Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physiology 1 > Exam 2: Neurophysiology Part 3 - CSF, BBB, EEG > Flashcards

Exam 2: Neurophysiology Part 3 - CSF, BBB, EEG Flashcards

(68 cards)

Start Studying
1
Q

Three layers that brain and spinal cord enveloped by

A

Dura mater - outermost layer

Arachnoid mater - middle layer

Pia mater - innermost layer

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

Dura mater

A

Thick layer of fibroblasts

Fuses with bone inner surface of skull bones

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

Arachnoid mater

A

Spider web like

thin layer of fibroblasts that trap CSF between it and pia mater

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

Pia mater

A

Single layer of fibroblasts

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

what is cerebrospinal fluid

A

clear fluid present in ventricles of brain, central canal of spinal cord, and subarachnoid space (brain and spinal cord)

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

CSF functions (4)

A

Cushion brain

Maintain consistent extracellular microenvironment for neurons and glial cells (homeostasis)

Waste control system for removal of potentially harmful cellular metabolites

Distribution medium for peptide hormones and growth factors that are secreted into the CSF

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

Where is CSF formed

A

most of CSF is formed by choroid plexuses located in each of the 4 ventricles at a constant rate

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

CSF flow

A

Lateral ventricles
Interventricular foramen (of Monroe)
Third ventricle
Cerebral aqueduct (of Sylvius) of midbrain
Fourth ventricle
Subarachnoid space through foramen of Luschka

Then on to the central canal of spinal cord or lateral aperture of fourth ventricle (foramen of Luschka)

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

What are the choroid plexuses

A

cauliflower like growth of capillaries covered by thin layer of ependymal cells that form a selective, tight junction barrier to the secretions of the leaky capillaries and to other surrounding fluids

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

What surrounds each choroid plexus

A

single layer of ependymal cells that have microvilli and tight junctions

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

relevant processes with CSF

A

Transport of Na (active), chloride, and bicarbonate into the ventricles via carriers and NaKATPase as primary active transporter

Water follows NaCl passively into the ventricle
Water leaves by osmosis

Metabolization of some potentially harmful waste products

Cl uses chlorine channels, HC3O uses bicarbonate channels

Na - H exchange is secondary active transport

Cl-Na exchange is secondary active transport

HC3O - Cl exchange is tertiary active transport

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

Hydration reaction

A

CO2 + H2O < — > H2CO3 < — > HCO3 + H

H2CO3 - carbonic acid
HCO3 - bicarbonate

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

Why does CSF need bicarbonate

A

Because it works as a buffer

Bicarb can accept 1 proton (H) to make carbonic acid and then convert it to CO2 and H2O

(Hydration reaction in reverse)

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

What causes CSF flow

A

CSF flows down a pressure gradient from site of formation at choroid plexuses through ventricular system and subarachnoid space into the venous system

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

What are the only organs that do not contain lymphatic vessels

A

Brain and spinal cord

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

What do brain and spinal cord use instead of lymphatic vessels

A

Glymphatic system

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

Glymphatic system

A

Countercurrent exchange system

Arteries and veins in the subarachnoid space have countercurrent flow, the CSF around those capillaries follow in same direction

CSF flows in same direction as artery in arterial perivascular space then goes into neural tissue via aquaporins then goes into venous perivascular space via aquaporins and follows veins away

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

where does CSF absorption into venous system take place

A

dura-lined venous sinuses within the skull

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

what happens when CSF reaches venous sinuses

A

leaves system - no backflow

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

process of CSF absorption

A

Most of fluid absorbed from subarachnoid space into dural sinuses through arachnoid villi

Absorption is pressure dependent an unidirectional

Constant absorption is important to remove waste and maintain pressure

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

Hydrocephalus

A

Increased CSF volume in skull

Often associated with increased ventricular volume and increased intracranial pressure

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

Non-communicating hydrocephalus

A

Normally caused by obstruction to CSF flow (narrow cerebral aqueduct or blocked exits from 4th ventricle)

Causes ventricular regions inside brain to expand at expense of surrounding brain tissue

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

Communicating hydrocephalus

A

Impairment of absorption (can be secondary to meningitis or hemorrhage)

Can increase CSF volume in subarachnoid space which increases pressure on outside surface of brain

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

what kind of cells are in blood capillaries and do they contain clefts

A

Endothelial cells

Do not contain clefts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Passage through intercellular clefts in brain capillaries
Blocked by tight junctions between endothelial cells Exchange of solutes is highly selective --> small uncharged lipid soluble substances
26
Characteristics of BBB (7)
Few or no fenestrations Pinocytosis uncommon in BBB Tight junctions Abluminal side - from one tight junction to other on brain side Luminal side - from one tight junction to another on blood side Specific carrier systems for uptake of solutes Endothelium surrounded by pericytes and astrocytes
27
Molecules that can easily pass across capillary endothelium of BBB
Small, uncharged, lipid soluble, unbound plasma proteins Ex - O2, CO2, ethanol, nicotine
28
Molecules that need specific carrier mediated transport mechanisms
glucose, amino acids Don't fit profile of small, uncharged, lipid soluble, etc.
29
Transport systems of BBB
``` GLUT MCT Amino acid transporters OATPs OCTs OATs ``` Pgd - MDRs (Multi drug resistance protein) MRPs - multi drug resistance associated protein
30
What does ABC mean
ATP binding cassette Protein that can hydrolyze ATP
31
Efflux pump Pgp
ABC Membrane protein, ATP dependent first identified in cancer cells as protein that provided resistance to anti cancer drugs Luminal side of membrane To prevent things from reaching brain When bad things in blood go toward brain multi drug resistance protein sends it back to lumen of capillary
32
MDR1
Multi drug resistance 1 Protective system against external harmful substances, poissons, and medicaments
33
what happened when Pgp (MDR) knockout mice got ivermectin
Ivermectin was able to reach brain and killed the mice because MDR (Pgp) was not there to send it away
34
what is an EEG
electrophysiological recording based on volume conduction theory (same as in ECG, electromyogram) spread of ionic currents within extracellular fluid that can be measured using electrodes on skin
35
EEG and BAER
EEG - record of spontaneous brain activity Variation - sensory-evoked potentials BAER - brainstem auditory evoked response --> record of artificially evoked activity in brainstem and auditory system after a click stimulus in ear
36
Cell types found in cerebral cortex (5)
``` Pyramidal cells Stellate cells Astrocytes Oligodendrocytes Microglia ```
37
Pyramidal cells
Projection neurons dendrites project up toward pial surface of cortex, some extend horizontally from cell body Generally excitatory Axons of pyramidal cells are efferent fibers
38
Stellate cells
local circuit interneurons within cortex either excitatory or inhibitory
39
Cortical neurons and basket cells
Basket cells project horizontally and make synapses with cortical neurons in level II and III
40
changes in voltage recordings
Positive direction - deflection is down Negative direction - deflection is up
41
Frequency and amplitude in EEG
Frequency - deflections per second (number of AP) Amplitude - strength of AP More AP = competition = weaker/shorter AP Less AP = less competition = stronger/longer AP
42
EEG of alert, relaxed, and sleeping dog
Alert - high frequency, low amplitude Relaxed - low frequency, high amplitude Sleeping - low frequency, very hig amplitude
43
Sensory receptors (7)
Mechanoreceptors - inner ear, skin, muscle spindle, Golgi tendon organ Chemoreceptors - mouth, nose, large blood vessels, brain Thermoreceptors - skin Photoreceptors - eye Electroreceptors - lateral line organ in fish Magnetoreceptors - birds (location unknown) Nociceptors - pain detection (located in most parts of body)
44
Mechanism of action - mechanoreceptors
Ion channel closed --> stretch --> ion channel open
45
Mechanism of action - chemoreceptors
Ion channel closed --> chemical stimulus attaches to thing next to channel --> causes something to bind to ion channel on inside of cell --> ion channel open
46
Mechanism of action - photoreceptors
Ion channel open when thin bound to it on inside of cell Light --> goes through cell and hits photoreceptor --> things that were bound to ion channel on inside of cell now gone --> ion channel closed
47
Thermoreceptors and what sensory nerve fibers they are associated with
perception of temperature associated with sensory nerve fibers: pain fibers cold fibers warmth fibers
48
Mechanoreceptors of the skin (5)
``` Hair follicle terminal -Whiskers (vibrassae) Ruffini's corpuscle Meissner's corpuscle Merkel's corpuscle Pacinian corpuscle ```
49
Are nerve fibers of mechanoreceptors myelinated
Nerve fibers of mechanoreceptors are all myelinated
50
Adaptation and stimulus: Meissner
Adaptation - rapidly Stimulus - touch and vibration
51
Adaptation and stimulus: Merkel
Adaptation - slowly Stimulus - touch and pressure
52
Adaptation and stimulus: Pacinian corpuscle
Adaptation - rapidly Stimulus - pressure and vibration
53
Adaptation and stimulus: hair follicle sensor (hairy skin)
Adaptation - rapidly Stimulus - touch and vibration
54
Adaptation and stimulus: Ruffini corpuscle
Adaptation - slowly Stimulus - pressure
55
Tonic receptors
Slow adapting receptors Generator potential spikes at on stage and slowly goes down until off stage AP (Sensory neuron) - lots at on stage, continue to have AP until off stage
56
Phasic receptors
fast adapting receptors Generator potential spikes at both on stage and off stage, nothing in between though AP (sensory neuron) - only at on stage and off stage, none in between
57
Viscerosensory receptors
Composed primarily of free nerve endings Visceral organs are not sensitive to cutting, heat, or cold
58
secondary vs primary neurons
Secondary neurons - second order neurons - entirely in CNS Primary neurons - first order neurons - in periphery
59
Spinothalamic tract
pain fibers cross midline and travel to contralateral white matter and go to brain
60
Spinomedullary tract
proprioception
61
what are viscerosensory fibers carried by
sympathetic (nociception) and parasympathetic (physiological receptors) nerves
62
Are viscerosensory fibers part of ANS
No, not considered part of ANS Structural component of autonomic nerves
63
Types of pain
Acute - fast, sharp, transmitted by A-delta fibers (fast conducting), low threshold Chronic pain - slow, dull, transmitted by C fibers (slow conducting), high threshold Referred pain - pain fibers from skin/internal organs have synapses on same neurons/segments of spinal cord (pain in one place causes pain in another place due to neurons being from same part of spinal cord) Phantom pain - perception of pain in an amputated limb Theories - ascending damage to peripheral nerves; increase in NT in spinal cord; reorganization of motor and sensory cortices
64
what are pain fibers
free nerve endings
65
withdrawal reflex
pain fibers on skin influence motor neurons in ventral horn of spinal cord via interneurons
66
withdrawal reflex example
Rear paw placed on something hot Stimulate motor neurons innervating muscles of rear of thigh - flexion of knee joint Inhibit motor neurons innervating antagonistic muscles in front of thigh Results in retraction of paw
67
How is withdrawal reflex useful in assessing depth of anesthesia
use it to make sure animal won't feel anything during surgery Pinch between toes, if there is a "twitch" anesthesia not deep enough
68
treatment of pain involves (4)
Drugs that inhibit activation of nociceptors aspirin, ibuprofen, NSAIDs - block synthesis of prostaglandins Drugs that block impulse conduction in pain fibers local anesthetics - block voltage gated Na channels Drugs that block signal transmission in pain pathways in CNS morphine and related substances Via activation of body's own pain-modulating system gate cells in spinal cord stimulated from skin through massage, touch, warm, and cold compresses

Physiology 1 (4 decks)

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