LIF101 Anatomy

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LIF101Anatomy

• Lecture 8
• Head and Neck Muscles,
• Eyes and Nose

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Muscles of the Head and Face

• Lie in scalp and face, just beneath skin
• Thinner, flatter than body muscles
• Insert into skin (instead of bone)
• Facilitate facial expressions

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Muscles of the Head and Face

• Epicraneous consists of 2 parts
• frontal portion inserts in the fascia of facial
  muscles and in the skin above the eyes and nose.
  Draws the scalp back
• occipital portion insertion points on nuchal
  lines and on mastoid process
• Connected by epicranial aponeurosis

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Connected by Epicranial Aponeurosis

• Connects frontal and occipital muscles

• A wide thin tendon that covers the top of the
  cranium.
• In humans, the epicraneous muscle only serves for
  facial expressions

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Corrugator draws eyebrows together. Wrinkles
forehead
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Muscles of the Head and Face

• Temporalis
• origin temporal line
• insertion coranoid process of mandible, which is
  just anterior to TMJ
• Function raises lower jaw/elevates and retracts
  mandible (holds it in place)
• Can be felt over temporal bone when clenching
  teeth

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Temporal-mandibular joint

• TMJ syndrome
• Pain or dysfunction of the temporal-mandibular
  joint is commonly referred to as "TMJ",
• Problems involving the TMJs and the muscles,
  tendons, ligaments, blood vessels, and other
  tissues associated with them.

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Muscles of the Head and Face

• Orbicularis Oris
• circular muscle around mouth
• for closing lips, puckering, kissing
• Orbicularis Oculi
• circular muscles around eyes
• for blinking, squinting

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Muscles of the Head and Face

• Levator Palpebra
• raises upper eyelid

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Muscles of the Head and Face

• Zygomaticus major and minor
• raises corners of mouth outward and upward
  (smile)
• minor is smaller and more anterior than major

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Zygomaticus minor

• origin zygomatic bone
• insertion corners of mouth

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Muscles of the Head and Face

• Triangularis
• origin mandible
• insertion corners of mouth
• Draws corners of mouth downward/frowning
• Quadratus labii inferioris
• origin mandible
• insertion below lower lip
• Draws lower lip outward and downward

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Muscles of the Head and Face

• Triangularis
• pulls down corners of mouth
• Quadratus labii inferioris
• draws lower lip down and out (pout)

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Muscles of the Head and Face

• Masseter
• origin anterior zygomatic arch
• insertion angle of mandible
• Function raises lower jaw
• Can be felt and seen over sides of mandible when
  chewing

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Muscles of the Head and Face

• Masseter
• for chewing
• can be seen during chewing (sometimes striations
  can be seen as well.)

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Muscles of the Neck

• Platysma
• Thin muscle that covers anterior neck and upper
  chest
• Draws lower lip downward and outward raises skin
  of neck from underlying parts
• signals strain

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The platysma is the muscle in your upper torso
starting from your face, neck, and upper chest.

• Controls facial expressions, by helping move the
  lower lip down and sideways.
• Exercising the platysma muscle has been a proven
  way to get rid of double chin, which occurs when
  unneeded fat gets stored in that area.

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Muscles of the Neck

• Sternocleidomastoid
• dual origin medial clavicle and manubrium of
  sternum
• insertion mastoid process of temporal bone
• Functions
• Together they lift face and tip head back
• Separately turns head to opposite sides

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Muscles of the Neck

• Sternocleidomastoid
• tilt head backward (both together)
• rotates head to opposite side (separately)

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Muscles of the Neck

• Sternohyoid
• origin sternum
• insertion hyoid bone
• often can be seen between the V of
  sternocleidomastoid
• Function draws hyoid bone backward and upward

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Hyoid Bone

• The hyoid is anchored by muscles from the
  anterior, posterior, and inferior directions and
  aids in tongue movement and swallowing.

• Doesnt articulate with any other bones

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Parotid Gland

• Anterior and inferior to ear
• partially covers masseter muscle
• gives roundness to face
• Largest salivary gland

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Thyroid Cartilage

• A.K.A. Adams Apple
• Anterior neck surface landmark
• Surrounds upper trachea
• Encloses larynx
• Larger and more angular in male

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The Eye

• Lies in orbit, slightly superior and lateral to
  center
• Spherical, except at cornea

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Parts of the Eye

• Sclera
• Iris
• Pupil
• Cornea
• Lids (upper and lower)

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Cornea

• Clear covering over the iris and pupil. Non
  vascular and easily transplantable. No nerves
  no feeling

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Parts of the Eye

• Inner canthus
• Outer canthus
• Caruncle
• Infrapalpebral furrow
• Eyelashes
• Eyebrow

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Parts of the Nose(underlying structures in
parentheses)

• Bridge (nasal bone)
• Lateral surfaces (lateral cartilage)
• Apex (alar cartilage)
• Ala (alar fat)
• Septum (septal cartilage)
• Alar furrows
• Nostrils (holes)

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Assignments

• Peck, pp. 96 101, 162 - 165, 168 169
• QUIZ NEXT WEEK Head, neck, and face muscles,
  eye and nose anatomy