Neuroanatomy part 2 Flashcards
What are meninges?
They are three concentric coverings that encase the
central nervous system and act to support and stabilise the brain
and spinal cord.
Name the three meninges from the outermost to the innermost layer
Dura matter
Arachnoid matter
Pia matter
What are the two layers of the dura matter?
Periosteal layer - in relation to the skull (adherent to it)
Meningeal layer - In relation to the arachnoid layer (Superior to it)
What are dural venous sinuses and where are they located?
Dural venous sinuses are venous drainage channels in between the two layers of the dura matter. They receive venous drainage from the cerebral cortex
-blood from the cortical veins drain blood into the venous sinuses
Name the three venous sinuses
Superior sagittal sinus
Inferior sagittal sinus
Straight sinus
Name the three septa or folds formed by the dura matter
falx cerebri which are present between the cerebral hemispheres,
* falx cerebelli which are present between the cerebellar hemispheres
* tentorium cerebelli which lies between the cerebrum and cerebellum
Describe the arachnoid mater
It lies adjacent to the dura mater
It has several layer of flattened cells
Has arachnoid trabeculae (Strands of connective tissue that go all the way to the pia mater
Describe the pia mater
Thin layer that is directly adherent to the brain
Follows the sulci and gyri of the brain
Highly vascularised
Which meningeal layer is avascular and has no innervation
Arachnoid mater
What is the space between the periosteal dura mater and the skull?
Epidural space
What is the space between the meningeal dura mater and the arachnoid mater?
Subdural space
What is the space between the arachnoid space and the pia mater?
subarachnoid space
Which space has cerebrospinal fluid?
Subarachnoid space
Unpaired sinus that is located in the superior margin of the falx cerebri, that drains blood from the lateral aspects of anterior cerebral hemispheres into the confluence of sinuses.
What is this sinus?
Superior sagittal sinus
Unpaired sinus located in the inferior margin of the falx cerebri.
What is this sinus, and which parts of the brain does it drain?
Inferior sagittal sinus.
Drains blood from the medial aspects of the cerebral hemisphere into the straight sinus
What does the straight sinus drain?
Receives blood from the inferior sagittal sinus and the cerebellum and
drains into the confluence
Describe the confluence
Formed by the merger of the superior sagittal sinus and the straight sinus
Drains blood into the transverse sinuses.
Which sinus drains blood from the confluence to the sigmoid sinus?
Transverse sinus
how many pairs of spinal nerves do we have? How many nerves in each vertebral level?
31 pairs
8 Cervical
* 12 Thoracic
* 5 Lumbar
* 5 Sacral
* 1 Coccygeal
True or false: Spinal nerves contain motor fibers only
False, spinal nerves have both sensory and motor fibers
Which fibers are found in the dorsal root and which fibers are found in the ventral root?
Dorsal root: sensory fibers from sensory neurons in the dorsal root ganglia, from the dorsal horn of the spinal cord
Ventral root: motor fibers of motor neurons from the ventral horn of the spinal cord
how does the mixed spinal nerve branch out
Dorsal and ventral ramus
True or false: the dorsal ramus of the spinal nerve only has sensory fibres.
False: The rami of the spinal nerve are formed once the nerve has been formed. Therefore it has both sensory and motor fibers.
What layers continue with spinal cord
Dura mater and meningeal layer
Which part of medulla oblongata continues in spinal cord
Anterior median fissure
What shows anteriorly on spinal cord
Anterior median fissure
What shows posterioly on spinal cord
(depression)
Posterior median sulcus
What is found at the anterior and posterior corresponding cord segments
Series of rootlets
What is found internally on the spinal cord
H-shaped gray matter
White matter
What does grey matter of spinal cord consist of
cell bodies of neurons
What does white matter of spinal cord consist of
myelinated axons
Horns of grey matter of spinal cord
Ventral- has motor neurons
Dorsal- has cell bodies that receive sensory info
Where are the sensory fibres on the dorsal root from
Dorsal root ganglia
What to remember about spinal nerves
Rami are after spinal nerve has been formed
Therefore, ramus would have mixed fibres
However, roots are before nerve has formed
Thus have specifically either motor or sensory fibres
