A&P - Chapter 20 (Part 2) Flashcards
What is the function of the CSF? (3)
- Protect/cushion the brain and spinal cord from trauma
- Supplies nutrients to the nervous system tissue of the brain and spinal cord
- Acts as the brain and spinal cords lymphatic system
What does the CSF prevent?
The brain from being crushed by its own weight
- floats
How heavy is the brain?
2-3lbs
What does the CSF in the lymphatic system do? (2)
- Removes waste products
2. Provides immunological protection to the CNS nervous tissue
Where is the most amount of CSF located?
In the subarachnoid space around the brain as well as within the cavities of the canals for the brain
Ventricles in the brain
4 fluid filled spaces in the brain and spinal cord
How does the formation of CSF occur?
By separation of fluid from blood in the choroid plexuses
Choroid plexuses
Are networks of capillaries that project from the pia mater into the lateral ventricles and into the roots of the third and fourth ventricles
Where does the choroid plexuses project from?
The pia mater
Where does the choroid plexuses project into? (2)
- 3rd ventricle
2. 4th ventricle
How does CSF circulate around the brain and through the ventricles and subarachnoid space and gets reabsorbed back into venous blood?
Through arachnoid villi
What is the total volume of CSF?
150ml
How often does CSF get replaced?
3-4 hours
What can lead to an accumulation of CSF?
Blockages anywhere along its path
What is an example of accumulation of CSF?
Hydrocephalus
How long is the spinal cord in the average adult?
17-18 inches long
Where is the spinal cord located?
On the posterior side of the body in a spinal cavity
What is most susceptible to injury in the body?
The spinal cord
Where does the spinal cord extend from?
The foramen magnum to the lower border of L1
What does the spinal cord have?
2 bulges
- enlargements
Where are the 2 bulges on the spinal cord located?
- Cervical regions
2. Lumbar region
Where is the dorsal root located?
Posterior
Dorsal root
Bundles of nerve fibres that carry sensory information into the spinal cord
What does the dorsal root contain?
Dorsal root ganglia
Dorsal root ganglia
Grouping of unmyelinated cell bodies of the sensory neurons
What does the dorsal root ganglia appear as?
Bulges
Where is the ventral root located?
Anterior
Ventral root
Bundles of nerve fibres that carry motor information out of the spinal cord
What kind of receptor is dorsal root?
Sensory
What kind of receptor is ventral root?
Motor
