The Muscular System: The Body's Powerhouse!!

Hello to all anatomy lovers!!! We just completed our last bones quiz and now we can say so long for a little while!! Yeah!!! We are off to bigger and better things; the muscles. It was quite the experience this past week having a first good look at the cadavers. Most my students would ask me, "How do you tell the muscles apart? They all look the same to me!" Well, as your TA I have a few tricks up my sleeve, most of which I am sure will be of great benefit to you. But let me be honest, I had the exact same thoughts cross my head when I first took the class too. So here are some things to remember when studying and learning the muscles:

1) Look for the muscles striations. When you do this you will be able to see the boundaries and tell how many muscles are in a certain area.

2) Pay attention to the muscle names. Most names give you lots of information regarding where the muscle is in the body. Here are a few examples:

Sternocleidomastoid: Tells you the origin and the insertion of the muscle all in its name. Originates on the sternum and clavicle and inserts behind the ear on the mastoid process.

Frontalis: Tells you which bone it sits on; the frontal bone.

Supraspinatus: Another muscle that tells you right where it is; the supraspinous fossa of the scapula.

Biceps Brachii: A few muscles on the arm have one or two heads. In open lab see if you can find the two heads of the biceps brachii. One goes to the supraglenoid tubercle and the other goes to the coracoid process. Both heads then join at the insertion which is the radial tuberosity of the radius bone.

These are just a few examples of some muscles that give hints as to where they are on the body. As you study, take a few moments to find a connection between where a muscle sits in the body and its name. You will be surprised how much faster you learn!

3) With regards to the forearm muscles, here are some things to always remember:
Longus = long tendon
Brevis = short tendon. Brevis muscles can usually be seen on both sides of the longus tendon.
Carpi = carpals (wrist). The term carpi always comes before radialis or ulnaris in the name. (example: extensor carpi ulnaris and flexor carpi radialis)
Digitorum = digits (fingers). These muscles can always be found in between the radialis and ulnaris muscles on the flexor and extensor sides of the forearm.
Pollicis = thumb
Ulnaris = ulna
Radialis = radius
Remember Extensor vs Flexor. Always remember that in anatomical position, extensor muscles will be on the posterior side and flexor muscles will be on the anterior side. (Review: Anterior means toward the front of the body and posterior means toward the back of the body. Anatomical position means that you are standing upright, your feet are parallel and flat on the floor, your head is level with your eyes facing forward, arms are at your sides with your palms facing anteriorly and your thumbs are pointing laterally or away from the body.)

Now here are a few fun mnemonics to help you in remembering all these muscles. If you think of any new ones or different ways to remember the names, let me know by leaving a blog post!

Epicranius
Galea Aponeurotica: Gay (happy) Ape scratches the top of his head
Corrugator Supercilii: An interrogator would eye you down while interviewing you

Circular Muscles: Orbit - Circular
Orbicularis oculi: oculi - eye
Orbicularis oris: oral - mouth

Muscles of the Neck
Semispinalis: semi spine (directly above spine)
**You can only semi see the semispinalis
Splenius capitis: location of receiving a splendid massage

Depressors
Depressor labii inferioris: frowning muscles; forms the rainbow under your lips
Depressor anguli oris: the triangular muscles at the corners of your mouth

Scapular Muscles
Rhomboids: resembles a rhombus
Serratus Anterior: think of the serrated edge of a saw
Latissiums dorsi: dorsal (posterior)

Upper Arm
Biceps brachii: two headed
Triceps brachii: three headed
Anconeus: resembles a cone
Brachioradialis: extends from the brachial region to the radial region

The 5 Member Family: Begins and ends with longus: longus, brevis, longus, brevis, longus
Extensor carpi radialis longus: tall twin
Extensor carpi radialis brevis: short twin
Abductor pollicis longus: awkward third child that gets abducted (only abductor)
Extensor pollicis brevis: extends the thumb
Extensor pollicis longus: extends the thumb

There you have it!! I hope these help for you quiz on the upper muscles. If you have any suggestions to make these posts better, please let me know. Happy studying!!!