Nervous System 2

Question 1

2 main glial cells of the PNS

Answer 1

1) schwann cells: produces myelin
2) satellite glia: associated with and support neurons. Surrounds them in ganglia.

Question 3

The schwann cells make myelin in layers surrouding the PNS neuron. Sometimes, the schwann cell cytoplasm gets stuck between the layers of myelin, forming ___ ___ ___.

Answer 3

Schmidt Lanterman Lines.

Question 4

T/F: one oligodendrocte (myelin producing in CNS) myelinates multiple fibers

Answer 4

TRUE. therefore, they do not surround each individual fiber with their cell membrane (neurillemma)

Question 5

What are the grey matter areas of the spinal cord? What do they contain?

Answer 5

gray matter is located in the posterior, lateral and anterior horns. They are filled with neuron cell bodies and astrocytes.

Question 6

what are the white matter areas of the spinal cord? What do they contain

Answer 6

white matter (myelin) is found in the dorsal, lateral and ventral columns. They contain fiber tracts and oligodendroctytes.

Question 7

a ___ ___ and ___ ___ join to form a spinal nerve

Answer 7

posterior root and anterior root

Question 8

___ ___ is internal, forming a roughly H—shaped structure that consists of two ____ horns and two ____ horns all joined by the gray commissure around the central canal

Answer 8

GREY MATTER. Two posterior and two anterior horns.

Question 9

which image is grey matter? white matter?

Answer 9

(c): Micrograph of the gray matter showing large nuclei, prominent nucleoli, and cytoplasm rich in chromatophilic substances (Nissl substance) (d): white matter showing fiber tracts seen here in cross—section with empty myelin sheaths surrounding axons. Also seen tracts running from one side of the cord to the other, seen here as several longitudinally sectioned tracts. H&E.

Question 10

Answer 10

White versus gray matter, stained. A cross section of spinal cord shows the transition between white matter (left) and gray matter (right). The white matter consists mainly of nerve fibers whose myelin sheaths were dissolved in the preparation procedure, leaving the round empty spaces shown. Each such space surrounds a dark—stained spot which is the axon. Neuronal cell bodies predominate in the gray matter

Question 11

dorsal gray horns of the spinal cord contains ___ ___ ___ and ___ ___ that carry impulses to the thalamus.

Answer 11

dorsal gray horns of the spinal cord contains INTERNEURON CELL BODIES and SENSORY NEURONS that carry impulses to the thalamus.

Question 12

Ventral gray horn contains ___ ___ ___ cell vodies

Answer 12

somatic motor neuron

Question 13

Lateral gray horns are involved in the ___ ___ __

Answer 13

autonomic nervous system

Question 14

purpose of CSf

Answer 14

1) shock absorber
2) maintains chemical homeostasis in brain
3) provides buoyancy

Question 15

3 layers of the meninges. Where do blood vessels and CSF flow thorugh?

Answer 15

1) dura
2) arachnoid
3) pia.

CSF and blood vessels are in the subarachnoid space between arachnoid and pia mater.

Question 16

Nerves in the PNS can either be ___ or ___

Answer 16

sensory or mixed

Question 17

T/F : fiber bundles in the CNS are associated with connective tissue and can be sensory or mixed

Answer 17

FALSE. Fibers form tracts in the CNS and are not associated with connective tissue. They can be ascending or descending, but they cannot be mixed, unlike PNS nerves.

Question 18

Nerves in the PNS are associated with ____ connective tissue. What’re the three connective tissue associations?

Answer 18

COLLAGENOUS (kind of like muscle bundles)

1- epineurium: ON SURFACE. fibrous covering that wraps and supports the nerve, separating it from fascia

2) perineurium: derived from epineurium, enters the nerve and forms nerve fiber bundles called fascicles.
3) endoneurium: delicate connective tissue layer derived from perineurium that surrounds each fiber and Schwann cell.

Question 19

neuron cell bodies in the PNS are found in structures called ____

Answer 19

ganglia

Question 20

dorsal root ganglia are located on the spinal cords at the dorsal root and are ___polar. They are ____ neuron cell bodies and are surrounded by ___ cells.

Answer 20

dorsal root ganglia are located on the spinal cords at the dorsal root and are UNIpolar. They are SENSORY neuron cell bodies and are surrounded by SATELLITE cells.

Question 21

Sympathetic ganglia enter the ___ side of the vertebral column. The are ___polar with ____ granules. Do they contain satellite cells?

Answer 21

Sympathetic ganglia enter the VENTRAL side of the vertebral column. The are MULTIpolar with LIPOFUSCHIN granules. They do not have as many satellite cells as dorsal root ganglia

Question 22

group of functionally related neurons in the CNS is called a ____

Answer 22

nucleus

Question 23

each spinal nerve is connected to the spinal cord by two roots these are the ___ root and the ___ root.

• even though all spinal cords are mixed, sensory and motor fibers segregate in the roots. All sensory fibers enter the spinal cord through the ___ ___ ganglion, and all motor fibers leave the cord through the ___ ___

Answer 23

each spinal nerve is connected to the spinal cord by two roots these are the DORSAL root and the VENTRAL root.

• even though all spinal cords are mixed, sensory and motor fibers segregate in the roots. All sensory fibers enter the spinal cord through the DORSAL ROOT ganglion, and all motor fibers leave the cord through the VENTRAL ROOT

Question 24

the cerebrum consists of 2 ____ connected by the ___ ___

Answer 24

2 hemispheres connected by the corpus callosum

Question 25

3 functions of cerebrum

Answer 25

1) higher thought processes (thoughts, reasoning)
2) interpretation of sensory info
3) memory

Question 26

4 lobes of each hemisphere of the cerebrum

Answer 26

frontal, parietal, temporal, occipital

Question 27

the cerebrum has an outer cortex of ___ ___ and an inner layer of __ ___

Answer 27

outer = grey matter

inner = white matter

Question 28

the cortex consists of ___ layers. Pyramidal cells are located in layer __ and __

Answer 28

6 layers. you can find pyramidal cells in layers 3 and 5

Question 30

What kind of neurons are these? where are they found?

Answer 30

pyramedal neurons. found in the cerebrum

Question 31

the ___ ___ joins the brain to the spinal cord. it also contains pyramidal tracts that cross to the opposite side at the ___ ___ ___ ___. These fibers continue down into the spinal cord to synapse with somatic motor neurons in the ventral gray horns.

Answer 31

the MEDULLA OBLONGOTA oins the brain to the spinal cord. it also contains pyramidal tracts that cross to the opposite side at the DECUSSATION OF THE PYRAMIDS. These fibers continue down into the spinal cord to synapse with somatic motor neurons in the ventral gray horns.

Question 32

Function of cerebellum. How are the two hemispheres connected at the cerebellum?

Answer 32

coordinating and refining motor activities. 2 hemispheres connected at the vermis.

Question 33

the outer cortex of the cerebellum is made of ___ matter and the inner medullary cortex is made of __- matter

Answer 33

he outer cortex of the cerebellum is made of GREY matter and the inner medullary cortex is made of WHITE matter

Question 34

the grey matter layer of the cerebellum is aka: ___ ___. what three layers are there?

Answer 34

aka CEREBELLAR CORTEX. Has a molecular layer (unmyelinated, minimal neurons), purkinje cell layer, and granular layer (more neurons)

Question 37

What part of the brain is this?

Answer 37

cerebellum

Question 38

T/F: purkinje cells are found in other regions of the brain other than the cerebellum

Answer 38

false. only found in cerebellum

Question 39

the body of the purkinje cells in the cerebellum are embedded in the ___ layer, while the dendritic processes project into the ____ layer

Answer 39

the body of the purkinje cells in the cerebellum are embedded in the GRANULAR layer, while the dendritic processes project into the UPPER MOLECULAR layer

Question 40

Answer 40

ML= molecular layer

GL= granular layer (there are purkine cells between the two layers)

M= cerebellar medulla. White matter.

Question 41

Answer 41

Purkinje cell of the cerebellum. Dendrites and dendritic spines are in the upper molecular layer of the cerebellar cortex, while the cell bodies of the purkinje cells rest in the granular layer.

Question 42

What structure is this? What is it comprised of? Purpose?

Answer 42

This is the choroid plexus. Makes CSF. The choroid plexus is specialized for transport of water and ions across the capillary endothelium and ependymal layer and the elaboration of these as CSF. made of Pia mater joined with cuboidal epyndymal cells.

Question 43

Explain this image. Which part of the nervous system would you find these structures?

Answer 43

Peripheral nerve connective tissue. Three layers of connective tissue in (a). (b): The outer epineurium (E) consists of a dense superficial region and a looser deep region that contains large blood vessels (A,V) and fascicles in which nerve fibers (N) are bundled. Each fascicle is surrounded by the perineurium (P), consisting of a few layers of unusual epithelial—like cells. Axons and Schwann cells are in turn surrounded by a thin layer of endoneurium. X140. H&E. (c): perineurium (d): This micrograph shows a longitudinally oriented nerve. Within fascicles is the endoneurium (En) is produced by the Schwann cells. Collagen of the endoneurium is stained blue and a node of Ranvier (N) and a Schwann cell nucleus (S) are also clearly seen. X400. Mallory trichome.

ONLY FOUND IN THE PERIPHERAL NERVES. FIBERS OF THE CNS ARE CALLED TRACTS AND DO NOT HAVE CONNECTIVE TISSUE

Question 44

lautonomic ganglia are associated with the Autonomic Nervous System (ANS) –maintains internal homeostasis. Where do sympathetic autonomic ganglia lie? para symp?

Answer 44

lsympathetic lie alongside the vertebral column in thoracic and lumbar regions

parasympathetic lie near organ

Question 45

craniospinal ganglia contain sensory nerves are are unipolar. The cell bodies are surrounded by satellite cells.

In sympathetic ganglia, neurons are mutlipolar, and the satellite cells are smaller and less regular.

In parasympathetic ganglia, there are fewer cell bodies, and are generally much smaller than sympathetic ganglia. What is an example of parasympathetic ganglia?

Answer 45

Auerbachs plexus.

Question 46

Sensory receptors can either be ___ ___ or ___ cells.

Answer 46

nerve endings or specialized cells.

Question 47

are meissner’s corpuscles encapsulated? Location? Function?

Answer 47

they are encapsulated. Location: upper part of the dermal papillae. Function: detect light touch

Question 48

name the structure

Answer 48

meissners corpuscles

Question 49

are pacinian corpuscles encapsulated? Location? Function?

Answer 49

they are encapsulated. Location: deeper in dermis, mesenteries, ligaments, some viscera. Function: detect pressure.

Question 50

What is this?

Answer 50

Pacinian corpuscles. Looks like onion and surrounded by fatty tissue.

Question 51

6 layers of the cerebral cortex

Answer 51

1) molecular layer. most superficial. closest to the pia.
2) outer granular layer
3) pyramedal cells
4) inner granular layer
5) pyramedal cells
6) multiform cell layer. Deepest in cortex. contains fusiform cells and white matter.

Question 52

white matter of the cerebrum is located under the 6th grey matter layer. What three tracts compose the white matter?

Answer 52

1) projection tracts: both ascending and descending tracts
2) commissural: connects the two hemispheres
3) association tracts: connects regions within a hemisphere

Question 53

What is this? What cell bodies does it house? Compare to a sympathetic ganglion.

Answer 53

Dorsal Root Ganglion. houses sensory, unipolar cell bodies.

Contains mores satellite glial cells for support, looks more organized.

Sympathetic ganglion is part of the peripheral NS but leaves from the ventral root horn (considered “efferent”). looks more messy because of lipofuscian granules.

Question 54

What is this? What makes it distinguishable from dorsal root ganglion? What type of cells are housed?

Answer 54

Sympathetic ganglion. Has LESS satellite cells, is LESS organized than dorsal root ganglion, and often has lipofuscian granules. Multipolar/efferent neurons are housed in the sympathetic ganglion, and they are found in the thoracolumbar region of the spinal cord

Question 55

the medulla has mainly ____ ganglion

Answer 55

parasympathetic ganglion. The medulla is responsible for a lot of subconcious processes/ breathing/blinking.

Question 56

parasympathetic or sympathetic? Where is this located?

Answer 56

auebachs plexus. parasymp. located between the inner circular and outer longitudinal layers of the muscularis externa.