Course of Nerves and Arteries

Question 1

o Brachial artery splits into:
o Radial artery
o Ulnar artery

How do they exit the fossa?

Answer 1

Radial artery – leaves through apex of cubital fossa

Ulnar artery – leaves with median nerve beneath pronator teres

Question 2

Where does radial and ulnar nerve sit at elbow joint

Answer 2

Radial nerve is apparent beneath the brachioradialis (lies on the supinator head)
o Superficial branch – leaves fossa travelling deep to brachioradialis
o Deep branch – dips between 2 heads of the supinator to reach back of arm.

Question 3

What does ulnar nerve pierce through to become anterior to posterior to anterior

Answer 3

medial intermuscular septum.

Question 4

Median Nerve:
Describe the ENTIRE flow from cubital fossa
-what does it sit on etc

Answer 4

Exits fossa Deep to pronator teres

Forearm:
o Travels beneath superficial muscles of front of forearm: PT, FCR, PL, FCR

o Travels beneath flexor digitorum superficialis and lies on FDP

Wrist:
o Emerges on:
o Lateral side of superficialis flexor tendons
o Medial side of FCR
o Passes with the flexor tendons through carpal tunnel

Palm:
o After carpal tunnel the median nerve supplies
- Thenar muscles
- 1st lumbrical muscle
- 3 Digital nerves: sensation from skin of:
 Thumb
 up to radial 1/2 3rd digit

The digital nerves, as well as sensation from palmar skin of fingers/thumb, also carry sensation
from nail bed on dorsum of fingers and thumb

Question 5

Ulnar nerve course from cubital fossa

Answer 5

Forearm:
* Enters forearm from behind the medial epicondyle.
* Passes between 2 heads of the flexor carpi ulnaris
* lies on surface of deep muscles of front of forearm.
* Travels down forearm:
o deep to the flexor carpi ulnaris
along medial edge of flexor digitorum superficialis

Wrist:
* Ulnar nerve becomes superficial at the radial side of the FCU tendon (where it inserts into the hamate & metacarpal V)
* Passes onto the surface of the flexor retinaculum
* Lies on radial side of the pisiform bone as it passes over the retinaculum.
* ALSO gives a dorsal cutaneous branch well above the level of the wrist
o Supplies sensation to ulnar side of dorsum of hands and fingers.

Hand:
* As ulnar nerve passes the pisiform bone:
All hypothenar muscles
o All deep muscles of palm:
 All Interosseous muscles
 Adductor pollicis
 Medial 2 lumbricals (lateral 2 are supplied by median nerve)

Question 6

Radial Nerve course

Answer 6

Superficial branch of radial nerve:
* Cutaneous
* Travels down forearm with the radial artery
* Travels deep to the the brachioradialis
* At end of radius, winds around the back of the forearm = passes over anatomical snuff-box

Supplies sensitivity to dorsal side of hand:
o Back of hand
o Thumb
o Index & middle fingers
o Radial half of ring finger
* Doesn’t supply nail beds – supplied by the median nerve

Deep branch:
* Passes between the two heads of the supinator muscle onto posterior aspect of arm

Question 7

Radial Artery

Answer 7

Both the superficial branch of radial nerve and the radial artery travel beneath the
brachioradialis muscle

WRIST AND HAND:
* Passes around lower end of radius and crosses anatomical snuff-box
* Reaches 1st intermetacarpal cleft
* Dips between the two heads of the 1st dorsal interosseous muscle

• Radial artery continues between the two heads of the adductor pollicis muscle
• Arrives in intermediate compartment of palm, deep to all the long flexor tendons of the palm.
• On the surface of the metacarpals, beneath the long tendons, the radial artery here forms the
  deep palmar arch, by anastomosing with the deep branch of the ulnar artery on the ulnar side of
  the palm.

Question 8

Ulnar Artery

Answer 8

Leaves the cubital fossa passing deep to the pronator teres.

Deep branch:
* Deep branches of the both the ulnar artery and nerve curve around the hook of the hamate
* Sink between the hypothenar muscles to gain deep plane of palm
* Deep branch of the ulnar artery then anasomoses with the termination of the radial artery to
form the deep palmar arch.

• Superficial branch:
• Continues over the flexor retinaculum
• Arches in a superficial plane over the palm to form the superficial palmar arch.
• Superficial palmar arch is completed by anastomosing with a small branch of radial artery.
• Arteries pass from the arch to the digits