Neuro: Lovett System Introduction

Front 1

What type of system is the nervous system?

Back 1

The nervous system is a cellular, electrochemical communication
system.

Front 2

What are the 4 main functions of the nervous system?

Back 2

1. It receives sensory messages from the environment (internal and external)

2. It integrates new inputs with information that is already stored

3. It uses integrated information to send out messages to muscles and glands

4. It provides the basis for conscious experiences and cognitive abilities

Front 3

Where do AFFERENT pathways go?

Back 3

Go AWAY

A is also superior

so these pathways go up toward our brains

afferent neurons (otherwise known as sensory or receptor neurons), carry nerve impulses from receptors or sense organs towards the central nervous system.

Front 4

What are EFFERENT pathways?

Back 4

Opposite the Afferent

efferent nerves, otherwise known as motor or effector neurons, carry nerve impulses away from the central nervous system to effectors such as muscles or glands (and also the ciliated cells of the inner ear).

Front 5

What can the peripheral nervous system be broken down into?

Back 5

Nothing

tricked ya hahahha :)

Front 6

What is the central nervous system broken down into?

Back 6

Brain and Spinal cord

Front 7

What is the spinal cord divided into?

Back 7

Gray and White Matter

Front 8

divisions of the NS

Picture

Back 8

Know this and be able to draw it out!

Front 9

What is Gray Matter?

Back 9

Cell Bodies****

Grey matter contains neural cell bodies***

In contrast to white matter, which does not and mostly contains myelinated axon tracts

Front 10

What is White Matter?

Back 10

Axons and Myelin Layers

In cross-section, the peripheral region of the cord contains neuronal white matter tracts containing sensory and motor neurons.

Front 11

What are the 3 divisions of the brain?

Back 11

1. Forebrain

2. Midbrain

3. Hindbrain

Front 12

What can the forebrain be divided into?

Back 12

Telencephalon and Diencephalon

Front 13

What can the Telencephalon be divided into?

Back 13

Neocortex

Hippocampus

Internal Capsule

Front 14

What can the Diencephalon be divided into?

Back 14

Talamus

Hypothalamus

Front 15

What can the midbrain be divided into?

Back 15

Superior colliculus

Inferior colliculus

Front 16

What can the hindbrain be divided into?

Back 16

cerebellum

pons

medulla

Front 17

What is the difference between the inside layers and outside layers of the brain?

Back 17

Inside Layer: core physiological functions

Outside Layer: More higher order functions

Front 18

What are your 3 sulcuses of the brain?

Back 18

Central

Lateral aka Sylvian

Parietal

Front 19

3 sulcuses


picture form

Back 19

Front 20

Are the lobes of the brain real anatomical structures?

Back 20

NO

We made them up

Front 21

What are the 4 lobes of the brain?

Back 21

Frontal

Temporal

Parietal

Occipital

Front 22

lobes pic

Back 22

Front 23

What does the temporal lobe function in?

Back 23

Hearing****

Heschl's gyrus: Primary auditory cortex

Wernike's Area: Associated Auditory cortex

Front 24

Just in case she asks:
What is the difference between Broca's and Wernicke's?

Back 24

Broca's: Higher order inability to speak. Think Broca's Brocken Boca

Wernicke's: Fluent aphasia with impaired conprehension.
Wernick's area = Superior Temporal Gyrus
Wernicke's = What?

Front 25

What does the occipital lobe function in?

Back 25

vision

Front 26

What does the parietal lobe function in?

Back 26

Sensation
Tacile
Tempo / Pressure
Sense of Touch

Front 27

What are brain sulci?

Back 27

Treches or ditches in brain

Front 28

What are brain gyri?

Back 28

Hills or top of mounds on the brain

Front 29

picture of cerebral cortex functions

first Aid

Back 29

Front 30

What sulcus forms the Cingulate Sulcus?

Back 30

The Cingulate Gyri

Front 31

What do the pre and post central gyrus do?

Back 31

Pre -central gyrus – motor function

Post-central gyrus – sensory strip

Front 32

Label this picture

Back 32

Front 33

Back 33

Front 34

What is the Insular Cortex?

Back 34

In each hemisphere of the mammalian brain the insular cortex (often called insula, insulary cortex or insular lobe) is a portion of the cerebral cortex folded deep within the lateral sulcus between the temporal lobe and the frontal lobe.

The insulae play a role in diverse functions usually linked to emotion or the regulation of the body's homeostasis. These functions include perception, motor control, self-awareness, cognitive functioning, and interpersonal experience. In relation to these it is involved in psychopathology.

Front 35

Back 35

Front 36

Back 36

Front 37

Back 37

Front 38

Back 38

Front 39

What is the optic tract?

Back 39

Beyond the optic chiasm

NOT the optic nerve

Front 40

What nerves operate the eye?

Back 40

2,4,6

Front 41

What is the function of cranial nerve:
1

Back 41

Olfactory

smell

Front 42

What is the function of cranial nerve:
2

Back 42

Optic

vision

Front 43

What is the function of cranial nerve:
3

Back 43

Oculomotor

Move eyeball
move eye lid
pupil

Front 44

What is the function of cranial nerve:
4

Back 44

Trochlear

move eyeball

Front 45

What is the function of cranial nerve:
5

Back 45

Trigeminal

movement & sensation of head and face

Front 46

What is the function of cranial nerve:
6

Back 46

Abducens

move eyeball

Front 47

What is the function of cranial nerve:
7

Back 47

facial

move face
move scalp
taste

Front 48

What is the function of cranial nerve:
8

Back 48

Vestibulocochlear

Audition and Position
Movement of Head

Front 49

What is the function of cranial nerve:
9

Back 49

Glossopharyneal

Swallowing and Taste

Front 50

What is the function of cranial nerve:
10

Back 50

Vagus

Heart
Larynx
Trachea
Visceral

Front 51

What is the function of cranial nerve:
11

Back 51

Spinal Accessory

palate
Larynx
Pharynx
Shoulder
Neck

Front 52

What is the function of cranial nerve:
12

Back 52

Hypoglossal

Tongue movement
speech

Front 53

Which Cranial Nerves function in sensory, motor, or both?

Back 53

Some Say Marry Money But My Brother Says Big Breasts Matter Most

S= sensory, M=motor, B=both

Front 54

The spinal nerves

first aid

Back 54

Front 55

What does the spinal cord look like?

Back 55

Butterfly-shaped central gray composed of collections of cell bodies. Surrounding mantle of white matter composed of bundles of axons that are either ascending or descending

Front 56

Where are the neurons located in the spinal cord?

Back 56

Gray Matter
Internal Structure of Spinal Cord


-Each half of spinal cord has posterior (dorsal) gray horn (extends posterolaterally almost to surface) and anterior (ventral) gray horn which extends ventrally but does not reach surface. A gray commissure, connecting the gray matter of the two sides, encompasses the central canal.

-In thoracic segments, a small pointed lateral horn is evident near base of anterior horn (associated with autonomic nervous system). Arranged in 10 laminae (layers). Lamina I is dorsal, lamina IX is ventral, and lamina X surrounds the central canal.

-Dorsal gray horn contains neuronal somata concerned with sensory information, ventral gray horn contains neuronal somata concerned with motor information.

Front 57

At what spinal Level do the Gracilus and Fasiculus appear?


EXAM****

Back 57

T7

Front 58

What about above and below T7?

EXAM****

Back 58

Posterior intermediate sulcus – only above T7

below do not have that****

Front 59

Picture of:
Posterior Intermediate Sulcus

Back 59

Front 60

What are the Fasciculus cuneatus and Fasiculus gracilis?

Back 60

Front 61

What do the fasciculus cuneatus and gracilis do?

Back 61

Fasciculus cuneatus:
Upper Body Extremities
More Lateral

Fasciculus gracilis
Lower Body Extremities
Located More Medial

Front 62

What is the circled area?

Back 62

Anterolateral System

functions in PAIN and THERMAL sense

Front 63

What is the circled area?

Back 63

Dorsal Column Lemnisus System

Proprioception
Vibratory sense
Descriminative Touch

Front 64

What is the circled gray area?

Back 64

Corticospinal fibers

somatomotor

Front 65

There are 2 main pathways for sensory and motor:

Back 65

1. one set for the entire body except for the orofacial complex

2. one set for the orofacial complex

Front 66

What is another name for the "entire body except for the orofacial complex"

Back 66

Ascending Spinal Pathways

Front 67

What are the 2 ascending spinal cord pathways

Back 67

1) Dorsal column/ medial lemniscus pathway


2) Anterior Lateral System (ALS)

Front 68

What does the Dorsal column/ medial lemniscus pathway function in?

Back 68

Carries information concerned with fine touch, proprioception, vibration.

Uses these following receptors:

Pacinian corpuscles
Joint receptors
Ruffini corpuscles
Meissner’s corpuscles
Golgi tendon organs
Muscle spindles

Peripheral processes of dorsal root ganglion cells provide axons to these receptors. Axons pick up information from the receptors and project to spinal cord.

Front 69

Central processes of dorsal root ganglion (DRG) cells enter the spinal cord in the posterior horn and enter the posterior funiculus.


Central processes of dorsal root ganglion (DRG) cells enter the spinal cord in the posterior horn and enter the posterior funiculus.

Back 69

The posterior funiculus on each side is divided by the posterior intermediate septum above T7 into two separate fasciculi - fasciculus gracilis (medial) and fasciculus cuneatus (lateral).

Front 70

Back 70

Front 71

At what levels is the Fasciculus gracilis found?

Back 71

present at all spinal levels - contains long ascending branches of fibers from sacral, lumbar and lower 6 thoracic dorsal roots.

Front 72

At what levels is the Fasciculus cuneatus found?

Back 72

first appears around T7 - contains long ascending branches of fibers from upper 6 thoracic and all cervical dorsal roots.

Front 73

Where are the 1st order neurons for the Dorsal Column Tract?

Back 73

Neurons in dorsal root ganglion which send their central processes ascending in fasciculus gracilis and cuneatus are considered to constitute the 1st order neuron for this pathway.

Fibers in the fasciculus gracilis and cuneatus ascend ipsilaterally and terminate (synapse) on nuclei in the medulla - the nucleus gracilis and nucleus cuneatus, respectively.

Front 74

Where are the 2nd order neurons for the Dorsal Column Tract?

Back 74

Nucleus gracilis and cuneatus give rise to 2nd order fibers which project ventromedially as internal arcuate fibers

Internal arcuate fibers decussate (cross the midline) and form a compact fiber bundle located on each side of the brain stem – the medial lemniscus.

The medial lemniscus ascends through the contralateral half of the brain stem, and its fibers terminate in the ventral posterolateral (VPL) nucleus of the thalamus

Front 75

Where do 3rd order neurons for Dorsal Column Tract appear?

Back 75

From VPL of thalamus, 3rd order neurons send fibers to postcentral gyrus of cerebral cortex (somatosensory cortex).

Front 76

Neumonics to help:

Back 76

Very pretty line drive – VPL - body

VPM – very pretty music - head

Front 77

What should you think of the thalamus as?

Back 77

you mommy

tells you what to do........that inner voice lol

Front 78

Mnemonic for remembering that Fasciculus gracilis caries lower extremity information

Back 78

Feet In the Grass

Front 79

Picture of Dorsal Column Pathway

Back 79

2nd order is in the medulla

VPL is in the thalamus

Front 80

Summary of Dorsal Column
Medial Lemniscus System

Back 80

Front 81

Which are fast fibers?

Pain or Fine touch?

Back 81

Fine touch****

- Fine touch are heavy myelinated and fast
- pain is slow fibers
- second order neuron

Front 82

What are the 3 neurons systems for the Anterior Lateral System?

Back 82

First order neuron- DRG neurons (A-sigma and C fibers)

Second order neuron- neuron in dorsal horn to VPL

Third order neuron- VPL to somatosensory cortex

Front 83

What is the function of the ALS?

Back 83

Conducts pain, temperature, and crude touch information

Front 84

What is Lissauer's Tract?

Back 84

First order neuron receives input from sensory receptors and projects to the dorsal horn where the neuron bifurcates (splits). These branches travel 1 to 3 segments up and down the cord in the dorsolateral tract, also known as Lissauer’s tract. The axons then enter the dorsal horn, where they synapse (mostly in laminae I and II, but also in V).

Front 85

Where do the axons of Lissauer's tract enter?

Back 85

First order neuron receives input from sensory receptors and projects to the dorsal horn where the neuron bifurcates (splits). These branches travel 1 to 3 segments up and down the cord in the dorsolateral tract, also known as Lissauer’s tract. The axons then enter the dorsal horn, where they synapse (mostly in laminae I and II, but also in V).******

Front 86

where are 2nd order neurons formed for the ALS tract?

Back 86

The second order neurons from the dorsal horn send axons that immediately cross the cord in the ventral white commissure. They ascend the spinal cord in the anterior lateral system (sometimes called the lateral spinothalamic tract) and synapse in the VPL. VPL neurons project to the somatosensory cortex.

Front 87

What is Somatotropic organization?

Back 87

In the lateral spinothalamic tract new neurons are added on the medial side, thus creating a somatotopic organization.

Front 88

Where are other places that the ALS 2nd prder neurons make synapses?

Back 88

On their way to the brainstem

1. Periaquaductal Gray matter
2. Reticular Formation
3. Intralaminar thalamic nucleus

Front 89

What does the periaquaductal gray matter in the midbrain do?

Back 89

activates descending pain control mechanims

Front 90

What does intralaminar thalamic nucleus do?

Back 90

provides emotional and arousal aspects of pain

Front 91

Diagram of the ALS

Back 91

Front 92

Summary of ALS

Back 92

Front 93

What pathways function to convey information regarding specific sensory modalities ultimately to cerebral cortex for conscious perception

Back 93

somatosensory pathways

Front 94

What are the somatosensory pathways?

Back 94

There are 2 sets:

1. one set for the entire body except for the orofacial complex

2. one set for the orofacial complex

Front 95

What are the trigeminal nerve cranial nerve 5 pathways?

Back 95

1. a trigeminal pathway for fine touch and vibration

2. a trigeminal pathway for pain and temperature

Front 96

How does the trigeminal nerve (5) function in touch?

Back 96

The primary sensory neuron has its soma in the trigeminal ganglion, and projects into the pons where it synapses in the chief (principle) sensory nucleus on the ipsilateral side

Front 97

The second order neuron (with its soma in the chief sensory nucleus) projects through the brainstem and synapses bilaterally in the ventral posterior medial thalamic nucleus (VPM) of the thalamus

Back 97

The third order neuron, with its soma in the VPM, projects to the primary somatosensory cortex. More details to follow…

Front 98

Picture of trigeminal nerve pathways

Back 98

Front 99

now let's review pain with the trigeminal nerve....cranial nerve 5

Back 99

The primary sensory neuron has its soma in the trigeminal ganglion, and projects into the brainstem where it synapses in the spinal trigeminal nucleus on the ipsilateral side

Front 100

The second order neuron (with its soma in the spinal trigeminal nucleus) projects to the contralateral side of the brainstem and ascends in the ventral trigeminal tract to synapse in the VPM.

Back 100

The third order neuron (with its soma in the VPM) projects an axon to synapse in the primary somatosensory cortex.

Front 101

wow get ready

Back 101

The primary sensory neuron has its soma in the trigeminal ganglion, and projects into the brainstem where it synapses in the spinal trigeminal nucleus on the ipsilateral side. The second order neuron (with its soma in the spinal trigeminal nucleus) projects to the contralateral side of the brainstem and ascends in the ventral trigeminal tract to synapse in the VPM. The third order neuron (with its soma in the VPM) projects an axon to synapse in the primary somatosensory cortex.

Front 102

What does each OPTIC TRACT Carry?

Back 102

Each optic tract carries information from the lateral ipsilateral retina and the medial contralateral retina.


Stated another way, each optic tract carries information from the contralateral visual field.

Front 103

Visual Field Pathways

Make sure you understand these

Back 103

Each optic tract carries information from the lateral ipsilateral retina and the medial contralateral retina.

Front 104

Where do all visual fibers eventually go?

Back 104

Lateral geniculate bodies

Right and Left

Front 105

Back 105

Front 106

Why is Meyer's Loop Important?

Back 106

Meyer’s loop very important – stroke or vascular system  if parts of visual field get knocked out and can lose blood supply

Front 107

What artery supplies the Meyer's Loop?

Back 107

Middle cerebral artery territory! Classic question on exam!

Front 108

Just know that the things you see in the periphery are deeper in the brain then things that are seen in the middle of your vision

Back 108

Front 109

You have to know these lesions!

Back 109

Front 110

What would happen if I cut the optic nerve?

Cut left eye

Back 110

Blindness in the ipsilateral eye

Left eye blindness

Front 111

What would happen if i cut the optic nerve?

Back 111

Bilateral hemianopia

#2

Front 112

What would happen if you cut the RIGHT optic tract?

Back 112

Homonymous hemianiopia
#4

Could not see anything on LEFT side of either eye

Front 113

What if you cut the RIGHT Meyes's Loop?

Back 113

LEFT Quadrant anopia

Front 114

this is important.......
what either diagram is not showing you is:

1. Meyer's Loop
2. Dorsal Optic Radiation

Back 114

Meyer's Loop:
Inferior retina
Loops around inferior horn of lateral ventricle

Dorsal Optic Radiation:
Superior retina
goes through internal capsule

Front 115

What if you cut both Meyer's Loop and Dorsal Optic Radiation on the LEFT side?

Back 115

LEFT Homonymous Hemianpoia with Foveal Sparing

Front 116

What happens if you hit in the back of the head with a baseball bat?

Back 116

Central Scotomas BOTH eyes

Front 117

know these cold lol

Back 117

Front 118

What fissure is the visual cortex located in?

Back 118

Calcarine Fissure

Front 119

What is the CORTICOBULBOSPINAL TRACT

Back 119

Cell bodies are in the cerebral cortex (mostly pre-central gyrus -Brodmann’s area 4 but also in 6)

They descend through the CNS and make synapses in the brainstem (corticobulbar axons) and in the ventral spinal cord (corticospinal axons).

Corticobulbal synapses are made on red nucleus and cranial nerve nuclei III, IV, V, VI, VII, X, XI, XII.

Front 120

From cortex, fibers converge in the corona radiata and travel in the posterior limb (corticospinal) and genu (corticobulbar) of the internal capsule. At midbrain levels, the corticospinal fibers form the middle 1/3 of the crus cerebri (cerebral peduncles), while the corticobulbar fibers are located just medial to the corticospinal fibers.

Back 120

In the pons, the fibers of the corticobulbospinal system are broken up into scattered fiber bundles in the basilar (ventral) portion of the pons.

Front 121

In the medulla, the fibers of this system coalesce again into the medullary pyramids. Nearly all of the axons cross the midline in the medulla at the pyramidal decussation. The crossed fibers travel through the spine in the lateral corticospinal tract and the uncrossed fibers (<10%) travel in the anterior corticospinal tract.

Back 121

The fibers of the lateral corticospinal tract enter into the ventral horn at all spinal levels and synapse on motor neurons and interneurons. The fibers in the anterior corticospinal tract cross the midline in the anterior white commissure at the same level they enter the ventral horn and make similar synapses as the lateral corticospinal tract.

Front 122

What does the Lateral Corticospinal tract do?

Back 122

movements of the extremities

****EXAM
This is the MOST clinically important descending motor pathway

Front 123

What does the Anterior corticospinal tract do?

Back 123

movement of axial muscles

Front 124

Diagram of the corticospinal tract

Back 124

Motor – just a 2 neuron pathway, desicates in the medulla

Most important is the lateral

Lower motor neuron lesion – lose of reflexes

Upper motor neuron lesion – very spastic and very ridgid

Front 125

What is the basal ganglia?

Back 125

The basal ganglia are a set of nuclei that function as a “consultant” to the cerebral cortex.

They provide the crucial physiological link between the idea of movement and the motor expression of that idea.****

EXAM

Front 126

Neuronal activity in the descending motor systems is closely correlated in time with the expression of a particular motor act. In contrast, most neuronal activity of the basal ganglia occurs before a particular movement begins.

Back 126

Disturbances in the function of the descending pathways result in paralysis or paresis, but lesions to the basal ganglia causes disturbances in the initiation or cessation of a motor event

Front 127

Basal Ganglia Picture

Back 127

Know the 3 in middle – help cortex need do what it wants to do

Front 128

Direct Pathway

Back 128

This pathway involves a circuit beginning in the cerebral cortex with connections to the caudate and putamen (together: neostriatum), which then project to the medial segment of the globus pallidus (GPm), which projects on to the thalamus, and then back to the cerebral cortex. Without input from other areas, GPm neurons are tonically active and inhibit thalamic neurons with GABA, preventing them from exerting an excitatory influence on the cerebral cortex. Activation of the direct pathway causes excitation of the neostriatum by the cerebral cortex. Neostriatal neurons secrete GABA and are inhibitory to neurons of the GPm. Therefore, when activated, neostriatal neurons will inhibit GPm cells, thus preventing them from inhibiting thalamic neurons (disinhibition). Thus, the result of activation of the direct pathway is increased output from the thalamus with a resultant increase in activation of the motor regions of the cerebral cortex.
Release of dopamine by substantia nigra compacta (SNc) cells onto neostriatal neurons with D1 receptors facilitates activity in the direct pathway.

Hint 128

Direct allows you to do what you want lol

Front 129

Indirect Pathway

Back 129

This pathway includes an additional loop through the lateral globus pallidus (GPl) and the subthalamic nucleus (ST). As with the direct pathway, the indirect pathway begins with excitatory projections from the cerebral cortex to the neostriatum. However, neostriatal output in this pathway is to the lateral, rather than medial, segment of the globus pallidus. These neostriatopallidal fibers are inhibitory (GABA is transmitter). Neurons of the GPl in turn send inhibitory connections (also GABAergic) to the subthalmic nucleus. These fibers to the subthalamic nucleus show high levels of spontaneous activity and tonically inhibit subthalamic neurons. Inhibition of GPl neurons by the neostriatum prevents GPl cells from inhibiting the subthalamic nucleus (disinhibition of ST). When active, subthalamic neurons are excitatory (glutamate is transmitter) to neurons of the GPm. Remember from the description of the direct basal ganglia pathway, that GPm neurons inhibit thalamic neurons. Thus, when the indirect basal ganglia pathway is activated, the result is decreased activity of the thalamus and therefore decreased activity of the motor regions of cerebral cortex.

Front 130

Basal Ganglia mnemonics

Back 130

1. Caudate Hotel
“book a date at the Caudate”

2. Putamen-Amen

3. Globus Palidus – two words, two parts

Front 131

Back 131

Front 132

We have to learn Blood Supply on our own so THANK YOU FIRST AID! :)

Back 132

Know the circle of willis

Front 133

Know what hemispheres supply these lobes of the brain for the CEREBRAL ARTERIES

Back 133

Anterior: anteromedial surface

Middle: Lateral suface

Posterior: posterior and inferior surfaces

Front 134

What is an epidural hematoma?

Back 134

usually an artery torn following skull fracture
high pressure arterial blood forms a rapidly expanding intracranial mass
displaces brain – increased intracranial pressure


Presentation of epidural hematoma:
initial unconsiousness (KO)
return to consciousness
secondary unconsiousness
death

Front 135

What is a subarachnoid hematoma?

Back 135

usually a vein
low pressure blood causes slowly increasing intracranial mass
displaces brain


Compromised mental function and clouding of consciousness may take days – weeks to develop
Surgery required to alleviate bleeding and decompress brain