cephalic Vein

Superficial Radial Nerve


What happens to the radial artery in the dorsum of the hand?

It penetrates the first dorsal interosseus muscle to form the deep palmar arch


How many dorsal interossei muscles are there in the hand?


What nerve innervates them?

4 dorsal interossei muscle


innervation from Ulnar nerve (deep branch)


What parts of the dorsal hand are innervated by the median, radial, and ulnar nerves? (sensory)

Median nerve: distal tips of fingers 2 and 3, part of 4

Ulnar nerve: half of proximal finger 3, the remainder of 4, all of 5. Medial half of hand

Radial nerve: everything else