The Skull Base

Arnab Rana

Background

Skull base foramina The Skull Base Skull base bones

Self learning exercise Arnab Rana References and feedback

Last updated 7th September 2020 Table of contents

The Skull Base

Arnab Rana

Background 1 Background

Skull base foramina

Skull base 2 Skull base foramina bones

Self learning exercise 3 Skull base bones References and feedback 4 Self learning exercise

5 References and feedback Understand briefly the various structures that go to form the base of the skull Describe the internal auditory meatus and its contents Year 2 Systems II (Part 1) Neuro Disorders of cranial nerves lecture Pg 44 Describe the anatomy and function of the 12 cranial nerves Pg 48 Describe the dural coverings of the brain and opening of the skull

Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base foramina

Skull base bones

Self learning exercise

References and feedback Describe the internal auditory meatus and its contents Year 2 Systems II (Part 1) Neuro Disorders of cranial nerves lecture Pg 44 Describe the anatomy and function of the 12 cranial nerves Pg 48 Describe the dural coverings of the brain and opening of the skull

Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base Understand briefly the various structures that go to form foramina the base of the skull Skull base bones

Self learning exercise

References and feedback Year 2 Systems II (Part 1) Neuro Disorders of cranial nerves lecture Pg 44 Describe the anatomy and function of the 12 cranial nerves Pg 48 Describe the dural coverings of the brain and opening of the skull

Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base Understand briefly the various structures that go to form foramina the base of the skull Skull base bones Describe the internal auditory meatus and its contents Self learning exercise

References and feedback Disorders of cranial nerves lecture Pg 44 Describe the anatomy and function of the 12 cranial nerves Pg 48 Describe the dural coverings of the brain and opening of the skull

Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base Understand briefly the various structures that go to form foramina the base of the skull Skull base bones Describe the internal auditory meatus and its contents Self learning Year 2 Systems II (Part 1) Neuro exercise

References and feedback Pg 44 Describe the anatomy and function of the 12 cranial nerves Pg 48 Describe the dural coverings of the brain and opening of the skull

Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base Understand briefly the various structures that go to form foramina the base of the skull Skull base bones Describe the internal auditory meatus and its contents Self learning Year 2 Systems II (Part 1) Neuro exercise

References Disorders of cranial nerves lecture and feedback Pg 48 Describe the dural coverings of the brain and opening of the skull

Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base Understand briefly the various structures that go to form foramina the base of the skull Skull base bones Describe the internal auditory meatus and its contents Self learning Year 2 Systems II (Part 1) Neuro exercise

References Disorders of cranial nerves lecture and feedback Pg 44 Describe the anatomy and function of the 12 cranial nerves Aberdeen MBChB learning guide links

The Skull Base

Arnab Rana

Background Year 2 Systems II (Part 1) ENT Pg 24 Skull base Understand briefly the various structures that go to form foramina the base of the skull Skull base bones Describe the internal auditory meatus and its contents Self learning Year 2 Systems II (Part 1) Neuro exercise

References Disorders of cranial nerves lecture and feedback Pg 44 Describe the anatomy and function of the 12 cranial nerves Pg 48 Describe the dural coverings of the brain and opening of the skull In the following slides I will mention some things which I think would help medical students pass exams First, I will show you an intricately-labelled diagram which I stumbled across on the internet Please don’t learn it, it is only for amusement!

Scope

The Skull Base

Arnab Rana

Background Skull base There is an enormous amount which could be learned foramina about the skull base Skull base bones

Self learning exercise

References and feedback First, I will show you an intricately-labelled diagram which I stumbled across on the internet Please don’t learn it, it is only for amusement!

Scope

The Skull Base

Arnab Rana

Background Skull base There is an enormous amount which could be learned foramina about the skull base Skull base bones In the following slides I will mention some things which I Self learning exercise think would help medical students pass exams

References and feedback Please don’t learn it, it is only for amusement!

Scope

The Skull Base

Arnab Rana

Background Skull base There is an enormous amount which could be learned foramina about the skull base Skull base bones In the following slides I will mention some things which I Self learning exercise think would help medical students pass exams References First, I will show you an intricately-labelled diagram which and feedback I stumbled across on the internet Scope

The Skull Base

Arnab Rana

Background Skull base There is an enormous amount which could be learned foramina about the skull base Skull base bones In the following slides I will mention some things which I Self learning exercise think would help medical students pass exams References First, I will show you an intricately-labelled diagram which and feedback I stumbled across on the internet Please don’t learn it, it is only for amusement!

Limitations

The Skull Base

Arnab Rana

Background Limitations of the models Skull base foramina I have put 3D models in the online PDFs for my other 3D Skull base bones tutorials. Unfortunately, the skull base model is too

Self learning complicated for conversion. exercise For a 3D model I highly recommend this link at The References and feedback Neurosurgical Atlas by Aaron Cohen-Gadol https://www.neurosurgicalatlas.com/sketchfab? id=7f9e990a7bb4478dadd9bbc5351b652a Two optic canals—optic nerve II—for vision Two foramina ovalia—mandibular branch of trigeminal nerve V3—needle entry point for trigeminal nerve anaesthesia Two foramina rotunda—maxillary branch of trigeminal nerve V2—numb patch on face after trauma Two jugular foramina—sigmoid sinuses go through this to become the two internal jugular veins—the main venous outflow tracts for blood from the brain

What are the openings of the skull?

The Skull Base Selected list page 1 Arnab Rana One foramen magnum—cervicomedullary junction, two Background vertebral arteries—important for all nervous functions Skull base foramina under the head Skull base bones

Self learning exercise

References and feedback Two foramina ovalia—mandibular branch of trigeminal nerve V3—needle entry point for trigeminal nerve anaesthesia Two foramina rotunda—maxillary branch of trigeminal nerve V2—numb patch on face after trauma Two jugular foramina—sigmoid sinuses go through this to become the two internal jugular veins—the main venous outflow tracts for blood from the brain

What are the openings of the skull?

The Skull Base Selected list page 1 Arnab Rana One foramen magnum—cervicomedullary junction, two Background vertebral arteries—important for all nervous functions Skull base foramina under the head Skull base bones Two optic canals—optic nerve II—for vision

Self learning exercise

References and feedback Two foramina rotunda—maxillary branch of trigeminal nerve V2—numb patch on face after trauma Two jugular foramina—sigmoid sinuses go through this to become the two internal jugular veins—the main venous outflow tracts for blood from the brain

What are the openings of the skull?

The Skull Base Selected list page 1 Arnab Rana One foramen magnum—cervicomedullary junction, two Background vertebral arteries—important for all nervous functions Skull base foramina under the head Skull base bones Two optic canals—optic nerve II—for vision Self learning Two foramina ovalia—mandibular branch of trigeminal exercise nerve V3—needle entry point for trigeminal nerve References and feedback anaesthesia Two jugular foramina—sigmoid sinuses go through this to become the two internal jugular veins—the main venous outflow tracts for blood from the brain

What are the openings of the skull?

The Skull Base Selected list page 1 Arnab Rana One foramen magnum—cervicomedullary junction, two Background vertebral arteries—important for all nervous functions Skull base foramina under the head Skull base bones Two optic canals—optic nerve II—for vision Self learning Two foramina ovalia—mandibular branch of trigeminal exercise nerve V3—needle entry point for trigeminal nerve References and feedback anaesthesia Two foramina rotunda—maxillary branch of trigeminal nerve V2—numb patch on face after trauma What are the openings of the skull?

The Skull Base Selected list page 1 Arnab Rana One foramen magnum—cervicomedullary junction, two Background vertebral arteries—important for all nervous functions Skull base foramina under the head Skull base bones Two optic canals—optic nerve II—for vision Self learning Two foramina ovalia—mandibular branch of trigeminal exercise nerve V3—needle entry point for trigeminal nerve References and feedback anaesthesia Two foramina rotunda—maxillary branch of trigeminal nerve V2—numb patch on face after trauma Two jugular foramina—sigmoid sinuses go through this to become the two internal jugular veins—the main venous outflow tracts for blood from the brain Two superior orbital fissures—oculomotor III, trochlear IV, ophthalmic V1 and abducens VI—pupil dilatation, drooping eyelid, eye movement syndrome and forehead sensation Two internal auditory meatii—facial VII and vestibulocochlear VIII—unilateral sensorineural deafness in vestibular schwannoma Two stylomastoid foramina—facial nerves VII Two carotid canals—internal carotid artery Two foramina spinosa—middle meningeal artery—artery may be damaged further up, deep to the pteryon

What are the openings of the skull?

The Skull Base Selected list page 2 Arnab Rana The cribriform plate—many small holes for the olfactory

Background receptor neurones—anosmia after trauma

Skull base foramina

Skull base bones

Self learning exercise

References and feedback Two internal auditory meatii—facial VII and vestibulocochlear VIII—unilateral sensorineural deafness in vestibular schwannoma Two stylomastoid foramina—facial nerves VII Two carotid canals—internal carotid artery Two foramina spinosa—middle meningeal artery—artery may be damaged further up, deep to the pteryon

What are the openings of the skull?

The Skull Base Selected list page 2 Arnab Rana The cribriform plate—many small holes for the olfactory

Background receptor neurones—anosmia after trauma

Skull base foramina Two superior orbital fissures—oculomotor III, trochlear IV,

Skull base ophthalmic V1 and abducens VI—pupil dilatation, bones drooping eyelid, eye movement syndrome and forehead Self learning exercise sensation

References and feedback Two stylomastoid foramina—facial nerves VII Two carotid canals—internal carotid artery Two foramina spinosa—middle meningeal artery—artery may be damaged further up, deep to the pteryon

What are the openings of the skull?

The Skull Base Selected list page 2 Arnab Rana The cribriform plate—many small holes for the olfactory

Background receptor neurones—anosmia after trauma

Skull base foramina Two superior orbital fissures—oculomotor III, trochlear IV,

Skull base ophthalmic V1 and abducens VI—pupil dilatation, bones drooping eyelid, eye movement syndrome and forehead Self learning exercise sensation References Two internal auditory meatii—facial VII and and feedback vestibulocochlear VIII—unilateral sensorineural deafness in vestibular schwannoma Two carotid canals—internal carotid artery Two foramina spinosa—middle meningeal artery—artery may be damaged further up, deep to the pteryon

What are the openings of the skull?

The Skull Base Selected list page 2 Arnab Rana The cribriform plate—many small holes for the olfactory

Background receptor neurones—anosmia after trauma

Skull base foramina Two superior orbital fissures—oculomotor III, trochlear IV,

Skull base ophthalmic V1 and abducens VI—pupil dilatation, bones drooping eyelid, eye movement syndrome and forehead Self learning exercise sensation References Two internal auditory meatii—facial VII and and feedback vestibulocochlear VIII—unilateral sensorineural deafness in vestibular schwannoma Two stylomastoid foramina—facial nerves VII Two foramina spinosa—middle meningeal artery—artery may be damaged further up, deep to the pteryon

What are the openings of the skull?

The Skull Base Selected list page 2 Arnab Rana The cribriform plate—many small holes for the olfactory

Background receptor neurones—anosmia after trauma

Skull base foramina Two superior orbital fissures—oculomotor III, trochlear IV,

Skull base ophthalmic V1 and abducens VI—pupil dilatation, bones drooping eyelid, eye movement syndrome and forehead Self learning exercise sensation References Two internal auditory meatii—facial VII and and feedback vestibulocochlear VIII—unilateral sensorineural deafness in vestibular schwannoma Two stylomastoid foramina—facial nerves VII Two carotid canals—internal carotid artery What are the openings of the skull?

The Skull Base Selected list page 2 Arnab Rana The cribriform plate—many small holes for the olfactory

Background receptor neurones—anosmia after trauma

Skull base foramina Two superior orbital fissures—oculomotor III, trochlear IV,

Skull base ophthalmic V1 and abducens VI—pupil dilatation, bones drooping eyelid, eye movement syndrome and forehead Self learning exercise sensation References Two internal auditory meatii—facial VII and and feedback vestibulocochlear VIII—unilateral sensorineural deafness in vestibular schwannoma Two stylomastoid foramina—facial nerves VII Two carotid canals—internal carotid artery Two foramina spinosa—middle meningeal artery—artery may be damaged further up, deep to the pteryon Vestibulocochlear nerve VIII

What are contents of the interal auditory canal?

The Skull Base

Arnab Rana

Background

Skull base foramina

Skull base bones Facial nerve VII Self learning exercise

References and feedback What are contents of the interal auditory canal?

The Skull Base

Arnab Rana

Background

Skull base foramina

Skull base bones Facial nerve VII Self learning exercise Vestibulocochlear nerve VIII References and feedback Temporal bone Sphenoid bone Frontal bone Ethmoid bone Maxillary and palatine bones if viewed from below

What structures form the skull base?

The Skull Base

Arnab Rana

Background Bones Skull base foramina Occipital bone Skull base bones

Self learning exercise

References and feedback Sphenoid bone Frontal bone Ethmoid bone Maxillary and palatine bones if viewed from below

What structures form the skull base?

The Skull Base

Arnab Rana

Background Bones Skull base foramina Occipital bone Skull base bones Temporal bone Self learning exercise

References and feedback Frontal bone Ethmoid bone Maxillary and palatine bones if viewed from below

What structures form the skull base?

The Skull Base

Arnab Rana

Background Bones Skull base foramina Occipital bone Skull base bones Temporal bone Self learning exercise Sphenoid bone

References and feedback Ethmoid bone Maxillary and palatine bones if viewed from below

What structures form the skull base?

The Skull Base

Arnab Rana

Background Bones Skull base foramina Occipital bone Skull base bones Temporal bone Self learning exercise Sphenoid bone References Frontal bone and feedback Maxillary and palatine bones if viewed from below

What structures form the skull base?

The Skull Base

Arnab Rana

Background Bones Skull base foramina Occipital bone Skull base bones Temporal bone Self learning exercise Sphenoid bone References Frontal bone and feedback Ethmoid bone What structures form the skull base?

The Skull Base

Arnab Rana

Background Bones Skull base foramina Occipital bone Skull base bones Temporal bone Self learning exercise Sphenoid bone References Frontal bone and feedback Ethmoid bone Maxillary and palatine bones if viewed from below Picture from http://aofoundation.org

The Skull Base

Arnab Rana

Background

Skull base foramina

Skull base bones

Self learning exercise

References and feedback More detailed picture from Clemente

The Skull Base

Arnab Rana

Background

Skull base foramina

Skull base bones

Self learning exercise

References and feedback

Zoom for detail Self learning exercise

The Skull Base Name the channels for as many of the following nerves as you

Arnab Rana can

Background

Skull base foramina

Skull base bones

Self learning exercise

References and feedback Acknowledgement of references / sources

The Skull Base

Arnab Rana AO Foundation Surgery reference Background https:

Skull base //www2.aofoundation.org/wps/portal/surgery foramina My favourite anatomy book. Carmine D Clemente. Skull base bones Anatomy: A Regional Atlas of the Human Body (third Self learning edition). Baltimore–Munich: Urban & Schwarzenberg, exercise 1987. References and feedback Encyclopedia Britannica www.britannica.com Dr H Jastrow’s webpage http://www.uni-mainz.de/FB/Medizin/Anatomie/ workshop/bones/skullbase.html Feedback contact

The Skull Base

Arnab Rana

Background

Skull base foramina

Skull base bones Thank you for viewing this presentation Self learning Any feedback, positive or negative, will be appreciated exercise

References Feedback can e-mailed to [email protected] and feedback