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Physiology
Exam 1 Study
Chapter 6 Communication
& homeostasis
1
What are the two basic
physiological signals?
2
-Chemical
-Electrical
3
What are the basic
methods of cell-cell
communication?
4
- Direct cytoplasmic transferGap junctions
- Contact-dependent signals
- Local communication
- Long distance communication
5
Which method of cell-to-cell
communication occurs by
chemicals that diffuse
through the extracellular
fluid?
6
-Local
Communication
7
This method of cell-to-cell
communication involves the
transfer of chemical and
electrical signals between
adjacent cells.
8
-Gap junctions
9
Where would you expect to
find Gap Junctions in the
body?
10
-Heart
-Smooth muscle of
the GI tract
11
What are the cells that
receive electrical or chemical
signals called?
12
-Target Cells
13
What is the simplest form of
cell-to-cell communication?
14
-Gap junctions
15
A gap junction forms from
the union of membranespanning proteins
called____.
16
-Connexon
17
When do connected cells
function like a synctium?
18
-When the gap
junction (connexon)
is open.
19
What is the only means by
which electrical signals can
pass directly from cell to
cell?
20
-Gap junctions
21
What method of cell-to-cell
communication utilize Cell
Adhesion Molecules (CAMs)
to transfer signals?
22
-Contact
Dependent
23
How is local cell-to-cell
communication
accomplished?
24
-Paracrine signaling
-Autocrine signaling
25
If a chemical signal acts on
the cell that secreted it, it is
called an _____ signal.
26
-Autocrine
27
If a chemical acts on cells in
the immediate vicinity of the
cell that secreted it, its is
called ____ signal.
28
-Paracrine
29
If a cell secretes chemicals
that act on distal cells it is a
____ signal.
30
-Endocrine
31
What is secreted by neurons
to act on itself or neighboring
cells?
32
-Neuromodulators
33
What are regulatory
substances that mediate
immune responses?
34
-Cytokines
35
Why are paracrine and
autocrine signals only able to
reach adjacent cells?
36
- Because both of these
signals reach their targets
by diffusing through the
interstitial fluid. Diffusion
is limited by distance.
37
Most long-distance
communication between cells
is the responsibility of what
two organ systems?
38
-Nervous system
-Endocrine system
39
An electrical signal travels
along a ___ until it reaches
the very end of the cell,
where it is translated into a
____ .
40
Neuron,
Neurocrine
41
If a neurocrine diffuses into
the blood it is called a ____.
42
Neurohormone
43
If a neurocrine acts more
slowly as an autocrine or
paracrine signal, it is called a
______.
44
Neuromodulator
45
If a neurocrine has a rapid
effect it is called a _____.
46
Neurotransmitter
47
What are Cytokines?
48
Cytokines are regulatory
peptides that act close to
the site where they
secreted.
49
True or False? Cytokines are
stored much like hormones?
50
False
(Cytokines are produced
on demand.)
51
True or False? A cytokine
can act as an autocrine and a
paracrine.
52
-True
53
Where are receptor proteins
located?
54
-Cytosol
-Cell membrane
-Nucleus
55
This type of receptor mimics
the effect of the naturally
occuring ligand?
56
-Agonist
57
Are First Messengers
Lipophilic or Lipophobic?
58
-Lipophilic, they
are able to enter
the cell.
59
Which signal molecule is
unable to enter the cell?
60
-Lipophobic
61
What are the four classes of
membrane receptors?
62
- Ligand-gated ion channels
- Intergrin linked to cytoskeleton
- G protein-coupled receptor with
seven membrane
- Receptor Enzyme
63
What is the result of a ligand
binding to a ligand gated
channel?
64
-Channel
opens or closes
65
Which type of regulation
results in the reduction in
the number of receptors
and/or binding affinity for
the ligand?
66
Downregulation
67
What is the result of a ligand
binding to a G protein
coupled receptor?
68
-The G-protein
receptor opens an
ion channel or alters
enzyme activity
69
Which membrane receptor
results in the activation of an
intracellular enzyme?
70
-Enzyme
receptor
71
Which membrane receptor
result in a change to the
cytoskeleton?
72
-Intergrin
73
Which of the four categories
of membrane receptors do
NOT use signal
transduction?
74
-Ligand gated
75