Lecture 17 Flashcards
Gray matter and White matter in the brain
- gray matter= ______ and cerebral ______; ___% of the brain
- white matter= _______ and ________; ___% of the brain
- cortex; cerebral nuclei; 40%
- inside; corpus callosum; 60%
gray matter= ________ and ________
white mater= bundles of ______
cell bodies and dendrites
axons in the form of tracts
corpus callosum
wide and thick bundle of nerve fibers that connect left and right hemispheres
Meninges:
3 protective membranes surrounding the brain and spinal cord
Sequence of meninges from cranium to cerebral cortex
- periosteal dura mater
- meningeal dura mater
- arachnoid mater
- pia mater
__________ is between periosteal dura mater and meningeal dura mater
superior sagittal sinus
_________ is between meningeal dura mater and arachnoid mater
subdural space
_________ is between arachnoid mater and pia mater
subarachnoid space
CSF=
-____________ is the space between the meninges in which it is filled with CSF and all cerebral _______ and _______ are located here
cerebrospinal fluid
- subarachnoid space
- arteries; veins
Ventricles:
interconnected cavities inside the brain (4) filled with the CSF
4 ventricles of the brain
1.
2.
3.
4.
1./2. Lateral ventricle
2. third ventricle
3. fourth ventricle
Choroid plexus
- produces ______ (from blood plasma)
- located in each _______
- CSF
- ventricle
Choroid plexus= spongy mass of _______ ________ on the floor or wall of each ventricle
-from these capillaries the __________ cells filtrate blood to produce ____
blood capillaries
- ependymal; CSF
CSF flows through the brain in the following order
1.
2.
3.
4.
5.
- Lateral ventricle
- Foramen of monro (inter ventricular foramen
- third ventricle
- Cerebral aqueduct (aqueduct of sylvius)
- Fourth ventricle
Dural (venous) sinuses
collecting pools of blood which drain venous blood circulating from the cranial cavity
-example= superior sagittal sinus
Arachnoid granulations
- cluster of arachnoid ________ invaginated into the dural sinuses through which ______ enters the venous system (to reach superior sagittal sinus)
- membrane; CSF
the BBB
- stands for the ______ _______ _______
- it regulates what substances can get from the ___________ into the brain’s ________ _________ (selectively permeable)
- Blood Brain Barrier
- bloodstream; extracellular fluid
There are places called ________ ______ (CVOs) in the ____ and _____ ventricles where the BBB is ABSENT, and the blood has direct access to brain neurons
circumventricular organs; 3rd and 4th ventricles
Three cellular components of the BBB
- Endothelial cells (lines interior surface of blood vessel)
- Pericyte (perivascular cells that wrap around blood capillaries
- Astrocyte (their end-feet)
Fenestrated=
- Blood-CSF Barrier endothelial cells are _______
- BBB endothelial cells are ______________
large pores
- fenestrated
- NON-fenestrated
The Blood-CSF Barrier is found in the ________ ______
- _______ and _______ cells form the blood-CSF-barrier
- ________ _______ between the ependymal cells in order to seal gaps in between adjacent cells to prevent the ______ movement of substances
Choroid plexus
-ependymal; endothelial
- tight junctions; free
The Brainstem includes..
function:
- the midbrain
- pons
- medulla oblongata
regulating basic life-sustaining functions
Structures of the midbrain:
-_________ __________ is formed by 4 colliculi (___ superior and ___ inferior)
- located on the tectum on the _______ side of the midbrain
- corpora quadrigemina; 2 and 2
- dorsal
Reflexes that the corpora quadrigemina are involved in:
- 2 superior colliculi=
- 2 inferior colliculi=
- visual reflex center
- auditory reflex center
Structures of the midbrain:
-________ ________: located on the VENTRAL (ANTERIOR) side of the midbrain
- the __________ tracts are in here
- cerebral peduncles
- corticospinal (motor descending pyramidal)
What is the tectum and where is it located?
word for roof and located above cerebral aqueduct in midbrain (dorsal)
Four main parts of the midbrain:
1.
2.
3.
4.
- tectum
- tegmentum
- substantia nigra
- crus cerebri
what is the red nucleus and where is it located?
- subcortical motor centers
- tegmentum
The ________ ______ consist of melanin-containing neurons that produces ________
- involved in ____ control
- located on ________ sides of crus cerebra
substantia nigra; dopamine
- motor
- posterior (dorsal)
the ______ ______ contains corticospinal (motor) tracts
crus cerebri
The _________ extends through the brainstem, _______ to the ventricular space. It contains the reticular formation, _____ nerves, ______, and tracts
tegmentum; anterior; cranial; nuclei
The medulla oblongata is located between the ______ and ______ ______
pons; spinal cord
________ ___________ ________ (______________): form the ventral face of the medulla oblongata (cross through the pyramid of the medulla
descending corticospinal tracts (pyramidal tract)
Decussation of the pyramids
here the fibers from the corticospinal tract cross over before entering the spinal cord
Visceral nuclei of the medulla control….
respiratory rate
heart rate & blood pressure
coughing
vomiting
________ cooperates with the medullary respiratory centers to control __________ rate and _____
pons; respiratory; depth
All _________ (sensory) and ________ (motor) fibers connecting brain and spinal cord pass through _______
ascending; descending; medulla
Reticular formation
net-like structure of various brainstem nuclei and neurons spanning the length of the brainstem
The ______ is a component of the reticular formation
RAS (reticular activating system)
Functions of the Reticular formation
- maintains the ______ state (consciousness) of the cerebral cortex (RAS) coordinating both ____-_____ cycle and ________
- helps regulate skeletal and visceral ______ ________
- filters out repetitive stimuli: ________
- alert; sleep-wake cycle and wakefulness
- muscle activity
- habituation
the ________ ________ connects the cerebellum to the brainstem
cerebellar peduncles
the _______ ______ connects the two hemispheres of the cerebellum (right & left)
cerebellar vermis
white matter of cerebellum= ________ ________
arbor vitae (resembles structure of a tree)
outer “wrinkles” of cerebellum= ______
folia
Which multipolar neurons are present in the cortex of the cerebellum between the granule cell layer and the molecular layer?
purkinje cells
Main function of the cerebellum:
adjust motor output, ensuring coordination and balance
