Bones of skull

Role of cranium?

Protection of brain, muscle attachments and passage for cranial neurovasculature

Neurocranium

Viscerocranium

What bones make up the neurocranium?

Occipital bone (1)

Parietal bones (2)

Frontal bone (1)

Temporal bones (2)

Sphenoid (1)

Ethmoid (1)

What is the role of a suture?

This is how cranial bones articulate with one another

How many cranial sutures are there?

4

What are the 4 cranial sutures and what do they separate?

Lambdoid - separates occipital from parietal and temporal

Sagittal - extends between parietal bones

Coronal - divides frontal and parietal bones

Squamous - either side of cranium, separates temporal and parietal bones

Parietal bone

Frontal bone

Temporal bone

Sphenoid bone

Zygomatic bone

Lacrimal bone

Coronal suture

Maxilla

Frontal bone

Coronal suture

Parietal lobe

Squamous suture

Lambdoid suture

Occipital bone

Temporal bone

Zygomatic process

Sphenoid bone

What is the pterion?

The point where the frontal, parietal, sphenoid and temporal bones meet.

Pterion

Frontal bone

Coronal suture

Sagittal suture

Parietal bone

Lambdoid suture

Occipital bone

What is the point where the frontal and parietal bones meet?

Bregma

Lambda

What bone is this?

Ethmoid bone

(NN)

Crista galli

What bone is this?

Sphenoid bone

Lesser wing

Greater wing

Pterygoid process

Body sphenoid bone

What bones form the anterior cranial fossa?

Frontal, ethmoid and sphenoid

What bones form the middle cranial fossa

Sphenoid and temporal bones

What forms the posterior cranial fossa?

Occipital, temporal, parietal and sphenoid bones

What is this?

Anterior cranial fossa

What is this?

Cribriform plate

NN

Crista galli

Foramen caecum

Middle cranial fossa

Foramen rotandum

Foramen ovale

Foramen lacerum

Foramen spinosum

Superior orbital fissure

Optic canal

Carotid canal

Foramen magnum

Jugular foramen

Internal acoustic mediatus

Hypoglossal canal

How many layers of meninges

3

Layer of meninges from superficial to deep

Dura mater

Arachnoid mater

Pia mater

What are the two layers of dura mater?

Periosteal dura mater

Meningeal dura mater

What does the pia mater follow?

Sulci and gyri

Where is epidural and subdural space?

In spinal cord (contains fat) or brain (potential space)

What does epidural space separate in spinal cord?

Between vertebrae and dura mater

Epidural space (contains fat)

Subdural space (contains CSF)

What does subdural space separate?

Dura mater and arachnoid mater

What does subarachnoid space separate?

Arachnoid mater and pia mater

What separates the cerebral hemispheres and cerebellum from cerebrum?

Dural folds

What is being drawn over in red?

Dural folds

What lies between meningeal dura mater and periosteal dura mater?

Dural venous sinuses

What does CSF flow back into dural venous sinuses by?

Arachnoid granulations

What are those grey projections called?

Arachnoid trabeculae

Primary brain vesicles (NN)

Forebrain AKA Prosencephalon

Midbrain AKA Mesencephalon

Hindbrain AKA Rhombencephalon

Secondary brain vesicles (NN)

Telencephalon

Diencephalon

Mesencephalon

Metencephalon

Myelencephalon

What does telencephalon become? (NN)

Cerebrum

What does diencephalon become? (NN)

Thalamus, hypothalamus and epithalamus

What does metencephalon become? (NN)

Pons and cerebellum

What does myencephalon become? (NN)

Medulla oblongata

What do brain ventricles contain?

CSF

What makes CSF?

Choroid plexus

Where does CSF go from ventricles?

Subarachnoid space to enter circulation via arachnoid granulations

Choroid plexus

What carries CSF from 4th ventricle to subarachnoid space?

Median and lateral apertures

Arachnoid granulations

Lateral ventricles

Interventricular foramen

Third ventricle

Cerebral aqueduct

Fourth ventricle

Central canal

What is grey matter?

Neuronal cells, dendrites, axon terminals and unmyelinated axons

(where processing occurs)

What is white matter?

Composed primarily of myelinated axons

(where signals travel through)

Gyri vs Sulci

Gyri = bulges that stick out from brain

Sulci = grooves/indentations

How many times is the cerebrum divided?

Has two hemispheres

What is the most anterior lobe?

Frontal lobe

What does frontal lobe do?

Personality and primary motor cortex/precentral gyrus