human nervous system

Question 1

human nervous system

Answer 1

• distinguished us from other vertebrates
• refelcts evolutionary changes
• contains neurons

Question 2

CNS consists of

Answer 2

brain and spinal cord

Question 3

What does the CNS do?

Answer 3

• recognizes and interprets info from the body and the environment
• organizes and executes actions, responses
• gets messages down spinal cord
• gets messages back up the spinal cord

Question 4

PNS consists of

Answer 4

• cranial nerves
• spinal nerves
• and their ganglia (nerve cells that do a certain function, outside the CNS)

Question 5

what does the PNS do?

Answer 5

• connect CNS with peripheral structures of the body

- conveys information to and from, between peripheral structures and CNS

Question 6

nerve-located in the PNS

Answer 6

• bundle of many axons, from many neurons (cell bodies)
• coming down from neurons (cell bodies)
• grouped together
• coated in myelin (like insulation)
• send (motor) and receive (sensory)
• conduct electrochemical impulses (messages) from muscle fibers, and from muscles back to brain
• to/from CNS

Question 7

spinal nerves

Answer 7

innervate body

connect through spinal cored

Question 8

cranial nerves

Answer 8

innervate head, mouth, articulators

connect through brain stem

Question 9

Tracts

Answer 9

located in the CNS

Question 10

gray matter

Answer 10

=cell bodies of neurons

• large group of cell bodies, give pink/gray color
• cell bodies in the cortex and sub cortex
• cell bodies are either neurons or glial cells

Question 11

white matter

Answer 11

=axons, dendrites

-covered in myelin, which is white in color

Question 12

what is a neuron?

Answer 12

• cells which can be stimulated to convey electro-chemical impulses to other cells
• capable of communicating with other nerve cells neurons

Question 13

what does a neuron do?

Answer 13

• recieve, conduct, or transmit neural impulses (to a muscle, gland, or to another neuron)
• cells metabolize certain chemicals called neurotransmitters

Question 14

how do neurons communicate neural impulses

Answer 14

• the blipped cell membrane allows only certain things “in” using specialty channels
• the channels allow neurotransmitters to breach the space between cell bodies, in order to cause reactions in the cell, which receives a sent message, causing it to “fire” some message in response

Question 15

cell body (soma, perikaryon)

Answer 15

• contains organelles made of molecules

- one of these organelles is the nucleus

Question 16

nucleus (inside cell body)

Answer 16

• where we keep our DNA (46 chromosomes)
• made of proteins
• enclosed by membrane
• contains cytoplasm and cytoskeleton for structure and support

Question 17

nucleolus (inside nucleus)

Answer 17

-contains cell RNA (support/messenger for DNA protein synthesis)

Question 18

cytoplasm

Answer 18

-metabolism, synthesis of proteins, flow of nutrients within the cell

Question 19

cytoskeleton (inside nucleus)

Answer 19

• maintains structure of entire cell
• molecular transport throughout cell
• comprised of protein “scaffolding”, including microfilaments, intermediate filaments and microtubules

Question 20

cell membrane (around nucleus)

Answer 20

• bilipid membrane insulates the nucleus from extracellular chemicals
• allowing only specific chemicals (neurotransmitters) to enter

Question 21

the dendrite

Answer 21

• receive incoming transmissions from other neurons
• cannot transmit impulses
• one dendrite per cell body = unipolar
• more than one dendrite at cell body = multiplier

Question 22

the axon

Answer 22

• conducts impulses away from neurons, to other neurons
• only 1 per cell body
• divides into terminal branches at end

Question 23

myelin sheath

Answer 23

• glial cells which grow to form sheath of electrical insulation around axon
• white in color; gives rise to calling axons “white matter” of brain
• support/ increase speed of neural transmission along axon

Question 24

synaptic cleft

Answer 24

• the site where terminal boutons from the axon of one cell meets the dendrite from another cell
• the point of contact whereby a neurotransmitter crosses from one axon (cell body) to another

Question 25

how do neurons communicate

Answer 25

by transmission of chemicals (neurotransmitters) from one cell to the next
-neurotransmitters are released by AP or electrical potential crossing the cell body membrane

Question 26

support cells

Answer 26

• neuroglial cellls
• cells which provide various support services to the nervous system
• help guide neuronal migration, during development
• do NOT conduct neural impulses
• have the same intracellular structure as neurons do

Question 27

astrocytes

Answer 27

• type of glial cell
• defense
• provides structural matrix to neurons in CNS
• form tight walls creating a BBB, so that substances cannot just pass from blood stream directly into neural tissue
• may be involved in neural plasticity/neural growth

Question 28

oligodendrocytes

Answer 28

• type of glial cell
• transport speed
• form and support myelin to cover axons
• also exist in the PNS, where they are called Schwann cells, to support myelin for nerves

Question 29

microglial

Answer 29

• type of glial cell
• zombies, doctors
• scavenger cells which clean up dead neurons
• migrate to site of lesion, turn into macrophages, eat
• orchestrate immune system responses to infection

Question 30

ependyma

Answer 30

• type of glial cell
• packing gel
• line the ventricle of the brain and spinal cord
• form the choroid plexus, which makes CSF