Brain and Cranial Nerves 1 Flashcards
By fourth week of development, 3 primary brain vesicles have formed
Prosencephelon, Mesencephelon, Rhombencephelon
By fifth week of development, there are 5 SECONDARY brain vesicles
Telencephelon: from prosencephelon forms__________
Diencephelon: from prosencephelon, forms __________, __________ __________
Mesencephelon: the only primary vesicle that does NOT form a new __________ vesicle
Forms the __________, __________, __________
Rhombencephelon:
- Metencephelon: forms __________ and __________
- Myelencephelon: forms __________ __________
Cerebrum
Thalamus, hypothalamus, epithalamus
Secondary, cerebral peduncle, superior colliculi, inferior colliculi
Pons, cerebrum
medulla oblangata
Gray matter:
- Houses __________ __________and __________ cell bodies, __________, __________, __________ axons
- Forms __________ __________, most of adult brain space
- Within white matter, gray matter forms deep clusters of neuron cell bodies called __________ __________
- Motor neuron, interneuron cell bodies, dendrites, telodendria, unmyelinated axon
- Cerebral cortex
- Cerebral nuclei
White matter:
- made of __________ axons
- __________ to gray matter of cortex
- Myelinated
- Deep
__________ __________ are connective tissue that function in:
- Separated brain from bones of cranium
- Protecting __________ __________of brain; form some large veins that drain blood from brain
- Containing and circulation __________
Three layers of meninges:
- __________ mater: thin, innermost layer adhering to brain
- __________ mater: has web of fibers called arachnoid trabeculae
- __________ mater: tough outer layer with two sublayers–> deeper __________ layer and superficial __________ layer
__________ space is an area between arachnoid and pia mater
Cranial menginges
- Blood vessels
- CFS
- Pia
- Arachnoid
- Dura, Meningeal, periosteal
Subarachnoid
The meningeal layer extends into cranial cavity at four locations to form double-layered dura called __________ __________ (dura folds): functions to partition brain and provide support
- __________ __________: projects into longitudinal fissure, separates left and right cerebral hemisphere
- __________ __________: horizontal fold that separates cerebrum from cerebellum
- __________ __________: separates left and right cerebellar hemispheres
- __________ __________: small septum between pituitary gland and hypothalamus (a roof for sella turcica)
The deeper meningeal layer (superficial to __________) and more superficial periosteal layer are usually FUSEd except where they separate to form __________ __________ __________
Cranial dura septa
- Falx cerebri
- tentorium cerebelli
- Falx cerebelli
- Diaphragm sellae
- subdural space, dural venous sinuses
Dura venous sinuses form in locations where the two layers of dura mater have separated
- Superior sagittal sinus: located within the superior margin of __________ __________
- Inferior sagittal sinus: located within the inferior margin of __________ __________
- Transverse sinuses: located within the posterior border of the __________ __________
- Occipital sinus: located in the posterior vertical border of the __________ ________
Several venous sinuses meet at the __________ of __________
- Falx cerebri
- falx cerebri
- Tentorium cerebelli
- Falx cerebelli
- Confluence of sinuses
Ventricles: Cavities that contain __________
Two lateral ventricles are separated by a thin __________ __________
Third ventricle in __________ communicates with lateral ventricles through __________ __________
Third ventricle communicates with fourth ventricle through __________ __________
Fourth ventricle between __________ and __________ merges with __________ __________ of spinal cord
CSF
Septum pellucidum
Diencephelon, interventricular foramen
Cerebral aqueduct
Pons, cerebellum, Central canal
Cerebrospinal fluid is a clear liquid that circulates in the __________ and __________ space.
Buoyancy: brain FLOATS in CSF
Protection: provides liquid cushion
Environmental stability: __________ nutrients and removes waste from brain
Formed by the __________ __________ in each ventricle
Composed of a layer of __________ cells and the __________ that lie within the __________ mater
CSF forms from __________ __________ and __________ cells
Blood from capillaries is __________ to form CSF
Ventricles, subarachnoid space
Transports
Transports
Choroid plexus
Ependymal, capillaries, pia
Blood plasma, ependymal
Filtered
Circulation of CSF
- CSF is produced by __________ __________ in ventricles
- Flow from __________ ventricle –> __________ ventricle THROUGH __________
- Flow from __________ ventricle –> __________ ventricle THROUGH __________
- CSF in fourth ventricle passes through PAIRED __________ __________ to __________ space OR __________ __________ to __________ __________
- Flows throughout __________ space
- Excess CSF flows into __________ __________ (arachnoid granulations) to drain into __________ __________ sinuses.
One way flow of CSF into sinuses, blood stays in venous sinuses
- Choroid plexus
- Lateral to third, interventricular foramen
- Third to fourth through cerebral aqueduct
- Lateral apertures to subarachnoid space, or single median aperture to central canal
- Subarachnoid space
- Arachnoid villi, dural veinous sinus
Blood brain barrier regulates what substances can enter __________ fluid of brain
What 3 things contribute to BBB?
BBB is missing or reduced in three locations of CNS:
- __________ (because the capillaries must be permeable to make CSF)
- __________(hormones are made that need ready access to blood)
- __________ __________(hormones are made that need ready access to blood)
Interstitial
- Capillary endothelial cells, astrocyte perivascular feet, continuous basement membrane
- Choroid plexus
- Hypothalamus
- Pineal gland
Cerebrum is location of __________ thought and origin of intellectual function
Contains many neurons needed for __________ analytical function
Contains outer __________, inner __________ __________, and deep regions of gray matter called __________ __________.
Surface is marked by __________ (ridges), __________ (grooves) and deep __________.
The cerebrum is composed of left and right cerebral hemispheres that are divided by longitudinal fissures
Conscious
complex
Outer cortex, inner white matter, cerebral nuclei
Gyri, sulci, fissures
Central White Matter:
The two hemispheres are SEPARATE except at a few locations where bundles of axons connect them.
Brain’s white matter is deep to __________ __________ matter.
Composed primarily of __________ axons
Association tracts: connect areas within ONE hemisphere
- __________ fibers within a lobe
- __________ __________ connect different lobes of same hemisphere
Commisural tracts: connect 2 hemispheres
- The __________ __________ is the largest comissural tract
Projection tracts: connect cerebrum to __________ areas
- Ex. Spinal cord
Cortical gray matter
Myelinated
Association tracts:
- Arcuate
- Longitudinal fasiculi
Commisural
- Corpus collosum
Projection: Lower
Cerebral nuclei (basal nuclei) are masses of __________ matter located deep within brain’s white matter
__________ nucleus: helps coordinate walking
__________ nucleus: involved in movement and muscle tone (composed of __________ and __________ __________)
__________: conscious and processing of multiple sensory stimuli
__________ __________: participates in emotional expression
Gray
Caudate
Lentiform, putamen and globus pallidus
Claustrum
Amygdaloid body
Each hemisphere is divided into five lobes:
Frontal, parietal, occipital, temporal, insula
