Arrangement of Fascicles Annabella Gonzalez Anatomy Physiology Period

Arrangement of Fascicles Annabella Gonzalez Anatomy & Physiology Period 5

Intro • The arrangement of fascicles is an important factor in the force and speed of a muscle. • Fascicles: bundles of fibers • The variety in their arrangements results in muscles that have different functions and shapes • The most common arrangements are circular, parallel, convergent, and pennate.

Circular • • Concentric rings Found sorrounding external body openings Also called sphincter Orbicularis (sorrounding the mouth and eyes)

Orbicularis Oris Circular fascicle arrangement Sphincter

Parallel • The length of the fascicles runs parallel to the long axis of the muscle • Spindle shaped or straplike • Biceps brachii • Sartorius muscle • Sometimes classified under FUSIFORM muscles due to its spindle shape

Parallel, cont. Biceps Brachii Sartorius

Convergent • Converge toward a single tendon of insertion • Triangular or fan-shaped • Pectoralis major muscle

Pectoralis major Convergent fascicle arrangement

Pennate • Short and attach obliquely to one central tendon that runs along the length of the muscle. There are three types: 1. Unipennate: fascicles insert into one side of the tendon (Ex. Extensor digitorum longus) 2. Bipennate: fascicles insert into the tendon from opposite sides (Ex. Rectus femoris) 3. Multipennate: attach obliquely from many directions to several tendons (Ex. Deltoid)

Pennate, cont.

Questions (easy) • What is also called a Sphincter? • What are fascicles?

Questions, cont. (intermediate) • How many different types of pennate fascicle arrangements are there? What are they called?

Questions, cont. (hard) • Define a convergent fascicle arrangement and give an example.

Sources • Textbook Marieb, Elaine Nicpon. Essentials of Human Anatomy & Physiology. Eighth ed. San Francisco: Benjamin Cummings, 2006. Print. • http: //anatomyandphysiologyi. com/muscle-mechanics-fasciclearrangement/ 142703215917995. "Muscle Mechanics: Fascicle Arrangement. " Anatomy & Physiology. N. p. , 23 July 2016. Web. 13 Dec. 2016. • https: //quizlet. com/7557149/fascicle-arrangement-of-musclesflash-cards/ Howells 122. "Fascicle Arrangement of Muscles. " Fascicle Arrangement of Muscles Flashcards | Quizlet. N. p. , n. d. Web. 13 Dec. 2016.