Head and Facial expression muscles

Occipitofrontalis (epicranius)

A broad muscle covering the top of your skull, made of two muscle bellies connected by a flat tendon sheet.

Frontalis belly: front muscle on your forehead

occipitals belly: back muscle at the base of your skull.

Galea aponeurotic: the smooth, flat tendon sheet across the top of your head connecting them.

action: frontalis raises your eyebrow and wrinkles your forehead; occipitals your scalp backward.

Memory tip: frontalis= front/ forehead; occipitals=back /occipital bone

corrugated supercilii

a small, narrow muscle located deep right above your inner eyebrows.

action: pulls your eyebrows together and down (creates vertical frowning lines between your eyes)

memory tip: think corrugator=wrinkler of the eyebrows

Orbicularis Oculi

the ring-shaped muscle that circles around your eye socket.

palpebral part: the inner part on your eyelid( gently closes eye/blinking)

orbital part: the outer ring around the bone (squeezes eye shut tightly)

action: closes your eyes, blinks and winks.

memory tip: orbit= circle around eye; oculi=ocular/eye

Procerus

A small muscle sitting on your bridge of your nose between your eyebrows.

Action: pulls the skin between your eyebrows down to create horizontal wrinkles across the bridge of your nose.

memory tip: precerus sits on top of the nose.

Nasalis

the main muscle covering the sides of your nose.

action: flares( widens) and compresses (narrows) your nostrils.

memory tip: nasal=nose.

zygomaticus major

a diagonal muscle running from your cheekbone down to the corner of your mouth.

action: pulls the corners to your mouth upward and outward ( the main smiling muscle).

memory tip: zygomatic= cheekbone; Major= Larger smiling muscle.

zygomaticus Minor

A thin muscle running from the cheekbone to the upper lip, sitting just above zygomaticus major.

Action: pulls your upper lip upward to show top teeth

memory tip: minor= Smaller helper muscle next to zygomaticus major.

Levator Labii superioris

A vertical muscle between your lower eye socket and upper lip.

action: lifts (elevates) your upper lip.

memory tip: levator=Lifts; labii=lip; superioris=upper lip

Risorius

a narrow horizontal muscle running flat across the side of your cheek to the mouth corner. pulls the mouth corner straight sideways (fake smile or grimace).

memory tip: Rigorous sounds like laughter/ grin

Depressor Anguli oris

a triangular muscle at the corner of your mouth pointing down to your jawline.

action: pulls the corners of your mouth downward (frowning muscle).

memory tip: depressor=pulls down; Anguli=angle/corner or mouth; Oris=Mouth.

Depressor Labii Inferioris

A small muscle located between your lip and chin.

Action: pulls your lower lip straight down.

Memory tip: Depressor= pulls down; Labii=lip; inferioris=lower

Mentalis

The V-shaped muscle covering your chin tip.

Action: pouts your lower lip out and wrinkles the skin on your chin.

memory tip= Mental region=chin

Buccinator

The deep horizontal wall muscle inside your cheek.

Action: Flattens cheek against teeth so food stays between teeth while chewing; helps blow air out (whistling/playing trumpet).

Memory Top: Think Buccal=cheek wall

Orbicularis Oris

The circular muscle ring surrounding your lips.

Closes, puckers, and pouts your lip (“kissing muscle”)

Memory tip: Oris= oral/ Mouth lips

Temporalis

A large fan-shaped chewing muscle covering the temple bone on the side of your skull.

Action: Lifts and closes your lower Jaw.

Memory Tip: Temporalis= Temple bone

Masseter

The thick, powerful rectangular muscle on the outer angle of your jaw.

Action: closes your jaw forcefully for biting and chewing.

Memory tip: Think Masseter= “mass-Eater” (chewing food).

Digastric

A V-shaped muscle under your chin with two parts: Anterior belly: front part under chin tip. Posterior belly: back part near ear/hyoid

Action: pulls jaw open and lifts and hyoid bone when swallowing.

Memory Top: Di=Two; Gaster=Bellies

Stylohyoid

A thin, slating muscle running from the styloid peg near your ear down to the hyoid bone.

Action: Lifts hyoid bone up and backward when swallowing.

Memory tip: style (styloid process) to hyoid bone.

Mylohoid

A flat muscle sheet that forms the main floor under your tongue.

Action: lifts floor of mouth and tongue up when swallowing

Memory Tip: Mylo= Floor of mouth.

Sternothyroid

A deep front neck muscle running from breastbone up to thyroid cartilage.

Action: pulls larynx (voice box) down after swallowing.

Memory tip: Sterno (sternum) to thyroid cartilage

Sternohyoid

A long surface strap muscle running from breastbone up to hyoid bone.

Action: Pulls hyoid bone down after swallowing

Memory Tip: stereo (sternum) to hyoid bone

Thyrohyoid

A short vertical muscle connecting thyroid cartilage to hyoid bone.

Action: Pulls hyoid down or lifts larynx up.

Memory tip: thyro (thyroid) to Hyoid bone.

Omohyoid

A long strap muscle running from shoulder blade across neck to hyoid bone.

Action: pulls hyoid bone down and back.

Memory Top: omo= shoulder blade region

Sternocleidomastoid (SCM)

The large diagonal band on each side of you neck. Action: both sides together: flexes neck forward (chin to chest) One side alone: turns head toward opposite shoulder.

Memory tip: connects sternum+ Clavicle (cleido) to Mastoid process being ear.

Anterior Scalene

The front muscle of the three scalene muscles on the side of the neck.

Actin: flexes neck sideways and lifts rib during deep breathing.

Memory tip: Anterior=Front scalene.

Middle Scalene

The largest, middle muscle of the scalene group on the neck side.

Action: Bends neck sideways and lifts 1st rib.

Memory tip: Middle=Between anterior and posterior.

Posterior Scalene

The back muscle of the scalene group attached to rib 2.

Action: bends neck sideways and lifts 2nd rib.

Pectoralis Major

the large fan-shaped muscle covering the front chest wall.

Action: Flexes, adducts (pulls arm across chest) and rotates arm inward.

Memory Tip: Pecs+largest chest muscle.

Pectoralis Minor

A small triangular muscle sitting deep underneath Pectoralis major.

Action: Pulls shoulder blade forward and down.

Memory tip: Minor= smaller chest muscle underneath.

Serratus Anterior

A saw-tooth shaped muscle on the side ribcage under armpit.

Action: pulls shoulder blade forward around chest wall (“boxer’s muscle” for throwing punches).

memory tip: serrates= serrated/Saw-tooth edge.

Levator Scapulae

A back-neck muscle running down from neck vertebrae to shoulder blade top corner.

Action: lifts (elevates) shoulder blade.

Memory Tip: Levator=Lifts; Scapulae= scapula/shoulder blade.

Rhomboid Major

The larger lower slant muscle between spine and shoulder blade.

Action: pulls shoulder blades backward toward spine (pinching shoulders together)

Major tip: major = bottom larger rhomboid block.

Rhomboid Minor

The smaller upper slant muscle sitting right above rhomboid major.

action: pulls shoulder blades backward toward spine.

Memory tip: minor= top smaller rhomboid block.

Trapezius

A large diamond-shaped muscle covering upper back and neck.

Superior part: upper nech region (lifts shoulder)

middle part: mid-back region (pulls shoulders back)

inferior part: lower region ( pulls shoulder down)

actions: moves, elevates, restricts and depresses shoulder blades.

memory tip: trapezius= trapezoid/Dimond shape

Latissimus Dorsi

Broad, flat muscle covering lower back (“lats”)

action: extends and pulls arm backward and down (swimmers muscle)

Memory tip: latissimus= wide; dorsi=back

Erector Spinae (general group on model)

Deep muscle columns running vertically along both sides of your spine.

action: straightens (extends) and keeps spine upright.

Memory top: erector= hold spine erect/upright

External oblique

outer layer of abdominal wall with fibers slanting down like hands in pockets.

Action: flexes spine and rotates trunk to opposite side.

memory tip: external=outside; oblique=slanted

internal oblique

Middle layer of abdominal wall with fibers slanting upward

Action: flexes spine and twists trunk.

memory tip: internal= middle layer under external oblique.

Transversus abdominis

Deepest abdominal layer with horizontal belt-like fibers.

Action: compresses stomach contents inward (acts like a corset)

memory tip: transversus= Traverse/ horizontal direction.

Rectus abdominis

Vertical from stomach muscle divided by tendon lines (“six-pack”).

Action: bends spine forward (doing crunches/sit-ups)

memory tip: rectus= straight vertical; abdominis= abdomen

External intercostal

outer layer of muscles sitting between ribs.

action: lifts ribcage up and out during inhalation ( breathing in)

Memory tip: external=outside rib layer; helps breath IN.

internal intercostal

middle layer of muscles sitting between ribs under external intercostal.

Action: pulls ribcage down during fateful exhalation (breathing out)

memory tip: internal=middle rib layer; helps push air OUT

Innermost intercostal

deepest muscle layer inside ribcage wall.

Action: helps depress ribcage during exhalation.

memory tip: innermost=deepest rib muscle wall layer.

Transversus Thoracis

Fan-shaped muscle layer on the inside back surface of the front sternum/ribs.

Action: depresses ribs during exhalation

memory tip: thoracis=inside chest cavity wall.

Levator Ani

Broad muscle sheet forming the main floor of the pelvic bowl.

action: support pelvic organs and resists abdominal pressure.

Memory tip: Levator= holds up/ lift pelvic organs

coccygeus

triangular muscle sitting behind elevator ani near tailbone. Action: supports pelvic floor and pulls tailbone forward.

Memory tip: coccygeus= attaches to coccyx (tailbone)

Platysma

very thin flat muscle sheet right under neck skin.

action: tenses neck skin and pulls lower lip/jaw down

memory tip: platysma=flat sheet on front neck ( not on models)

Spinalis

most medial (innermost) column of the erector spine group lying right against spine processes

Action: extends spine

memory tip: spinalis= closest to spine ( not on models)

Longissimus

middle, longest column of the erector spinae group.

nation: extends and rotates spine.

memory tip: longissimus=longest column ( not on models)

lliocostalis

most lateral(outermost) column of erector spine group running from hip to ribs.

action: extends and bends sideways

memory tip: Ilio (hip) to costal (ribs) ( not on models)