Head, Skull, Brain, and Arterial Supply

How many bones are in the skull?

8 Cranial Bones, 14 facial bones (Total 22 bones!)

What are sutures?

Joints between the bones of the skull

How many fossae are in the skull

Three! Each become progressively deeper in the frontal- > occipital direction

Anterior Cranial Fossa → Middle Cranial Fossa → Posterior Cranial Fossa

*In the posterior cranial fossa, you’ll find the foramen magnum

What are the singular bones centered in the midline of the cranial bone

Singular Bones!

1. Frontal

2. Ethmoidal

3. Sphenoidal

4. Occipital

What are the pairs of cranial bones?

The Bilateral Pairs!

1. Tempral

2. Parietal

Label the Cranial bones

Label the Cranial Bones

Whats a good mnemonic (from front to back) cranial bones?

Ethan’s Fried Spanish Pasta Tempted Octavia

(Ethmoid, Frontal, Sphenoid, Parietal (2), Temporal (2), Occipital)

Label the cranial bones

Label the bones!

What are the singular facial skeletal bones

Mandible and Vomer

What are the paired facial skeletal bones?

Maxila, Inferior Nasal Concha, Zygomatic, Palatine, Nasal, Lacrimal

Label the Facial Bones

Label the Facial Bones

Label the Facial Bones

What are the bones of the nasal septum?

Superior → Perpendicular plate of ethmoid bone

Inferior → Vomer

Label the Sinuses

Label the Orbit

What are the nerve/s that go through the Optic Canal?

The Optic Nerve (II)

What are the nerve/s that go through the Superior Orbital Fissure?

Occulomotor Nerve (III), Trochlear Nerve (IV), Trigeminal Nerve (V1) , Abducens Nerve (VI)

Label the facial bones

Label the skull

Label the skull

Label the skull

Label the skull

Label the Occipital Bone

Label the Occipital Bone

Label the Mandible

Label the Skull

Label these bones

Label the Ethmoid bone

Label this diagram of the skull

Label this diagram of the skull

Label this diagram of the skull

What does the Sphenoid Bone articulate with?

Occipital, Frontal, Ethmoid, Vomer, Tempral, Parietal, Zygomatic, Palantine

Describe the Sphenoid Bone

• Has a body and 6 processes

  • 2 greater and 2 lesser wings

  • 2 Pterygoid Processes

Label the sphenoid Bone

Label the Sphenoid

Label the Sphenoid

Describe the Superior Orbital Fissure

• Cleft between Greater and Lesser Wings of Sphenoid Bone in Middle Cranial Fossa

  • Opens Anteriorly into the Orbit

Describe the Optic Canal

• Passes through the lesser wing of the Sphenoid Bone

• Located -

  • Medial to Anterior Clinoid Process

  • Medial to Superior Orbital Fissure

  • Lateral to body of sphenoid bone in middle cranial fossa

• Communicates with Orbit

Describe the three foramina in the sphenoid bone (the foramens)

Foramen Rotundum, Oval, and Spinosum

• All pass through the Greater wing of the sphenoid bone

• Located in the middle Cranial Fossa

  • Foramen Rotundum

    • Runs anteriorly/Horizontally, opens into pteryogopalantine fossa (Bony formation between sphenoid, maxilla, and palantine bones)

  • The foramina Ovale and Spinosum

    • Opens inferiorly into the infratemporal fossa

Label this diagram of the sphenoid

Label the scalp of these two diagrams

Label the skull bone layers

Label the meninges

Label the lobes of the brain

What does each lobe of the brain do?

Frontal → Planning, Decision-making, personality

Parietal → Senses and spatial awarness

Temporal → Hearing, Memory, Language

Occipital → Vision

Describe the Brainstem and Cerebellum

BS → connects spinal cord to cerebrum

Cere. → Inferior to occipital lobe, helps with balance and coordination

What are the three parts of the brainstem?

Midbrain, Pons, Medulla Oblongota

Label this diagram

Label this diagram and describe each part of the diencephalon

1. Hypothalamus

   1. Inferior to the thalamus, and superior to brainstem

2. Thalamus

   1. Superior to the hypothalamus

• Corpus Callosum

  • Spans the midline of the brain, connecting the right and left hemispheres

• Pituitary Gland

  • Inferior to the hypothalamus

Describe the Dural Sinuses & Dural reflection

• Vein-like channel formed between layers of the dura mater that drains venous blood from the brain

  • sits between the periosteal and meningeal layers of the dura mater

• Drains venous bloodfrom the cerebral veins into the internal jugular veins

• Dural reflection:

  • Fold of the meningeal layer of the dura mater that projects inward into the cranial cavity

  • Instead of just lining the skull, the dura folds in on itself

Label these dural reflections/infoldings

Describe Each of the Dural Reflections/Infoldings

Falx Cerebri

• Seperates right and left cerebral hemispheres

  • From the crista gali and frontal crest to the internal aspect of the occipital bone

Tentorium Cerebelli

• Seperates Occipital lobes and Cerebellum

Falx Cerebelli

• Inferior to Tentorium Cerebelli

  • Seperates cerebellar hemispheres

Diaphragma Sellae

• suspended between clinoid processes

  • forms a partial roof over sella turcica and covers pituitary gland

Label tis diagram of the veins

Describe the locations of each of the sinuses

Superior Sagittal Sinus

• Superior border of falx cerebri

Inferior Sagittal Sinus

• Inferior border of falx cerebri, ends in straight sinus

Straight Sinus

• Runs along attachment of falx xerebri and tentorium cerebelli

Occipital Sinus

• Posterior border of falx cerebelli

  • joins with confluence of sinuses

Transverse sinus

• runs laterally from the confluence, continuous with sigmoid sinus

Sigmoid sinus

• Continous with transverse sinus, s-shaped and continues as internal jugular veins

Cavernous Sinus

• On sides of the sella turcica (or pituitary gland)

Describe the different relationships of the brain

Center → pituitary gland

Floor → sella turcica

Roof → Diaphragma sellae (dura)

Sides → Cavernous sinus (venous channels with cranial nerves + ICA)

Label these diagrams of the cranial cavity

Label the diagram and describe the arteries that supply the brain

Vertebral Artery

• Ascends from subclavian artery and travels through transverse foramen of C1-C6

External and Internal Carotid Artery

• Branch off the carotid sinus from the common carotid artery

Label the arteries in the brain

What are the three branches of the vertebral artery?

• Two vertebral arteries along the medulla oblongata and becomes the 1. Basilar Artery at the pons

• 2. Posterior Inferior Cerebellar artery branches off the vertebral artery

• 3. Anterior Spinal artery branches off the vertebral artery, and travels along the spinal cord

What are the arteries that branch off the basilar artery

1. Anterior Inferior Cerebellar artery

2. Superior Cerebellar artery

   1. Both branch off the basilar artery and supply the cerebellum

3. Posterior Cerebral artery

   1. Supply occipital lobe and inferior temporal lobe

4. Pontine arteries

   1. Supply the pons

Label these arteries

Label these arteries

The basilar artery branches to give the —— which is connected to the internal carotid artery via ——

Posterior Cerebral Artery, Posterior Communicating artery

Label this diagram

What are the branches of the internal carotid artery

1. Middle Cerebral Artery

2. Opthalmic Artery

3. Anterior Cerebral artery

4. Posterior Communicating branches

What are the arteries that contribute to the circle of willis

1. Internal carotid artery

2. posterior communicating branch

3. Posterior cerebral artery

4. Anterior cerebral artery

Label this diagram

Label the arteries in the cerebrum

Label these arteries of the cerebrum

Label the brain

Label the brain

Label the brain