BIO201 LESSON 9 THE MUSCULAR SYSTEM II

facial muscles

• Epicranius • Orbicularis oris • Zygomaticus • Platysma

The muscles that stabilize the pectoral girdle make it a steady base on which other muscles can move the arm. Note that the pectoralis major and deltoid, which move the humerus, are cut here to show

Pectoral Girdle muscles

Anterior Trunk Muscles

Pectoralis major Deltoid Rectus abdominis External oblique Internal oblique Transversus abdominis

neck muscles is to move the head and shoulder girdle. The neck muscles include:

Platysma Sternocleidomastoid

Moves eyes down and away from nose; rotates eyeball from 6 o'clock to 9 o'clock

Superior oblique

Moves eyes up and toward nose; rotates eyes from 1 o'clock to 3 o'clock

Superior rectus

Fascicle

When a group of muscle fibers is "bundled" as a unit within the whole muscle by an additional covering of a connective tissue called perimysium

convergent muscles

When a muscle has a widespread expansion over a sizable area, but then the fascicles come to a single, common attachment point, the muscle is called

A nursing infant develops a powerful sucking muscle that adults also use for whistling called the

buccinator

The ___________ is the largest, strongest tendon in the body

calcaneal tendon (Achilles tendon)

Mastication

chewing

The muscles that are found at openings of the body are collectively called:

circular muscles

Fascicles can display a

circular, convergent, parallel, or pennate pattern

Orbicularis oculi

closes eye

Temporalis

closes jaw

orbicularis oris

closes lips

Masseter

closes the jaw

Transversus abdominis

compresses abdominal contents

Buccinator

compresses cheek

internus=

internal

To exhale forcibly, one would contract the:

internal intercostals and diaphragm

What is a fascicle?

is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue

The first part of orbicularis, orb (orb = "circular")

is a reference to a round or circular structure

bipennate muscle

muscle fibers on both sides of the tendon; rectus femoris

multipennate muscle

muscle fibers wrap around the tendon, sometimes forming individual fascicles in the process

Occipitofrontalis

muscle moves up the scalp and eyebrows

Synergist

muscle that aids a prime mover in a movement and helps prevent rotation

prime mover or agonist muscle

muscle with the major responsibility for a certain movement

intercostal muscles

muscles between the ribs

In a pennate muscle pattern:

muscles look like a feather

Based on their movements, muscles can be classified into four functional groups

prime movers, antagonists, synergists, and fixators

Severing of the patellar tendon would inactivate the

quadriceps group

Zygomaticus

raises the corners of the mouth upward (smiling)

Trapezius

raises, rotates, retracts, and stabilizes the scapula.

bi/di=

two

Sub =

under

The extensor digitorum longus has which type of fascicle arrangement?

unipennate

There are three subtypes of pennate muscles.

unipennate bipennate multipennate

digastric muscle

work to elevate the hyoid bone and larynx when one swallows; it also depresses the mandible

corrugator supercilii

wrinkles brow

The moveable end of the muscle that attaches to the bone being pulled is called the muscle's

insertion

stylohyoid muscle

moves the hyoid bone posteriorly, elevating the larynx

Pennate muscles

(penna = "feathers"), blend into a tendon that runs through the central region of the muscle for its whole length, somewhat like the quill of a feather with the muscle arranged similar to the feathers

A muscle that provides the major force for producing a specific movement is called:

An agonist

facilitate swallowing and speech. The suprahyoid muscles originate from above the hyoid bone in the chin region. The infrahyoid muscles originate below the hyoid bone in the lower

Anterior Neck muscles

flexor

Decreases the angle of a joint

Epicranius has two functions:

Frontalis raises the eyebrows. Occipitalis pulls the scalp posteriorly.

Moves eyes up and away from nose; rotates eyeball from 12 o'clock to 9 o'clock

Inferior oblique

Moves eyes down and toward nose; rotates eyes from 6 o'clock to 3 o'clock

Inferior rectus

Moves eyes away from nose

Lateral rectus

Opens eyes

Levator palpabrae superioris

chewing (mastication) muscles include

Masseter Temporalis Buccinator

Moves eyes toward nose

Medial rectus

The skeletal muscles of the body typically come in seven different general shapes.

Muscle Shapes and Fiber Alignment

The muscles that move the lower jaw are typically located within the cheek and originate from processes in the skull. This provides the jaw muscles with the large amount of leverage needed for chewing.

Muscles That Move the Lower Jaw

Many of the muscles of facial expression insert into the skin surrounding the eyelids, nose and mouth, producing facial expressions by moving the skin rather than bones.

Muscles of facial expression

The superficial and deep muscles of the neck are responsible for moving the head, cervical vertebrae, and scapulas.

Posterior and Lateral Views of the Neck.

The insertion of the biceps brachii is on the ________

Radius

extrinsic eye muscles

Six muscles attach to the outer surface of the eye and produce eye movements

Belly of the muscle

The middle part of the muscle

Muscle Shapes and Fiber Alignment.

The skeletal muscles of the body typically come in seven different general shapes.

Muscles are only able to pull, they never push.

True

Latissimus Dorsi

adducts and medially rotates the arm, and is the prime mover of arm extension.

Deltoid

adducts and medially rotates the arm, and is the prime mover of arm flexion.

Pectoralis major

adducts and medially rotates the arm, and is the prime mover of arm flexion.

Gracilis

adducts thigh

Deltoid

adducts, and is the prime mover of arm abduction.

away from, to move

abductor, ab = duct =

Which of the following muscles is a flexor of the thigh?

adductor magnus

to, toward, to move

adductor, ad = , duct=

anti=

against

What do geniohyoid, hyoglossus, and stylohyoid have in common?

all act on the tongue

unipennate muscle

all the muscle fibers are on the same side of the tendon

suprahyoid muscles

are a group of muscles that lie superior to the hyoid bone and help form the floor of the oral cavity

Circular muscles

are also called sphincters, orbicularis oris muscle is a ______ that goes around the mouth

Which of the following muscles is involved in abduction?

deltoid

geniohyoid muscle

depresses the mandible in addition to raising and pulling the hyoid bone anteriorly.

Muscle spasm of the back would often include the

erector spinae

extensor carpi radialis brevis

extends and abducts the wrist and is short

Erector Spinae

extends and bends the vertebral column laterally

extends and abducts wrist

extensor carpi radialis longus and brevis

extends thumb

extensor pollicis longus and brevis

externus=

external

The arrangement of a muscle's __________ determines its range of motion and power

fascicles

What muscle is responsible for keeping your toes from dragging when walking?

fibularis tertius / peroneous tertius

Scissors demonstrate which type of lever?

first class lever

Muscles that help to maintain posture are often called

fixators

External oblique

flexes and rotates the vertebral column, and rotates and laterally flexes the trunk.

Internal oblique

flexes and rotates the vertebral column, and rotates and laterally flexes the trunk.

Rectus abdominis

flexes and rotates the vertebral column.

Sternocleidomastoid

flexes neck; rotates head

Flexes the wrist

flexor carpi ulnaris

Powerful wrist flexors that also stabilize the wrist during finger extension

flexor carpi ulnaris

Slow-acting finger flexor

flexor digitorum profundus

Valsalva maneuver

forcible exhalation against a closed glottis, resulting in increased intrathoracic pressure

quad=

four

A cute, little curly haired child is sitting behind you in church. You turn around for a moment and she sticks her tongue out at you. Which tongue muscle did she use?

genioglossus

A muscle located on the dorsal side of the body is the:

infraspinatus

Paralysis of which of the following would make an individual unable to flex the knee?

hamstring muscles

Parallel muscles

have fascicles that are arranged in the same direction as the long axis of the muscle

Paralysis of which of the following would make an individual unable to flex the thigh?

iliopsoas and rectus femoris

First-class levers:

in the body can operate at a mechanical advantage or mechanical disadvantage, depending on specific location

Trunk muscles

include the muscles that move the vertebral column; the anterior thorax muscles that move the ribs, head, and arms; and the muscles of the abdominal wall that help to move the vertebral column and form the muscular support of the abdominal body wall

extensor

increases the angle of a joint

Maximus=

largest

The broadest muscle of the back is the ________

latissimus dorsi.

first-class, second-class, and third-class levers

levers may be classified as; third-class levers are the most common type of lever of the body.

mylohyoid muscle

lifts it and helps press the tongue to the top of the mouth

If a lever operates at a mechanical disadvantage, it means that the

load is far from the fulcrum and the effort is applied near the fulcrum

Longus=

long

longissimus=

longest

Posterior

major muscles of the body

anterior view

major muscles of the body

multi=

many

The chewing muscle covering the ramus of the mandible is the _______

masseter muscle

Adductor magnus, adductor longus, and adductor brevis are parts of a large muscle mass of the:

medial compartment of the thigh

medius=

medium

gluteus medius

medium muscle of the buttock

abductor

moves bone away from midline

adductor

moves bone toward midline

epi=

on top of

uni=

one

Closes eyelids

orbicularis oculi

the end of the muscle attached to a fixed (stabilized) bone is called the

origin

hyoglossus

originates on the hyoid bone to move the tongue downward and flatten it.

genioglossus

originates on the mandible and allows the tongue to move downward and forward

Palatoglossus

originates on the soft palate to elevate the back of the tongue,

styloglossus

originates on the styloid bone, and allows upward and backward motion

Example of convergent muscle

pectoralis major

Movements of the thigh are accomplished by muscles anchored to the ___________

pelvic girdle

glossus

refers to the tongue

Brevis=

short

gluteus minimus

smallest and deepest gluteal muscle

ductor=

something that moves

Fixator

stabilizes the origin of a prime mover

Spasms of this straplike muscle often result in wryneck or torticollis.

sternocleidomastoid

rectus=

straight

A muscle group that works with and assists the action of a prime mover is a(n):

synergist

Platysma

tenses skin of neck

deglutition

the act of swallowing

Tennis players often complain about pain in the arm (forearm) that swings the racquet. What muscle is usually strained under these conditions?

the brachioradialis

What is the major factor controlling the manner in which levers work?

the difference in the positioning of the effort, load, and fulcrum

With regard to muscle fiber arrangement in a pennate muscle

the fascicles are short and attach obliquely to a central tendon that runs the length of a muscle

To produce horizontal wrinkles in the forehead, which of the following muscles is involved?

the frontalis

Which of the following muscles inserts by the calcaneal tendon?

the gastrocnemius

gluteus maximus

the largest muscle of the buttock

The names of muscles often indicate the action of the muscle. When the term levator is part of the descriptive term for a muscle's action, this means that:

the muscle elevates and/or adducts a region

When the term biceps, triceps, or quadriceps forms part of a muscle's name, you can assume that

the muscle has two, three, or four origins, respectively

Which of the following muscles is involved in crossing one leg over the other while in a sitting position?

the sartorius

Which group of muscles flexes and rotates the neck?

the scalenes

What primarily determines the power of a muscle?

the total number of muscle cells available for contraction

Which of the following muscles serves as a common intramuscular injection site, particularly in infants?

the vastus lateralis

Which of the following statements is true regarding the total number of skeletal msucles in the human body?

there are over 600 muscles in the body

antagonistic muscles

they maintain body or limb position, such as holding the arm out or standing erect, they control rapid movement, as in shadow boxing without landing a punch or the ability to check the motion of a limb.

tri=

three

Which of the following muscles is involved in inversion at the ankle joint?

tibialis anterior

Minimus=

tiny; little

The supraspinatus is named for its location on the posterior aspect of the scapula above the spine. What is its action?

to stabilize the shoulder joint and help prevent downward location of the humerus and to assist in abduction

apo=

to the side of

posterior trunk muscles

trapezius, latissimus dorsi, erector spinae, deltoid

In flexing the forearm at the elbow, the:

triceps brachii acts as antagonist