Unit 3: The Muscular SystemLab 2: Muscles of the Appendicular Skeleton

Jessica Radke-Snead, RD, MSBio 241 Anatomy and Physiology

Making Sense of the Muscles

• Description Location Function– Use muscle origins and insertions to describe

where the muscle is located AND what it does• Origin: attachment of a muscle tendon to the

stationary bone • Insertion: attachment of the other muscle

tendon to the moving bone• Action: the movement that occurs at the joint

due to the muscle contraction

Practice

Muscle: Pectoralis MajorOrigin: Clavicle, sternum and ribsInsertion: Greater tubercle and

intertubercular sulcus/groove of humerus

Function: 1. Adducts and medially rotates arm at shoulder

joint (try this yourself!)2. Clavicular head flexes arm3. Sternocostal head extends arm

Muscles: Upper Extremity

• Movement of– Shoulder and arm– Forearm and hand

• Origin/insertion requirement– Shoulder and arm: ALL– Forearm and hand: All BUT flexor carpi radialis, extensor carpi

radialis longus, flexor carpi ulnaris, extensor carpi ulnaris• Cadaver

– Shoulder and arm: All BUT levator scapulae, subscapularis and subclavius

– Forearm and hand: ALL

Muscles: Upper Extremity

Muscles: Upper Extremity

Muscles: Upper Extremity

Muscles: Upper Extremity

Practice

Muscle: Rectus femorisOrigin: Iliac spineInsertion: Patella and tibial tuberosity

Function: 1. Extension at knee2. Flexion at hip

Muscles: Lower Extremity

• Movement of– Femur– Leg and thigh– Leg and foot

• Origin/insertion requirement– Femur: All BUT gluteus minimus, piriformis and illiopsoas– Leg and thigh: ALL– Leg and foot: ALL

• Cadaver requirement– Femur: All BUT illiopsoas– Leg and thigh: All BUT sartorius– Leg and foot: All BUT tibialis posterior

Muscles: Lower Extremity

Muscles: Lower Extremity

Lab Objectives

• Return exam 2—review your exam and the keys– Please see me if you need assistance with course material

• Today: Ensure that you are able to identify each muscle defined in your lab guide, including indicated origins and insertions, on all lab models/diagrams

• Break into 3-4 Cadaver Groups– BEFORE: Review the Lab 2 muscles designated with a (C) – DURING: Please wear a provided lab coat and work

efficiently so as to respect all student’s time spent with the cadavers