Lecture 5 8/30/23

Question 1

What are the two parts of the central nervous system?

Answer 1

-brain
-spinal cord

Question 2

What are the two parts of the peripheral nervous system?

Answer 2

-nerves
-ganglia

Question 3

What does the central nervous system arise from?

Answer 3

neuroectoderm

Question 4

What does the peripheral nervous system arise from?

Answer 4

neural crest cells

Question 5

What are the characteristics of neurons?

Answer 5

-main part of cell
-contains the nucleus
-found in the grey matter

Question 6

What is the role of dendrites?

Answer 6

receive signals and relay them to the neuron nucleus

Question 7

What is the role of axons?

Answer 7

convey signals away from neuron nucleus and to cells/target tissues

Question 8

What is the role of axon terminals?

Answer 8

transfer signals to next neuron or target tissue (synapse)

Question 9

What are astrocytes?

Answer 9

-most common neuroglia cell in gray matter
-support and nurture the neuronal cell bodies
-fill the space between neuronal cell bodies
-form blood-brain barrier

Question 10

How do neuron cells arrange between gray and white matter?

Answer 10

-gray matter contains neuronal cell bodies
-white matter contains axons

Question 11

What is neuropil?

Answer 11

the “pink stuff” between nuclei that contains the axons, dendrites, etc.

Question 12

What are microglia?

Answer 12

-mesenchymal cells
-macrophages of the brain

Question 13

What are ependymal cells?

Answer 13

cells that line the ventricles of the brain and central canal of the spinal cord

Question 14

What are oligodendroglia?

Answer 14

-most numerous cells in white matter
-wrap around axons to myelinate them

Question 15

What is the equivalent of oligodendroglia in the peripheral nervous system?

Answer 15

Schwann cells

Question 16

How do oligodendroglia myelinate the axons?

Answer 16

branches of the oligodendroglia cell will wrap around multiple axons and arrange down the entirety of each axon

Question 17

What are the gaps between oligodendroglia cells?

Answer 17

nodes of Ranvier

Question 18

What is the importance of myelination and nodes of Ranvier?

Answer 18

-action potentials move node to node rather than down entire axon
-makes the process faster

Question 19

What is different about how oligodendroglia cells and Schwann cells myelinate axons?

Answer 19

-one oligodendroglia cell myelinates multiple axons
-one Schwann cell myelinates only one axon

Question 20

What are non-myelinated axons?

Answer 20

-provide pain sensation
-less myelination, but still myelinated
-slower conduction
-multiple axons “embedded” in a single Schwann cell

Question 21

What is the function of the choroid plexus?

Answer 21

makes the cerebrospinal fluid

Question 22

What are the characteristics of the cerebral spinal fluid?

Answer 22

-bathes/nurtures central nervous system
-gets re-absorbed into blood
-constant turnover

Question 23

What is hydrocephalus?

Answer 23

when too much water is in the ventricles, leading to them becoming enlarged

Question 24

What are the characteristics of the meninges?

Answer 24

-connective tissue layers
-support blood vessels
-contain CSF
-tether brain to bone

Question 25

What are the three layers of the meninges, from outermost to inner most?

Answer 25

-dura mater -arachnoid mater -pia mater

Question 26

What is meningitis?

Answer 26

inflammation of the meninges

Question 27

What are the sections of the brain?

Answer 27

-cerebrum -cerebellum -brainstem

Question 28

How are grey matter and white matter arranged in the cerebrum and cerebellum?

Answer 28

-gray matter outside -white matter inside

Question 29

What are gyri?

Answer 29

raised portions of the cerebrum

Question 30

What are sulci?

Answer 30

the grooves on the cerebrum

Question 31

What is laminar cortical necrosis?

Answer 31

death of neural cell bodies in the laminar cortex

Question 32

What is the laminar cortex?

Answer 32

various layers of tissue that make up the cerebrum

Question 33

How can you determine whether the brain matter you are looking at microscopically is grey or white matter?

Answer 33

-linearity = axons =white matter -more uniformity = oligodendroglia only = white matter

Question 34

Why is the cerebellum also known as the tree of life?

Answer 34

the arrangement of white matter within the gray matter looks like a tree

Question 35

How is the cerebellum microscopically arranged?

Answer 35

gray matter: -outer molecular layer -row of Purkinje cells - inner granular cell layer white matter

Question 36

What are the characteristics of the brainstem organization?

Answer 36

-gray matter and white matter mixed -"nuclei" of gray matter dispersed within white matter

Question 37

How are gray matter and white matter arranged in the spinal cord?

Answer 37

-gray matter on the inside (butterfly shape) -white matter outside

Question 38

What is the central canal?

Answer 38

a canal through the spinal cord containing CSF

Question 39

What are sensory nerves?

Answer 39

nerves that bring impulses to the spinal cord from the body

Question 40

What are interneurons?

Answer 40

nerves that transmit signals between the sensory and motor nerves

Question 41

What are motor nerves?

Answer 41

nerves that send impulses from the spinal cord to the target tissue

Question 42

What are ganglia?

Answer 42

collections of neurons in the peripheral nervous system

Question 43

What is the role of ganglia?

Answer 43

to relay signals from target tissues

Question 44

What are satellite cells?

Answer 44

the supportive cells of the peripheral nervous system

Question 45

How do nerves travel?

Answer 45

to the target tissues

Question 46

What is a collection of axons called in the CNS?

Answer 46

tract

Question 47

What is a collection of axons called in the PNS?

Answer 47

nerve