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