Chapter 20 Part 1 Flashcards
What are the organs of the central nervous system?
- brain
- spinal cord
What are the functions of the CNS?
- integrator
- evaluate incoming information and formulate response
What are the two protective coverings of the CNS?
- bone: cranial bones and vertebrae
- meninges: dura mater, arachnoid mater, pia mater
Which contains blood vessels?
-pia mater
Describe the three meningeal coverings.
- dura: hard, strong white fibrous tissue, outer layer (2 and 1)
- arachnoid: spiderweb layer, delicate, middle layer
pia: adheres to surface of the brain, transparent
What are the three extensions of the dura mater?
- falx cerebri: between hemispheres of cerebrum
- falx cerebelli: separates the two hemispheres of the cerebrum
- tentorium cerebelli: separates the cerebellum from the cerebrum
What are the three spaces made by the meninges?
- epidural space
- subdural space
- subarachnoid space
What is contained by the epidural space?
- fat and other connective tissue
- between bone and dura
What is contained by the subdural space?
- small amount of lubricating serous fluid
- between dura and arachnoid
What is the contained by the subarachnoid space?
- cerebrospinal fluid
- between arachnoid and pia
Which of the three spaces is nonexistent in the skull?
-there is no epidural space in the skull
What is cerebrospinal fluid?
-fluid around and within the brain and spinal cord
What are the functions of CSF?
- cushion of fluid (protection)
- maintains internal homeostasis ex. carbon dioxide and pH levels
In what space do you find CSF?
-found in the subarachnoid space
In what cavities do you find CSF?
- within the canals and cavities of the brain and spinal cord
- ventricles and central canal
How many ventricles are there?
- 2 lateral
- third
- fourth
What connects the lateral ventricles to the third ventricle?
-foramen of Monro
What connects the third ventricle to the fourth ventricle?
-cerebral aqueduct
What makes CSF?
- choroid plexuses
- networks of capillaries
- covered in ependymal cells
Through what structures is CSF absorbed? Where does it get reabsorbed into?
- arachnoid villi
- sinuses
What is a lumbar puncture?
-withdrawal of some cerebrospinal fluid from the subarachnoid space
Where is the lumbar puncture performed and why?
- above or below the 4th lumbar vertebra
- no spinal cord there and to test for presence blood, bacteria, or other abnormalities
What is hydrocephalus?
-blockage of draining of CSF
What can cause hydrocephalus?
- tumor
- inflammation
- developmental malformation
- infection such as meningitis
- hemorrhage or injury
