Day 41 Anatomy Review

Good evening.

I've been thinking that I originally started this blog to update my life through the trials and tribulations of medical school, yet I have written about very few medical things. Well, tonight, on the eve of my Anatomy Lab Practical, I've decided to give you all a little lesson in anatomy. Now, this post won't be for everyone, but bear with me.

BTW, thank you Spice for the words of encouragement. I appreciate it...

Ok, today's lesson is going to be about the upper limb, aka the arm. I am going to do all of this through memory, so we will see how far it takes us.

We will start with what I know best. Nerves. Your arm is innervated by the brachial plexus, which is comprised of the ventral roots of spinal nerves C5, C6, C7, C8, T1. These 5 roots form into 3 trunks, superior, middle, inferior. Off of the superior we have the dorsal scapular which goes to ur rhomboids major/minor, and levator scapulae, the supraspinatus nerve, and the subclavical nerve. From the 3 trunks we have 3 anterior and posterior divisions, which form 3 cords, lateral, medial, and posterior. Off of the lateral cord we have the lateral pectoral nerve. Off of the medial cord we have the medial pectoral nerve, the medial cutaneous branch of the arm, and the medial cutaneous branch of the forearm. The posterior cord gives rise to the upper subscapular, the lower subscapular, and the thoracodorsal nerve. These 3 cords give rise to 5 main branches of the brachial plexus, the musculocutaneous, the axial, the radial, the medial, and the ulnar. Remembered by the mnuemonic, and i quote "My Aunt Raped My Uncle." Yes, medical minds are so smart.

Musculocutaneous: flexor muscles of the arm (bicep, brachials, coracobrachials)

Axillary: deltoid, teres minor

Radial: All the extensor muscles of the arm, forearm, and hand (about 15)

Medial: Most of the flexors of the forearm (about 15)

Ulnar: Most of the muscles involved in your ring finger and pinky (about 8, yeah, I said 8)

Each of the branches have minor branches coming off of them as well. Easy stuff, right?

Next, lets move on to ARTERIES!! My weakness.

The axillary artery arises from the subclavian artery. There are 6 major branches off the axillary remember by, "She Tastes Like Sweet Apple Pie."

1) Superior Thoracic which divides into 3 branches

2) Thoracoacromial: ABCD

- acromial branch

- (Breasts) = Pectoral branch

- clavicular branch

- deltoid branch

3) Lateral Thoracic

4) Subscapular

5) Anterior humeral circumflex

6) Posterior humeral circumflex

Each of these have various branches that you must know, but I'll most on, so at this point we started just before your shoulder, now we are at about an inch below your armpit...yes all those are in a 4 inch span...mmm hmmm, FML.

The axillary artery turns into the brachial artery which has a few branches of its own.

1) Profundii Brachi (which in itself is just as important and complicated as the actual brachial artery its just the artery for the back of the arm)

2) Superior Ulnar Collateral

3) Inferior Ulnar Collateral

Each with their own branches

Then the brachial artery splits into the radial and ulnar artery. Both of those are as complicated as the previous. They take blood from the elbow to through the hand and back. And yes, anastomses. That word means that each of the arteries connect with one another looping around circling back and forth so if one gets constricted the others will work. FML.

Okay, enough.

Now, each of these nerves and arteries all have specific muscles that they supply. The 50 some muscles in one of your arms. I never even mentioned the 25 some bones in each arm. Oh yes, they need to be supplied as well. Each muscle has a tendon. There are 50 some ligaments. There are disorders to go with each nerve as well. Claw hand, Ape thumb deformity, Colles fracture, wrist drop. Hand of Benediction. And this is just the ARM!!!

The lab tomorrow covers the arm and back/spinal cord. ALL of this information is far game, plus the loads I left out. Dr. S, how may questions are there to test all of your knowledge? 40!!!!!!!!!!!!! Are you shitting me?! FFFFFFFMMMMMMMMMMMLLLLL.

Class dismissed,

Dr. Samsun