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Arrangement of Fascicles
MELANIE HERRERA
fascicles
A fascicle is several sheathed muscle fibers wrapped by a coarse fibrous
membrane
Different types

Circular

Convergent

Parallel

Pennate

Unipennate

Multipennate

Fusiform

Bipennate
Circular

When fascicles are arranged in concentric rings (sphincters)

Circular muscles are typically found surrounding external body opening
which they close by contracting

Examples are the orbicularis muscles surrounding the eyes and the mouth.
Convergent

When the fascicles converge to a single insertion

Triangular or fan-shaped

A broad area converges on attachment

site (tendon, aponeurosis, or raphe)

Muscle fibers pull in different
depending on stimulation
directions,
Parallel

The length of the muscle runs parallel to the long axis of the muscle

Strap likeFibers parallel to the long axis ofmuscle

Most skeletal muscles are arranged this way

The center or body of the muscle
thickens when parallel muscle contracts

Parallel muscles contract extensively

However, some scientists classify spindle-shaped muscles into a separate
class as fusiform muscles.
Pennate

Short fascicles

Attach obliquely to a central
tendon

Three type of forms:

Unipennate

Bipennate

multipennate
• Pennate = “feather-like”
• Form an angle with the tendon
• Do not move as far as parallel
muscles
• Contain more myofibrils than
parallel muscles
• Develop more tension than
parallel muscles
unipennate

insert into one side of the tendon

fibers angled on 1 side of tendon

– e.g., extensor digitorum
Bipennate

inserts into opposite sides of the tendon

fibers angled on both sides of tendon

– e.g., rectus femoris
multipennate

inserts into multiple places of the tendon

tendon branches within muscle

A muscle with several tendons of origin and several tendons of insertion, in
which fibers pass obliquely from a tendon of origin to a tendon of insertion
on each side

e.g., deltoid
Overview
Your text here
Different types of fascicles and
where they can be found.
Video presentation
https://www.youtube.com/watch?
v=FhYPCQ0Ix9E
Question 1

Sphincter muscles consist of which arrangement of fascicles?

A. parallel

B. Circular

C.Pennate
Answer A
Question 2

When the arm is flexed, the biceps brachii bulges in the middle. This type of
muscle consists of __________ fascicles

A.Parallel

B.circular

C.Pennate
Answer C
Question 3

Muscle fibers are bundled into groups known as

A myotendrils

B endomysium

C myosin

D.fascicles
Answer D
Bibliography

“Muscle mechanics: Fascicle arrangement.” Muscular. Anatomy &
Physiology, 11 July 2014. Web. 15 Dec. 2016.

Marieb, Elaine Nicpon N. Essentials of Human Anatomy and Physiology.
9th ed. San Francisco: Benjamin-Cummings Publishing Company, Subs of
Addison Wesley Longman, 2009. Print.

Dr. Lorena Canelon. “1. Arrangement of Fascicles in Muscles.” YouTube.
YouTube, 21 June 2016. Web. 15 Dec. 2016.