Introduction to Gross Brain Laboratory and Spinal Cord Exercise

Question 1

The somatosensory cortex is _________ to the Rolandic fissure. It is also called the ____________.

Answer 1

posterior; postcentral gyrus

Question 2

The somatotopic area of the wrist is _________ to the area of the hand.

Answer 2

medial

Question 3

The area where the motor-neuron axons cross is called the ____________.

Answer 3

decussation

Question 4

The cingulate gyrus is immediately superior to the _____________.

Answer 4

corpus callosum

Question 5

Superior to the cingulate gyrus is the ____________.

Answer 5

cingulate sulcus

Question 6

The motor neuron axons are wrapped in a structure called the ___________.

Answer 6

internal capsule

Question 7

The corticospinal pathway is also called the ___________.

Answer 7

pyramidal tract

Question 8

The caudate and putamen together are called the ___________.

Answer 8

striatum

Question 9

The corticospinal tract splits the ___________ into the medial caudate and lateral putamen.

Answer 9

ganglionic eminence

Question 10

The internal capsule has a bend in ___________ slices.

Answer 10

axial

Question 11

The corticospinal tracts are on the _________ surface of the medulla.

Answer 11

ventral (these form the “eyes” in Dr. Ojemann’s mnemonic)

Question 12

Motor neurons from the corticospinal tract synapse on ___________.

Answer 12

alpha motor neurons – which reside in the spinal cord and send axons into the periphery

Question 13

The intermediolateral cell column (aka lateral grey column) in the spinal cord contains ____________.

Answer 13

sympathetic neurons

Question 14

Hyperreflexia is caused by __________ damage.

Answer 14

upper motor neuron

Question 15

What is spasticity?

Answer 15

Inability of muscle cells to relax

Question 16

What are fasciculations?

Answer 16

Individual motor units contracting, leading to noticeable rippling of muscle fibers

Question 17

Paresis is ____________.

Answer 17

weakness (as opposed to plegia, which means total loss of control)

Question 18

The ___________ contains all of the sensory axons from the lower extremity.

Answer 18

fasciculus gracilis

Question 19

The ____________ contains all of the sensory axons from the upper extremity.

Answer 19

fasciculus cuneatus

Question 20

The fasciculus cuneatus is _________ to the fasciculus gracilis.

Answer 20

lateral

Question 21

Pain-sensing neurons synapse on a fasciculus in the spinal cord called the __________.

Answer 21

Lissauer’s fasciculus

Question 22

What is the division of the two hemispheres called?

Answer 22

The interhemispheric fissure

Question 23

The insula is within the __________.

Answer 23

Sylvian fissure

Question 24

What is between the paracentral lobule and the precuneus?

Answer 24

The cingulate sulcus

Question 25

What is the corticospinal tract when it passes the medulla?

Answer 25

The medullary pyramid

Question 26

Where does the corticospinal tract become contralateral?

Answer 26

In the medullary decussation

Question 27

Describe the differing responses to upper-motor neuron (UMN) and lower-motor neuron (LMN) injury.

Answer 27

UMN: immediate weakness followed by hyperreflexia and spasticity LMN: immediate and long-lasting weakness

Question 28

Describe the cell chain involved in sensing pain.

Answer 28

First neuron enters spine – synapses on neuron that crosses midline then extends to the thalamus – synapses on thalamic neuron that carries signal to cortex

Question 29

In the cerebrum, the fibers of the internal capsule splay out into ______________.

Answer 29

the corona radiata

Question 30

The putamen is ____________ to the globus pallidus.

Answer 30

lateral

Question 31

In the midbrain, the internal capsule is referred to as ___________.

Answer 31

the crus cerebri

Question 32

The caudate is ____________ to the thalamus.

Answer 32

superior

Question 33

Approximately _________ percent of the corticospinal axons decussate.

Answer 33

80%

Question 34

How many lower-motor neurons can one upper-motor neuron innervate?

Answer 34

A "pool" (Ojemann's word)

Question 35

Muscle fasciculations are characteristic of _____________ damage.

Answer 35

lower-motor neuron

Question 36

Where is the nucleus gracilis?

Answer 36

The bottom of the brainstem

Question 37

The nucleus cuneatus contains the second-order sensory neurons for the ____________ and is lateral to the ___________.

Answer 37

upper extremities; nucleus gracilis in the brainstem