ANAT Unit 3 - M20: Blood Supply to the Brain, meninges, ventricles, and CSF

cerebrospinal fluid (CSF)

- clear solution fluid produced in the ventricles of the brain that flows in the subarachnoid space and bathes the meninges. - it circulates throughout the brain and spinal cord - limited amount of the constituents of blood, is essentially water, small mlcs, and electrolytes

Third ventricle

- the ventricle located in the center of the diencephalon

Lateral ventricles

A set of paired ventricles lying within the cerebral hemispheres

Choroid plexus

A specialized structure, highly vascular portion, of the lining of the ventricles that secretes cerebrospinal fluid (CSF) - found in all 4 ventricles

Superior sagittal sinus

A venous sinus that runs in the groove of the median longitudinal fissure where it absorbs CSF from the meninges - superior area between the two hemispheres

basilar artery

An artery, formed by the fusion of the vertebral arteries, that supplies blood to the brainstem and to the posterior cerebral arteries.

Median aperture

An opening in the roof of the 4th ventricle that connects to the subarachnoid spaced

selective

Blood-Brain Barrior (BBB): Endothelia transport across the BBB is highly ___

lipid

Blood-Brain Barrior (BBB): ____-soluble compounds can freely diffuse across the endothelial cell membranes

vesicles

Blood-Brain Barrior (BBB): the endothelial cells of the BBB contain small numbers of pinocytotic ____

tight junctions

Blood-Brain Barrior (BBB): the endothelial cells of the bbb are extensively interconnected with ___ ___

all 4 ventricles ependymal high constantly choroid plexus

CSF Production: - it is produced WITHIN the ___ - it involves ____ cells and ___(high or low) permeable capillaries - is produced ____(only when needed or constantly)___ - is produced BY the __ ___

falx cerebelli

Dural reflections __ __ is located between the right and left hemispheres of the cerebellum

falx cerebri

Dural reflections __ __ is located within the median longitudinal fissure

tentorium cerebelli

Dural reflections ___ ___ is located inferior to the occipital lobes, between the cerebrum and cerebellum

Arachnoid granulations

Extensions/emergings of the arachnoid mater into the dural sinuses that allow excess CSF to be absorbed by the dural sinuses - where the CSF is filtered and drained back into blood stream

cerebral aqueduct

Flow of CSF through and around the brain: 3rd ventricle to ➝

median/lateraal apertures

Flow of CSF through and around the brain: 4th ventricle to ➝

dural venous sinuses

Flow of CSF through and around the brain: arachnoid granulations to ➝

4th ventricle

Flow of CSF through and around the brain: cerebral aqueduct to ➝

3rd ventricle

Flow of CSF through and around the brain: intervertebral foramen (of Monro) to ➝

intervertebral foramen (of Monro)

Flow of CSF through and around the brain: lateral ventricles to ➝

subarachnoid space

Flow of CSF through and around the brain: median/lateraal apertures to ➝

arachnoid granulations

Flow of CSF through and around the brain: subarachnoid space to ➝

transports maintains buoyancy

Functions of CSF: ____ hormones, nutrients, chemicals, and wastes _____ the environment around brain provides ____ for the brain

septum pellucidum

The __ ___ separates the right and left lateral ventricles from each other.

Posterior communicating artery

The artery of the Circle of Willis that transports blood from the internal carotid artery to the posterior cerebral artery - a right and left one

Pia mater

The outer surface of the CNS is covered in the thin fibrous membrane - the innermost layer of the meninges - extends into every convolution of the CNS, lining the inside of the sulci in the cerebral and cerebellar cortices - helps to support large cerebral blood vessels on the surface of the brain.

subarachnoid space

The space surrounding the brain within the meninges that contains CSF is called the __ ___

Internal jugular vein

Vein located at the side of the neck to collect blood from the brain and parts of the face and neck and bring it back to the heart

arachnoid

Which layer of meninges?? (dura, arachnoid, or pia mater) contains filamentous mesh called trabeculae

arachnoid

Which layer of meninges?? (dura, arachnoid, or pia mater) contains granulations that allow CSF to return to teh bloodstream

dura

Which layer of meninges?? (dura, arachnoid, or pia mater) contains the venous sinuses

pia

Which layer of meninges?? (dura, arachnoid, or pia mater) follows the contours of the sulci and gyri

dura

Which layer of meninges?? (dura, arachnoid, or pia mater) forms reflections that fit into large crevasses in the brain

dura

Which layer of meninges?? (dura, arachnoid, or pia mater) has a periosteal and meningeal layer

arachnoid

Which layer of meninges?? (dura, arachnoid, or pia mater) middle layer of meninges

dura

Which layer of meninges?? (dura, arachnoid, or pia mater) outer layer of meninges

pia

Which layer of meninges?? (dura, arachnoid, or pia mater) supports large cerebral blood vessels on the surface of the brain

dura

Which layer of meninges?? (dura, arachnoid, or pia mater) thickest layer of meninges

arachnoid

Which layer of meninges?? (dura, arachnoid, or pia mater) thin, avascular, and transparent membrane

pia

Which layer of meninges?? (dura, arachnoid, or pia mater) thin, innermost layer of the meninges

Circle of Willis

a confluence of arteries that can maintain perfusion of the brain even if narrowing or a blockage limits flow through one part

Ependymal cells

a glial cell that surrounds blood capillaries in the choroid plexus and filter the blood to make CSF - found between the capillaries and the ventricles

Cerebral aqueduct

a narrow tube interconnecting the 3rd and 4th ventricles of the brain

Blood Brain Barrier (BBB)

a selective mechanism that protects the brain from toxins and infections - tight junctions, continuous capillaries, astrocytes

Meninges of the brain

a series of CT membranes that cover the outer surface of the CNS - protect the brain - dura mater, arachnoid mater, pia mater

Subarachnoid space

a space in the meninges beneath the arachnoid membrane and above the pia mater that contains the circulating cerebrospinal fluid - arachnoid trabeculae found here

Inferior sagittal sinus

a venous sinus that runs within the inferior margin of the falx cerebri within the median longitudinal fissure - drains into the straight sinus

Internal carotid arteries

arteries that branch from the common carotid artery on each side and enter the cranium through the carotid canal in the temporal bone - a right and left one

Vertebral arteries

arteries that branch off of the subclavian arteries on each side - enter the cranium through the foramen magnum of the occipital bone. - a right and left one

Anterior cerebral arteries

artery in the circle of willis that branches from the internal carotid artery and supplies blood to the anterior, medial, and very superior portions of the frontal lobe - a right and left one

Middle cerebral arteries

artery in the circle of willis that branches from the internal carotid artery and supplies blood to the posterior frontal lobe and most of the temporal and parietal lobes. - a right and left one

Posterior cerebral arteries

basilar artery divides into these arteries which supply the occipital lobe and lower aspect of thee posterior temporal lobe - a right and left one

Anterior communicating artery

connects right and left anterior cerebral arteries - one artery

Straight sinus

dural sinus that drains blood from the deep center of the brain to collect with the other sinuses - Connects inferior and superior sagittal sinuses to confluence of sinuses

Sigmoid sinus

dural sinus that drains into internal jugular vein - returns blood from transverse sinus to jugular vein

Transverse sinuses

dural sinuses that run within the posterior border of the tentorium cerebelli - receives from confluence of sinuses - drains into the sigmoid sinuses

Tentorium cerebelli

extension of the dura mater that forms a shelf-like structure between the occipital lobes of the cerebrum and the cerebellum - transverse sinus runs within

Falx cerebri

extension of the dura mater that separates the two cerebral hemispheres (more vertical) - located within the median long. fissure - superior sagittal sinus runs within

Falx cerebelli

extension of the dura mater that separates the two hemispheres of the cerebellum

Dural reflections

infoldings of the dura that fit into large crevasses of the brain.

Meningeal layer (dura mater)

inner layer of dura mater that is adjacent to the arachnoid mater of the cranial meninges

Dural venous sinuses

large veins in the dura mater that drain the cranium created by gaps formed between the inner and outer layers of the dura-mater.

vertebral column cilia constant production

movement of the __ ___ ; movement of ____ on the ependymal cells ; and pressure from the ___ ___ of CSF help move the CSF around the brain and spinal cord

Periosteal layer

outer Layer of Dura mater that is attached to the surface of skull.

Lateral apertures

pair of openings from the 4th ventricle to the subarachnoid space

Interventricular foramen (of Monro)

passageway that allows CSF to flow from the lateral ventricles into the 3rd ventricle - connects lateral and third ventricles

Subdural space

space between the arachnoid and dura mater layers of the meninges

Epidural space

space between the dura mater and the wall of the vertebral canal

frontal

the anterior cerebral artery supplies blood to the anterior, medial, and very superior portions of the ___ lobe

frontal temporal parietal

the middle cerebral artery supplies blood to the posterior ____ lobe and most of the ____ and ___ lobes

Arachnoid mater

the middle layer of the meninges

ventricles of the brain

the open spaces/canal within the brain where CSF circulates/is contained - there are 4 within the brain

occipital temporal

the posterior cerebral artery supplies blood to the ___ lobe and the inferior aspect of the posterior ___ lobe

blood vessels

the subarachnoid space contains ___ ___

arachnoid trabeculae

the subarachnoid space has ___ ___, which are web-like threads extending across the subarachnoid space

arachnoid pia

the subarachnoid space is located between the ___ mater and ___ mater

Fourth ventricle

the ventricle located between the cerebellum and the pons and upper medulla

Septum pellucidum

thin membrane that separates lateral ventricles

dura mater

tough, thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord - encloses the entire CNS and major blood vessels that enter the cranium and vertebral cavity

transverse foramina

vertebral arteries are protected as they pass through the neck region by the ___ ___ of the cervical vertebrae

Arachnoid trabeculae

web like threads/filaments extending from arachnoid to pia mater within the subarachnoid space - beneath arachnoid - thin, filamentous mesh