Chapter 10- Muscles, Levers, and Torque Lecture Review

Flashcards covering muscle naming conventions, specific muscles and their actions/locations, and the principles of levers, torque, and mechanical advantage in the human body.

Major

A term used in muscle naming to denote 'large'.

Maximus

A term used in muscle naming to denote 'largest', e.g., Gluteus maximus.

Minor

A term used in muscle naming to denote 'small'.

Minimus

A term used in muscle naming to denote 'smallest'.

Longus

A term used in muscle naming to denote 'long'.

Brevis

A term used in muscle naming to denote 'short'.

Rhomboideus

A term used in muscle naming to describe a rhomboidal shape.

Trapezius

A term used in muscle naming to describe a trapezoidal shape.

Teres

A term used in muscle naming to describe a round or cylindrical shape.

Deltoid

A term used in muscle naming to describe a triangular shape.

Capitis

A term used in muscle naming to indicate 'of the head'.

Cervicis

A term used in muscle naming to indicate 'of the neck'.

Pectoralis

A term used in muscle naming to indicate 'of the chest'.

Thoracis

A term used in muscle naming to indicate 'of the thorax'.

Intercostal

A term used in muscle naming to indicate 'between the ribs'.

Abdominis

A term used in muscle naming to indicate 'of the abdomen'.

Femoris

A term used in muscle naming to indicate 'of the femur, or thigh'.

Brachii

A term used in muscle naming to indicate 'of the arm'.

Carpi

A term used in muscle naming to indicate 'of the wrist'.

Digiti

A term used in muscle naming to indicate 'of a finger or toe' (singular).

Digitorum

A term used in muscle naming to indicate 'of the fingers or toes' (plural).

Pollicis

A term used in muscle naming to indicate 'of the thumb'.

Hallucis

A term used in muscle naming to indicate 'of the great toe'.

Superficialis

A term used in muscle naming to indicate a muscle is superficial.

Profundus

A term used in muscle naming to indicate a muscle is deep.

Biceps

A term used in muscle naming to indicate 'two heads'.

Triceps

A term used in muscle naming to indicate 'three heads'.

Quadriceps

A term used in muscle naming to indicate 'four heads'.

Transversus

A term used in muscle naming to indicate a transverse orientation.

Rectus

A term used in muscle naming to indicate a straight orientation.

Oblique

A term used in muscle naming to indicate a slanted orientation.

Adductor

A term used in muscle naming to indicate a muscle's action of adducting (moving toward the midline).

Abductor

A term used in muscle naming to indicate a muscle's action of abducting (moving away from the midline).

Flexor

A term used in muscle naming to indicate a muscle's action of flexing.

Extensor

A term used in muscle naming to indicate a muscle's action of extending.

Pronator

A term used in muscle naming to indicate a muscle's action of pronating.

Supinator

A term used in muscle naming to indicate a muscle's action of supinating.

Levator

A term used in muscle naming to indicate a muscle's action of elevating.

Depressor

A term used in muscle naming to indicate a muscle's action of depressing.

Sternocleidomastoid

A superficial muscle of the neck.

Latissimus dorsi

A broad muscle covering the lower back.

Splenius capitis

A muscle of the neck and back, acting on the head.

Levator scapulae

A muscle that elevates the scapula.

Rhomboideus major

A muscle of the back, deeper than the Trapezius.

Supraspinatus

A rotator cuff muscle located above the spine of the scapula.

Infraspinatus

A rotator cuff muscle located below the spine of the scapula.

Teres minor

A rotator cuff muscle located inferior to the infraspinatus.

Serratus anterior

A muscle that causes lateral rotation, abduction, and protraction of the scapula.

Erector spinae

A group of deep muscles of the back that straighten the vertebral column.

Gluteus maximus

The largest muscle of the buttocks, primarily responsible for hip extension.

Multifidus

A group of deep muscles of the back, providing stabilization to the vertebral column.

Diaphragm

A parachute-shaped muscle essential for breathing, separating the thoracic and abdominal cavities.

Rectus abdominis

A straight muscle of the abdomen, involved in trunk flexion.

Linea alba

A fibrous band running down the midline of the abdomen, where aponeuroses of abdominal muscles meet.

Quadratus lumborum

A muscle of the posterior abdominal wall involved in lateral flexion of the trunk.

Rotator cuff

A collective term for four muscles (Supraspinatus, Infraspinatus, Teres minor, Subscapularis) that stabilize and move the shoulder joint.

Subscapularis

A rotator cuff muscle located on the anterior aspect of the scapula.

Pectoralis major

A large muscle of the chest involved in adduction, flexion, and medial rotation of the humerus.

Triceps brachii

A muscle with three heads located on the posterior arm, responsible for elbow extension.

Biceps brachii

A muscle with two heads located on the anterior arm, responsible for elbow flexion and supination.

Brachialis

A muscle deep to the biceps brachii, a primary elbow flexor.

Iliopsoas

A collective term for the Iliacus and Psoas major muscles, essential hip flexors.

Pectineus

A muscle of the inner thigh that adducts and flexes the thigh.

Adductor magnus

A large muscle of the medial thigh that adducts the thigh.

Gracilis

A long, slender muscle of the medial thigh that adducts the thigh and flexes the knee.

Tensor fascia lata

A muscle involved in hip flexion and abduction, tightening the iliotibial band.

Sartorius

The longest muscle in the body, involved in hip flexion, abduction, and lateral rotation, and knee flexion.

Quadriceps femoris

A group of four muscles (Rectus femoris, Vastus lateralis, Vastus medialis, Vastus intermedius) that are hip flexors and knee extensors.

Hamstring

A group of muscles (Biceps femoris, Semitendinosus, Semimembranosus) located on the posterior thigh, responsible for hip extension and knee flexion.

Gastrocnemius

A superficial muscle of the posterior lower leg, responsible for plantar flexion of the foot.

Soleus

A deep muscle of the posterior lower leg, inferior to the gastrocnemius, responsible for plantar flexion.

Levers of the Body

Bony segments of the skeleton that act as levers.

Axis/fulcrum

In the body, these are the joints around which movement occurs.

Force arm

The perpendicular distance between the line of force application and the axis (also known as moment arm or torque arm).

Resistance arm

The perpendicular distance between the axis and the point/line of resistance application.

Torque

A twisting force, calculated as force multiplied by the force arm (or resistance multiplied by the resistance arm).

Mechanical Advantage (MA)

The relationship between the force arm and resistance arm (MA = FA / RA), ideally allowing a small effort to move a greater resistance.

First-class lever

A lever system where the fulcrum is located between the load and the effort (Load-Fulcrum-Effort), e.g., raising the head off the chest.

Second-class lever

A lever system where the load is located between the fulcrum and the effort (Fulcrum-Load-Effort), e.g., standing on tip-toe.

Third-class lever

A lever system where the effort is located between the load and the fulcrum (Load-Effort-Fulcrum), e.g., flexing the forearm by the biceps brachii.

Mechanical disadvantage (speed levers)

Lever systems where force is lost, but speed and range of movement are gained.

Mechanical advantage (strength levers)

Lever systems that are slower but more stable, used where strength is a priority.

Wheels and axles in musculoskeletal system

Components (usually bone and joint interactions) that enhance range of motion and speed of movement, where a muscle typically moves the axle, and both wheel and axle turn together.