Phizz chapter 5, chemical messengers

Question 1

what are the 4 types of chemical messengers?

Answer 1

• autocrine
• paracrine
• neurotransmitters
• endocrine

Question 2

what does autocrine chemical messengers do?

Answer 2

• secreted by cells in a local area, influences the activity of the same cell or cell type from which it was secreted

Question 3

what does paracrine chemical messenger do?

Answer 3

• produced by a wide variety of tissues and secreted into the extracellular fluid
• has a localized effect on other tissues

Question 4

describe the action of neurotransmitters?

Answer 4

• produced by neurons and secreted into the synaptic cleft, by presynaptic nerve terminals
• travels short distances, influences postsynaptic cells

Question 5

describe the action of endocrine as a chemical messengers

Answer 5

• secreted into the blood by specialized cells
• travels some distance to target tissues
• results in coordinated regulation of cell function

Question 6

what are gap junctions composed of?

Answer 6

• membrane proteins

Question 7

what do gap junctions do?

Answer 7

• Link the cytosol of two adjacent cells
• Particle movement between cells acts as a signal
• Communication is direct
• Common in smooth and cardiac muscle

Question 8

what are the 6 steps of chemical messengers?

Answer 8

1. The messenger is produced by the source cell
2. The messenger is released, often by secretion
3. The messenger travels to the target cell
4. The target cell has receptors for the messenger
5. Binding of the messenger to the receptor triggers
   a target cell response
6. Communication is indirect

Question 9

what are the two types of classifications of chemical messengers?

Answer 9

• Classification by function
• Classification by chemical properties
  * Solubility properties
  * Chemical class

Question 10

what are all the chemical Messenger Classification by Function?

Answer 10

• Paracrine chemical messenger
• Autocrine chemical messenger
• Neurotransmitter
• Hormone
• Neurohormone

Question 11

what is the function of Paracrine chemical messenger?

Answer 11

• Chemical that signals a nearby cell
• Example: Histamine, responsible for an inflammation
  response

Question 12

what is the function of Autocrine chemical messenger?

Answer 12

• subclass of paracrine
• chemical that signals the same cell source or target
• source and target that are the same

Question 13

what is the function of a neurotransmitter?

Answer 13

• messenger produced by neurons
• released into the ECE