Exam 3 Lecture Notes Flashcards
Functions of the skull:
- Speech.
- Chewing.
- Swallowing.
- Blood flow.
- Protection of the brain.
The shape of the skull is unique because of -
- Bones grow over the lobes.
Function of the frontal lobe -
Reasoning and logic.
How many bones are in the neurocranium?
8 bones.
Overview of the bones in the cranium:
- 2 parietal bones.
- 2 temporal bones.
- frontal bone.
- ethmoid bone.
- sphenoid bone.
- occipital bone.
The cranial vault is made up by what?
Neurocranial bones.
__________: the skull cap, that gets cut off in the lab.
Calvaria.
__________ ______: Area at the bottom portion of the head, where every nerve connects to and from the brain.
Cranial base.
Bones of the facial skeleton:
- Mandible.
- Vomer.
- 2 nasal bones.
- 2 lacrimal bones.
- 2 maxillary bones.
- 2 palaixtine bones.
7 2 zygomatic bones.
The upper jaw consists of what bones:
The 2 maxillary bones.
The lower jaw consists of what bones:
The mandible bone.
The cheekbones consist of what actual bones:
The zygomatic bones and temporal bones.
What space houses the brain?
The cranial vault.
What space houses the eyes?
The orbital cavities.
What space is continuous with the nasal cavity?
The middle ear cavities.
Which bones have paranasal cavities
- Frontal bones.
- Maxillary bones.
- Ethmoid bone.
- Sphenoid bones.
What is the clinical significance of the sinuses behind the paranasal sinuses of the sphenoid bone?
It is between the nasal cavity and pituitary gland - giving clinical access to the pituitary gland and brainstem without having to open te cranial vault.
What are the functions of the sinuses of the skull?
- Decrease the weight of the skull - weight conservation.
- Speech resonance.
- Temperature regulation.
Non-movable articulations between bones of the skull are called:
Sutures.
_____________ in babies, these are gaps where the sutures would be. These allow the baby’s head to pass through the vaginal canal.
Fontanelles.
the ___________ suture separates frontal and parietal bones.
coronal suture.
the ____________ suture separates the two parietal bones.
Sagittal suture.
the _____________ suture separates the occipital bones from the parietal bones.
Lambda.
Fontanelles are made up of:
Very thick connective tissue.
TMJ joint stands for:
Temporomandibular joint.
Temporomandibular joint: general info -
- Synovial - both hinging and planar gliding.
- Hinge = opening and closing of the jaw.
- Gliding = grinding of jaw.
- Is between the mandible condyles and the mandibular fossa of the temporal bone.
Hinging of the temporomandibular joint is to -
elevates or depresses the jaw.
The gliding of the temporomandibular joint is to -
to protract (move anteriorly) and retract (move posteriorly) the mandible.
Is elevating and depressing the mandible the only way to open and close the mouth.
FALSE - you can open and close the mouth as well by contracting and relaxing the orbicularis oris muscle.
In the nasal cavity, what structures are a part of the ethmoid bone.
The superior and middle conchae are part of the ethmoid bone.
In the nasal cavity, what structure makes up its own individual bone?
The inferior conchae.
What is the function of the conchae of the nasal cavities?
To increase surface area, so that we can warm and humidify inhaled air and remove particles.
Anterior cranial fossa:
Where the cribriform plate is, where olfactory nerves go through.
Houses frontal lobes of the brain.
Middle cranial fossa:
Houses temporal lobes.
Lots of formina for nerves, arteries, veins, and lymphatics.
Has the sella turcica.
_____________ is the saddle-shaped depression in the skull that houses the pituitary gland.
The sella turcica.
Posterior cranial fossa:
Houses the cerebellum, pons, and medulla.
has the foramen magnum.
Right side pathway of blood to the cranial vault.
- Brachiocephalic trunk.
- Right common carotid.
- Internal carotid artery.
Left side pathway of blood to the cranial vault:
- Aortic arch.
- Left common carotid artery.
- Internal carotid artery.
Epidural bleeds are always -
arterial.
Location and function of the carotid sinus:
Location: in the internal carotid artery.
Function: use baroreceptors to regulate blood pressure to the brain.
Location and function of the carotid body:
Location: In between the internal and external carotid arteries.
Function: To sense changes in pH (specifically co2)of the blood.
Internal carotid passes through the _________ ________ that has two 90 degree turns.
Carotid canal.
_________ arteries ascend the transverse foramina.
Vertebral.
______________ _______ is the arterial anastomosis of the brain that connects the internal carotid system with the vertebrobasilar system.
Cerebroarterial circle.
Posterior communicating arteries are branches of what artery?
Left and right internal carotid arteries.
Anterior communicating arteries are branches of what arteries?
anterior cerebral arteries.
The posterior communicating artery allows for blood flow between what two arteries?
The internal carotid artery and the posterior cerebral artery.
Posterior cerebral arteries branch off of what arteries?
Basilar artery.
What two arteries join to make the basilar artery?
The left and right vertebral arteries.
Vertebral arteries branch off from what artery?
The left and right subclavian arteries.
Passage of vertebral arteries into the cranial vault:
Through transverse foramina of cervical vertebrae, and into the foramen magnum.
What are the two types of cerebrovascular accidents?
- Stroke.
- Transient ischemic attack.
Define transient ischemic attacks:
- Cerebrovascular accidents.
- Due to lack of blood flow to the brain.
- Not due to neuronal damage.
Define ischemic strokes and the two subtypes:
- Loss of neurons due to a depleted blood supply.
- Accounts for the majority of strokes.
- Thrombus ischemic stroke: Occlusion is stationary and develops and stays in one place.
- Emobolis ischemic stroke: Occlusion is mobile and flows through blood until it reaches a vessel it is too big to pass through.
Define hemorrhagic strokes:
- Compromised blood vessel.
- Happens due to aneurysm.
- Subarrachnoid space will become filled with blood
- Often due to trauma.
The venous sinus system returns ______ and _____ back to the heart.
- Deoxygenated blood.
- CSF
Which meningeal layer is intimate with the brain?
Pia mater.
Which meningeal layer adheres to the skull?
Dura mater
True or false: There is a large epidural space in the meninges of the brain.
FALSE - there is no epidural space in the dura mater of the spine.
What are the two layers of skull dura mater:
- Periosteal dura - against the bone of the skull.
- Meningeal dura - Adherent to the arrachnoid mater.
________________: where periosteal and meningeal dura separates from each other, creating sinuses.
Dural infoldings.
Functions of dural infoldings:
- Compartmentalizes brain structures.
- Creates a space for venous return via venous sinuses.
Three types of dural infoldings:
- Falx cerebri.
- Falx cerebelli.
- Tentorium cerebelli.
Function of the falx cerebri:
Dural infolding that separates the right and left cerebral hemispheres.
Function of the falx cerebelli:
Dural infolding that separates the right and left cerebellum.
Function of the tentorium cerebelli:
Dural infolding that separates the cerebrum and cerebellum.
True or false: The confluence of sinuses is a venous sinus that connects the sigmoid sinus and inferior/superior sinuses.
FALSE - The confluence of sinuses is where the superior sagittal sinus and inferior sagittal sinus meet, that is not a sinus itself, but drains into the transverse sinus.
Which dural infolding gives rise the superior and inferior sagittal sinuses?
The falx cerebri.
The tentorium cerebelli gives rise to what venous sinuses (in order):
- Transverse sinus.
- Sigmoid sinus.
- Superior petrosal sinus that joins where transverse sinus becomes sigmoid sinus.
- Internal jugular vein.
- Inferior petrosal sinus - joins at inferior petrosal sinus.
Head trauma can cause ________ bleeds, these are always _________.
- Subdural bleeds.
- Always venous.
If you are a red blood cell in the superior sagittal sinus, what would be your blood flow back to circulation?
Sup. sagittal sinus —> confluence of sinuses —-> transverse sinus ——> sigmoid sinus ——> internal jugular vein ——> jugular vein ——–> superior vena cava ——–> right atrium.
If you are a red blood cell in the inferior sagittal sinus, what would be your blood flow back to circulation?
Inferior sagittal sinus —–> straight sinus ——-> confluence of sinuses ——> transverse sinus ——-> Sigmoid sinus ——> internal jugular vein —–> jugular vein ——> Superior vena cava.
Venous return from the face is mostly via what vein? Where does this vein drain into?
The facial vein, drains into the internal jugular vein.
What structure does the facial vein have an anastomosis with?
The cavernous sinus.
Why is it possible for blood to flow up from the facial vein to the cavernous sinus?
Because there are no valves in the vein surrounding the nose and eyes, allowing blood to be forced up when a pimple or boil is popped. This allows for a passage way of bacteria into the cavernous sinus.
What passes through the cavernous sinus?
- CN III - Oculomotor.
- CN IV - Trochlear.
- CN VII - Facial
- Opthalmalic Nerve - V1.
- Maxillary nerve - V2.
- Internal carotid arteries.
What can be said for the blood flow through the cavernous sinus?
Blood flow through the cavernous sinus has limited laminar flow, due to the amount of nerves and the internal carotid arteries that run through it.
True or false: Only the cavernous sinus has a significant amount of vessels and nerves running through it.
True!
What muscle allows the eyes to look upward?
Superior rectus muscle.
What muscle allows the eyes to look downward?
Inferior rectus muscle.
What muscle allows you to move your eye medially?
Medial rectus muscle.
What muscle allows you to look laterally?
Lateral rectus muscle.
Lateral rectus muscle is innervated by CN ____, ___________.
CN VI Abducens.
The medial rectus muscle, superior rectus muscle, and inferior rectus muscle, are all innervated by CN ___, __________
CN III Oculomotor.
What 2 muscles help to rotate the eyeball?
- Superior oblique muscle.
- Inferior oblique muscle.
Trochlear CN IV innervates which muscle to the eye?
Superior oblique muscle.
Inferior oblique muscle of the eye is innervated by which nerve?
Oculomotor CN III.
What muscle will lift the eye lid?
Levator palpebrae superioris muscle.
Levator palpebrae superioris muscle is innervated by which nerve?
CN III oculomotor.
What structures produce CSF, and where are they located?
The choroid plexuses, which are located in all of the ventricles.
Interventricle foramina connect which two structures?
Connects the lateral ventricles to the third ventricles.
The _________________ attaches the third ventricle to the fourth ventricle.
Aqueduct of the midbrain.
What is the function of apertures of the fourth ventricle?
To allow passage of CSF from the fourth ventricle into the sub-arachnoid space.
What would occur if there was a blockage of fluid in the aqueduct of the midbrain?
Hydrocephaly of the brain - build-up of CSF in the lateral ventricles and 3rd ventricles.
What would occur if there was a blockage of fluid in the interventricular foramen?
Hydrocephaly of the brain - Build-up of CSF in the lateral ventricles.
What would occur if there was a blockage in the aperture of the fourth ventricle?
Hydrocephaly of the brain - Build-up of CSF in the lateral ventricles, 3rd ventricle, and 4th ventricle.
Functions of cerebrospinal fluid?
- Supportive of CNS.
- Protective - limits the movement of the brain.
- Maintains ionic balance of CNS.
- Lymphatic function.
What do the ventricles of the brain develop from?
The ventricles develop from the neural tube in fetal development.