Multicellular organisms

Question 1

tight junction

Answer 1

stitches the cell plasma membranes together. Like a coffee filter, makes an impermeable membrane to bigger solutes.

Question 2

gap junction

Answer 2

like a hallway. lets materials pass through the hall between the two cells. can be used to couple neighboring cells, pass excitement–like in cardiac and smooth muscle

Question 3

demosome

Answer 3

like a staple, a point connection between cells. anchoring two cells together, very strong because attaching cytoskeletons together. ex. heart and skin

Question 4

hemidesmosome

Answer 4

not a cell-to-cell junction. attaches a cells cytoskeleton to the extracellular matrix

Question 5

epithelial tissue

Answer 5

held together in continuous sheets–epithelium.

Question 6

epithelium

Answer 6

continuous sheets of epithelial tissue. anchored to a thin mat of basement membrane

Question 7

cutaneous membrane

Answer 7

covers body surfaces. stratified because it is acting as a protective barrier

Question 8

serous membranes

Answer 8

cover organs and body cavities. for organs that move a lot, like the heart

Question 9

mucous membranes

Answer 9

line the lumen of hollow organs that are open to the external environment. like the stomach and intestines

Question 10

simple epithelial membranes

Answer 10

stratified for the transport of materials. epithelial cells have structural and functional polarity

Question 11

basolateral side

Answer 11

where you have an underlying basement membrane. thin sheet of extracellular material that the cell is anchored to

Question 12

apical membrane

Answer 12

lumenal membrane. facing the inside of the tube or hollow organ. inside of things=lumen

Question 13

metabotropic receptors use second messenger pathways

Answer 13

Ca2+, cAMP, cGMP, IP3 and DAG

Question 14

Ca2+

Answer 14

Ca2+–>calmodulum–>kinases

Question 15

cGMP

Answer 15

guanylate cyclase–>cGMP–>protein kinase G

Question 16

cAMP

Answer 16

adenlylate cyclase–>cAMP–>protein kinase A

Question 17

IP3 and DAG

Answer 17

Phospholipase C–>PIP2–>IP3 and DAG–> Ca2+ release and activation of protein kinase C

Question 18

benefits of metabotropic receptors

Answer 18

prolonged action, amplify primary message. Each G-protein can activate multiple adenylate cyclase=more cAMP= more kinase activation. Gives a much stronger response because multiple events are happening

Question 19

Hydrophilic chemical messengers

Answer 19

can be synthesized in advance because they can just be stored in vesicles. no need to synthesize on demand. Release via exocytosis. Dissolve in the ECF, bind to transmembrane receptors on the surface of target cell.

Question 20

Hydrophobic chemical messengers

Answer 20

signal cells must be synthesized on demand (can’t be packaged). released via simple diffusion directly across lipid bilayer. transported bound to carrier proteins within the bloodstream. Bind to intracellular receptors, molecules can just diffuse across the plasma membrane without any help

Question 21

Intracellular receptors act as

Answer 21

transcription factors.

Question 22

Activated intracellular receptors

Answer 22

hormone-receptor complex can translocate to the nucleus, make mRNA, translate the protein, then you have a physiological change

Question 23

hydrophilic vs hydrophobic chemical messengers

Answer 23

hydrophilic faster, hydrophobic slower

Question 24

fastest vs slowest chemical messenger pathway

Answer 24

ionotropic–>metabotropic–>hydrophillic–>hydrophobic

Question 25

Intercellular communication must be ___ after it is turned on

Answer 25

terminated. the chemical messenger must be removed/degraded–must no longer have access to receptors

Question 26

buffer base

Answer 26

anything in the body fluids that can act as a buffer

Question 27

buffer base in ECF (interstitual fluid and plasma)

Answer 27

bicarbonate and proteins

Question 28

buffer base in plasma

Answer 28

bicarbonate and proteins

Question 29

buffer base in interstitual fluid

Answer 29

just proteins

Question 30

buffer bases in intracellular fluid (ICF)

Answer 30

proteins and phosphate buffer

Question 31

ECF

Answer 31

high Na+, low K+. contain bicarbonate

Question 32

ICF

Answer 32

low Na+, high K+, phosphate, proteins

Question 33

epithelial tissue cells

Answer 33

specialize in selective exchange of materials/secretion

Question 34

connective tissue cells

Answer 34

structural support, binds everything together. actual cells specialize in secretion

Question 35

muscle tissue cells

Answer 35

specialize in contraction, movement. able to change shape

Question 36

nervous tissue cells

Answer 36

specialize in the rapid transmission of info