Question

Consider the different muscle fiber arrangement bundles (circular, pennate, parallel, and convergent). Briefly define each organization pattern and pick a muscle that would be defined in that category (i.e., circular arrangement orbicularis oris, parallel arragnement rectus abdominis, convergent pectoralis major, and pennate arrangement deltoid.) You must choose a different muscle for each category that was listed as an example to help you get started.

Next, pick one of the muscles you chose in your arrangement category. Identify a movement that would have that particular muscle be an agonist. Next chose an antagonist and a synergist muscle that would be involved in the movement you identified.

Answer 1

Types of fascicles arrangement pattern in muscles with examples :-

1. Circular -The fascicles are arranged in concentric rings. The site of these muscles are external body openings.Contraction of these muscles will helps in closure of the openings.Eg. Orbicularis oris, orbicularis oculi

2.Convergent - Fascicles will converge towards a single tendon, an aponeurosis or a raphae. Here, muscle has a widespread expansion over an area, then they converge to a single point. Eg - Pectoralis major, temporalis.

3.Parallel - Fascicles run parallel to the long axis of muscle. It can be with spindle (fusiform) shaped fascicles or strap like fascicles.

Eg-Biceps brachi(fusiform), Sartorius( strap like)

4. Pennate - In this type, fascicles are short. They attaches obliquely to a central tendon which runs along the length of muscle. It is again devided into unipennate, bipennate and multipennate

Eg- Rectus femoris

• Biceps brachi :

Function - flexion of elbow

Antagonist muscle - Triceps brachi, which helps in extension of elbow

Synergist muscle - Brachioradialis, it also helps in flexion of elbow.

**Antagonist muscle - oppose the action of agonist muscle

**Synergist muscle - they perform or help to perform the same action of agonist muscle.