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