Facial, Skull, and Brain Anatomy Overview

Cerebrum

Largest portion of the brain.

How many cranial nerves come from the brain stem

10 out of the 12!!! Cn1 and cn2 dont come from the brain stem

Where does cranial nerve 1 and 2 originate from if it's not the brain stem then?

The Cerebrum!!!!!

Brainstem

Small mass of tissue packed with motor and sensory nuclei; 10 of the 12 cranial nerves originate from the brainstem.

Cerebellum

small brain

Major regulator of motor activities; maintains balance, regulates muscle tone, and coordinates voluntary movement.

Sphenoid Bone

Called the 'keystone' of the cranium; articulates with all other cranial bones.

Facial Bones

14 bones including Nasal (2), Lacrimal (2), Maxilla (2), Palatine (2), Zygoma (2), Inferior Nasal Conchae (2), Vomer (1), Mandible (1).

Maxilla

Formed by two maxillary bones; makes up the upper part of the mouth and anterior ¾ of hard palate.

Zygoma

Cheek bones; form the inferior and lateral walls of the orbits.

Nasal Conchae

Project medially and inferiorly along the nasal cavity; have a scroll-like appearance.

Vomer

Projects superiorly from the base of the nasal cavity to form the inferior portion of the nasal septum.

Mandible

Jaw bone; only moveable bone in the skull and the largest and strongest facial bone.

Temporomandibular Joint (TMJ)

Hinge joint that allows for the necessary motions of mastication (chewing).

Paranasal Sinuses

Include Ethmoid, Maxillary, Sphenoid, and Frontal; lined with cuboidal epithelium composed of ciliated and mucus producing cells.

Optic Nerve (II)

The nerve of sight; blindness at 5000 cGy. (td55 5000cgy)

Optic Chiasm

Where the optic nerves from both eyes cross, located near the dorsum sella; blindness at 5000 cGy. (td55 = 5000cgy)

Cranium

Composed of 8 bones: Occipital (1), Temporal (2), Sphenoid (1), Ethmoid (1), Parietal (2), Frontal (1).

Frontal Bone

Forms the forehead, the anterior part of the skull, and roof of the orbital cavities.

Ethmoid Bone

Located between the orbits; contains the cribiform plate that transmits the olfactory nerves.

Crista Galli

Provides attachment to the falx cerebri.

Falx cerebri ( also called midline falx)

Separates the cerebral hemispheres; attaches to the crista galli of the ethmoid bone.

Sella Turcica

Located within the sphenoid bone; houses the pituitary gland.

Foramen Magnum

Passage for the brain stem into the spinal canal.

Cerebrospinal Fluid (CSF)

Cushions the brain from injury; produced in the choroid plexus of the ventricles.

Circle of Willis

Located within the subarachnoid space; supplies arterial blood to the cerebrum.

Cranial Nerves

Includes Olfactory (I), Optic (II), Oculomotor (III), Trochlear (IV), Trigeminal (V), Abducens (VI), Facial (VII), Acoustic (VIII), Glossopharyngeal (IX), Vagus (X), Accessory (XI), Hypoglossal (XII).

Lateral Rectus

One of the muscles of the eye.

Medial Rectus

Another muscle of the eye.

Ventricles of the Brain

Include Lateral, Third, Cerebral Aqueduct, and Fourth Ventricle.

Cerebral Aqueduct

Passage of CSF from the lateral and third ventricles to the fourth ventricle.

Fourth Ventricle

Rests on the pons and medulla oblongata; receives CSF through the cerebral aqueduct.

Gray Matter

The cortex of the brain.

White Matter

Located beneath the cortex of the brain.

Corpus Callosum

White matter connecting the left and right cerebral hemispheres.

oh oh oh to touch and feel a girls vagina, ah heaven

(I AM SO SORRY SO(F/PH)IA BUT IT’LL HELP ME REMEMEBER)

Jk we only need 1,2,5,7 and 10 rn

Olfactory (I)
Optic (II)
Oculomotor (III)
Trochlear (IV)
Trigeminal (V)
Abducens (VI)
Facial (VII)
Acoustic(VIII)
Glossopharyngel(IX)
Vagus (X)
(Spinal) Accessory (XI)
Hypoglossal (XII)

(absolutely insane)

Check body habitus stuff from the previous tests!!!

BODY HABITUS MEMORIZE PLS

Most common brain diagnostic

Brain Mets

Most common primary brain in adult

Astrocytoma

Most common pediatric brain

Medullarblastoma

Where is astrocytome/glioblastlma normally in adults

Cerebrum

Where is medullarblastoma found

Cerebellum

What is the vertex setup

Beam is coming from top of the head

Where is the superior orbital margin

The bony Part behind eyebrow

What bones r behind the inner canthus

Lacrimal bones

What part of the ear is good for leveling

The Tragus

Is the vermillion sensitive to radiation

Yes!!

What is the off cord field

Rad field.that is away from spinal cord

What is Off axis

Rad field that is going away from the central axis of the beam

Look at common metastatic areas

On previous dragon

If a adult primary brain goes infra tentorium does that mean a better or worse prognosis

It means a worse prognosis because the cancer has moved from Cerebrum to the cerebellum

If a pediatric patient's primary cancer grows supratantorium Does that mean a worse or better prognosis for them?

It means a worse prognosis because the cancer has moved from the cerebellum to the cerebrum

What is the blood brain barrier made out of?

The blood brain barrier is a line of astrocytes around the inner part of the brain

The blood brain barrier acts as what

A Filter allowing only certain things thru

Temodar is what type of drug

Nitrosaurous drug

What does the drug Temodar do?

Breaks the blood brain barrier and acts as a radiosensitizer

The mastoid tip is on what bone

TEMPORAL BONE

What two things are looked at to determine prognosis with brain cancers

Whether the cancer has passed the tantorium And whether there's a lot of necrotic tissue inside of the tumor

If it’s whole brain is it palliative or curative

Palliative 30-40 gy treatments

When u treat whole brain how do u set up the gantry

Parallel opposed laterals

90 and 270 degrees

Where do they like to treat down to for brain

Around c2 cause that’s where the fourth ventricle is

If the collimators angle on one side is 340 degrees what is the angle needed on the opposite side so the collimators become mirrored

360-340=20

20 degrees

What is flash

The light field beyond area being treated

It means u have the entire area covered (in case of like movement)

What is a keystone structure?

A structure that holds other things so if you take away that structure all the things around, it would fall out of place

What's an example of a keystone structure in the head?

Sphenoid bone

Why do they tend to go down to C2 when doing a whole brain radiation?

Because the fourth ventricle ends at C2

What is the external part of the ear called

Pinna, auricle, helix

What is an acoustic neuroma?

Benign tuber that grows behind the tympanic membrane, Will usually get treated with radiation can’t b removed surgically

What happens if you over radiate the cochlea?

The cochlea has fluid in it so the fluid will dry out, The fluid helps maintain balance

What is the bony base of the skull called?

Petrous ridge

The crista galli is part of what bone

Ethmoid bone

What is the vertex

Top of head

When kids have a medullarblastoma, what is the tumor usually pushing on? That causes hydrocephalus

The fourth ventricle of the brain

Gives them instability when standing up and nausea

With structure sends the signals to the pituitary gland to secrete hormones

Hypothalamus

What are the layers of the Menengies from outer to inner

Dura matter

Arachnoid matter

pia matter

The tentorium and falx cerebri r both an extension of what

The dura matter

Is the sella Turcica/ sella dorsum a supratentorial or infratentorial?

Supra tentorial

Where does the brain metastasize to?

Brain usually doesn't metastasize, but if it does, it will be to other parts of the brain or the cerebral spinal fluid

When treating a brain, where don't you want flash

Over the nasion because that means that you're gonna treat the contra lateral eye

Red

Lateral ventricle

(The blue is the third ventricle)

Third ventricle

Purple

Cerebral aquaduct

Red

Forth ventricle

What makes the cerebral spinal fluid?

The choroid plexus

What makes up the choroid plexus

The inner lining of the ventricles that makes the cerebral spinal fluid

What connects the lateral and third ventricles

Intraventricular foramen aka foramen of Monro

Intraventricular foramen

What connects the third ventricle to the forth ventricle

Cerebral aqueduct

Cerebral aqueduct

Gyrus

Sulcus

Cortex of brain is

Grey matter

Beneath the cortex is

White matter

The corpus callsosum is white or grey matter

White matter

The brain stem is made up of

The midbrain pons and medulla oblongota

What is the function of the midbrain

Visual and auditory reflex center

What is the function of the pons

Regulates relaxation

Relay signal between spinal cord and brain

What is the function of the medulla oblongota

Contains a vital center

Responsible forCardiac vasomotor and respiratory

When does the medulla oblongota Become the spinal cord

Once it passes the foramen Magnum

What is cranial nerve one

Olfactory nerve

What is cranial nerve two

Optic nerve