Anatomy: The Skull and Cranial Bones (Skull Part 1)

• The lecture discusses the skull, its components, and associated features.
• The lecture aims to teach the importance of these components.

Learning Outcomes

• By the end of Parts 1-5 you will be able to name the bones of the cranium and their sutures
• By the end of Parts 1-5 you will be able to label views of the cranium
• By the end of Parts 1-5 you will be able to identify bony features of the Sphenoid and Ethmoid bones
• By the end of Parts 1-5 you will be able to discuss the relevance of the Infratemporal & Pterygopalatine Fossa’s

Formative Assessment

• There will be a formative assessment at the end of all lectures

Definition of the Skull

• The skull, or cranium, is the skeletal structure of the head
• The skull supports the face
• The skull also protects the brain
• The skull consists of 22 individual bones

The Skull Sections

• The skull is composed of 2 sections
• The Neurocranium consists of the cranial bones
• The Viscerocranium consists of the facial bones

Glossary of Terms

• Articulate: Joining or touching
• Ridge: Raised linear elevation
• Foramen: Opening/hole allowing passage of blood/nerve
• Fossa: Shallow depression
• Process: Large distinctive projection
• Canal: A tunnel through bone
• Groove: An open channel
• Tubercle: Small prominent elevation
• Eminence: Elevation of bone
• Tuberosity: Bulbous feature
• Internal: Inner or inside
• External: Outer or outside
• Medial: Towards midline
• Lateral: Away from midline
• Anterior: Towards the front
• Posterior: Towards the back
• Inferior: Underneath or below
• Superior: Above
• Superficial: Nearer the skin
• Deep: Away from the skin
• Roof: Top
• Floor: Bottom
• Plate: Flat area of bone
• Margin: Border or edge

Neurocranium Function

• Protection is a function of the Neurocranium
• Provides attachment sites for the origin and insertion of muscles of facial expression and mastication
• It is the framework for the cranial and orbital cavities
• The Neurocranium Protects All Functions

Lobes of the Brain

• The cerebrum is divided into 4 lobes
• The Frontal lobe is one of the 4 lobes of the brain
• The Parietal lobe is one of the 4 lobes of the brain
• The Occipital lobe is one of the 4 lobes of the brain
• The Temporal lobe is one of the 4 lobes of the brain

Lobe Responsibilities

• The frontal lobe is responsible for personality, behavior, emotions
• The frontal lobe is responsible for judgement, planning, problem solving
• The frontal lobe is responsible for speech, speaking, and writing (Broca's area)
• The frontal lobe is responsible for body movement (motor strip)
• The frontal lobe is responsible for intelligence, concentration, and self awareness
• The parietal lobe interprets language; words
• The parietal lobe creates you sense of touch, pain, temperature (sensory strip)
• The parietal lobe interprets signals from vision, hearing, motor, sensory and memory
• The parietal lobe is responsible for spatial and visual perception
• The occipital lobe interprets vision (color, light, and movement)
• The temporal lobe is for understanding language (Wernicke's area)
• The temporal lobe is responsible for memory
• The temporal lobe allows you to hear
• The temporal lobe allows for sequencing and organization

Broca and Wernicke's Areas

• Broca's area lies in the left frontal lobe
• Damage to Broca's area can cause difficulty moving the tongue or facial muscles to produce speech sounds
• A person can still read and understand spoken language but has difficulty speaking and writing, Broca's aphasia
• Wernicke's area lies in the left temporal lobe
• Damage to Wernicke's area causes Wernicke's aphasia
• A person may speak in long sentences that have no meaning
• A person may add unnecessary words, and even create new words
• A person can make speech sounds; however, they have difficulty understanding speech and are unaware of mistakes

Neurocranium Sutures

• The main sutures of the skull are the Coronal, Sagittal, Lambdoid and Squamosal sutures.
• The Metopic suture, or frontal suture, is variably present in adults
• The coronal suture unites the frontal bone with the parietal bones
• The sagittal suture unites the 2 parietal bones in the midline
• The lambdoid suture unites the parietal bones with the occipital bone
• The squamosal suture unites the squamous portion of the temporal bone with the parietal bones
• The metopic suture, if present, unites the 2 frontal bones