Bones of the Skull and Anatomy of the Head

Mr. Brewer

The Skull

The Skull is composed of 22 bones.

All of these bones are joined together through “immovable joints” called sutures.

* The only exception is the Mandible Bone aka the “Jaw Bone”.

Bones and Sutures

Bones

Frontal Bone (1)Ethmoid Bone (1)Sphenoid Bone (1)Parietal Bones (2)Temporal Bones (2)Occipital Bone (1)

Skull

https://www.youtube.com/watch?v=Nc5IRj3OJhE

- Watch brief clip explaining the bones of the skull.

FaceAlthough they are still considered to be part of the skull, the following bones are more specifically referred to as the bones of the face.

The Mandible is the only bone that has a moveable joint (Temporal-Mandibular Joint).

The Mandible is also known as the “Jaw Bone”.

The Maxilla and Zygomatic bones make up the inferior portion of the orbital eye socket.

The Zygomatic bones are also known as the “cheek bones”.

Tooth Anatomy• Adults typically will have 32

teeth:• Incisors (8 total): The

middlemost four teeth on the upper and lower jaws.

• Canines (4 total): The pointed teeth just outside the incisors.

• Premolars (8 total): Teeth between the canines and molars.

• Molars (8 total): Flat teeth in the rear of the mouth, best at grinding food.

• Wisdom teeth or third molars (4 total): These teeth erupt at around age 18, but are often surgically removed to prevent displacement of other teeth.

Tooth Anatomy• Enamel: The hardest, white outer part of the tooth. Enamel is mostly made of calcium phosphate, a rock-hard mineral.• Dentin: A layer underlying the enamel. Dentin is made of living cells, which secrete a hard mineral substance.• Pulp: The softer, living inner structure of teeth. Blood vessels and nerves run through the pulp of the teeth.• Cementum: A layer of connective tissue that binds the roots of the teeth firmly to the gums and jawbone.• Periodontal ligament: Tissue that helps hold the teeth tightly against the jaw.

Eye Anatomy The eye is a slightly asymmetrical globe, about an inch in diameter. The front part of the eye (the part you see in the mirror) includes:• The iris (the pigmented part)• The cornea (a clear dome over the iris)• The pupil (the black circular opening in the iris that lets light in)• The sclera (the white part)• The conjunctiva (a thin layer of tissue covering the front of the eye, except the cornea)• The Lens (Sits behind the Iris

and adjust to focus sight)

Eye Movement

- The Eye has several muscles that allow us to intricately move AND control our eyes.

- Like most muscles, they are named for their location, shape, and/or position.

- https://www.youtube.com/watch?v=vd7OOJ7c1q4

Ear Anatomy

• The ear is broken down into the Outer, Middle and Inner ear.

Ear Anatomy• The Outer Ear is simply made up of the

Auricle and the External Auditory Meatus(Ear Canal).

• Cuts and other external injuries can occur to the Auricle.

• The Ear Canal can cause what is known as “Swimmers ear” if water entered the canal and stayed there for an extended period of time.

• In those type of dark, warm and moist conditions, bacteria forms causing an infection known as Otitis Externa aka “Swimmer’s Ear.

• The “Outer Ear” ends at the end of the canal where the Tympanic Membrane is located.

• Tympanic Membrane is better known as the “Eardrum”.

• How the Ear works:– https://

www.youtube.com/watch?v=qgdqp-oPb1Q

Ear Anatomy• The Malleus, Incus and Stapes are three bones of the middle ear.• They are more commonly known as the Hammer, Anvil and Stirrup because

of their shape.• These 3 bones are considered to be the 3 smallest bones in the human body

(technically 6 because there are 2 sets of these 3 bones, one for each ear.• Their main function is to amplify sound, and relay that sound to the inner ear

for the brain to interpret.

Throat Anatomy• The throat has 2 functions:

– To Provide a passageway for food to reach the Esophagus for digestion.– To provide a passageway for air to reach the Trachea(wind-pipe), which

eventually allows oxygen to get to the lungs.– The Hyoid bone is a unique sesamoid bone located in the throat.

Throat Functions

• There are some key parts of throat that have important roles in the human body.

• One of the most important roles the throat has to play, is allowing food and air to get where they need to be during breathing and eating.

• Food in the lungs can be very detrimental, just as too much air in the GI tract can cause problems such as distension as well.

• I.E. Swallowing vs. Inhaling.• https://www.youtube.com/watc

h?v=pNcV6yAfq-g