TEST BANK For Principles of Human Physiology, 6th Edition by
Stanfield
Direct communication - ANSWER:Gap junctions
Ligand - ANSWER:Molecules that bind to proteins reversibly
Indirect communication - ANSWER:Chemical messengers
Chemical messenger steps - ANSWER:1. Messenger is produced by source cell
2. Messenger is released, often by secretion
3. Messenger travels to the target cell
4. Target cells has receptors
5. Messenger binds to target cell receptors and triggers a response
6. Communication is indirect
3 classifications of chemical messengers - ANSWER:Paracrine
Neurotransmitter
Hormone
Paracrines - ANSWER:chemicals that communicate with neighboring cells. Target cell
must be close enough to be reached by simple diffusion.
Paracrine includes: - ANSWER:Amines, peptides/proteins, eicosanoids
Neurotransmitter includes - ANSWER:Amino acids, amines, peptides/proteins
Hormones include: - ANSWER:Amines, steroids, peptides/proteins
Example of paracrine - ANSWER:Histamine
Histamine - ANSWER:Important in allergic reactions and inflammation. Secreted by
mast cells.
Autocrine chemical messenger - ANSWER:A subclass of paracrines
Chemical that signals the same cell that secreted it
Source and target are the same
Synaptocrine chemical messenger - ANSWER:Produced by neurons and released into
the ECF of the synaptic cleft.
Chemical that signals between neurons. Communication within the synapse
Example of synaptocrine - ANSWER:Neurotransmitters Acetylcholine, GABA,
serotonin
, These 2 chemical messengers do not enter the blood - ANSWER:Paracrine and
autocrine
Examples of hormones: - ANSWER:insulin, adrenaline, thyroxin
Chemical messenger produced by endocrine cells - ANSWER:Hormone
Chemical messenger secreted into the blood via interstitial fluid - ANSWER:Hormone
Neurohormone - ANSWER:Produced by neurons and secreted into the blood
Examples of neurohormone: - ANSWER:ADH, oxytocin
Lipophobic ligand - ANSWER:Water soluble; not lipid soluble
Does not cross the cell membrane
Receptors on the cell membrane
General action of target response: enzyme activation, membrane permeability
changes
Lipophillic ligand - ANSWER:Lipid soluble.
Easily crosses cell membrane.
Has intracellular receptors.
General action of target response is via gene activation.
Amino acids made from glucose - ANSWER:Glutamate, aspartate
Amino acid made from 3-phosphoglycerate - ANSWER:Glycine
Amino acid made from glutamate - ANSWER:Glutamic acid decarboxylase (GABA)
3 things to know about Amino acids - ANSWER:Synthesized within a neuron
Stored in vesicles until needed
Released by exocytosis
Amines - ANSWER:Made or derived from an amino acid
Target receptors on cell membrane
Most or lipophobic (except thyroid hormones)
Peptide/protein messengers - ANSWER:***-Most abundant type of ligand***
-Lipophobic
-Target receptors on the cell membrane
-Made of chains of amino acids
--Peptide ligand (<50 amino acids)
--Protein ligand (>50 amino acids)
Steroid ligands - ANSWER:Lipophilic
Stanfield
Direct communication - ANSWER:Gap junctions
Ligand - ANSWER:Molecules that bind to proteins reversibly
Indirect communication - ANSWER:Chemical messengers
Chemical messenger steps - ANSWER:1. Messenger is produced by source cell
2. Messenger is released, often by secretion
3. Messenger travels to the target cell
4. Target cells has receptors
5. Messenger binds to target cell receptors and triggers a response
6. Communication is indirect
3 classifications of chemical messengers - ANSWER:Paracrine
Neurotransmitter
Hormone
Paracrines - ANSWER:chemicals that communicate with neighboring cells. Target cell
must be close enough to be reached by simple diffusion.
Paracrine includes: - ANSWER:Amines, peptides/proteins, eicosanoids
Neurotransmitter includes - ANSWER:Amino acids, amines, peptides/proteins
Hormones include: - ANSWER:Amines, steroids, peptides/proteins
Example of paracrine - ANSWER:Histamine
Histamine - ANSWER:Important in allergic reactions and inflammation. Secreted by
mast cells.
Autocrine chemical messenger - ANSWER:A subclass of paracrines
Chemical that signals the same cell that secreted it
Source and target are the same
Synaptocrine chemical messenger - ANSWER:Produced by neurons and released into
the ECF of the synaptic cleft.
Chemical that signals between neurons. Communication within the synapse
Example of synaptocrine - ANSWER:Neurotransmitters Acetylcholine, GABA,
serotonin
, These 2 chemical messengers do not enter the blood - ANSWER:Paracrine and
autocrine
Examples of hormones: - ANSWER:insulin, adrenaline, thyroxin
Chemical messenger produced by endocrine cells - ANSWER:Hormone
Chemical messenger secreted into the blood via interstitial fluid - ANSWER:Hormone
Neurohormone - ANSWER:Produced by neurons and secreted into the blood
Examples of neurohormone: - ANSWER:ADH, oxytocin
Lipophobic ligand - ANSWER:Water soluble; not lipid soluble
Does not cross the cell membrane
Receptors on the cell membrane
General action of target response: enzyme activation, membrane permeability
changes
Lipophillic ligand - ANSWER:Lipid soluble.
Easily crosses cell membrane.
Has intracellular receptors.
General action of target response is via gene activation.
Amino acids made from glucose - ANSWER:Glutamate, aspartate
Amino acid made from 3-phosphoglycerate - ANSWER:Glycine
Amino acid made from glutamate - ANSWER:Glutamic acid decarboxylase (GABA)
3 things to know about Amino acids - ANSWER:Synthesized within a neuron
Stored in vesicles until needed
Released by exocytosis
Amines - ANSWER:Made or derived from an amino acid
Target receptors on cell membrane
Most or lipophobic (except thyroid hormones)
Peptide/protein messengers - ANSWER:***-Most abundant type of ligand***
-Lipophobic
-Target receptors on the cell membrane
-Made of chains of amino acids
--Peptide ligand (<50 amino acids)
--Protein ligand (>50 amino acids)
Steroid ligands - ANSWER:Lipophilic
