Outcome 6 - Central Nervous System Flashcards
What are the two types of protection that the spinal cord has?
- vertebral column
- spinal meninges
What is the spinal meninges?
- three layers of connective tissue that surrounds the spinal cord for support and protection
What is the spinal cord structure?
- bone-vertebral column
- epidural space
- dura mater - meninx
- subdural space
- arachnoid mater - meninx
- subarachnoid space
- pia mater - meninx
- spinal cord
Is epidural space found between the dura mater and the brain?
Nope. Just between the dura mater and the spinal cord.
What are denticulate ligaments?
- extensions from the Pia mater into the arachnoid mater and the inner layer of the dura mater to protect it from displacement
- extension to adhere Pia mater to spinal cord as well
- located between the anterior and posterior nerve roots of each spinal nerve
What is the arachnoid mater?
it is the middle avascular layer of the spinal meninges made up of collagen and elastic fibres
Where is the starting point of the spinal meninge?
a hole in the occipital
Where does the spinal cord start and end?
medulla oblongata to L2
What is the epidural space?
it is the space between the bone and the dura mater and acts as protection for the spinal cord
What does the epidural space contain?
adipose tissue and blood vessels
What is the dura mater?
it is the thick, strong outer most layer of the meninges; forms a sac from the foramen magnum to S2
What is the dura mater made up of?
dense irregular connective tissue
What is the subdural space?
interstitial fluid-filled area between the first two layers of the spinal meninges
What is the difference between the dura mater of the cranial and the spinal cord?
cranial - two layers of dura mater
spinal - one
What are the two layers of the cranial dura mater called?
- periosteal layer (external)
- meningeal layer (internal)
What is the subarachnoid space?
CSF-filled space
What is the Pia mater?
thin, transparent inner most layer that is made up of interlacing collagen fibres and elastic fibres
What is significant about the Pia mater?
it adheres directly to the spinal cord and is very vascular
What is the filum terminale?
it is the extension of the Pia mater inferiorly to adhere the cord to the coccyx
Where are the 2 enlargements of the spinal cord found?
- cervical: C4-T1
- Thoracic: T9-T12
Where do nerves to the upper limbs originate on the spinal cord?
C4-T1
Where do nerves to the lower limbs originate on the spinal cord?
T9-T12
What is the conus medullaris? Where does it occur?
tapering of the cord - L1 and L2
What is the caudal equine?
the root of nerves extending from the end of the spinal cord
How many pairs of spinal nerves are there? What is the breakdown of the spinal nerves?
31.
cervical - 8 pairs
Thoracic - 12 pairs
Lumbar - 5 pairs
Sacral - 5 pairs
coccygeal - 1 pair
What is the gray commissure?
the cross of the “H”
- has the central canal that is filled with CSF
- extends the length of the cord + superiorly into the 4th ventricle
What are the 4 major parts of the brain?
- cerebrum
- cerebellum
- diencephalon
- brain stem
What makes up the cerebrum?
2 hemispheres
What makes up the cerebellum?
2 hemispheres
What makes up the diencephalon?
thalamus, hypothalamus and the epithalamus
What makes up the brain stem?
midbrain, pons, and medulla oblongata
What is the structure of cranial meninges?
- cranium (bone)
- 2 layers of dura mater WITHOUT epidural space
- subdural space
- arachnoid mater
- subarachnoid space
- pia mater
- brain tissue
What are the three extensions of the dura mater within the cranium?
- falx cerebi - separates the two cerebral hemispheres
- falx cerebelli - separates the two cerebellar hemispheres
- tentorium cerebelli - separates the cerebrum and the cerebellum
Where does the inferior portion of the brain stem start and end?
at the foramen magnum to the pons
What is the desuccation of the pyramids?
when 90% of the tract crossing over to the other side; occurs right before medulla oblongata joins the spinal cord
What is the medulla oblongata responsible for?
controlling vital reflex functions such as heart beat + contraction strength, resp rate, coughing, sneezing, swallowing, hiccuping and vomiting
What is the pons responsible for?
- acts as a bridge between cerebellum and other parts of the brain
- helps control breathing (contains the pontine respiratory group)
What is the cerebral aqueduct?
it is situated in the midbrain
- where the csf flows from the 3rd ventricle to the 4th ventricle
What is the midbrain responsible for?
- reflex enters for visual an auditory activities and helps control muscle activities
How is the cerebellum and cerebrum separated?
by the transverse fissure
What is the superficial layer of gray matter called in the cerebellum?
cerebellar cortex
What is the deeper white matter called in the within the arbor vitae?
cerebellar nuclei