General Terminology and Spinal Cord Morphology

Question 1

The brain is composed of forebrain, cerebellum, and brainstem; what are the 2 components of the forebrain

Answer 1

Cerebral hemispheres

Diencephalon

Question 2

Cell directly sensitive to various stimuli (e.g., touch or temp. change) or receive direct connections from non-neuronal receptor cells

Answer 2

Sensory neurons

Question 3

Cells that directly contact muscles, glands, or other neurons (PNS ganglia)

Answer 3

Motor neurons

Question 4

Neurons that have processes confined to a single small area of the CNS

Answer 4

Local interneurons

Question 5

Neurons with long axons connecting different areas, as in a neuron in the cerebral cortex whose axon reaches the spinal cord

Answer 5

Projection neurons

Question 6

Difference between gray matter and white matter

Answer 6

Gray = areas containing neuronal/glial cell bodies and dendrites

White = areas where there is a collection of axons, many covered with myelin

Question 7

Fasciculus, funiculus, lemniscus, peduncle, and tract, are all terms for ____ matter

Answer 7

White

Question 8

____ = collections of cell bodies with common function

____ = layers of gray matter over other parts of the CNS

Answer 8

Nuclei

Cortex

Question 9

The diameter of the spinal cord changes along its length. What are the 2 enlargements?

Answer 9

Cervical enlargement: innervates the upper limbs (inferior cervical region)

Lumbosacral enlargement: innervates the lower limbs

Question 10

31 pairs of spinal nn

Answer 10

8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 11

Tapering inferior end of spinal cord

Answer 11

Conus medullaris

Question 12

Inferior to conus medullaris, groups of axons project from the spinal cord as the _____ _____

The ____ ___ is a thin strand of pia mater that helps anchor the conus medullaris to the coccyx

Answer 12

Cauda equina

Filum terminale

Question 13

The SC is anatomically segmented into ant. and post. horns.

Posterior rootlets enter the SC in the ____ ___, a shallow longitudinal groove

Anterior rootlets leave from the poorly defined ______ sulcus

Anterior and posterior rootlets join forming spinal nn

Answer 13

Posterolateral sulcus

Anterolateral sulcus

Question 14

Which part of SC consists of interneurons whose processes remain within the SC and projection neurons whose axons collect into ascending sensory pathways?

Answer 14

Posterior horn

Question 15

2 prominent parts of posterior horn of SC, present at all levels:

________ = distinctive region of gray matter that caps the posterior horn

_________ = consists of interneurons and projection neurons that transmit somatic and visceral sensory info

Answer 15

Substantia gelatinosa

Body

Question 16

_____ = white matter located between substantia gelatinosa and the surface of the SC

Answer 16

Lissauer’s tract (contains finely myelinated/unmyelinated fibers with which interact with substantia gelatinosa)

Question 17

Which part of the spinal cord contains cell bodies of the large motor neurons that supply skeletal muscle — lower motor neurons?

Answer 17

Anterior horn

Question 18

Intermediate gray matter contains _______ neurons

At specific levels, it also includes ______ nucleus

Answer 18

Autonomic (preganglionic)

Clarke’s

Question 19

What is clarke’s nucleus?

Answer 19

Collection of large cells located on the medial surface of the base of the posterior horn (T1-L2)

Has prominent role in sensory processing and is typically treated as part of posterior horn

Question 20

Preganglionic sympathetic neurons lie in segments T1-L3, most located in the ________ ____ ____

This forms a pointy lateral horn on the spinal gray matter; their axons leave through the ventral roots

Answer 20

Intermediolateral cell column

Question 21

Cells in a corresponding location in S2 to S4 constitute the ____ ____ ___, but do not form a distinct lateral horn; axons synapse on postganglionic parasympathetic neurons for _____ viscera

Answer 21

Sacral parasympathetic nucleus; pelvic

Question 22

10 lamina of spinal cord gray matter

Answer 22

Lamina 1 (marginal zone): thin gray matter covering substantia gelatinosa

Lamina 2: substantia gelatinosa

Lamina 3-6: body of posterior horn

Lamina 7: intermediate gray matter (including Clarke’s nucleus), also extensions into anterior horn

Lamina 8: some interneuron zones of anterior horn

Lamina 9: clusters of motor neurons embedded in anterior horn

Lamina 10: zone of gray matter surrounding central canal

Question 23

Associated levels, lamina, and function of marginal zone nucleus

Answer 23

All levels

Lamina I

Function: some spinothalamic tract cells

Question 24

Associated levels, lamina, and function of substantia gelatinosa nucleus

Answer 24

All levels

Lamina II

Function: modulate transmission of pain and temp

Question 25

Associated levels, lamina, and function of body of posterior horn nuclei

Answer 25

All levels Lamina 3-6 Function: sensory processing

Question 26

Associated levels, lamina, and function of clarke’s nucleus

Answer 26

Levels T1-L2 Lamina VII Function: posterior spinocerebellar tract cells

Question 27

Associated levels, lamina, and function of intermediolateral column

Answer 27

Levels T1-L3 Lamina VII Function: preganglionic sympathetic neurons

Question 28

Associated levels, lamina, and function of sacral parasympathetic nucleus

Answer 28

Levels S2-S4 Lamina VII Function: preganglionic parasympathetic neurons —> pelvic viscera

Question 29

Associated levels, lamina, and function of accessory nucleus

Answer 29

Levels: medulla-C5 Lamina IX Function: motor neurons —> SCM and trapezius

Question 30

Associated levels, lamina, and function of phrenic nucleus

Answer 30

Levels C3-5 Lamina IX Function: motor neurons —> diaphragm

Question 31

Bundle of axon fibers in the posterior column-medial lemniscus pathway of SC; carries sensory info from arms; ascending tract relaying info to brain via SC

Answer 31

Fasciculus cuneatus (FC)

Question 32

Bundle of axon fibers in the posterior column-medial lemniscus pathway of SC; carries sensory info from middle thoracic and lower limbs of the body; ascending tract relaying info to the brain via SC

Answer 32

Fasciculus gracilis (FG)

Question 33

Sensory axons (cell bodies in DRG) enter SC and branch, terminating on neurons in spinal ____ matter Axons emerge from motor neurons (____ horn) and exit SC to innervate skeletal mm

Answer 33

Gray Anterior

Question 34

Functional Contents of white matter

Answer 34

Long descending tracts (from brainstem and forebrain) Long ascending tracts (to brainstem, cerebellum, and forebrain) Local axons interconnecting spinal levels

Question 35

Functional contents of gray matter

Answer 35

Motor neuron cell bodies Endings of incoming sensory axons Second order sensory cell bodies Endings of long descending tracts and local interneurons

Question 36

4 prominent sulci that divide each cerebral hemisphere into 5 lobes

Answer 36

Central sulcus Lateral sulcus (fissure) Parietooccipital sulcus Cingulate sulcus

Question 37

The frontal lobe extends medially to the _____ sulcus

Answer 37

Cingulate

Question 38

Medially, the parietal lobe is bounded inferiorly by the ____ and ____ sulci

Answer 38

Subparietal; calcarine

Question 39

Medially, the temporal lobe’s posterior boundary is an imaginary line extending from the preoccipital notch toward the corpus callosum, and part of its superior boundary is the _____ sulcus

Answer 39

Collateral

Question 40

_______ lobe is a strip of cortex that encircles the telencephalon-diencephalon junction

Answer 40

Limbic lobe

Question 41

The nervous system develops from the neural tube, that contains a central cavity. This cavity persists in adults as a system of interconnected ____

Answer 41

Ventricles

Question 42

Path of lateral ventricles to central canal

Answer 42

``` Lateral ventricles Interventricular foramen (of Monro) 3rd ventricle Cerebral aqueduct (of sylvius) 4th ventricle Central canals ```

Question 43

Central white matter that connects cortical areas within the same sulci/gyri

Answer 43

Arcuate fibers

Question 44

Central white matter that connects cortical areas within same hemisphere

Answer 44

Longitudinal/association fasciculi

Question 45

Central white matter that connects cortical areas within R/L hemispheres

Answer 45

Commissural tracts

Question 46

Central white matter that connects cortical areas within other body regions

Answer 46

Projection tracts

Question 47

Largest fiber bundle in the brain

Answer 47

Corpus callosum

Question 48

Part of corpus callosum with commissural fibers to/form temporal lobe, especially inferior parts

Answer 48

Anterior commissure

Question 49

Area of cerebral cortex not included in 5 main lobes; lies buried in lateral sulcus

Answer 49

Insula

Question 50

Insula can be seen by removing the ____, the portion of given lobe that is overlying (may be frontal, parietal, or temporal) ____ sulcus outlines the insula and marks its borders

Answer 50

Opercula Circular

Question 51

Which lobe contains motor areas

Answer 51

Frontal lobe

Question 52

4 gyri that make up lateral surface of frontal lobe

Answer 52

Precentral gyrus Superior frontal gyrus Middle frontal gyrus Inferior fronal gyrus

Question 53

Preceentral gyrus houses what?

Answer 53

Primary motor cortex — origin of descending motor paths and voluntary movements Other frontal gyri have premotor and supplementary motor areas

Question 54

Area of frontal lobe, usually on left side, opercular and triangular parts of inferior frontal gyrus important in motor aspects of written and spoken language

Answer 54

Broca’s area

Question 55

Which lobe has somatosensory areas?

Answer 55

Parietal lobe Includes postcentral gyrus, superior and inferior parietal lobules

Question 56

Which lobe has auditory areas

Answer 56

Temporal Composed of superior, middle, and inferior temporal gyri

Question 57

Inferior surface of temporal lobe is made up of broad ____ ____

Answer 57

Occipitotemporal (fusiform) gyrus

Question 58

4 functions of temporal lobe

Answer 58

Primary auditory cortex Wernicke’s area (may combine with parietal) Higher order processing of visual info Learning and memory

Question 59

Which lobe has visual areas

Answer 59

Occipital

Question 60

Lateral surface of occipital lobe has lateral occipital gyri ____ = wedge shaped area between parietooccipital sulcus and calcarine sulci Lingual gyrus is inferior to calcarine sulcus and is usually continueous with the ____ gyrus Primary visual cortex is contained in walls of ____ sulcus

Answer 60

Cuneus Parahippocampal Calcarine [remainder of lobe is visual association cortex]

Question 61

Limbic lobe is mostly composed of ___ and ____ gyri

Answer 61

Cingulate; parahippocampal

Question 62

Anterior end of parahippocampal gyrus hooks backward on itself, forming a medial bump called the ___

Answer 62

Uncus

Question 63

Folded into the temporal lobe at the hippocampal sulcus is the ______ The ____ lies beneath the uncus of temporal lobe

Answer 63

Hippocampus Amygdala

Question 64

Function of limbic lobe

Answer 64

Emotional responses Drive-related behavior Memory

Question 65

4 divisions of diencephalon

Answer 65

Thalamus Hypothalamus Epithalamus Subthalamus

Question 66

3 divisions of brainstem

Answer 66

Midbrain - continuous with diencephalon Pons Medulla

Question 67

Lobes of cerebellum

Answer 67

Anterior —receives afferents from SC, coordinates trunk and limb movements Flocculonodular — receives afferents from vestibular system, controls eye movements and postural adjustment Posterior — receives afferents from cerebral cortex via pons, role in voluntary movement

Question 68

Group of nuclei that lie deep in cerebral cortex in each hemisphere

Answer 68

Caudate nucleus | Lenticular nucleus = putamen + globus pallidus

Question 69

T/F: With few exceptions, the components of sensory primary afferents are all ipsilateral

Answer 69

True