Lab #7 Skeletal Muscle

What is the origin, insertion, innervation, action of the Long Head Biceps Brachii?

Origin: Supraglenoid tubercle of the scapula

Insertion: Radial Tuberosity

Action: Flex the shoulder and elbow/forearm

Innervation: Musculocutaneous

What is the origin, insertion, innervation, action of the Short Head Biceps Brachii?

Origin: Coracoid Process of Scapula

Insertion: Radial Tuberosity

Action: Flex the shoulder and elbow/forearm

Innervation: Musculocutaneous

What is the origin, insertion, innervation, action of the Long Head Triceps Brachii?

Origin: Infraglenoid tubercle of the scapula

Insertion: Olecranon Process

Action: Extend the shoulder and elbow/forearm

Innervation: Radial Nerve

What is the origin, insertion, innervation, action of the Lateral Head Triceps Brachii?

Origin: Posterior shaft of humerus

Insertion: Olecranon Process

Action: Extend the elbow/forearm

Innervation: Radial Nerve

What is the origin, insertion, innervation, action of the Medial Head Triceps Brachii?

Origin: Posterior shaft of humerus

Insertion: Olecranon Process

Action: Extend the elbow/forearm

Innervation: Radial Nerve

What is the origin, insertion, innervation, action of the Deltoid?

Origin: Acromion, Clavicle, Scapular Spine

Insertion: Deltoid Tuberosity

Action: Abduct the arm, medial and lateral rotation, flexion and extension of shoulder

Innervation: Axillary Nerve

What is iliopsoas?

A mixture of illiacus and Psoas major

What is the origin, insertion, innervation, action of the Illiacus?

Origin: Iliac Fossa

Insertion: Lesser trochanter of femur

Action: Flex the hip

Innervation Femoral Nerve

What is the origin, insertion, innervation, action of the Psoas Major?

Origin: Lumbar Vertebrae

Insertion: Lesser trochanter of femur

Action: Flex the hip

Innervation: Femoral Nerve

What is the origin, insertion, innervation, action of the Rectus Femoris?

Origin: Anterior Inferior Iliac Spine

Insertion: Tibial Tuberosity

Action: Extend the knee and hip flexion

Innervation: Femoral Nerve

What is the origin, insertion, innervation, action of the Vastus Lateralis?

Origin: Greater trochanter of the femur

Insertion: Tibial Tuberosity

Action: Extend the knee

Innervation: Femoral Nerve

What is the origin, insertion, innervation, action of the Vastus Intermedialis?

Origin: Intertrochanteric line of the femur

Insertion: Tibial Tuberosity

Action: Extend the knee

Innervation: Femoral Nerve

What is the origin, insertion, innervation, action of the Vastus Medialis?

Origin: Anterior shaft of the femur

Insertion: Tibial Tuberosity

Action: Extend the knee

Innervation: Femoral Nerve

What is the origin, insertion, innervation, action of the Gastrocnemius?

Origin: Medial and Lateral condyles of the femur

Insertion: Calcaneus

Action: Flex the knee and plantar flexion

Innervation: Tibial Nerve

What is concentric?

Shortening action of the muscle

What is eccentric contraction?

Lengthening action of the muscle

What is isometric contraction?

A contraction that creates force without movement

• The muscle length doesn’t change

What is isotonic contraction?

A contraction that creates force and moves a load

• The muscle length does change

During knee flexion the ________________ is the agonist.

Quadriceps muscles

During knee flexion the ________________ is the antagonist.

Hamstring muscles

Name 4 groups of antagonistic muscle groups (Include the hip)

1. Biceps and triceps

2. Hip flexors and gluteal muscles

3. Quadriceps and hamstring muscles

4. Anterior leg muscles and posterior leg muscles

5. Anterior forearm muscles and posterior forearm muscles

Suppose you hold a 10-pound weight steadily in your right hand with your elbow slightly bent, so that you maintain a contraction of your biceps brachii muscle. After some time, you experience pain and it becomes increasingly difficult to keep the weight at the same level.

Using your resources, explain why this is so. (What type of contraction is being used as well)

You are isometric contraction

• Prolonged use of this type of contraction produces muscle fatigue from restrict blood flow and lack of oxygen

One of your patients was injured at work after falling off a ladder. He fell on his back and the doctors report the patient sustained a complete C6 spinal cord injury. List 5 muscles’ origin, insertion, and peripheral nerve supply that may be affected.

1. Palmaris Longus

2. Extensor Digitorum Superficialis

3. Coracobrachialis

4. Pronator Teres

5. Extensor Pollicis Longus

What are your 5 favorite muscles (O, I, I, A)

1. Sartorius

2. Latissimus Dorsi

3. Serratus Anterior

4. Levator Scapulae

5. Pronator Quadratus

What percentage of the body is made of skeletal muscle?

40%

How does skeletal muscles attach to bone?

By tendons made of collagen

What is antagonist muscle group?

Pair of flexor and extensor muscle groups that affect a particular joint

Why must a muscle be long enough?

To permit normal mobility of joints

Why must a muscle be short enough?

To contribute to joint stability

If a muscle is excessive in length and weak, what does it mean for its antagonist?

It is strong but short

What is agonist?

The prime mover that contracts to create movement

What is antagonist

The relaxer that provides resistance or control