Lecture 1 - Intro and Gross Brain Structure 2 Flashcards
Brainstem:
- 3 subdivisions:
- midbrain, pons, medulla
The brainstem conveys information to and from the ______ of the brain. Radiating from it are the ______ nerves.
- cerebrum
- cranial nerves
The cranial nerve terminating at the olfactory bulb at the anterior end of the olfactory tract is the _____ nerve.
- olfactory (CN I)
The ______ nerves join into the optic chiasm posteriorly and give rise to the optic tracts. The optic tracts then end at the ______. Embryologically, these nerves are part of the _______, so they are part of the CNS (not PNS).
- optic (CN II)
- thalamus
- diencephalon
CN III, also known as the ______ nerve, emerges from the ________ fossa posterior to CN II.
- occulomotor (CN III)
- interpeduncular
The _____ nerve is the only CN to arise from the dorsal aspect of the brainstem.
- trochlear (CN IV)
CN’s _____ all arise from the pons.
- CN V - VIII
- trigeminal (V), abducens (VI), facial (VII), vestibulocochlear (VIII)
CN VIII (_______ nerve) arises from the pons, emerging from the ___________ angle.
- vestibulocochlear (VIII)
- cerebellopontine
CN’s _______ all arise from the medulla.
- CN IX - XII
- glossopharyngeal (IX), vagus (X), accessory (XI), hypoglossal (XII)
CN XI (_______ nerve) of the medulla emerges from the upper cervical ______ _______, ascends into the ______, then reverses and goes back into the _____.
- accessory (XI)
- spinal cord
- skull
- neck
The most medial aspect of the cerebellum, located on the midline between the two hemispheres is called the _____.
- vermis
The HEMISPHERES of the cerebellum are divided into _____ and ______ sides based on functionality, not anatomy.
- medial
- lateral
The vermal and hemispheric parts of the __________ lobe are lost during development, and hidden by the brainstem.
- flocculonodular
The hemispheric part of the cerebellum is the _______, while the vermal part is the _______.
- flocculus
- nodule
The flocculonodular lobe is important in mediating _____ movements, and is interconnected with the ______ system.
- eye
- vestibular
The LOBES of the cerebellum are divided into the _____ and ______ based on their location relative to the primary fissure. The third lobe is the _______ lobe.
- anterior
- posterior
- flocculonodular
The anterior lobe of the cerebellum receives input from the _____ _____, and is responsible for movement of the _____ and ______.
- spinal cord
- trunk
- limbs
Many structures, such as the cerebrum, have a “____” shape due to embryological development.
- C
3 basal ganglia of brain:
caudate, putamen, globus pallidus
Basal ganglia (Anatomy):
The _____ is made of the caudate and putamen. The ________ nucleus is made of the putamen and globus pallidus.
- striatum
- lenticular
The basal ganglia is separated from the thalamus by the ______ _______, a fiber bundle interconnecting cortex and deep structures.
internal capsule
The basal ganglia function is associated with _____ ______.
movement control
In a coronal section of the brain, the globus pallidus is _____ to the putamen. The putamen is ______ to the insula (hidden lobe) of the cerebrum. Both globus pallidus and the putamen are superior to the _______, and lateral to the _______ ______.
- medial
- medial
- amygdala
- third ventricle
Limbic System (emotions):
The ______ is found beneath the uncus in the temporal lobe. The hippocampus is located in the medial _____ lobe.
- amygdala
- temporal
A cavity of embryonic neural tube, filled with CSF made in the ______ ______ is called a ________.
- choroid plexus
- ventricle
3 roles of ventricles:
- suspend brain
- regulate ECF composition
- path for neurotransmitter distribution in CNS
4 ventricles of CNS:
The 2 _____ ventricles mirror the posterior aspects of the left and right cerebral hemispheres. The ___ ventricle is between the thalami of the diencephalon. The ___ ventricle is anterior to the cerebellum.
- lateral
- 3rd
- 4th
The lateral ventricles drain CSF to the 3rd ventricle via the ________ ________. The 3rd ventricle drains CSF to the 4th ventricle via the ______ _______ of the midbrain. The 4th ventricle then drains to the central canal of the spinal cord via the _____.
- interventricular foramen (of Monroe)
- cerebral aqueduct (of Sylvius)
- obex
CSF is produced in the _____ ______ of the ventricles. This structure is made of modified ependymal cells.
choroid plexus
Large CSF filled spaces between the dura mater and the arachnoid mater are called _______ ________. The largest of these spaces is _____ _____.
- subarachnoid cisterns
- cisterna magna
After the 4th ventricle, CSF can drain into the ______ and ______ apertures.
median, lateral
The lateral aperture of the 4th ventricle allows CSF to drain _______ to the spinal cord and _____-______ around the cerebrum.
- anterior
- anterio-superiorly
The median aperture of the 4th ventricle allows CSF to drain into the cisterna magna, then _______ to the spinal cord and ______-______ around the cerebrum.
- posterior
- posterio-superiorly
When CSF pressure is greater than venous pressure, the venous blood flow reabsorbs CSF through valves called ____ _____.
- arachnoid villi ( arachnoid granulations)
_________ is a buildup of fluid inside the skull that leads to brain swelling.
Hydrocephalus
An increase in pressure forces the uncus of the temporal lobe against the tentorium and brainstem in an ______ herniation.
uncal
The tonsils of the cerebellum protrude into the foramen magnum during a _______ herniation.
tonsillar
The cingulate gyrus of the frontal lobe is pushed under the falx cerebri during a __________ herniation.
subfalcine
The brain and spinal cord coverings, or _______, suspend the brain and spinal cord, and allow it to turn with the head. ______ aids these coverings by acting as a buyoant, shock-absorbing liquid to support the brain.
- meninges
- CSF
From most superficial to deep, what are the 3 layers of the cranial meninges? Which layers compose the leptomeninges?
- dura mater, arachnoid mater, pia mater
- arachnoid + pia
CSF is housed in the ________ space.
subarachnoid
Purpose of dura mater:
mechanical strength
The dura mater is composed of 2 layers: the outer layer, the ______, adheres to the inner skull; the inner layer is the ______ dura.
- periosteal
- meningeal
Potential spaces can develop in the dura mater. Between the dura and calvaria (skull) is an ______ space. Beneath the innermost dural layer, a _____ space can form.
- epidural
- subdural
A tear in the meningeal arteries between the skull and dura leads to a _______ hematoma. A ______ hematoma occurs when bridging veins are torn.
- epidural
- subdural
The two dura reflections are the _____ _____ between cerebral hemispheres and ______ ______ between the cerebrum and cerebellum.
- falx cerebri
- tentorium cerebelli
The space in the tentorium cerebelli where the brainstem passes through is called the ______ ______.
tentorial notch/incisure
Bilateral portions of dural reflections are not fused. They remain open for _____ blood flow through sinuses lined by ______.
- venous
- endothelium
Along the superior portion of the falx cerebri, blood flows through the _____ _____ sinus. Superior of the tentorium is the ______ sinus that is bilaterally paired. Passing along the line where falx and tentorium fuse is the _____ sinus. Together, these meet at the _______ __ ______.
- superior saggital
- transverse
- straight
- confluence of sinuses
2 largest supplies of arterial blood to CNS:
- internal carotid artery
- vertebral artery
Internal Carotid Artery, Circle of Willis (Anatomy):
- Ascends neck, traverses petrous ______ bone, goes through ______ sinus, and acts as the source of the ______ artery as the ICA enters the subarachnoid space.
- temporal
- cavernous
- ophthalmic
Internal Carotid Artery, Circle of Willis (Anatomy):
- Travels along optic _______, bifurcates into _____ (MCA) and ______ ______ (ACA) arteries.
- chiasm
- middle cerebral
- anterior cerebral
Circle of Willis:
The anterior choroidal artery is a long, thin branch of the ____ _____ artery. It is involved with ______.
- internal carotid artery (ICA)
- strokes
Circle of Willis:
The optic tract, choroid plexus, internal capsule, thalamus, and hippocampus are all supplied by the _____ ______ artery.
anterior choroidal
Circle of Willis:
The middle cerebral artery (MCA)/internal carotid artery and posterior cerebral artery (PCA) are joined by the _____ _______ artery inferior to the optic tract.
posterior communicating
The ACA (____ _____ artery) runs through the longitudinal fissure, then follows the ____ ______.
- anterior cerebral
- corpus callosum
The anterior cerebral artery (ACA) supplies the _____ and ______ lobes.
- frontal
- parietal
The two anterior cerebral arteries (ACA) are joined by the _____ _____ artery.
- anterior communicating
The _____ ______ artery travels into the lateral sulcus, divides into many branches, and supplies most of the lateral cerebral hemispheres.
middle cerebral
A mass of arteries between the cerebral peduncles and around the optic chiasm area that supply the basal ganglia, thalamus, and internal capsule are known as the _______ arteries.
perforating
- ex: anterior choroidal artery (ACha), lenticulostriate artery (LsA)
The _______-______ system of arteries eventually supplies the circle of Willis. It arises from the fusion of the vertebral arteries into the basilar artery at the _____ of the brainstem. It supplies the ______ and _______.
- vertebral-basilar
- pons
- brainstem
- cerebellum
Vertebral-Basilar System:
Prior to fusing into the basilar artery, the vertebral arteries give off the _______ ______ arteries, supplying the posterior 1/3 of spinal cord.
posterior spinal
Vertebral-Basilar System:
Prior to fusing into the basilar artery, the vertebral arteries give off the _____ ______ arteries, supplying the anterior 2/3 of spinal cord.
anterior spinal
Vertebral-Basilar System:
Prior to fusing into the basilar artery, the vertebral arteries give off the _____ arteries, supplying the inferior cerebellum and lateral medulla.
PICA (posterior inferior cerebellar artery)
Circle of Willis:
The terminal bifurcation of the basilar artery forms 2 ______’s.
PCA (posterior cerebral arteries)
Circle of WIllis:
Before it bifurcates, the basilar artery gives rise to _____ and ______ arteries.
- AICA (anterior inferior cerebellar arteries)
- SCA (superior cerebellar artery)
Circle of WIllis:
AICA supplies the ______ cerebellum (flocculus) and caudal _____.
- inferior
- pons
Circle of Willis:
SCA supplies 3 things:
- superior cerebellum
- caudal midbrain
- rostral pons
Circle of Willis:
The posterior cerebral artery (PCA) supplies the medial & inferior surfaces of the ______ and _______ lobes of the cerebrum. There are also branches to the rostral ______ and posterior _______.
- temporal
- occipital
- midbrain
- diencephalon
Circle of Willis:
The internal carotid and vertebral-basilar system are linked by the _____ ______ artery.
posterior communicating
Circle of Willis:
The _____ ______ artery connects the right and left sides of the circle of Willis.
anterior communicating
TRUE or FALSE:
The posterior communicating arteries that link the internal carotid and vertebral-basilar system have little blood flow/interchange.
True
Occlusion of a vessel in the circle of Willis can still allow adequate blood supply via ________ flow.
anastomatic
3 mechanisms for cerebral blood flow regulation:
- ________: vasoconstriction (if low pressure) and vasodilation (if pressure is high)
- _______ ______: brain and vessel collaboration in response to increased brain activity
- _______ _______ (?)
- autoregulation
- glutamate sensing
- cerebral vascular autonomics
The anatomic and physiologic barrier that controls movement of materials from extracellular fluid of body to extracellular fluid of brain is the ____ _____ _____.
blood-brain barrier
3 components of the blood-brain barrier:
- arachnoid mater
- endothelial tight junctions
- lack of pinocytic vessels
In the blood-brain barrier, diffusion of _____-soluble substances occurs freely. ______ is transported by facilitated diffusion. Everything else must use ATP to cross via _______ transport.
- lipid
- glucose
- active
Areas where fenestrations of cerebral capillaries allow communication between blood and brain extracellular fluid are called ____________ organs.
circumventricular
Circumventricular organs are located around the ______ and ______ ventricles.
- 3rd
- 4th
Circumventricular organs have sensory functions to monitor ______ composition. Others release ______ from neurons into the bloodstream.
- CSF
- hormones
Circumventricular organs have specialized ependymal cells called ________ , which overlie the ventricular surface.
tanycytes
Venous drainage of the brain starts in the ______ veins of the brain. It then drains into the ______ sinuses, and finally into the _____ ______ vein and ______ venous plexus at the base of the brain/apex of spinal cord.
- cerebral
- dural
- internal jugular (IJV)
- epidural
The cerebral venous system is unique because it has many ______, unlike the rest of the body.
anastomoses
Venous Drainage:
Superficial drainage of the brain usually empties into the _____ _____ sinus. Deep drainage of internal structures empty into the ______ sinus.
- superior saggital
- straight
Venous Drainage:
Superior veins drain into ______ ______ sinus and ______ ______ sinus. Inferior veins drain into ______ sinus and ______ sinus.
- superior saggital (SSS)
- inferior saggital (ISS)
- transverse
- cavernous
Venous Drainage (superficial):
3 main superficial veins:
- superficial middle cerebral vein
- superior anastomotic vein (of Trolard)
- inferior anastomotic vein (of Labbé)
Venous Drainage (deep):
The main vein of the deep drainage system is the _____ _____ vein. These veins are _____ than superficial veins.
- internal cerebral
- smaller
Venous Drainage (deep):
The ______ _______ vein is formed by the confluence of the septal, thalamostriate, and choroidal veins. This paired vein eventually fuses to form the _______ _____ vein (of Galen), then flows to the ______ sinus.
- internal cerebral
- great cerebral
- straight
Venous Drainage (deep):
The _____ vein (of Rosenthal) forms near the optic chiasm, and drains the orbitofrontal cortex, insula, inferior basal ganglia, and parts of the temporal lobe. It joins the _____ _____ vein (of Galen) before draining into the _____ sinus.
- basal
- great cerebral
- straight
