UMKC Anatomy 218 Exam 1 (1.05-1.06) upper body muscles

Dr. Allen

Facial Expression — Eye Region

*Facial expression muscles attach to the subcutaneous layer/skin or skull, which is how they move the skin of your face.

Orbicularis oculi

Think O = around the eye

→ circular muscle surrounding the eye
→ closes the eye
→ blinking, winking, squinting

Corrugator supercilii

→ near the eyebrow
→ pulls eyebrows inferiorly + medially
→ makes the vertical wrinkles between/above your eyebrows

Levator palpebrae superioris

Levator = lifts
palpebrae = eyelid
superioris = upper

→ elevates the upper eyelid

Quick associations

Orbicularis oculi → CLOSE eye
Levator palpebrae superioris → OPEN/elevate upper eyelid
Corrugator supercilii → eyebrows down + inward

Mouth/Face Muscles

Orbicularis oris

Oris = mouth

→ circular muscle surrounding the mouth
→ closes and protrudes/purses the lips

Buccinator

→ muscle of the cheek
→ compresses the cheek

Zygomaticus major & minor

→ extend from the zygomatic/cheekbone region toward the mouth
→ associated with elevating the lip/corner of the mouth

Risorius

→ extends laterally from the corner of the mouth
→ pulls the corner of the mouth laterally

Mentalis

→ located around the chin/lower lip

Muscles of Mastication

These are the chewing muscles

Masseter

→ thick muscle on the side of the jaw
→ runs between the zygomatic region and mandible

Temporalis

→ broad, fan-shaped muscle on the side of the skull/temporal region
→ connects toward the mandible

Pterygoid muscles

There are two:

Medial pterygoid
Lateral pterygoid

→ both are deep muscles of mastication associated with the mandible.

Remaining Face + Neck

Nose

Procerus → moves/wrinkles the nose
Nasalis → associated with movement/compression of the nose

Lower mouth

Depressor anguli oris → pulls corners of mouth down → think frown

Depressor labii inferioris → pulls lower lip down → think pout

Mentalis → protrudes lower lip + wrinkles chin

Neck Muscles

Sternocleidomastoid

Big superficial muscle on each anterolateral side of the neck.

For now, recognize the name/location. Think:

Scalenes

Three muscles:

Anterior scalene
Middle scalene
Posterior scalene

They run between the cervical vertebrae and ribs.

Posterior neck

Splenius capitis
→ runs obliquely from cervical vertebrae → back of skull

Suboccipital muscles
→ small, deep muscles at the posterior neck/base of skull.

Back / Vertebral Column

Erector spinae

Think “erect spine” → long muscle group running along the vertebral column.

It's actually three columns:
Iliocostalis → Longissimus → Spinalis

*I Love Spines = Iliocostalis, Longissimus, Spinalis

Transversospinalis group

A deeper group of back muscles.

Quadratus lumborum

→ lumbar/lower-back region
→ part of the posterior abdominal wall
→ between the most inferior rib and hip

*Lumborum = lumbar = lower back

Respiration + Abdominal Wall

Respiration

Diaphragm
→ primary muscle for breathing in/inhalation
→ forms a partition between the thorax and abdomen

Between the ribs:

External intercostals

Internal intercostals

Transversus thoracis

→ involved with inhalation/exhalation

*Scalenes can also assist with inhalation.

Abdominal wall — FOUR pairs

External oblique
→ superficial lateral muscle
→ fibers run inferomedially

Internal oblique
→ deep to external oblique
→ fibers run superomedially

Transversus abdominis
→ deepest lateral abdominal muscle
→ fibers run horizontally

Rectus abdominis
→ long anterior muscle
→ fibers run superiorly

*As a group, these help flex the vertebral column and assist with exhalation.

Memory

External = superficial
Internal = deeper
Transversus = deepest
Rectus = front

Muscles that make up the epicranius (occipitofrontalis)

• Frontalis = frontal belly

• Occipitalis = occipital belly

Muscles make up the transversospinalis group?

Semispinalis + Multifidus + Rotatores

• Deep to the erector spinae

• Semispinalis + multifidus are the two largest

Pectoral Girdle

Stabilize or move the scapula.

Posterior group

Trapezius → superficial

Deep to trapezius:

• Levator scapulae

• Rhomboid minor

• Rhomboid major

Think:

Trap = superficial
Levator + rhomboids = deep

Broad attachments:

• Trapezius: occipital bone/vertebral column → clavicle + scapula

• Levator scapulae: cervical vertebrae → scapula

• Rhomboids: vertebrae → scapula

Anterior thoracic group

These are deep to pectoralis major:

Pectoralis minor → ribs → scapula
Serratus anterior → ribs → scapula
Subclavius → rib → clavicle

Posterior:
Trapezius = superficial
Levator + rhomboids = deep

Anterior:
Pec minor + serratus anterior = ribs → scapula
Subclavius = rib → clavicle

Shoulder + Rotator Cuff

S — Supraspinatus
I — Infraspinatus
T — Teres minor
S — Subscapularis

SITS = rotator cuff

Their tendons surround the glenohumeral (shoulder) joint.

The slide lists nine arm muscles that attach to the scapula:

Rotator cuff (4):
Supraspinatus
Infraspinatus
Teres minor
Subscapularis

Plus:
Teres major
Deltoid
Coracobrachialis
Biceps brachii
Triceps brachii

Arm + Elbow

Muscles are organized into compartments. The compartments are separated by intermuscular septa, surrounded by deep fascia, and contain functionally related muscles.

Anterior compartment

• Biceps brachii

• Brachialis

• Coracobrachialis

Posterior compartment

• Triceps brachii

Forearm

Two compartments:

Anterior compartment → Think FLEXOR side.

Major names to recognize:

• Pronator teres

• Flexor carpi radialis

• Palmaris longus

• Flexor carpi ulnaris

• Flexor digitorum muscles

• Pronator quadratus

Posterior compartment → Think EXTENSOR side.

Major names to recognize:

• Brachioradialis

• Extensor carpi muscles

• Extensor digitorum

• Supinator

ANTERIOR = mostly FLEXORS + PRONATORS
POSTERIOR = mostly EXTENSORS + SUPINATOR

Pectoralis major vs Latissimus dorsi

Two prime movers of the glenohumeral joint:

Pectoralis major

• Anterior

• Clavicle + ribs + sternum → humerus

Latissimus dorsi

• Posterior

• Ribs + ilium + thoracolumbar fascia → humerus

Pecs = front, Lats = back

Intrinsic hand muscles

Thenar eminence → thumb side

• Abductor pollicis brevis

• Flexor pollicis brevis

• Opponens pollicis

Hypothenar eminence → little-finger side

• Abductor digiti minimi

• Flexor digiti minimi brevis

• Opponens digiti minimi

THenar = THumb is the easiest way to remember it.

Intrinsic muscles of the hand.

• Lumbricals

• Dorsal interossei