13 - Gross Anatomy of the Muscular System

What does the Deltoid muscle’s name tell us about its shape?

Triangular-shaped.

If a muscle is named Flexor Carpi Radialis, what does it do?

Flexes the wrist on the radial (thumb) side.

What is the function of a synergist muscle?

Assists the prime mover.

What muscle group stabilizes the shoulder joint?

Rotator cuff muscles.

What muscle is the prime mover for forearm flexion?

Biceps Brachii.

What muscle is the antagonist to the Biceps Brachii?

Triceps Brachii.

What muscle assists the Biceps Brachii as a synergist in forearm flexion?

Brachioradialis.

What muscle is responsible for forearm extension?

Triceps Brachii.

What is the prime mover for arm flexion?

Pectoralis Major.

What muscle is the prime mover for arm abduction (raising the arm sideways)?

Deltoid.

What muscle group is the prime mover for knee extension?

Quadriceps (Rectus Femoris).

What lower limb muscle is responsible for plantar flexion (pointing the toes)?

Gastrocnemius.

What muscle group is the prime mover for knee flexion?

Hamstrings.

What muscle flexes the vertebral column (helps with sit-ups)?

Rectus Abdominis

What muscle is responsible for thigh flexion & abduction (used when crossing legs)?

Sartorius (“Tailor’s Muscle”).

Where is the origin of the Biceps Brachii?

Scapula (Shoulder Blade).

Where is the insertion of the Triceps Brachii?

Olecranon of the Ulna (Elbow).

Where is the origin of the Rectus Femoris (Quadriceps)?

Ilium (Hip Bone)

Where is the insertion of the Gastrocnemius (calf muscle)?

Calcaneus (Heel Bone) via Achilles Tendon.

What is the insertion of the Sternocleidomastoid?

Mastoid Process (Temporal Bone, behind the ear).

What muscle inserts into the Ischium?

Adductor Magnus

What muscle is used for smiling?

Zygomaticus.

What muscle is used for jaw closure (chewing)?

Massater

What muscle is used to raise the eyebrows?

Frontalis.

What muscle is responsible for head rotation and tilting the head toward the shoulder?

Sternocleidomastoid

What muscle sucks in the cheeks (used for whistling)?

Buccinator.

What muscle is used for blinking and squinting?

Orbicularis Oculi

What muscle pulls the corners of the mouth downward (pouting)?

Depressor Anguli Oris.

What muscle elevates the rib cage during breathing?

External Intercostals.

What muscle group assumes major responsibility for forming the abdominal wall?

Rectus Abdominis.

What muscle pulls the scapula forward and downward?

Pectoralis Minor.

What muscle moves the scapula forward & rotates it upward?

Serratus Anterior.

What muscle extends the fingers?

Extensor Digitorum.

What weak hand flexor tenses palm skin?

Palmaris Longus

What two muscles are responsible for plantar flexion (pointing the toes)?

Gastrocnemius & Soleus.

What muscle is responsible for extending the toes?

Extensor Digitorum Longus.

What muscle helps plantar flex & evert the foot?

Fibularis Longus.

What muscle adducts the thigh (used when standing at attention)?

Adductor Longus.

What two quadriceps muscles extend the leg and stabilize the knee?

Vastus Lateralis & Vastus Medialis.

What muscle is commonly affected by lateral epicondylitis (“tennis elbow”)?

Extensor Carpi Radialis Brevis.

What muscles contract during bruxism (teeth grinding)?

Massater, Temporalis, Medial & Lateral Pterygoid muscles.

Name two muscles that are named based on their location.

Temporalis (on the temporal bone), Intercostals (between the ribs).

Name the two muscles that are named based on their shape.

Deltoid & Trapezius

Name two muscles that are named based on their size.

Gluteus Maximus & Pectineus

Name two muscles that are named based on their fiber Direction.

Rectus Abdominis (straight), Transversus Abdominis (horizontal).

Name two muscles that are named based on the number of Origins.

Biceps Brachii (2 origins), Triceps Brachii (3 origins).

Name two muscles that are named based on the location of attachments.

Sternocleidomastoid (sternum & clavicle), Brachioradialis (arm & radius).

Name two muscles that are named based on their action.

Flexor Carpi Radialis (flexes wrist), Extensor Digitorum (extends fingers).