meneghini 3-4

Question 1

two portions of the nervous system

Answer 1

central: brain and spinal cord
peripheral: nerves (spinal nerves, cranial nerves and ganglia cells)
the PNS has the function to connect the CNS to sensory organs and other peripheral organs of the body

Question 2

why does the grey matter have a brownish appearance?

Answer 2

due to the fact that contain the cell bodies (somas) of the neurons

Question 3

what is contained in the white matter?

Answer 3

axons of the neurons, enriched in oligodendrocytes (mielinating cells)

Question 4

what are the names of the 3 layers of connective tissue that cover the brain ?

Answer 4

meninges, located under the skull
-pia mater
-dura mater
-arachnoid mater
they protect the brain and recycle cerebrospinal fluid

Question 5

what are the cells that lead to the formation of the peripheral nervous system from the neural tube?

Answer 5

neural crest cells

Question 6

CNS cell types

Answer 6

1. neurons
2. glia cells
   -oligodendrocytes, astrocytes, ependymal cells (all of them derive from the neural stem cells or also called radial glia cells) and microglia (derive from the hematopoietic lineage)

Question 7

each neuron is composed of

Answer 7

soma (cell body)
multiple dendrites (that receive infos)
one single axon for each neuron that has multiple terminals->that give infos to target cells

Question 8

types of neurons

Answer 8

multipolar
one axon, multiple dendrites
(common in CNS)
bipolar
one axon, one dendrite (ex: in the olfactory mucosa)
pseudounipolar
only one axon and peripheral branches as a T shape (connect CNS with peripheral NS)

Question 9

Nissl bodies

Answer 9

aggregate of free ribosomes and rough ER
can be present in the soma and in the dendrites
not present in the axons
can be visualized with basic dies

Question 10

what dictates the shape of the neuronal cells?

Answer 10

the neurofilaments
generated thanks to the production of structural proteins

Question 11

what part of the dendrites receive the signal from the axon of the neighboring neurons?

Answer 11

spiny processes of the dendrites

Question 12

where does the axon originate?

Answer 12

at the axon hillock, a region in the soma of neurons

Question 13

what is the resting membrane potential of a neuron?

Answer 13

-60mV

Question 14

what is the event that generates a depolarization in the membranes of neurons?

Answer 14

when an input arrives, voltage gate sodium channels open causing an influx of sodium ions that will change the neuronal resting potential from -60mV to +40mV (depolarization).
the depo. generates an electrical stimulus that is then transmitted along the axon

Question 15

which of the 2 types of synapses (electric and chemical) is the one more common in mammals?

Answer 15

chemical one
neurotransmitters are used to communicate the electrical impulse between neurons

Question 16

what is the most common inhibitory neurotransmitter?

Answer 16

GABA

Question 17

what is the most common excitatory neurotransmitter?

Answer 17

glutamate

Question 18

what are the myelinating cells of the CNS?

Answer 18

olygodendrocytes

Question 19

what are the myelinating cells of the peripheral nervous system?

Answer 19

Schwann cells

Question 20

which are the glia cells directly involved in the formation of the blood brain barrier?

Answer 20

astrocytes

Question 21

3 types of astrocytes

Answer 21

protoplasmic
fibrous
intralaminar

Question 22

tripartite synapsis comprehend:

Answer 22

1. pre synaptic neuron
2. post synaptic neuron
3. astrocyte

Question 23

astrogliosis

Answer 23

when astrocytes change their shape in response to injuries/diseaes of the CNS

Question 24

glial fibrillary acidic protein (GFAP)

Answer 24

express by astrocytes
over expressed during astrogliosis

Question 25

GLIAL BARRIER

Answer 25

formed by the foot processes of astrocytes between the CNS and the connective tissue (that can be found both at the meninges or sorrounsign big blood vessels) this barrier avoids that the cells of the connective tissue invade the CNS and vice versa

Question 26

BLOOD BRAIN BARRIER

Answer 26

made by astrocyte processes pericytes endothelial cells a barrier that regulates the passage of substances between blood and the CNS.

Question 27

do microglia cells originate from neural stem cells like all the other glia cells?

Answer 27

no they derive from the hematopoietic lineage

Question 28

microglia in the homeostatic brain express 2 markers that can be used to distinguish them from boarder associated macrophages, which 2 markers?

Answer 28

PTY12, SALL1

Question 29

what's the name of the microglia in the homeostatic brain? shape?

Answer 29

resting microglia with a very branched shape

Question 30

ependyma

Answer 30

ciliated simple columnar epithelium made by ependymal cells that surround the ventricular system in the brain and the central canal in the spinal cord.

Question 31

which are the cells that produce the cerebrospinal fluid?

Answer 31

ependymal cells fluid rich of ions and proteins essential for the survival of the cells of the CNS

Question 32

what is the name of the capsule that surrounds each nerve?

Answer 32

epineurium

Question 33

what is the name of the specialized connective tissue that is in between the bundle of axons?

Answer 33

perineurium, highly vascularized

Question 34

what is the name of the connective tissue inside each bundle of axons?

Answer 34

endoneurium enriched of Schwann cells

Question 37

Glia limitans barrier

Answer 37

Formed by the foot processes of Astrocytes To divide the CNS tissue from the connective tissue present either at the level of the meninges or at the level of big blood vessels

Question 38

Amoeboid microglia

Answer 38

Phagocytose the debris at the inflammatory site

Question 39

We have 3 ventricles

Answer 39

3rd, 4th and lateral ventricle

Question 40

Sensory ganglia

Answer 40

Dorsal root of spinal nerve, in the spinal cord Contain sensory (afferent) neurons

Question 41

Motor ganglia

Answer 41

Involved in autonomic nervous system

Question 42

Which type of neurons we have in the sensory ganglia? In the motor ganglia?

Answer 42

Pseudounipolar neurons in the sensory ganglia Multipolar neurons in the motor ganglia NB:higher number of neurons and of satellite cells in the sensory ganglia