A&P Test 2

Question 1

Venous structures in the brain are called

Answer 1

sinuses

Question 2

The walls of the sinuses in the brain are made up of the

Answer 2

dura mater

Question 3

why are most subdural hematomas venous?

Answer 3

because the sinus’s are made of the dura mater and if something rips through the dura part of the wall then the venous structures rip too

Question 4

our brain blood flow rate depends on what?

Answer 4

the brain’s metabolic demands

Question 5

How does the brain prevent under profusion?

Answer 5

by vasodilating the blood flow pathways in the brain

Question 6

How does the brain prevent over profusion?

Answer 6

by constricting the blood flow pathways in the brain

Question 7

Why do we have a circular pathway in the brain?

Answer 7

it ensures collateral pathways if we have a blockage in a feed artery

Question 8

Where do the internal carotid arteries enter into the circle of willis?

Answer 8

In the middle, one on each side

Question 9

Where do the vertebral arteries connect with the circle of willis?

Answer 9

they come together to form one artery called the basilar artery

Question 10

The vertebral arteries come together over what anatomical landmark to make the basilar artery?

Answer 10

at the base of the pons

Question 11

Where does the basilar artery come into the circle of willis?

Answer 11

in the middle on the posterior side

Question 12

What are the 3 large arteries that connect to the circle of willis?

Answer 12

Posterior cerebral artery
Middle cerebral artery
Anterior cerebral artery

Question 13

Of these, which is the largest?
Posterior cerebral artery
Middle cerebral artery
Anterior cerebral artery

Answer 13

middle cerebral artery

Question 14

The middle cerebral artery supplies what area of the brain?

Answer 14

The middle and lateral portions

Question 15

Which part of the brain is supplied by the anterior cerebral artery?

Answer 15

the front and midline portions

Question 16

Which part of the brain is supplied by the posterior cerebral artery?

Answer 16

Back and far lateral areas

Question 17

What are the two parts of the anterior cerebral artery?

Answer 17

Early; Pre-communicating A1
Late; Post-communicating A2

Question 18

Which part of the anterior cerebral artery touches the circle of willis?

Answer 18

Early; Pre-communicating A1

Question 19

Which part of the anterior cerebral artery does not touch the circle of willis?

Answer 19

Late; Post-communicating A2

Question 20

What is the small artery that attaches the two anterior cerebral artery?

Answer 20

anterior communicating artery

Question 21

After the internal carotid’s touch the circle of willis, their names change to

Answer 21

middle cerebral artery

Question 22

Which part of the posterior cerebral artery touches the circle of willis?

Answer 22

early; Pre-communicating part P1

Question 23

Which part of the posterior cerebral artery does not touch the circle of willis?

Answer 23

Late; Post-communicating P2

Question 24

Which artery connects the middle cerebral arterties to the posterior cerebral arteries?

Answer 24

The posterior communicating artery

Question 25

Which artery supplies the front and top of the cerebellum

Answer 25

superior cerebellar artery

Question 26

What artery does the superior cerebellar artery come from

Answer 26

the basilar artery

Question 27

Which artery supplies the middle of the cerebellum

Answer 27

anteroinferior cerebellar artery

Question 28

What artery does the anterioinferior cerebellar artery come from

Answer 28

the basilar artery

Question 29

What supplies the back portion of the cerebellum?

Answer 29

posteriorinferior cerebellar artery

Question 30

What artery does the posteriorinferior cerebellar artery come from

Answer 30

vertebral arteries

Question 31

the anteriorinferior artery comes off of the basilar artery, right over the

Answer 31

middle of the pons

Question 32

the posteriorinferior artery comes off of the vertebral arteries, right over the

Answer 32

brainstem

Question 33

most epidural hematomas are a result of

Answer 33

trauma

Question 34

subdural hematomas are a result of

Answer 34

tearing the dural walls like a bad wreck and you have whiplash

Question 35

subarachnoid hemorrhage is the most messy, why?

Answer 35

because in the other types, the blood typically tends to aggregate into one place which can be solved by a drain or opening the skull there

Question 36

Which type of bleed is associated with aneurysms and hemorrhagic strokes?

Answer 36

subarachnoid hemorrhages

Question 37

subarachnoid hemorrhages are typically venous or arterial?

Answer 37

arterial

Question 38

what is a cause of hemorrhagic strokes?

Answer 38

bad lifestyle choices, alcoholism, long term hypertension

Question 39

When metabolism goes up in the brain, so should

Answer 39

blood flow

Question 40

What is the top byproduct of metabolism that is involved in regulation of brain blood flow?

Answer 40

CO2

Question 41

why does blood flow increase when metabolic demands increase?

Answer 41

CO2 is created as a metabolic byproduct (increased metabolism=increased CO2), and then leaks into the surrounding tissues, blood flow increases to get rid of that excess CO2 as well as replace any nutrients expended in metabolism

Question 42

What is the number 1 regulator of brain blood flow?

Answer 42

CO2

Question 43

we need as much cerebral bloodflow as it takes to

Answer 43

remove the CO2 that's being produced

Question 44

Once all of the CO2 is removed from the cerebral blood flow, then blood flow

Answer 44

doesn't increase anymore, it just curtails

Question 45

What is the range of systemic blood pressure (map) that is required for brain blood flow? *autoregulation*

Answer 45

50-150

Question 46

If our cerebral metabolism hasn't changed, but our blood pressure is increased, than the brain blood flow should

Answer 46

stay about the same because the vessels constrict to prevent over profusion

Question 47

Systemic blood pressure is used to drive

Answer 47

brain blood flow

Question 48

if there was no autoregulation, what would we see on a graph of brain blood flow and blood pressure?

Answer 48

a linear line with low blood flow arising from low blood pressure

Question 49

If we have under profusion of the brain we would have

Answer 49

cell death

Question 50

If we have over profusion of the brain we would have

Answer 50

bursting of aneurysms

Question 51

More recently they have thought that autoregulation would cut off after the map drops below

Answer 51

60-70

Question 52

after about a map of 50, the brain vessels can't constrict anymore so we would see

Answer 52

a reduction in brain blood flow

Question 53

what is the point when the blood vessels in the brain cannot dilate any further?

Answer 53

the lower limit autoregulation **LLA**

Question 54

what is the point when the blood vessels in the brain cannot constrict any further?

Answer 54

the upper limit autoregularion **ULA**

Question 55

if we have a patient who has prolonged HTN, what happens to their lower and upper limits?

Answer 55

the system adapts, and the LLA and ULA will shift to the right

Question 56

How do the brain vessels adapt to squeeze tighter than the upper limit when exposed to prolong HTN?

Answer 56

The vessels harden atherosclerosis

Question 57

What will happen when the lower limit is raised d/t atherosclerosis and the patient's map drops to 50

Answer 57

The brain tissue will now be under perfused

Question 58

What is a way that the body adapts to a clot in the vessels?

Answer 58

collateral blood flow

Question 59

often times when someone is trying to get a handle on cardiovascular health then they look at

Answer 59

the ability of the blood vessels to dilate

Question 60

Collateral blood flow is something that we are

Answer 60

born with

Question 61

HTN and diabetes zap the ability to _______ in the blood vessels

Answer 61

dilate. this gives them more serious strokes and MI's

Question 62

Anesthetic drugs takes some of our _____ ofline

Answer 62

autoregulation

Question 63

in an anesthetic that affects autoregulation just a little, you would expect the middle line on the graph to be

Answer 63

slightly sloped

Question 64

in An anesthetic that affects autoregulation a lot, you would expect the middle line on the graph to be

Answer 64

steeper

Question 65

Most of the textbooks say that anesthetics don't effect autoregulation, but we know that isn't really true, and they are simply taking into account the

Answer 65

Error bar that arises from variability from testing humans

Question 66

the wider the error bar, they say the data is

Answer 66

statistically insignificant, and therefore cannot prove that the anesthetic takes autoregulation offline, even if the graph clearly shows that it does

Question 67

an action protentional moves down an axon d/t

Answer 67

fast Na+ channels

Question 68

What is in the axon wall that helps reset the cell after depolarization?

Answer 68

Na+/K+ pumps and voltage gated K+ channels

Question 69

When the action potential reaches the end of the neuron, it opens up a second set of voltage gated ion channels specific for

Answer 69

Ca++

Question 70

What is another name for the voltage gated Ca++ channel?

Answer 70

P-Type voltage gated Ca++ channels

Question 71

When Ca++ floods into the cell after an action potential, what does it do?

Answer 71

It binds to VP₂ ACh storage vesicles and pushes it to the cell wall for exocytosis

Question 73

What is the difference between a VP₂ ACh storage vesicles and a VP₁ ACh storage vesicle?

Answer 73

VP₂ ACh storage vesicles are at the cell wall, ready to be spilled out into the synapse. VP₁ ACh storage vesicles are either not full or not low enough to the synapse

Question 74

What does VP₂ stand for in a ACh storage vesicles?

Answer 74

Vesicle pool

Question 75

What shuts off the ACh dumping into the synapse after an action potential?

Answer 75

Ca++ pumps using ATP Na+/K+ pumps K+ channel Ca++ sensitive K+ channels all of these remove + charges

Question 76

What is found on the target skeletal muscle that ACh binds to?

Answer 76

nACH receptor

Question 77

nACh receptors function as cylinders that open when 2 ACh molecules bind to it at the same time, and this allows what movement of ions?

Answer 77

Na+ floods, some Ca++ comes in, and a tiny but of K+ goes out

Question 78

Why is it that in a healthy muscle cell, an endplate potential will always trigger an action potential?

Answer 78

because we have way way way more ACh receptors and ACh neurotransmitters

Question 79

What is an endplate potential?

Answer 79

localized depolarization that happens in the muscle d/t ACh receptors opening up

Question 80

Endplate potentials in a healthy muscle is always going to be enough to trigger an

Answer 80

an action potential by opening fast sodium channels, which results in a muscle contraction

Question 81

What is the bare minimum end plate potential that is required to create an action potential in the post synaptic cell?

Answer 81

500,000 receptors activated