Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Lectures > L6 > Flashcards

L6 Flashcards

(90 cards)

Start Studying
1
Q

What is the primary function of the Blood-Brain Barrier (BBB)?

A

Protects the brain and spinal cord from general circulation and carefully controls the ionic composition of extracellular fluid around neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What would happen if KCl was injected past the BBB?

A

Decreased K+ concentration gradient → depolarization → inactivation of Na+ channels → no more action potentials produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why can’t neurotransmitters float freely in the brain?

A

They would disrupt normal neuronal signaling by activating receptors inappropriately

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How can the BBB be thought of structurally?

A

As a 2-fold entity: between blood vessels & interstitial fluid and between blood vessels & CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the potassium concentration in interstitial fluid compared to blood?

A

Lower in interstitial fluid (2.8 mEq/L) compared to blood (4.5 mEq/L)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the relationship between interstitial fluid and CSF?

A

Almost no barrier between them - virtually free diffusion with nearly identical chemical composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is interstitial fluid in the brain?

A

The fluid bathing the neurons with carefully regulated ionic composition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is CSF in relation to the brain?

A

Fluid that fills the cavities (ventricles) of the brain from general circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why can’t dopamine be directly used to treat Parkinson’s disease?

A

It cannot cross the BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What treatment is used instead of direct dopamine for Parkinson’s disease?

A

L-DOPA, a precursor to dopamine that can cross the BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What side effect may occur in patients treated with L-DOPA?

A

Increased addictive behaviors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What causes the muscle stiffness in Parkinson’s disease?

A

Lack of dopamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why does MSG consumption often cause thirst?

A

It activates receptors outside the brain where the BBB doesn’t protect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why might someone experience neck stiffness after consuming MSG?

A

MSG activates glutamate receptors outside the brain and in the PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Can MSG cross the blood-brain barrier?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Is the BBB continuous throughout the entire brain?

A

No, it’s purposely broken in certain areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why is the BBB broken at the hypothalamus?

A

To allow neurons to communicate freely with the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the relationship between the pituitary gland and the BBB?

A

The BBB is broken to allow hormone release from the pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are circumventricular organs and why do they lack BBB?

A

Regions around the 3rd ventricle where neurons need to sense specific chemicals in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What’s the general rule about where the BBB is broken?

A

In areas that interact with the endocrine system or require sensitivity to blood metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the three layers of meninges from outermost to innermost?

A

Dura mater, arachnoid membrane, and pia mater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the dura mater?

A

A very tough membrane forming a sac that contains the brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the arachnoid membrane?

A

A delicate tissue layer between the dura mater and pia mater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the pia mater?

A

The innermost meningeal layer that lies directly on top of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What connects the pia mater to the arachnoid membrane?
Arachnoid trabeculae.
26
What fills the subarachnoid space?
Cerebrospinal fluid (CSF)
27
What is the function of CSF in the subarachnoid space?
It allows the brain to float, protecting it from mechanical stress
28
Why do athletes wear mouth guards?
To prevent passing out by protecting the reticular formation from violent shaking
29
How does CSF provide cushioning despite being incompressible?
The surrounding membranes can stretch and bend to absorb impact
30
Where is the BBB located in relation to the subarachnoid space?
Between the capillaries and brain tissue in the subarachnoid space
31
Why must blood vessels not freely interact with brain tissue?
To maintain the controlled environment needed for proper neural function
32
What structure contains the blood vessels that supply the brain?
The subarachnoid space
33
What is the reticular formation?
A collection of loose nerve cells connecting the brain to behavior
34
Where is the reticular formation located?
Between the brain and spinal cord
35
What are fenestrations in blood vessels?
Windows or gaps where molecules can pass through the endothelial lining
36
How do brain endothelial cells differ from those in general circulation?
Brain endothelial cells are tightly bound with no gaps, forming the BBB
37
What is the key structural feature that constitutes the BBB?
Tight junctions between endothelial cells with no gaps
38
How do substances cross the BBB?
Everything must be specifically transported across the barrier
39
What are ventricles in the brain?
Cavities deep inside the brain filled with CSF
40
Describe the lateral ventricles.
Large curving structures inside each cerebral hemisphere, paired across the midline
41
What connects the 3rd ventricle to the 4th ventricle?
The Aqueduct of Sylvius
42
Where is the 3rd ventricle located?
In the middle, deep in the brain under the cerebral hemispheres
43
What is the pathway of CSF flow through the ventricles?
Lateral ventricles → 3rd ventricle → 4th ventricle → central canal
44
What is the Central Canal and where is it located?
A canal extending from the 4th ventricle that runs through the middle of the spinal cord
45
What fills all the ventricles in the brain?
Cerebrospinal fluid (CSF)
46
How are the ventricles of the brain connected?
They have continuous connections - all chambers are connected
47
What is the path of CSF drainage?
CSF drains through ventricles and central canal, moves to subarachnoid space, and exits at the top of the brain into venous sinuses
48
Where does CSF ultimately drain to?
Into either venous sinuses or veins, returning to general circulation
49
What are Arachnoid Villi and what is their function?
Outpouchings of arachnoid tissue that allow about half of CSF to drain into the venous system
50
How does CSF circulation differ from blood circulation?
CSF circulation occurs without a pump (unlike the heart for blood)
51
What are Arachnoid Villi?
Outpouchings of arachnoid tissue that stick out through the dura mater into venous sinuses
52
What is the function of Arachnoid Villi?
They allow CSF to drain into the venous system, returning to general circulation
53
What is CSF described as in relation to the brain?
The bathing medium of the brain with highly regulated ionic content and few macromolecules
54
Where is CSF produced?
Primarily by the choroid plexus, which lines the ventricles (LV, 3rd, and 4th)
55
How does CSF circulate without a pump?
It circulates passively, allowing for cleansing mechanisms
56
What spaces are filled with CSF?
Ventricles and subarachnoid space, with communication between them
57
How much CSF does the Choroid Plexus produce daily?
550 mL/day.
58
What is the structure of Choroid Plexus?
A dense network of capillaries ballooning into the ventricular wall with tight junctions
59
What cellular components make up the Choroid Plexus?
Epithelial cells connected by tight junctions
60
Why do substances need to be transported across the Choroid Plexus?
Because of tight junctions that prevent passive diffusion
61
Where is CSF produced?
By the choroid plexus in the ventricles
62
What spaces does CSF fill?
Ventricles and subarachnoid space
63
How does CSF's osmolarity and Na+ concentration compare to blood?
Same osmolarity and Na+ concentration as blood
64
Which ions are reduced in CSF compared to blood?
K+, Ca2+, and Mg2+
65
What is the total CSF volume in an average person?
215mL
66
How is CSF distributed in the brain and spinal cord?
140 mL cranial (25 mL in ventricles, 115 mL in subarachnoid space) and 75 mL spinal
67
How much CSF is produced daily and how often is it replaced?
550 mL daily, replaced about 3 times a day
68
What is the primary function of CSF in the subarachnoid space?
Serves as a cushion for the brain
69
What is a lumbar puncture and why is it performed?
A diagnostic/therapeutic procedure to collect CSF samples for analysis of infections
70
What structures are found on the walls of capillaries in the brain?
The 'end feet' of glial cells, particularly astrocytes
71
What bridging function do astrocytes perform?
They provide a bridge between neurons and blood vessels
72
How do astrocytes obtain nutrients?
By wrapping around capillaries where they pick up nutrients like glucose
73
What metabolic process are astrocytes efficient at?
Glycolysis, producing ATP for energy
74
What is the end product of astrocyte metabolism that benefits neurons?
Lactate, which neurons can use as a substrate for ATP production
75
What neurotransmitter-related function do astrocytes perform?
They remove neurotransmitters from synapses
76
How do astrocytes arrange themselves in relation to blood vessels?
They line up in single file, latching onto blood vessels
77
Where do astrocytes attach their end feet?
Some to blood vessels, others to neurons
78
Why are astrocytes positioned at synapses?
To help remove neurotransmitters
79
What do astrocytes provide to neurons?
Energy substrates
80
What role do astrocytes play in blood flow?
They regulate local blood flow by signaling blood vessels when to dilate or constrict
81
Why are astrocytes well-positioned to regulate blood flow?
They bridge the gap between blood vessels and neurons
82
What triggers astrocytes to send signals to blood vessels?
Increased neuronal signaling at synapses
83
Q: What direction does the metabolic signal from astrocytes travel?
Outward to blood vessels (opposite to nutrient flow)
84
What neurotransmitter in synapses triggers the astrocyte response?
What neurotransmitter in synapses triggers the astrocyte response?
85
What receptor on astrocytes detects synaptic activity?
mGluR (metabotropic glutamate receptor)
86
What happens inside astrocytes when glutamate binds to its receptors?
Ca²⁺ release within the astrocyte
87
How does the calcium signal travel through the astrocyte?
As a calcium wave from synapse to end-foot
88
What does the astrocyte release at its end-foot?
Prostaglandin (PGE2)
89
What effect does PGE2 have on blood vessels?
Causes vasodilation, increasing blood flow
90
What is the overall purpose of this astrocyte signaling mechanism?
To increase blood flow to areas with high neuronal activity

Lectures (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions