Phizz chapter 5, chemical messengers Flashcards
1
Q
what are the 4 types of chemical messengers?
A
- autocrine
- paracrine
- neurotransmitters
- endocrine
2
Q
what does autocrine chemical messengers do?
A
- secreted by cells in a local area, influences the activity of the same cell or cell type from which it was secreted
3
Q
what does paracrine chemical messenger do?
A
- produced by a wide variety of tissues and secreted into the extracellular fluid
- has a localized effect on other tissues
4
Q
describe the action of neurotransmitters?
A
- produced by neurons and secreted into the synaptic cleft, by presynaptic nerve terminals
- travels short distances, influences postsynaptic cells
5
Q
describe the action of endocrine as a chemical messengers
A
- secreted into the blood by specialized cells
- travels some distance to target tissues
- results in coordinated regulation of cell function
6
Q
what are gap junctions composed of?
A
- membrane proteins
7
Q
what do gap junctions do?
A
- Link the cytosol of two adjacent cells
- Particle movement between cells acts as a signal
- Communication is direct
- Common in smooth and cardiac muscle
8
Q
what are the 6 steps of chemical messengers?
A
- The messenger is produced by the source cell
- The messenger is released, often by secretion
- The messenger travels to the target cell
- The target cell has receptors for the messenger
- Binding of the messenger to the receptor triggers
a target cell response - Communication is indirect
9
Q
what are the two types of classifications of chemical messengers?
A
- Classification by function
- Classification by chemical properties
* Solubility properties
* Chemical class
10
Q
what are all the chemical Messenger Classification by Function?
A
- Paracrine chemical messenger
- Autocrine chemical messenger
- Neurotransmitter
- Hormone
- Neurohormone
11
Q
what is the function of Paracrine chemical messenger?
A
- Chemical that signals a nearby cell
- Example: Histamine, responsible for an inflammation
response
12
Q
what is the function of Autocrine chemical messenger?
A
- subclass of paracrine
- chemical that signals the same cell source or target
- source and target that are the same
13
Q
what is the function of a neurotransmitter?
A
- messenger produced by neurons
- released into the ECE