1 Physiology Exam 1 Study Chapter 6 Communication & homeostasis

2 What are the two basic physiological signals?

3 -Chemical -Electrical

4 What are the basic methods of cell-cell communication?

5 -Direct cytoplasmic transfer- Gap junctions -Contact-dependent signals -Local communication -Long distance communication

6 Which method of cell-to-cell communication occurs by chemicals that diffuse through the extracellular fluid?

7 -Local Communication

8 This method of cell-to-cell communication involves the transfer of chemical and electrical signals between adjacent cells.

9 -Gap junctions

10 Where would you expect to find Gap Junctions in the body?

11 -Heart -Smooth muscle of the GI tract

12 What are the cells that receive electrical or chemical signals called?

13 -Target Cells

14 What is the simplest form of cell-to-cell communication?

15 -Gap junctions

16 A gap junction forms from the union of membrane- spanning proteins called____.

17 -Connexon

18 When do connected cells function like a synctium?

19 -When the gap junction (connexon) is open.

20 What is the only means by which electrical signals can pass directly from cell to cell?

21 -Gap junctions

22 What method of cell-to-cell communication utilize Cell Adhesion Molecules (CAMs) to transfer signals?

23 -Contact Dependent

24 How is local cell-to-cell communication accomplished?

25 -Paracrine signaling -Autocrine signaling

26 If a chemical signal acts on the cell that secreted it, it is called an _____ signal.

27 -Autocrine

28 If a chemical acts on cells in the immediate vicinity of the cell that secreted it, its is called ____ signal.

29 -Paracrine

30 If a cell secretes chemicals that act on distal cells it is a ____ signal.

31 -Endocrine

32 What is secreted by neurons to act on itself or neighboring cells?

33 -Neuromodulators

34 What are regulatory substances that mediate immune responses?

35 -Cytokines

36 Why are paracrine and autocrine signals only able to reach adjacent cells?

37 -Because both of these signals reach their targets by diffusing through the interstitial fluid. Diffusion is limited by distance.

38 Most long-distance communication between cells is the responsibility of what two organ systems?

39 -Nervous system -Endocrine system

40 An electrical signal travels along a ___ until it reaches the very end of the cell, where it is translated into a ____.

41 Neuron, Neurocrine

42 If a neurocrine diffuses into the blood it is called a ____.

43 Neurohormone

44 If a neurocrine acts more slowly as an autocrine or paracrine signal, it is called a ______.

45 Neuromodulator

46 If a neurocrine has a rapid effect it is called a _____.

47 Neurotransmitter

48 What are Cytokines?

49 Cytokines are regulatory peptides that act close to the site where they secreted.

50 True or False? Cytokines are stored much like hormones?

51 False (Cytokines are produced on demand.)

52 True or False? A cytokine can act as an autocrine and a paracrine.

53 -True

54 Where are receptor proteins located?

55 -Cytosol -Cell membrane -Nucleus

56 This type of receptor mimics the effect of the naturally occuring ligand?

57 -Agonist

58 Are First Messengers Lipophilic or Lipophobic?

59 -Lipophilic, they are able to enter the cell.

60 Which signal molecule is unable to enter the cell?

61 -Lipophobic

62 What are the four classes of membrane receptors?

63 -Ligand-gated ion channels -Intergrin linked to cytoskeleton -G protein-coupled receptor with seven membrane -Receptor Enzyme

64 What is the result of a ligand binding to a ligand gated channel?

65 -Channel opens or closes

66 Which type of regulation results in the reduction in the number of receptors and/or binding affinity for the ligand?

67 Down- regulation

68 What is the result of a ligand binding to a G protein coupled receptor?

69 -The G-protein receptor opens an ion channel or alters enzyme activity

70 Which membrane receptor results in the activation of an intracellular enzyme?

71 -Enzyme receptor

72 Which membrane receptor result in a change to the cytoskeleton?

73 -Intergrin

74 Which of the four categories of membrane receptors do NOT use signal transduction?

75 -Ligand gated