Midterm 3: Dorsal Regions - Superior (Dustin) Flashcards
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
- skin
- subcutaneous with fat and nerves
- superficial cervical fascia
- three superficial nuchal muscles (detailed later)
- deep cervical fascia
- deep nuchal muscles with suboccipital triangle
what are the 3 superficial nuchal muscles, from outer to inner?
what nerves innervate them?
2 and 3 innervated by suboccipital nerve
- trapezius (from CN XI)
- splenius capitis
- semispinalis capitis
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?
Arteries:
- Occipital artery (from ext carotid)
- Vertebral artery (from subclavian)
Nerves:
- suboccipital nerve (motor innervation for suboccipital muscles)
- greater occipital nerve (sensory)
- 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?
- skin
- subcutaneous tissue / fat
- fascia of superficial muscles
- superficial muscles (trapezius, deltoid)
- supraspinal and infraspinal fascia
- 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?
supraspinatus
infraspinatus
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
- skin
- subcutaneous tissue/fat, with subcutaneous nerves
- brachial fascia
- 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
- skin
- subcutaneous tissue/fat/nerves/veins
- posterior antebrachial fascia
- extensor muscles of forearm
- 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?
- Medial cutaneous antebrachial (from medial cord)
- Lateral cutaneous antebrachial (from musculocutaneous {lateral cord})
- Posterior cutaneous antebrachial (from radial {posterior cord})
What 3 muscles make up the superficial radial extensor group?
(posterior antebrachial region)
Brachioradialis
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)
Supinator
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
- skin
- subcutaneous tissue/fat
- fascia of forearm
- extensor retinaculum (by the dorsal carpal ligament)
- tendons of extensor muscles
- carpal bones
What 2 superficial important veins travel over the posterior carpal region?
Cephalic
Basilic
What are the tendons passing through the 6 extensor compartments in the extensor retinaculum?
(for the posterior carpal region)
Pattern: 221211
- Abductor pollicis longus and extensor pollicis brevis (2)
- extensor carpi radialis longus and brevis (2)
- extensor pollicis longus (1)
- extensor digitorum and extensor indicis (2)
- extensor digiti minimi (1)
- 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)
Contains:
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
