Anatomy Chapter 11 - The Muscular System
Flexor muscle
Decreases angle at the joint
What muscle pair plays a role in respiration?
Diaphragm and scalene
Origin
End of a skeletal muscle that is attached to another structure in a fixed position
Insertion
End of a skeletal muscle that is attached to the structure that is moved when the muscle contracts
Gluteus Maximus
Extensor
Which muscle name does not make sense?
Extensor minimus longus
What effect does fascicle arrangement have on a muscle's action?
Fascicle arrangements determine what type of movement a muscle can make For instance, circular muscles act as sphincters, closing orifices
Pennate muscle
Fascicles that are arranged based on their angles to the tendon
Convergent muscle
Fascicles that extend over a broad area and converge on a common attachment site Ex.: pectoralis major
Why is the rotator cuff important?
Forms a foundation on which the arms and shoulders can be stabilized and move
Biceps Brachii
Fusiform
What is the largest muscle in the lower leg?
Gastrocnemius
The large muscle group that attaches the leg to the pelvic girdle and produces extension of the hip joint is the __________ group.
Gluteal
Semimembranosus
Hamstring
Biceps Femoris
Hamstring Fusiform
Semitendinosus
Hamstring Fusiform
Parallel muscle
Has a pattern of fascicles running along the long axis of the muscle Ex.: Rectus abdominis; belly
Synergist
Helps a prime mover in an action Helps an agonist work
Fixator
Holds origin firmly in place
Extensor muscle
Increases angle at the joint
Medialis
Inside
Latissimus Dorsi
Larger, flat, dorsolateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal regio
Maximus
Largest
Longus
Long
Medius
Medium
Why are the muscles of the face different from typical skeletal muscle?
Most skeletal muscles create movement by actions on the skeleton. Facial muscles are different in that they create facial movements and expressions by pulling on the skin—no bone movements are involved
Abductor
Moves bone away from midline
Adductor
Moves bone towards midline
Internal oblique
Muscle in the abdominal wall that lies below the external oblique
Transversus Abdominus
Muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle
Fusiform
Muscle that has fascicles that are spindle-shaped to create large bellies
Movements of the body occur at joints. Describe how muscles are arranged around the joints of the body.
Muscles work in pairs to facilitate movement of the bones and joints Agonists are the prime movers Antagonists oppose the movements of the agonists Synergists assist the agonists Fixators stabilize a muscle's origin
Where is the temporalis muscle located?
On the side of the head
Trapezius
One of two large superficial muscles that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula
Antagonist
Opposes the action of an agonist Ex.: triceps brachii; quadriceps femoris
Which is moved the least during muscle contraction?
Origin
Lateralis
Outside
Rectus abdominus
Parallel
Deltoid
Pennate
Extensor Digitorum
Pennate
What is the function of the erector spinae?
Postural support
Which abdominal muscle is not a part of the anterior abdominal wall?
Quadratus lumborum
Vastus Intermedius
Quadriceps
Vastus Lateralis
Quadriceps
Vastus Medius
Quadriceps
Rectus Femoris
Quadriceps Fusiform
Sartorius
Quadriceps Parallel
The vastus intermedius muscle is deep to which muscle?
Rectus femoris
Perineum Muscles
Region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone)
Agonist (prime mover)
Responsible for producing a particular motion Ex.: biceps brachii; hamstrings
Brevis
Short
Minimus
Smallest
External and internal intercostal muscles
Span spaces between ribs Assists in breathing by changing dimensions of rib cage
Rectus
Straight
What happens during flexion?
The angle between bones is decreased
Where is the inferior oblique muscle located?
The eye socket
How do the muscles that form the hamstrings function together?
The hamstrings flex the leg at the knee joint
What is the origin of the wrist flexors?
The medial epicondyle of the humerus
Which arrangement best describes a bipennate muscle?
The muscle fibers feed in on an angle to a long tendon from both sides
Which muscle produces movement that allows you to cross your legs?
The sartorius
What is unique to the muscles of face expression?
They insert into the skin
Tri
Three
The rhomboid major and minor muscles are deep to the __________.
Trapezius
Which muscle extends the forearm?
Triceps brachii
Bi
Two
External oblique
Unipennate Largest and most superficial of the three flat muscles of lateral anterior abdomen
Describe the different criteria that contribute to how skeletal muscles are named.
Word roots are Latin or Greek Portions of the word give clues about the function, shape, or action of the muscle
The names of the extrinsic tongue muscles commonly end in __________.
-glossus
What is the linea alba?
A long tendon that runs down the middle of the rectus abdominis
Sternocleidomastoid
A prime mover in head flexion
The location of a muscle's insertion and origin can determine __________.
Action
Explain how a synergist assists an agonist by being a fixator.
Agonists are the prime movers while antagonists oppose or resist the movements of the agonists Synergists assist the agonists, and fixators stabilize a muscle's origin
Oblique
Angled
Describe the fascicle arrangement in the muscles of the abdominal wall. How do they relate to each other?
Arranged into layers The muscles of the abdominal wall are the internal and external obliques, which run on diagonals The rectus abdominis runs straight down the midline of the body The transversus abdominis wraps around the trunk of the body
Describe the muscles of the anterior neck.
Arranged to facilitate swallowing and speech
Which muscles stabilize the pectoral girdle?
Axial and scapular
Explain the difference between axial and appendicular muscles.
Axial muscles originate on the axial skeleton (the bones in the head, neck, and core of the body) Appendicular muscles originate on the bones that make up the body's limbs
Gastrocnemius
Bipennate
What is the action of the masseter?
Chewing
Sphincter
Circular muscle Fascicles that are concentrically arranged around an opening
Patellar Ligament
Common tendon of the quadriceps femoris
Diaphragm
Contracts and retracts for inhalation Agonist
Pectoralis Minor
Convergent Situated at the upper part of the chest