N3 Anatomy and Physiology AY 2023-2024

Activity 3

1. It is immunization day at the health center. The first patient is a 2-month old well female infant who is scheduled for the following vaccinations: pneumococcal conjugate vaccine (PCV), pentavalent vaccine (Penta) and oral polio vaccine. PCV and Penta are given via intramuscular route. Where are the sites of injection? What muscle is targeted in the injection? Write down its origin, insertion and action. How do you locate this area? 

   1. Site of injection: Anterolateral portion of the thigh

   2. Muscle targeted in injection: Vastus Lateralis

      1. Origin: Greater trochanter and linea aspera of femur.

      2. Insertion: Patella via quadriceps tendon and then tibial tuberosity via patellar ligament.

      3. Action: All four heads extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint.

   3. How to locate this area: Medications are injected into the bulkiest part of the vastus lateralis thigh muscle, which is the junction of the upper and middle thirds of this muscle.

2. The baby’s 65-year-old grandfather also came to the center because influenza vaccine is being offered to senior citizens. The flu vaccine is given intramuscularly. Which muscle is the preferred site for IM injection in this case? Write down its origin, insertion and action. How do you locate this area?

   1. Site of injection: Arm

   2. Muscle targeted in injection: Deltoid

      1. Origin: Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of scapula (posterior fibers).

      2. Insertion: Deltoid tuberosity of humerus.

      3. Action: Lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially rotate arm at shoulder joint; posterior fibers extend and laterally rotate arm at shoulder joint.

   3. How to locate this area: The deltoid muscle is located in your shoulder. The brachial artery and the radial nerve sit behind the deltoid and come down from the muscle. The injection site is a smaller triangle-shaped area, in the middle of the deltoid, above the deltoid tuberosity.

References:

Tortora, G. J., & Derrickson, B. H. (2017). Principles of Anatomy & Physiology. Wiley.