Neuroanatomy Review

Question 1

How is the primary motor cortex organized ?

Answer 1

Somatotopically organized

Question 2

Where is the primary somatosensory cortex located?

How is it organized?

Answer 2

The postcentral gyrus (parietal lobe)

It is also somatotopically organized

Question 3

Name the four subcortical structures

Answer 3

Diencephalon (thalamus, hypothalamus, epithalamus, sub thalamus)

Basal ganglia

Substantia nigra

Sub thalamic nucleus

Question 4

Where is the cerebellum located? What is it involved with?

Answer 4

In the rear part of the brain BELOW the cerebrum

It is involved in coordination

Question 5

Where is the brain stem? What originates from the brain stem?

Answer 5

Between the subcortical structures and spinal cord

Where the cranial nerves originate

Question 6

Where do upper motor neurons originate? Where do they terminate

Answer 6

UPPER motor neurons originate in the cortex, they terminate on lower motor neurons in the spinal cord OR the brain stem

Question 7

What is the name of the tract that hold the lower motor neurons in the spinal cord?

Answer 7

Corticospinal

Question 8

What is the name of the tract that holds the lower motor neurons in the brainstem ?

Answer 8

Corticobulbar tract

Question 9

TRUE/FALSE: LMNs ONLY originate in the spinal cord

Answer 9

FALSE!

LMNs can originate in the spinal cord OR the brainstem

Question 10

Where do

LMNs terminate?

Answer 10

They terminate on the muscles they innervate

Question 11

What type of the neuron innervation do the muscles of the limbs receive?

Answer 11

Unilateral contralateral innervation

Question 12

TRUE/FALSE: muscles of the head and neck mostly receive bilateral motor innervation

Answer 12

TRUE!

They receive innervation from both hemispheres! I.e. Contralateral (opposite side) AND ipsilateral (same side) innervation

Question 13

What is the pyramidal system responsible for? Which tracts are in the pyramidal system?

Answer 13

Responsible for VOLUNTARY movements in speech and limbs

Consists of:
Corticobulbar tracts
Corticospinal tracts

Question 14

Where does the corticospinal tract cross? Which muscles does it innervate?

Answer 14

Crosses at the level of the medulla

Innervates the muscles of the limbs

Question 15

Where does the corticobulbar pathway cross? What muscles are innervated?

Answer 15

crosses at the level of the cranial nerves nuclei they innervate

Innervates ALL MUSCLES involved in speech and swallowing!!

Question 16

Where is the primary motor cortex located?

Answer 16

The precentral gyrus (frontal lobe)

Question 17

What is the extra pyramidal system? Damage to this system causes ?

Answer 17

It is an Indirect activation pathway and control circuits

IT INDIRECTLY influences muscles NO DIRECT CONNECTION

Question 18

TRUE/FALSE: the basal ganglia and the cerebellum are the control circuits of the extrapyramidal system

Answer 18

True! Damage to the control circuits can cause speech disorders

Question 19

Name the two damage effects of the indirect activation pathway (I.e extrapyramidal system)

Answer 19

Hyperreflexia

Spasticity

Question 20

Where do the pathways of the extrapyramidal system originate/terminate?

Answer 20

These pathways originate in the cortex, synapse in the brainstem then travel to the cranial nuclei

Question 21

TRUE/FALSE: the control circuits project to the LMNs

Answer 21

FALSE! They send their output in the cerebral cortex

Question 22

Name two effects of spasticity on speech

Answer 22

Causes slowness and hyper ADDuction of the vocal folds (hypernasality)

Question 23

What are some results of spasticity?

Answer 23

Spastic dysarthria

Unilateral upper motor neuron dysarthria

Question 24

What are parts of basal ganglia

Answer 24

Caudate nucleus
Putamen
Globus pallidus

Brainstem structures included: 
Subthalamic nucleus 
Substantia nigra (dopamine produced here)

Question 25

What is the function of the basal ganglia?

Answer 25

Initiates movement and it's an inhibitory to cortical discharges

Question 26

What do we typically see when the basal ganglia is damaged?

Answer 26

Reduced movement or | Excess involuntary movement (excessive movement-jerks)

Question 27

What is the difference between paralysis and paresis?

Answer 27

Paralysis- absence of movement (gross limitation of movement) Paresis- weakness of movement (incomplete paralysis)

Question 28

TRUE/FALSE: UMNs AND LMNs damage can result in paralysis OR paresis

Answer 28

TRUE

Question 29

What are the three common signs associated with UMN damage?

Answer 29

Hypertonia/Spasticity(excessive tone, resistance to passive stretch) Hyperreflexia(exaggerated muscle stretch reflex) Weakness (due to bilateral innervation)

Question 30

What are the two major signs associated the LMN damage?

Answer 30

Hypotonia(reduced muscle tone): can cause paralysis or paresis Atrophy (loss of muscle bulk): fasciculation- involuntary muscle controls (visible to the eye) or fibrillations- involuntary contraction of individual muscle fibers (not visible)

Question 31

What is dyskinesia?

Answer 31

Refers to extrapyramidal damaged BUT can be used for other movement disorders Classified by fast, slow, rhythmic or nonrhythmic movement

Question 32

Name the six types of dyskinesias

Answer 32

``` Tremor Chorea Tartive Athethosis Dystonia Myoclonus ```

Question 33

TRUE/FALSE: the cerebellum does not have lobes

Answer 33

FALSE! It has three lobes Anterior, posterior, flocculonodular

Question 34

What is the function of the cerebellum?

Answer 34

Coordination of different muscle groups and helps with balance ``` Plays a role in: motor Programming (not muscle specific) , Maintenance of muscle tone and motor learning ```

Question 35

TRUE/FALSE: the cerebellum has MORE efferent pathways than after want pathways

Answer 35

FALSE! It has MORE afferent pathways

Question 36

What is motor planning?

Answer 36

Formulates a strategy of action by specifying motor goals This is NOT muscle specific

Question 37

What is apraxia?

Answer 37

Impairment of motor planning Inability to execute skilled, learning motor acts DESPITE normal function of motor, sensory systems, comprehension, cooperation and coordination

Question 38

Which lobe is primarily responsible for motor planning?

Answer 38

The frontal lobe Where: premotor cortex

Question 39

How does the cerebellum help in the coordination of movements?

Answer 39

Takes in all the sensory information, uses a feed forward, and sensory feedback mechanism

Question 40

What is the feedforward, sensory feedback mechanism? Where is it located?

Answer 40

It's in the cerebellum Feedforward- provides information about the movements of the muscles, tendons and joints This information is compared to the sensory feedback from the cerebral cortex. Then corrections are made if necessary

Question 41

What is ataxia

Answer 41

Lac of coordination of voluntary motor acts The rate, range, timing, direction and force of movement may be affected

Question 42

What is the difference better motor planning and motor programming?

Answer 42

Motor planning is NOT muscle specific; it sets sequential motor goals that are articulator specific Motor programming IS muscle specific; motor programs are sets of motor specific commands