Motor I, II, and III

Question 1

Motoneurons innervating axial and proximal muscles are located (laterally/medially) in the ventral horn of the spinal cord.

Answer 1

Medially

Question 2

Motoneurons innervating distal muscles are located (laterally/medially) in the ventral horn of the spinal cord.

Answer 2

Laterally

Question 3

Motoneurons innervating extensor muscles are located (ventral/dorsal) to those innervating flexor muscles.

Answer 3

Ventral

Question 4

(T/F) Interneuron pools in the intermediate gray that innervate motoneurons are segregated in the same way as motoneurons in the ventral horn.

Answer 4

True.

Question 5

(T/F) Descending tracts are located in the white matter adjacent to the relevant motoneuron pools they control.

Answer 5

True.

Question 6

Proprioceptive input to a cortical column arises in the joint (proximal/distal) to the muscle that the column controls.

Answer 6

Distal

Question 7

Cutaneous input to a cortical column arises where?

Answer 7

From a skin region in the path of limb movement that the column controls.

Question 8

Inputs to the cortical columns travel through the ______________ and _____________ thalamic nuclei.

Answer 8

Ventroanterior and ventrolateral thalamic nuclei

Question 9

The standard visuo-motor reflex takes about ___ms.

Answer 9

240ms

Question 10

The standard cortical reflex takes about ___ms.

Answer 10

120ms

Question 11

90% of the corticospinal tract arises in the ____________ and ___________ cortices.

Answer 11

Precentral and postcentral

Question 12

Pathways controlling axial and proximal muscles for use in posture typically undergo (phasic/tonic) innervation.

Answer 12

Tonic

(TPP) = Tonic, Proximal, Posture

Question 13

Pathways controlling distal muscles for use in discrete movements typically undergo (phasic/tonic) innervation.

Answer 13

Phasic

(PDD) = Phasic, Distal, Discrete

Question 14

Muscle tracts that make use of tonic innervation include:

Answer 14

• Pontine reticulospinal
• Vestibulospinal
• Tectospinal

Tonic = Control Postuer (Axial and proximal muscle groups)

Question 15

Muscle tracts that makes use of phasic innervation include:

Answer 15

• Corticospinal
• Rubrospinal
• Medullary reticulospinal

Phasic = Control Discrete Muscle Movement (Distal muscle groups)

Question 16

The lateral corticospinal tract primarily terminates upon (flexor/extensor) interneurons.

Answer 16

Flexor interneurons

Question 17

The rubrospinal tract usually (activates/inhibits) flexors and (activates/inhibits) extensors of the upper body.

Answer 17

• Activates flexors
• Inhibits extensors

Massive effect on force (flexor part of emergency control; i.e. grabbing onto tree when you fall)

Acts on alpha motor neurons

Question 18

The medullary reticulospinal tract usually (activates/inhibits) flexors and extensors.

Answer 18

Inhibits flexors
Inhibits extensors

Question 19

(T/F) Upon entering sleep, the medullary reticulospinal tract hyperpolarizes the body’s flexor and extensor interneurons. This is a defense mechanism to cause paralysis during sleep and prevent movement during vivid or imaginative dreams.

Answer 19

True.

Question 20

The vestibulospinal tract primarily activates (flexor/extensor) alpha motor neurons and interneurons. It is important in maintaining balance and prevention of injury while falling.

Answer 20

Extensors

Question 21

The pontine reticulospinal tract typically (activates/inhibits) extensor interneurons.

Answer 21

Activates extensors

Helps you stand up

Question 22

The tectospinal tract activates (extensor/flexor) interneurons of the upper cervical areas to track objects on the edges of the field of vision by moving the neck.

Answer 22

Extensor

Question 23

What path do fibers in the corticospinal tract travel after leaving the motor cortices?

Answer 23

1. Corona radiata
2. Internal capsule (posterior limb)
3. Cerebral peduncle (middle third)
4. Pons
5. Pyramids
6. Decussation into lateral and anterior corticospinal tracts

Question 24

Glutamate is (excitatory/inhibitory).

Answer 24

Excitatory

Question 25

**Inputs to the striatum** (caudate nucleus and putamen) **from the cerebral cortices** use the neurotransmitter \_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 25

Glutamate

Question 26

**Inputs to the striatum** (caudate nucleus and putamen) **from the thalamus** use the neurotransmitter \_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 26

Glutamate

Question 27

**Inputs to the striatum** (caudate nucleus and putamen) **from the substantia nigra** use the neurotransmitter \_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 27

Dopamine

Question 28

**Inputs to the striatum** (caudate nucleus and putamen) **from the raphe nucleus** use the neurotransmitter \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 28

Serotonin

Question 29

**Outputs from the striatum** travel to the _________ and \_\_\_\_\_\_\_\_\_.

Answer 29

**Globus pallidus** and **substantia nigra**

Question 30

The ___________ and __________ function to **regulate output from the striatum**.

Answer 30

**Subthalamic nucleus** and **external pallidum** (of globus pallidus)

Question 31

Outputs travel from the striatum to the globus pallidus and substantia nigra. **Outputs** leaving the **internal pallidum** and **substantia nigra** then ascend to the ______________ and descend to the ____________ simultaneously.

Answer 31

* *Ascend** to the **thalamus** (VA & VL) * *Descend** to the **midbrain** (Subthalamic Nuclei)

Question 32

What are the key functions of the **basal ganglia**?

Answer 32

* Preparation and planning of movement * Organization of sequence of movements * Learning of hierarchically organized movements * Sensory and motor modulation

Question 33

What are the key functions of the **cerebellum**?

Answer 33

* Unconscious control of movement * Regulation of rapid (preprogrammed) movements * Posture, muscle tone, and equilibrium

Question 34

The **archicerebellum (flocculonodular)** lobe of the cerebellum is primarily involved in (distance judgments/vestibular balance and eye movements/muscle tone control).

Answer 34

**Vestibular balance** and **eye movements**

Question 35

The **paleocerebellum (anterior) lobe** of the cerebellum is primarily involved in (distance judgments/vestibular balance/muscle tone control).

Answer 35

**Muscle tone control**

Question 36

The **neocerebellum (posterior) lobe** of the cerebellum is primarily involved in (distance judgments/vestibular balance/muscle tone control).

Answer 36

**Distance judgments**

Question 37

The cerebellar cortex has a _____________ outer layer, _____________ intermediate layer, and ____________ inner layer.

Answer 37

* **Outer molecular l**ayer * **Intermediate Purkinje** layer * **Inner granular** layer

Question 38

**Mossy fiber**s terminate on glomeruli containing _____________ dendrites and _____________ axons.

Answer 38

* Granule cell dendrites * Golgi cell axons

Question 39

After receiving **excitatory inputs from mossy fibers**, granule cells **climb to the molecular layer** and **bifurcate**, forming ______________ that **run perpendicular to the dendrites** of **Purkinje cells**.

Answer 39

**Parallel fibers**

Question 40

**Parallel fibers** provide **excitatory input** to \_\_\_\_\_\_\_\_\_\_\_\_\_\_, which then travel through the **cerebellar white matter** and **form inhibitory synapses** on the **cerebellar deep nuclei**.

Answer 40

**Purkinje** cells

Question 41

**Parallel fibers** provide **excitatory input** to what other two types of cells besides Purkinje cells?

Answer 41

* **Golgi** cells (inhibitory output to mossy fibers cells) * **Basket** cells (inhibitory output to Purkinje cell one row on either side of the row that was activated by parallel fibers)

Question 42

(Basket/Stellate) cells provide **inhibition** by **terminating on Purkinje cell dendrite**s in the molecular layer.

Answer 42

Stellate

Question 43

(Basket/Stellate) cells provide **inhibition** by **surrounding the Purkinje cell body**.

Answer 43

**Basket** cells

Question 44

\_\_\_\_\_\_\_\_\_\_\_\_\_ fibers provide **excitatory** input to **Purkinje cells** by wrapping around its cell body and proximal dendrites.

Answer 44

**Climbing** fibers * From **inferior olive**

Question 45

An easy way to remember excitatory and inhibitory inputs is that excitatory inputs travel (up/down) and inhibitory inputs travel (up/down).

Answer 45

* **Excitatory** travels **up** (Mossy fibers, granule cells that become parallel fibers, climbing fibers) * **Inhibitory** travels **down** (Stellate cells, basket cells, golgi cells, Purkinje cells)

Question 46

\_\_\_\_\_\_\_\_\_\_\_ cells provide **inhibition** by terminating on **granule cell** dendrites within the **glomerulus**.

Answer 46

**Golgi** cells

Question 47

(T/F) **Climbing fibers** originate in the superior olivary nucleus.

Answer 47

**False**. Climbing fibers arise exclusively from neurons in the contralateral **INFERIOR** **olivary nucleus.**

Question 48

**Afferent** information about **limb movements** is conveyed to the cerebellum by the **dorsal spinocerebellar tract** for the (upper/lower) extremities.

Answer 48

Lower

Question 49

**Afferent** information about **limb movements** is conveyed to the cerebellum by the **cuneocerebellar tract** for the (upper/lower) extremities.

Answer 49

Upper

Question 50

Information about **activity of spinal cord interneurons** and **intended pattern generator outputs** is conveyed to the cerebellum by the **ventral spinocerebellar tract** for the (upper/lower) extremity interneurons.

Answer 50

Lower

Question 51

Information about **activity of spinal cord interneurons** and **intended pattern generator outputs** is conveyed to the cerebellum by the **rostral spinocerebellar tract** for the (upper/lower) extremity interneurons.

Answer 51

Upper

Question 52

**Mossy fibers** traveling through the **dorsal spinocerebellar** and **cuneocerebellar tract** enter the (ipsilateral/contralateral) **cerebellum** through the (inferior/middle/superior) **cerebellar peduncle**.

Answer 52

* Ipsilateral cerebellum * Inferior cerebellar peduncle

Question 53

(T/F) **Olivocerebellar fibers decussate before** entering the cerebellum as climbing fibers.

Answer 53

True.

Question 54

Fibers from the most **lateral** portion of the **cerebellum** enter the ______________ deep cerebellar nucleus.

Answer 54

Dentate

Question 55

Fibers from the **intermediate** portion of the **cerebellum** enter the ____________ and ____________ deep cerebellar nuclei.

Answer 55

**Emboliform** and **globose**

Question 56

Fibers from the **flocculonodular lobe** and **vermis**, the most **medial** portions of the cerebellum, enter the ______________ deep cerebellar nucleus.

Answer 56

Fastigial

Question 57

Most **outputs** of the **cerebellum** travel through the (superior/middle/inferior) cerebellar peduncle.

Answer 57

Superior

Question 58

What **cerebellar inputs** travel through the **middle cerebellar peduncle**?

Answer 58

* Pontocerebellar

Question 59

What **cerebellar inputs** travel through the **inferior cerebellar peduncle**?

Answer 59

* Dorsal (posterior) spinocerebellar * Cuneocerebellar * Olivocerebellar * Vestibulocerebellar * Reticulocerebellar

Question 60

What **cerebellar inputs** travel through the **superior cerebellar peduncle**?

Answer 60

* Ventral (anterior) spinocerebellar

Question 61

What is the mnemonic to remember the deep cerebellar nuclei in order from most lateral to most medial?

Answer 61

Don't (Dentate) - Most lateral Eat (Emboliform) Greasy (Globose) Food (Fastigial) - Most medial

Question 62

All movements of the body have an underlying rhythm of \_\_Hz.

Answer 62

10Hz

Question 63

(T/F) A long latency reflex that stabilizes the body's posture will become weaker when elicited repetitively.

Answer 63

False. A long latency reflex that stabilizes the body's posture will become **STRONGER** when elicited repetitively.

Question 64

What lesion will cause an intention tremor?

Answer 64

**Lateral hemisphere** of **cerebellum** * **Dentate** nucleus is located here * Dysmetria