A&P Test 2 Flashcards
1
Q
CNS is surrounded by 3 layers of connective tissue called the
A
Pia- thin layer
arachnoid mater-thin layer
dura mater- thick and leathery
2
Q
subarachnoid hemorrhage happen in the
A
subarachnoid space
3
Q
What is the dividing point between the cns and pns?
A
spinal nerves
4
Q
the Pia, arachnoid, and dura mater cover the nerve until the point of
A
where the rootlets join together and form that spinal nerve
5
Q
Spinal meninges are the
A
pia mater
arachnoid mater
dural mater
6
Q
The meninges are covering up the
A
central nervous system
7
Q
What is immediately outside of the dura layer?
A
epidural space
8
Q
epidural space is filled with
A
fat and venous blood vessels
9
Q
Because the epidural space is fatty, many of our lipophilic drugs are going to be
A
sucked into the adipose tissue making onset longer and wearing off longer after the drugs are stopped
10
Q
What is a spinal?
A
when drugs are injected into the subarachnoid space. Onset is faster, but more dangerous
11
Q
Where is the safest place to do a spinal? why?
A
In the lower back below L1
The spinal cord splits up into the cauda equina
12
Q
What is the tip of the spinal cord called?
A
Conus medullaris
13
Q
Where is the conus medullaris found?
A
L1
14
Q
The enlargement at the top of the spine is called the
A
cervical enlargement
15
Q
Where is the cervical enlargement found?
A
C3-C6
16
Q
The enlargement at the bottom of the spine is called the
A
lumbar enlargement
17
Q
Where is the lumbar enlargement found?
A
T11-L1
18
Q
The cervical enlargement nerves exit the spinal cord and form the
A
brachial plexus
19
Q
The lumbar enlargement nerves exit the spinal cord and form the
A
lumbar plexus and sciatic nerve
20
Q
The dura mater are continuous with the nerves all the way down until the
A
bottom of the sacrum
21
Q
What is the cuada equina made of?
A
posterior and anterior spinal roots
22
Q
What is the extension of the pia matter that comes off the conus medullaris and ends in the dural sac, that anchors the cord and all of those structures to the spine?
A
the Filum terminale
23
Q
What is the dural sac filled with?
A
CSF
24
Q
What is the dural sac?
A
a continuation of the dura and arachnoid maters
25
What is another name for the lumbar sac?
Lumbar cycstern
26
the dural sac extends to the level of
S2
27
What is the upper portion of the ligament called at the end of the spinal cord?
Filum Terminale Internum
from end of cord to end of sac
28
What is the ligament that starts at s2 and anchors the bottom portion of the dural sac in place?
Filum Terminale Externum
29
Where does the conus medullaris end in a newborn?
L3
30
Why does the conus medullaris shift upwards as we mature?
Because the bones grow faster than the cord lengthens.
31
What is the downside to having the lumbar cystern at the bottom of the spine?
The CSF in the Lumbar cystern is "stale"
32
Where is a good place to sample CSF?
in the lower back; in the subarachnoid layer
33
Which vertebral space do we use to pull CSF or infuse meds into the spine?
L3-L4 interspace
L4-L5 interspace
34
Take CSF results from the lumbar cystern with a grain of salt because
the CSF is "stale" here
35
Besides the L3-L4 and L4-L5 interspaces to inject meds, what is another access point in the spine?
Sacral hiatus
36
What is one benefit to using the epidural space instead of giving a spinal?
You don't puncture the CSF holding space so CSF doesn't leak out when you pull the needle out
37
What is a place to inject meds in the sacral spine?
posterior sacral foramina
38
What angle should you shift the needle while giving an epidural or spinal?
15 degree angle
39
What is a arachnoid trabeculae?
pillar like structures the help hold open the arachnoid space and makes sure there is enough room for our blood vessels and CSF to provide a cushion for the brain
40
our bones are not solid structures and are innervated by
arteries and veins
41
When we crack the skull, we create an
epidural hematoma
42
majority of the epidural hematomas are
arterial
43
Subdural hemorrhages are mostly
venous, because the dura layer is basically continuous with some of the venous sinuses
44
subarachnoid hemorrhages are typically
arterial
45
CSF pH is_____
why?
7.31
there is less HCO3-
CO2 is constantly made through cellular metabolism making it more acidic
46
Na+ levels in the CSF are
140mOsm, about the same as plasma
47
Cl- levels in the CSF are
close to the Na+ levels, about 140mOsm which is more than the plasma
48
K+ in the CSF is about ____ than in the plasma
40% less
49
Mg+ in CSF are _____ than plasma
higher
50
What electrolyte concentrations are going to limit our neurological activity?
Na+
Cl-
K+
Mg+
51
CSF glucose is about
60mg/dL
52
Plasma glucose is about
90mg/dL
53
What color should CSF be?
clear
54
What is the volume of CSF?
150mL
55
How fast is CSF made in a day?
500mL/day
56
What separates the CSF from the cardiovascular system?
Ependymal cells
57
Ependymal cells are leaky to which electrolytes?
Na+
Cl-
Water
58
How does an ependymal cell get electrolytes into the CSF?
Through a Na+ ATP pump
Sodium leaves the cell
Cl- follows Na+
Water follows both Cl- and Na+
59
How can anesthetics increase or decrease CSF production?
by slowing down or speeding up the Na+ ATP pump
60
Which cell manages K+ levels in the CSF?
astrocytes
61
what is a group of ependymal cells called?
choroid plexus. found in a bunch of the parts of the brain's CSF circulatory system.
62
What are the containers of the CSF circulatory system called?
Ventricles
63
The third ventricle is located where the
diencephalon and hypothalamus is
64
The fourth ventricle is located where?
middle of the brainstem next to the cerebellum
65
what are the two ventricles called at the top of the brain?
the left and right lateral ventricles
66
where is CSF made?
in choroid plexuses in the ventrucles
67
Name the CSF flow through the brain
1. Left and right lateral ventricles
2. interventricular foramen (foramen of monroe)
3. 3rd ventricle
4. cerebral aqueduct (aqueduct of Sylvius)
5. 4th ventricle
* central canal
* lateral apertures (foramen of Luschka)
* median aperature (foramen of Magendi)
- cerebellomedullary cistern (cisterna magna)
68
The foramen of monroe is also called
the interventricular foramen
69
The aqueduct of Sylvius is also called
the cerebral aqueduct
70
The foramen of Magendi is also called
the median aperture
71
If we occlude one of the exit points in the CFS pathway, we would expect
the ventricles to swell and cause a problem
72
Where is the most common block in the CSF pathway?
in the cerebral aqueduct (aqueduct of sylvius)
73
What is non-communicating hydrocephalus?
A block in the pathway of the production and emptying system
74
What is communicating hydrocephalus?
ventricular system is intact but for whatever reason the CSF isn't being absorbed like it should be so we have pressure building up surrounding the brain
75
Hydrocephalus gives us
high ICP and problems with brain profusion
76
normally CSF is absorbed at the same clip that it is
being made
77
Where are CSF reabsorbed in the CSF circulation?
at arachnoid granulations
78
What are arachnoid granulations?
infoldings found at the longitudinal fissure. They are the CSF blow-off valves that open for a ICP > 10mmHg to mediate CSF reabsorption
79
What is a normal ICP?
10mmHg
80
The majority of the CSF is reabsorbed at the arachnoid granulations but some is reabsorbed in the
spinal cord
81
If we have a stroke and clots form over the arachnoid granulation, you would expect to see
communicating hydrocephalus and increased pressures throughout the system
82
What is the cerebellum?
part of the brain that is responsible for coordinating complex tasks
83
What is the compartment located at the base of the skull that can be accessed to pull fresh CSF?
Cerebellomedullary cistern (cisterna magna)
84
What is another name for the Cisterna magna?
cerebellomedullary cistern
85
What feeds the Cerebellomedullary cistern (cisterna magna) with CSF?
the median aperture
86
Sinus in the cardiovascular system is a
big vein
87
What is the sinus that runs midline in the sagittal plane of the skull is called the
superior sagittal sinus
88
Parallel and Below the Sagittal sinus is the
Inferior sagittal sinus
89
What is the fan of connective tissue that separates the left brain from the right cerebral hemispheres?
Falx Cerebri
90
The Falx cerebri continues down to the back of the brain and provides a floor for the occipital lobe to sit on called the
Tentorium cerebelli
91
Below the Tentorium cerebelli is the
cerebellum
92
The small stretch of vessel that connects the superior and inferior sinus is called the
straight sinus
93
From the straight sinus, blood follows a lateral path to the left and right of the skull to provide an exit point for the blood returning from the superior and inferior sagittal sinuses called the
transverse sinus
94
The sinus confluence is where
the superior sagittal, inferior sagittal and straight sinus all connect
95
The blood comes from the transverse sinuses and makes a hairpin turn at the
sigmoid sinus
96
The venous collection pool that is located in the front middle part of the brain that feeds the face and front of the brain is called the
cavernous sinus
97
Where is all of the cranial blood emptied into?
The internal jugular
98
The exertnal jugular takes care of the more
superficial structures on the side of the head
99
We have vertebral arteries that supplies blood to the
back of the brain
100
we have two internal carotid arteries that supplies blood to the
internal structures of the brain
101
The external carotid arteries are in charge of supplying blood to the more
superficial parts of the brain
102
Arterial blood flow is about ______mL/min
and _____ of our CO
750
15%
103
Cardiac output is
5L/min
104
the brain makes up what percent of the body weight?
2-3%
lopsided blood flow
105
How much blood is supplied per minute per grams of tissue?
50mL/min/100g of tissue
106
how much of blood flow to the brain goes to grey matter?
80%
107
The main metabolic requirement of the CSN is to get blood to the
grey matter
