ch15

Question 1

how many unique cell types in humans are there

Answer 1

abt 200

Question 2

the body begins as…

Answer 2

one cell, a zygote

Question 3

zygote

Answer 3

fertilized egg

Question 4

differentiation

Answer 4

a lineage of cells becoming more specialized across generations

occurs over several rounds of stem cell division

Question 5

stem cells

Answer 5

unspecialized cells that can turn into others

Question 6

terminally differentiated

Answer 6

final cells cannot become another type

Question 7

what are the different types of stem cells

Answer 7

embryonic stem cells
adult stem cells

Question 8

embryonic stem cells

Answer 8

can become about any cell type

Question 9

adult stem cells

Answer 9

specific cell types reside in different organs

replenish organ when cells die
can only make a certain type of cell

Question 10

main cell type in the nervous sytem

Answer 10

neurons

Question 11

sensory neurons

Answer 11

recieve info

Question 12

motor neurons

Answer 12

send response out

Question 13

interneurons

Answer 13

relay message from sensory to motor neurons

Question 14

dendrites

Answer 14

projections that receive signals

Question 15

axon

Answer 15

long region that message travels along

Question 16

myelin sheath

Answer 16

coating around axon that speeds up signal

Question 17

axon terminals

Answer 17

branches that connect to the end of next neurons

Question 18

synapses

Answer 18

area where neurons connect

Question 19

neurotransmitters

Answer 19

small molecules that send message to next neuron

about 60 in humans

Question 20

action potential

Answer 20

signal sent along axon

Na+ and K+

Question 21

what is the myelin sheath made up of

Answer 21

lipids and proteins

Question 22

glial cells

Answer 22

support cells that take care of neurons

Question 23

blood-brain barrier

Answer 23

brain separated from the blood by a barrier of cells

Question 24

what cell type lines the blood brain barrier vessels

Answer 24

endothelial cells

tightly packed together

Question 25

function of the blood brain barrier

Answer 25

prevent toxins or pathogens from entering brain

Question 26

what cell makes up the pineal gland

Answer 26

pinealocytes

Question 27

what does the pineal gland secrete

Answer 27

melatonin

Question 28

why is the pineal gland more susceptible to blood-borne pollutants

Answer 28

not protected by BBB

Question 29

neurogenesis

Answer 29

creation of new neurons

Question 30

synaptogenesis

Answer 30

formation of new synapses/connection between neurons

Question 31

neurodegeneration

Answer 31

death of neurons

Question 32

three layers of the immune system

Answer 32

barrier defenses innate immune system adaptive immune system

Question 33

what are the barrier defenses of the immune system

Answer 33

skin epithelial cells endothelial cells

Question 34

barrier defenses

Answer 34

protect body from internalization of pathogens

Question 35

innate immune system

Answer 35

cells that offer a GENERAL response to pathogens

Question 36

adaptive immune system

Answer 36

cells that offer a SPECIFIC response to pathogens

Question 37

hematopoietic stem cells

Answer 37

produced by bone marrow differentiates into all other immune cells

Question 38

granulocytes

Answer 38

first responders that promote inflammation sense injury/infection and release granules

Question 39

granules

Answer 39

group of proteins

Question 40

types of granulocytes

Answer 40

neutrophil basophil eosinophil

Question 41

macrophages

Answer 41

eat and destroy pathogens, damaged cells, or debris

Question 42

natural killer cells (NK cells)

Answer 42

recognize infected cells and tumors release cytotoxic molecules to kill cells

Question 43

perforin function

Answer 43

cytotoxic molecule that pokes holes in membrane of target cell

Question 44

T cells

Answer 44

offer SPECIALIZED recognition of foreign or damaged cells have a T Cell Receptor on the surface that recognizes antigens

Question 45

B cells

Answer 45

produces antibodies that surround and eat target cells

Question 46

antibodies

Answer 46

proteins that specifically bind to a target antigen

Question 47

opsonize

Answer 47

surround

Question 48

where do T cells mature

Answer 48

thymus

Question 49

what filters blood and stores B cells

Answer 49

spleen