Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 1: 06. Neuro Exam 2 > Lecture 2: Cerebral Vasculature and Brain Homeostasis > Flashcards

Lecture 2: Cerebral Vasculature and Brain Homeostasis Flashcards

1
Q

Is CSF recirculated?

A

No

Blood is

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

Where can CSF be found?

A
  • Ventricles (2 lateral, 3rd, and 4th)
  • Cisterns
  • Subarachnoid Space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What connects the lateral ventricles to 3rd ventricle?

A

Foramen of Monro or Intraventricular Foramen

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

What connects the 3rd ventricle to 4th ventricle?

A

Cerebral Aquaduct

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

What is the function of CSF?

A
  1. Cushioning
  2. Distribution of secretory signals
  3. Regulates neurogenesis
  4. Waste clearance
  5. Buoyancy for brain (significantly reduces weight of brain)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is CSF made?

A
  • Main: Choroid Plexus
  • Other: Tissue lining ventricles and blood vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Briefly, how is CSF made?

A

Filtration of plasma by choroid plexus

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

How does fluid from the blood vessels move into the ventricles?

A
  1. Fluid movement is dependent on hydrostatic and oncotic pressure.
  2. The oncotic pressure of the choroid plexus cells and capillaries cancel each other out.
  3. Due to the high hydrostatic pressure in the capillary, it pushes fluid out into the ventricles.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does water enter the ventricles?

A

Net flux of Na+, Cl-, and bicarbonate from the blood creates an osmotic gradient that drives water into ventricles via Aquaporin 1

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

True or false?

Production of CSF is variable over a wide range of intracranial pressures.

A

FALSE!

Production of CSF is CONSTANT over a wide range of intracranial pressures.

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

How does plasma concentration compare to CSF?

A
  • Same: Na+ and Bicarbonate
  • CSF > Plasma: Cl-, Mg2+, Carbon Dioxide
  • CSF < Plasma: Protein, Glucose, K+, Ca2+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is more acidic, CSF or plasma?

A

CSF

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

What reabsorbs CSF?

Where does CSF go next?

A

Arachnoid Villi

  • Fusion of endothelium of sinus and villi membane
  • Pinoctysosis plays role
  • CSF will enter venous sinuses by bulk flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Absorption is ______ to intracranial pressure.

A

proportional

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

What is the bare minimum of intracranial pressure necessary for CSF absorption?

A

68 mm CSF

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

What is the normal value of intracranial pressure necessary for CSF absorption?

A

112 mm CSF

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

What can increased intracranial pressure cause?

A

Damage to neurons

18
Q

What two components do capillaries have in the brain that composes the Blood Brain Barrier?

A
  • Tight junctions between endothelial cells
  • Glial Endfeet (close contact with blood vessel)
19
Q

What is BBB highly permeable to?

A
  • Water
  • Carbon Dioxide
  • Oxygen Lipid-soluble hormones (free)
20
Q

What is BBB slightly permeable to?

A
  • Na+
  • Cl-
  • K+
21
Q

What is BBB not permeable to?

A
  • Plasma
  • Proteins
  • Non-lipid soluble organic molecules
22
Q

What is the major energy source for neurons?

A

Glucose

23
Q

What glucose transporter is utilized in the brain?

What is special about this transporter?

A

GLUT 1 (insulin independent)

Can be used all the time

24
Q

What uses the 45 K Glut 1 transporter?

A

Astroglia

25
Q

What uses the 55 K Glut 1 transporter?

A

Capillaries

26
Q

What uses the GLUT 3 transporter?

A

Neurons

27
Q

What does the Na+/K+/2 Cl- transporter do?
What controls its expression?

A
  • Transports ions (Na+, K+, 2 Cl-) from CSF to blood
  • Controlled by release of endothelin 1 and 3 from endothelial cells of blood vessels
  • Related to [K+] in CSF
28
Q

What moves drugs that cross the BBB and don’t belong there?

A

P-glycoproteins

29
Q

What are the functions of the BBB?

A
  1. Protection from blood-borne agents
  2. Maintains electrolyte composition of CSF and neural parenchyma
  3. Excludes toxins
  4. Contains neurotransmitters
30
Q

In areas in the brain that are not enclosed by BBB, what do these capillaries lack?

A

Tight Junctions between endothelial cells

31
Q

What areas of the brain lack the BBB?

Why?

A

Circumventricular Organs

  1. Posterior Pituitary: needs to know what is going in blood to regulate hormones
  2. Area Postrema: Detects toxins in blood and initiates vomiting in response to chemotactic triggers
  3. Organum Vasculosum of Lamina Terminals (OVLT): regulation of total body water and thirst
  4. Subfornical Organ: regulation of total body water and thirst
32
Q

Does the blood from ICA and Basilar Artery mix?

What does this mean if they do or do not?

A

No they do not

  • Due to little mixing, there will be localized areas of ischemia in case of blood vessel damage
33
Q

What neurotrasmitters lead to sympathetic innervation of the cerebral circulation?

What do they do?

A

NT: Norepinephrine and Neuropeptide Y

  • Receptors: alpha adrenergic
  • Effects: blood vessel constriction and increase of BP
34
Q

What neurotrasmitters lead to parasympathetic innervation of the cerebral circulation?

What do they do?

A

NT: Acetylcholine, VIP, PHM-27

  • Receptors: on large blood vessles
  • Effects: vasodilation
35
Q

Blood vessels have their own sensory innervation. What NT will act on the blood vessels to dilate them? Why are the activated?

A
  • Substance P
  • Neurokinin A
  • CGRP

Activated if there is any torsion or manipulation and can lead to bad headaches

36
Q

What can cause torsion of blood vessels?

A

Reduced CSF causing brain to feel heavy

Basically decreased CSF –> brain moving more –> blood vessesl being torqued –> activate sensory neurons –> release of NT at torqued areas –> dilation of blood vessels

37
Q

What controls where cerebral blood flow will go?

A

Oxygen

38
Q

When is cerebral blood flow low?

A

When mean arterial blood pressure is really low (< 60 mm Hg)

39
Q

When is cerebral blood flow constant?

A

When mean arterial blood pressure is between 60-140 mm Hg

Has to be really high before it is interrupted

40
Q

How does the body maintain constant cerebral blood flow when the mean arterial blood pressure is high?

A

Sympathetic stimulation will vasoconstrict vasculature and protect capillaries in the brain and BBB from damage

41
Q

What happens if there is an increase of intracranial pressure?

A

Obstruction of venous outlflow and reduced cerebral blood flow

42
Q

What can cause an increase in intracranial pressure?

A
  1. Hydrocephalus
  2. Cerebral Edema
  3. Infection
  4. Intracranial Bleeding
  5. Tumor Blockage

Year 1: 06. Neuro Exam 2 (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions