A walk through the brain - week 3

Question 1

What is a nerve?

Answer 1

A nerve consists of a membrane sheath encasing bundles of axons.

Question 2

Where are the nerves in the brain?

Answer 2

Cranial nerves

Question 3

What do nerves do?

Answer 3

Nerves are bundles of fibers that transmit electrical impulses from the central nervous system to the body and back.

Question 4

What are the 4 structures of a neuron?

Answer 4

Cell body (soma)
Dendrites
Axon
Terminals

Question 5

What is the soma (cell body)?

Answer 5

The neuronal cytosol
Contains nucleus
contains cellular organelles

Question 6

What do dendrites do?

Answer 6

Receive messages from another neuron’s terminal buttons

Question 6

What do dendrites do?

Answer 6

Receive messages from another neuron’s terminal buttons

Question 7

What is an axon ?

Answer 7

Slender tube - covered by a myelin sheath

Carries messages (electric charges) from the soma to terminal buttons

Question 8

What are terminals or (terminal buttons)

Answer 8

Small knowbs end of terminals which release neurotransmitters

Question 9

Where do neurons communicate with each other?

Answer 9

The Synapse

Question 10

What is the ave. length of a neuron?

Answer 10

< 1.0mm

Question 11

How long is the sciatic nerve on ave?

Answer 11

1meter

Question 12

What are nodes of ranvier?

Answer 12

Unmyelinated gaps on the axon

Question 13

In the CNS myelination is made from what cells?

Answer 13

Oligodendrocytes

Question 14

In the PNS, myelination is made from what cells?

Answer 14

Schwann cells

Question 15

What is myelination important for?

Answer 15

Sensory & motor transmission (PNS)
Neuron to neuron communication (CNS)

Question 16

Afferent stimulation =

Answer 16

Carry messages to CNS
Alerts about environment

Question 17

Efferent stimulation =

Answer 17

Motor neurons carry messages AWAY FROM CNS
causes muscle movement

Question 18

What’s the ave. percentage of neuronal cells in the brain?

Answer 18

10 - 15%

Question 19

What is the ave. % of glial cells in the brain?

Answer 19

85%

Question 20

What do glia do?

Answer 20

Glue CNS together
Supply nutrients to soma
Insulate neurons
Destroy/remove dead neurons

GLIA = GLUE

Question 21

How many types of neuroglial cells are there?

Answer 21

6

Question 22

How many types of glia in the PNS?

Answer 22

2

Question 23

How many types of glia in the CNS?

Answer 23

4

Question 24

What are the 2 types of glia in the PNS?

Answer 24

Schwann Cells Satellite Cells

Question 25

What are the 4 types of glia cells in the CNS?

Answer 25

1. Astrocytes 2. Oligodendrocytes 3. Microglia 4. Ependymal cell

Question 26

What is the connectome?

Answer 26

A comprehensive map of neural connections in the brain 'Wiring diagram' INCL. every neuron, synapse & component

Question 27

What is the connectome trying to achieve?

Answer 27

Map functional neuronal connectivity and structures Identify how these complexities influence behaviour and consciousness

Question 28

How many cranial nerves are there?

Answer 28

12

Question 29

Name the 12 cranial nerves in order

Answer 29

I - Olfactory II - Optic III - Oculomotor IV - Trochlear V - Trigeminal VI - Abducens VII - Facial VIII - Vestibulocochlear IX - Glossopharyngeal X - Vagus XI - Accessory XII - Hypoglossal

Question 30

What is the BBB?

Answer 30

A semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain’s capillaries.

Question 31

Where is the BBB?

Answer 31

Around the brain

Question 32

What does the BBB do?

Answer 32

he blood–brain barrier helps prevent pathogens from entering the brain, it can also prevent molecules from entering.

Question 33

How does the BBB function?

Answer 33

The BBB regulates the composition of extracellular neuronal fluid Protects the brain from harmful chemicals

Question 34

Why does the BBB do it's (function)?

Answer 34

To protect the brain

Question 35

How does the reflex in Fig. 2.13 work in foundations of behavioural neuroscience?

Question 36

What is an interneuron?

Answer 36

A neuron located entirely within the central nervous system.

Question 37

What direction is anterograde?

Answer 37

In a direction along an axon from the cell body toward the terminal buttons.

Question 38

What direction is retrograde?

Answer 38

In a direction along an axon from the terminal buttons toward the cell body.

Question 39

What is a cytoskeleton?

Answer 39

Formed of microtubules and other protein fibers, linked to each other and forming a cohesive mass that gives a cell its shape

Question 40

What is a microtubule?

Answer 40

A long strand of bundles protein filaments hollow core; part of the cytoskeleton transports substances within the cell.

Question 41

What does the nucleus contain?

Answer 41

Chromosomes

Question 42

What is a chromosome?

Answer 42

A strand of DNA, with associated proteins, found in the nucleus; carries genetic information.

Question 43

What does DNA stand for?

Answer 43

deoxyribonucleic acid (DNA)

Question 44

What is a gene?

Answer 44

The functional unit of the chromo- some, which directs synthesis of one or more proteins.

Question 45

What is an astrocyte?

Answer 45

A glial cell that provides sup- port for neurons of the central nervous system, provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid. ASTROCYTE = STAR CELL

Question 46

What is phagocytosis?

Answer 46

The process by which cells engulf and digest other cells or debris caused by cellular degeneration.

Question 47

What is the function of oligodentrocytes?

Answer 47

Provide support to axons Produce myelin sheath

Question 48

What are 6 things microglia cells do?

Answer 48

Smallest glial cells Phagocytosis Engulfs & breaksdown dead & dying neurons Brain immunity Protects brain from invasions Associated with inflammatory reactions

Question 49

Is the BBB selectively permeable?

Answer 49

Yes

Question 50

How is the BBB formed?

Answer 50

CNS capillaries don’t have gaps substances cannot leave the blood to enter the brain. The tightly packed cells of the capillaries in the brain make up the blood–brain barrier.

Question 51

What area of the brain controls vomiting and why?

Answer 51

postrema The blood–brain barrier is much weaker there neurons detect the presence of toxic substances