Central nervous system - spinal cord Flashcards
What two main body structures are in the central nervous system?
the brain and the spinal cord
What two main structures are in the peripheral nervous system?
nerves
sensory organs
what are the three segments of the spine?
cervical
thoracic
lumbar
What is the name of the spinal segment at the neck?
cervical spine
what is the name of the spinal segment by the lungs?
thoracic
What is the name of the spinal segment in the lower back/pelvis area?
lumbar
what is at the bottom of the lumbar spine?
sacrum
coccyx
what is in-between the vertebrae?
vertebral disks
Where does the spinal chord extend from?
the brain stem
What is the name of the hole in the vertebrae that the spinal chord passes through?
the vertebral foramen
What shape/structure is the spinal cord? (4)
elongated, almost cylindrical structure
slightly flattened posteriorly and anteriorly
that gives off nerve pairs throughout its length
45cm long in males approx thickness of little finger
the spinal cord and cranial nerves are the only nervous tissue link between what?
the brain and the rest of the body
why is the spinal cord like a motorway?
because it is the main route for nerves to convey impulses from the brain to the various organs and tissues, where the defending nerves leave the cord at appropriate levels to pass to the structure that they supply
where do the sensory nerves from organs and tissues enter to ascend to the brain?
the spinal cord
what are the three primary functions of the spinal chord?
- to relay impulses to and from the brain
- to relay impulses from brain to tissues/organs
- to give sensory information from organs and tissues to the brain
what is the secondary function of the spinal cord?
to provide spinal reflexes independent of the brain
where does the spinal cord extend from in the skull?
the foramen magnum of the skull
where does the spinal cord extend to?
the region of the disc between the first and second lumbar vertebrae
What is the film terminale?
the trend of connective tissue connecting the lower end of the spinal cord to the lower end of the sacrum and coccyx
What is the Cauda equina?
the region of nerve routes surrounding the film terminals
What is the vertebral canal?
an elongated body cavity enclosed within the vertebrae that stores the spinal cord
what are the 2 functions of the vertebral canal?
to offer bony protection
to allow for normal movement to occur without the cord being compromised
What is cerebrospinal fluid?
a clear, colourless body fluid found in the brain and spinal cord
what is the function of cerebrospinal fluid? (4)
as it goes around the brain and spinal chord it
1. cushions organs
2. picks up needed supplies from the blood
3. gets rid of waste products from brain cells
4. homeostasis
How can cerebrospinal fluid help doctors find things out?
if the CSF has viruses or bacteria that can attack the brain so the doctor can examine this to see what is going on
What happens if there is a loss of CSF? (2)
- it can cause the brain to sag inside the skull, causing headaches
- it can cause a lower of pressure in the skull (intracranial hypotension)
Can leaks occurs in CSF?
yes it can occur in the brain (cranial CSF leak) or any point along the spinal cord (spinal CSF leak)
How does CSF protect the brain from damage?
it acts as a shock absorber, preventing damage from occurring when the cranium is hit/jolted
How does CSF help with homeostasis?
it regulated the distribution of metabolites surrounding the brain, keeping the environment ideal to prevent any damage to the nervous system
How does CSF help with clearing waste?
waste products from brain move into the CSF which then clears out through the arachnoid granulations into the Venous sinus so it can be absorbed into the blood stream
How many membranes are there covering the spinal cord? what are the layers called as a group?
3
meninges
What is the outermost layer of the meninges?
The dura mater
What is the dura mater?
a tough, thick, fibrous membrane, densely packed with collagen and elastin that surrounds the brain and spinal chord
What does the collagen and elastin provide to the dura mater? (3)
protection (both)
strength (collagen)
elasticity and reciprocal property (elastin)
what is the middle layer of the meninges?
the arachnoid mater