Chapter 3: The Nervous System's Functional Units

Question 1

Cell body/soma

Answer 1

core region of the cell; contains the nucleus and other organelles for protein making

Question 2

Dendrite

Answer 2

branching extension that increases the surface area and collects info

Question 3

Axon

Answer 3

root, single fibre of a neuron that carries messages to other neurons

Question 4

Dendritic spine

Answer 4

protrusion that increases dendrite’s surface area; usually the place where dendritic contact occurs

Question 5

Axon Hillock

Answer 5

juncture of soma and axon

Question 6

Terminal button

Answer 6

knob end tip of axon that conveys info

Question 7

Synapse

Answer 7

spatial junction between one neuron and another; forms information transfer gate between neurons

Question 8

Sensory neurons (2 types)

Answer 8

they conduct info from sensory receptors

1) Bipolar: 1 axon and 1 dendrite
2) Somatosensory: brings sensory info in from body to spinal cord

Question 9

Interneurons (2 types)

Answer 9

also called association cells; they link sensory and motor information and branch widely

1) Pyramidal cell: long axon, pyramid body and 2 dendrite sets
2) Purkinje cell: extremely branched with a fan shape (info from cerebellum)

Question 10

Motor neurons

Answer 10

extensive dendritic networks, large cell bodies and axons; located in the lower brainstem and spinal cord

Question 11

Glial cell

Answer 11

provides insulation, nutrients and support that aids in repairing neurons and eliminating waste products; 5 types; can result in tumors

Question 12

Ependymal cell

Answer 12

a glial cell that makes and secretes CSF; found on the walls of the ventricles

Question 13

Astrocyte cell

Answer 13

glial cell that is star shaped; provides structural support to CNS and transports nutrients; located in the blood brain barrier; enhance brain activity and healing

Question 14

Microglia

Answer 14

a glial cell that originates in the blood and aids in cell repair and scavenging debris; essentially immune cells that multiply in response to injury/disease; sensitive to K+

Question 15

Oligodendroglia

Answer 15

a glial cell that myelinates axons in the CNS

Question 16

Schwann cells

Answer 16

a glial cells that myelinate sensory and motor axons in the PNS; function as “sign posts” for when axons are severed; decay in MS

Question 17

Myelin

Answer 17

coating that surrounds axons; prevents adjacent neurons from short circuiting and allows for fast movement of impulses

Question 18

Lysosome

Answer 18

transport incoming supplies and remove/store wastes

Question 19

Cell membrane

Answer 19

double layer; regulates movement in and out of cell; phospholipid bilayer

Question 20

Genes

Answer 20

DNA segment that encodes synthesis of a particular protein; thousands of genes in each chromosome

Question 21

Chromosome’s and their components (4)

Answer 21

double strand of DNA; adenine-thymine & guanine-cytosine

Question 22

Protein Manufacturing (3)

Answer 22

1) DNA opens up and is a template for RNA to be formed (transcription)
2) mRNA carries protein code to endoplasmic reticulum
3) Ribosome translates mRNA into amino acids (protein molecules) (translation)

Question 23

Protein

Answer 23

folded up polypeptide chain that serves a particular function in the body

Question 24

Golgi Body function

Answer 24

“wraps” and labels the proteins based on location they are being sent to

Question 25

Channel

Answer 25

opening in a protein embedded in the cell membrane that allows for the passage of specific ions

Question 26

Gate

Answer 26

protein in cell membrane that allows substances to pass through the membrane on some occasions but not others

Question 27

Pump

Answer 27

actively transports a substance across the membrane (a protein)

Question 28

Allele

Answer 28

alternative form of a gene; a gene pair contains 2 alleles

Question 29

Homozygous vs Heterozygous

Answer 29

having 2 identical alleles for a trait vs having 2 different alleles for a trait

Question 30

Mutation

Answer 30

alteration of an allele that yields a different version of its protein

Question 31

Tay Sachs Disease

Answer 31

loss of genes that code the breakdown of certain lipids in the brain; intellectual disability and death by 5; recessive allele on the 15th chromosome

Question 32

Huntington Disease

Answer 32

build up of huntingtin protein that kills brain cells; involuntary movements, dementia and death; dominant allele on chromosome 4

Question 33

Transgenic techniques

Answer 33

one or more gene is introduced or removed from a species to alter what is passed on and expressed (knock in vs knock out)

Question 34

Gene (DNA) methylation

Answer 34

methyl group attaches to a DNA sequence, suppressing or enabling expression (transcription is blocked or enabled)

Question 35

Histone modification

Answer 35

disables the unspooling of DNA or allows for it to happen