Midterm 3: Dorsal Regions - Superior (Dustin)

Question 1

Nuchal region borders?

Answer 1

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

Question 2

Nuchal region: layers from outer to inner?

6 things

Answer 2

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

Question 3

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

what nerves innervate them?

Answer 3

2 and 3 innervated by suboccipital nerve

1. trapezius (from CN XI)
2. splenius capitis
3. semispinalis capitis

Question 4

what are the borders of the suboccipital triangle?

what are the contents?

Answer 4

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

Question 5

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

Answer 5

Arteries:

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

Nerves:

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

Question 6

Scapular region: boundaries

Answer 6

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

Question 7

What are the 2 superficial muscles of the scapular region?

What nerve innervates them?

Answer 7

Trapezius (CN XI)

Deltoid: spinous part (axillary n)

Question 8

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

Answer 8

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.)

Question 9

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

Answer 9

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

Question 10

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

Answer 10

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

Question 11

What is the content of the medial axillary hiatus?

also called medial triangular space

Answer 11

circumflex scapular artery

Question 12

what is the content of the lateral axillary hiatus?

also called the quadrangular space

Answer 12

posterior circumflex humeral artery

axillary nerve

Question 13

What muscles do the suprascapular nerve innervate?

From which trunk of the brachial plexus does it originate?

Answer 13

supraspinatus

infraspinatus

comes from superior trunk

Question 14

What nerve innervates the rhomboids and levator scapulae?

from which trunk does it originate?

Answer 14

Dorsal Scapular Nerve

from Superior Trunk

Question 15

What muscles do the subscapular and thoracodorsal nerves innervate?

From which cord of the brachial plexus do they originate?

Answer 15

Subscapular: Subscapularis and Teres Major

Thoracodorsal: Latissimus Dorsi

Originate in the posterior cord

Question 16

What nerve invervates teres minor?

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

Answer 16

Axillary nerve (also innervates deltoid)

from Posterior Cord

Question 17

Posterior brachial region: borders

Answer 17

Proximal: posterior axillary fold level

Distal: 3 fingers above the olecranon

medial: medial bicipital groove
lateral: lateral bicipital groove

Question 18

4 layers of posterior brachial region

Answer 18

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

Question 19

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

Answer 19

radial nerve

deep brachial artery

Question 20

Which septa divide the posterior brachial and anterior brachial regions?

Answer 20

Lateral and Medial Intermuscular Septa

Question 21

What nerve innervates triceps brachii?

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

Answer 21

Radial nerve

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

Question 22

label 17, 18, 19, 20

Answer 22

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

Question 23

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

From what nerve do they originate?

Answer 23

Posterior cutaneous brachial

Posterior cutaneous antebrachial

Both from radial nerve

Question 24

Posterior cubital region: borders

Answer 24

proximally and distally: three finers above and below olecranon

medially and laterally: medial/lateral epicondyles of humerus

Question 25

What nerve supplies the sensory innervation of the posterior cubital region? from which nerve does it originate?

Answer 25

Posterior Cutaneous Antebrachial Nerve from Radial Nerve

Question 26

What arterial anastomoses occurs on the posterior cubital region? Which arteries contribute?

Answer 26

**Rete Olecrani** from the collateral and recurrent arteries (collaterals from brachial and deep brachial, recurrent from ulnar artery)

Question 27

What important nerve passes on the medial side of the posterior cubital region? What cord of the brachial plexus is it from?

Answer 27

Ulnar nerve (in ulnar groove) from Medial Cord

Question 28

Posterior antebrachial region: borders

Answer 28

Proximally: 3 fingers below olecranon Distally: ulnar head Laterally: lateral epicondyle -\> styloid process of ulna Medially: medial epicondyle -\> styloid process of radius

Question 29

Posterior antebrachial region: 5 layers, starting at skin

Answer 29

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

Question 30

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?

Answer 30

**Deep Radial Nerve** Travels through **Supinator** Canal From **Posterior** Cord

Question 31

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

Answer 31

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

Question 32

What 3 muscles make up the superficial radial extensor group? (posterior antebrachial region)

Answer 32

Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis

Question 33

What 3 muscles make up the superficial ulnar extensor group? (posterior antebrachial region)

Answer 33

Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris

Question 34

What 5 muscles make up the deep extensor group of forearm? hint: 3 extensors, 2 others (posterior antebrachial region)

Answer 34

Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor Indicis

Question 35

Posterior carpal region: borders (this one is pretty useless)

Answer 35

Proximal: head of ulna Distal: base of metacarpals Ulna and radius as lateral borders

Question 36

Posterior carpal region: layers 6 things from skin

Answer 36

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

Question 37

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

Answer 37

Cephalic Basilic

Question 38

What are the tendons passing through the 6 extensor compartments in the extensor retinaculum? (for the posterior carpal region)

Answer 38

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)

Question 39

Dorsum of the hand: borders

Answer 39

proximal: *basis* of the metacarpals distal: *heads* of the metacarpals lateral margins based on the ulnar & radius

Question 40

What tendons make up the anatomical snuff box (foveola radialis)? What important artery, vein, and nerve are in this area?

Answer 40

Extensor compartment 1 (abductor pol. longus/ ext. pol. brev) + Extensor compartment 3 (ext pol. longus) _Contains:_ Radial artery Cephalic Vein Superficial Radial Nerve

Question 41

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

Answer 41

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

Question 42

How many dorsal interossei muscles are there in the hand? What nerve innervates them?

Answer 42

**4** dorsal interossei muscle innervation from **Ulnar** nerve (deep branch)

Question 43

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

Answer 43

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