Lecture 1: Communication, Integration & Homeostasis

Question 1

Responsible for most communication within the body

Answer 1

Chemical signals

Question 2

4 basic methods of communication

Answer 2

Gap junctions, Contact-dependent signals, Direct contact and local cell-to-cell communication, Long distance cell-to-cell communication

Question 3

Form direct cytoplasmic connections between adjacent cells

Answer 3

Gap junctions

Question 4

Require interaction between membrane molecules on two cells

Answer 4

Contact-dependent signals

Question 5

Direct contact and local cell-to-cell communication

include what signals?

Answer 5

Autocrine and paracrine

Question 6

This type of cell-to-cell communication involves neurotransmitters, which are chemicals secreted by neurons that diffuse across a small gap to the target cell

Answer 6

Long distance cell-to-cell communication

Question 7

_____________ may act as both local and long-distance signals

Answer 7

Cytokines

Question 8

All ___________ synthesize and secrete cytokines in response to stimuli

Answer 8

Nucleated cells

Question 9

4 categories of membrane receptors that are for lipophobic signal molecules

Answer 9

Receptor-channel, receptor-enzyme, G-protein-coupled receptor, integrin receptor

Question 10

__________ convert extracellular signals into intracellular messages which create a response

Answer 10

Transducers

Question 11

____________ converts chemical signals into cellular responses

Answer 11

Biological signal transduction

Question 12

Steps of signal transduction pathway form a cascade. _______ provides an example of this

Answer 12

Blood clotting

Question 13

A three-part transducer molecule

Answer 13

G protein

Question 14

When G proteins are activated, they open ___________ in the membrane and alter ____________ on the cytoplasmic side of the membrane

Answer 14

Ion channels; Enzyme activity

Question 15

Ca2+ binds to the protein _________, found in all cells, and alters enzyme or transport activity or gating of ion channels

Answer 15

Calmodulin

Question 16

__________ regulates protein troponin, which initiates muscle contraction in skeletal muscles

Answer 16

Calcium

Question 17

Ca2+ binds to regulatory proteins to trigger _________ and neurotransmitter release

Answer 17

Vesicular fusion

Question 18

Ca2+ binds directly to ___________ to alter gating states

Answer 18

Ion channels

Question 19

Ca2+ entry into the fertilized egg initiates development of the ____________

Answer 19

Embryo

Question 20

Electrical signal: ACh receptor binds ACh, and allows sodium into the cell along a gradient, thus __________ the cell

Answer 20

Depolarizing

Question 21

Skeletal muscles mechanism for contraction involves what type of signal?

Answer 21

Electrical

Question 22

Novel signal molecules

Answer 22

Calcium, Nitric oxide (NO), Carbon monoxide (CO), hydrogen sulfide, lipids

Question 23

Calcium as an intracellular messenger can alter protein activity and cause _________

Answer 23

Exocytosis

Question 24

NO activates __________, which forms ________

Answer 24

Guanylyl cyclase; cGMP

Question 25

NO is produced by endothelial cells, and diffuses into smooth muscle and causes ______________

Answer 25

Vasodilation

Question 26

The enzyme __________ catalyzes the formation of nitric oxide from arginine.

Answer 26

Nitric oxide synthase (NOS)

Question 27

Carbon monoxide (CO)
also activates \_\_\_\_\_\_ and cGMP

Answer 27

Guanylyl cyclase

Question 28

CO targets smooth muscle and ________

Answer 28

Neural tissue

Question 29

Hydrogen sulfide targets the cardiovascular system, causing ______

Answer 29

Vasodilation

Question 30

The arachidonic acid cascade produces ___________ messengers

Answer 30

Lipid

Question 31

The primary
ligand activates
a receptor, and an _____ also activates
the receptor

Answer 31

Agonist

Question 32

An __________
blocks receptor
activity

Answer 32

Antagonist

Question 33

Target response depends on the target receptor: Epinephrine causes _______ on the alpha-receptor of intestinal blood vessels and __________ on the beta-receptor of skeletal muscle blood vessels

Answer 33

Vasoconstriction; vasodilation

Question 34

Up-regulation: With increased signal (ligand), there is an initial _________ response, but cells may attempt to bring their response back to normal by either _______ or desensitization

Answer 34

Increased; Down-regulation

Question 35

Down-regulation occurs by decreasing the number of ________ and by decreasing the __________. This is one explanation for _______

Answer 35

Receptors; Binding affinity; drug tolerance

Question 36

Which type of Cell to Cell contact involves direct transfer of ions, chemical and electrical signals?

Answer 36

Gap junctions

Question 37

True or False: GPRC pathways always result in signal amplification.

Answer 37

True