Animal Physiology - Chapters 48, 43, 11
Animals employ a number of body systems to maintain homeostasis. The nervous and endocrine
systems work coordinately to respond to changes in an organism’s internal and external
environment. The immune system responds to pathogens. The cells that make up these systems use a
number of mechanisms to communicate with each other. Messages are received and decoded by cells
through signal-transduction pathways. The messages may tell a cell to divide, express a gene, undergo
apoptosis, or differentiate.
Learning Objectives
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describe the structure of a neuron
explain how sodium-potassium pumps are involved in generating action potentials
summarize the organization of the human nervous system
distinguish between innate and adaptive immunity
describe the humoral immune response and cell-mediated immune response
summarize the function of immunizations
distinguish between and provide examples of transmembrane receptors
describe mechanisms of signal transduction
Vocabulary
neuron
PNS
parasympathetic division
sympathetic division
enteric division
CNS
nerves
sensory neuron
motor neuron
interneuron
cell body
axon
dendrites
synapse
neurotransmitters
glial cells
nodes of Ranvier
synaptic terminals
membrane potential
resting potential
ion channels
action potential
voltage-gated ion channel
refractory period
innate immunity
adaptive immunity
neutrophil
macrophage
dendritic cell
natural killer cell
interferon
complement system
inflammatory response
mast cell
histamine
cytokines
lymphocytes
thymus
T cells and B cells
antigen
epitope
antibody (immunoglobulin)
effector cell
memory cell
primary immune response
secondary immune response
humoral immune response
cell-mediated immune response
cytotoxic T cell
plasma cell
active immunity
passive immunity
immunization
signal transduction pathway
local regulators
hormones
reception
transduction
ligand
G-protein-coupled receptor
G protein
receptor tyrosine kinases
ligand-gated ion channel
transcription factor
intracellular receptor
ATP
ADP
phosphorylation
dephosphorylation
protein kinase
protein phosphatases
second messengers
adenylyl cyclase
cyclic AMP (cAMP)
Ca
signal amplification
scaffolding proteins
paracrine signaling
synaptic signaling
2+
Analysis Questions
1.
Describe the basic pathway of information flow through neurons that causes you to turn your head
when someone calls your name.
2.
Suppose a cell’s membrane potential shifts from -70mV to -50mV. What changes in the cell’s
permeability to K+ and Na+ could cause such a shift?
3.
Ouabain, a plant substance used in some cultures to poison hunting arrows, disables the
sodium-potassium pump. What changes in the resting potential would you expect to see if you
treated a neuron with Ouabain? Explain.
4.
Why is the adaptive immune response to an initial infection slower than the innate response?
5.
Describe two advantages of having memory B cells when a pathogen is encountered for the first
time.
6.
Suppose that a snake handler bitten by a particular venomous snake species was treated with
antivenin. Why might the same treatment for a second such bite have different results?
7.
How do your lymphocytes distinguish between what is your cells (self) and what is not
(non-self)?
8.
The human immunodeficiency virus (HIV) infects helper T cells, macrophages, and dendritic
cells. Explain how lower numbers of these leukocytes are likely to affect the performance of
immune system. In your explanation, discuss whether the HIV has a greater effect on the humoral
immune response or cell-mediated response.
9.
What determines whether a cell responds to a hormone such as epinephrine? What determines
how a cell responds to such a hormone?
10.
How are the structures of a GPCR and a RTK similar? In what key way does triggering of signal
transduction pathways differ for these two types of receptors?
11.
What is the difference between a protein kinase and a second messenger? Can both types of
molecules operate in the same signal transduction pathway?
12.
What mechanisms in the cell terminate its response to a signal and maintain its ability to respond
to new signals?