Muscle Lecture – Summarized Notes

These flashcards cover key vocabulary from the muscle lecture for exam review.

Agonist

The main muscle doing an action.

Antagonist

The muscle that does the opposite action of the agonist.

Synergist

A muscle that helps the agonist and reduces unwanted movement.

Fixator

A muscle that stabilizes a bone or joint.

Myotomes

Embryonic tissues that give rise to muscle.

Somatomeres

Segments of mesoderm that contribute to muscle development.

Splanchnic mesoderm

Mesoderm layer that forms smooth and cardiac muscles.

Visceral muscles

Smooth and cardiac muscles.

Axial muscles

Muscles located in the head, neck, and trunk responsible for posture and trunk movement.

Limb muscles

Muscles organized into compartments in the arms and legs.

Flexors

Muscles that reduce the angle at a joint.

Extensors

Muscles that increase the angle at a joint.

Musculocutaneous nerve

The nerve responsible for flexing the anterior arm.

Triceps

The muscle responsible for extending the posterior arm.

Dorsiflex

An action where the toes are lifted upwards.

Plantar flex

An action where the toes are pointed downwards.

Eversion

Movement of the foot to turn the sole outward.

Brachialis

A muscle named for its location in the arm.

Deltoid

A muscle named for its triangular shape.

Maximus/minimus

Terms referring to the size of muscles.

Rectus/transverse

Terms that describe the direction of muscle fibers.

Cranial nerve VII

The facial nerve responsible for controlling facial expressions.

Masseter

A muscle that closes the jaw.

Temporalis

A muscle that assists in closing the jaw.

Cranial nerve XII

The hypoglossal nerve responsible for tongue movement.

Suprahyoid muscles

Muscles that assist in swallowing.

Erector spinae group

Muscles that extend the spine and maintain posture.

Diaphragm

The primary muscle responsible for inhalation.

External intercostals

Muscles that lift the ribs during inhalation.

Internal intercostals

Muscles that lower the ribs during exhalation.

Abdominal muscles

Muscles that compress the abdomen and aid in breathing.

Linea alba

The midline of connective tissue in the abdomen.

Levator ani

A muscle that supports pelvic organs.

Pectoralis major

A muscle that adducts and rotates the arm.

Serratus anterior

A muscle that moves the scapula forward.

Key differences in limb functions

Flexor and extensor differences between arms and legs.