Transcript Action Potential or Nerve Impulse

Week #3 (1/19 – 1/22)
Warm Up – Tues, 1/19:
- Game of Telephone
Pick up:
Action Potential
notes
Anatomy Fun Fact:
Neurons, which are the
largest cells in the
human body, do not
undergo the process of
mitosis.
- Why is this important to
know?
Agenda:
1. Finish Reflex Lab and Abstract
Discussion
2. Begin Action Potential notes
Homework:
1.
Reflex Lab
Abstract (5I) –
MOVED Mon,
1/25
2. Action Potential
Quiz – Fri, 1/22
• In your lab groups,
• 20 mins –
• Share out any data that was gathered at home (V/K Test)
• Complete ANY remaining tests
• Complete your group’s answers to ALL FOLLOWQUESTIONS (in complete sentences)!
• When finished with a test,
• Clean your station by putting EVERYTHING
back in the tub,
• Turn in your group’s Reflex Lab data/answers to the
Hmwk Bin!
• Return to the front & begin working on Ch. 14 Tour (Brain) .
• If you writing this lab as an Abstract, make sure you take down your
groups’ data & answers to questions!
UP
Quickest Reaction Time
Analysis Questions:
1.
Explain your observations of the Patellar reflex using your knowledge of a
Reflex Arc. Did each group member have the reflex? Do you think the
patellar reflex is a monosynaptic or polysynaptic reflex arc? Back your
answer up.
2.
Describe the Reflex Arc involved in the direct Pupillary Light Reflex &
Consensual Pupillary Light Reflex. Label each component with specific
organ names. What cranial nerves play a role in this reflex? Identify them
by name & Roman Numeral.
3.
Explain the protective function of Pupillary Light Reflex & Uvular Reflex (be
specific).
Analysis Questions:
4. Describe which division of the peripheral nervous system (ANS or SNS) are
employed for each reflex (Patellar, Visual/kinesthetic, Uvular & Pupillary)?
Defend your answers.
5.
Describe the differences of neural communication between the ANS & SNS
neuron systems (monosynaptic? polysynaptic?)
6.
Discuss the accuracy of your smell sense. Which sense is more accurate
without the assistance of sight…smell or taste? Scientifically explain your
answer.
7.
Investigate & discuss thoroughly, using A & P
terminology, 1 additional reflex most humans
have, not investigated during the lab.
- Must provide a Works Cited page in MLA.
• DUE: Mon, 1/25
• Title Page: Title of Lab, Name, Date, Period
• Data & Observations:
• Data Table(s) with collected Reflex test(s) info for each
of your group members
• Conclusions & Applications:
• Answers to Analysis Questions 1-7 (in paragraph form)
• Case Study: Actual application in which reflex has
helped keep someone alive/healthy
• MLA Works Cited
• Let’s play a game of “Telephone”! I’ll start by giving a message
to….
• In a Reflex Arc, what role are you & I playing (hint: it’s a cell)?
• Neurons
• In anatomy, what is the space between each communicator
called?
• Synaptic cleft or synapse
• Was the message sent successfully?
• If not, why not?
How many parts were there to communicating the message?
1st: the person had to receive it (listening) – role of the dendrites of a neuron
2nd: the listener had to process the information (understanding the context of the
words) –
role of the
soma/cell body
3rd: the person
had to send the
message
(speaking/
sending it to the
next person) –
role of the axon
Understanding
• Information from one neuron flows to another neuron across a
synapse/synaptic cleft…
• a small gap separating
neurons that consists of:
• a presynaptic ending
(axon terminals) that
contains neurotransmitters
(NTs), mitochondria &
other organelles,
• a postsynaptic ending
(dendrites) that contains
receptor sites for NTs &
• a synaptic cleft or space
between the presynaptic
& postsynaptic endings.
Week #3 (1/19 – 1/22)
Warm Up – Wed, 1/20 & Thurs, 1/21:
Turn in:
Anatomy Fun Fact:
Have out:
- Review of Intro to NS
The sciatic nerve is the largest
in the human body, about as
thick as a pencil (~0.78 in). It
is composed of nerve fibers
(collection of neurons) that run
from the spinal cord to & down
the back of each leg.
Agenda:
1.
Action Potential/Getting the Message
across the Synapse lecture
2. Analyzing the Change in Impulse
3. Begin Pushing the Limits: Brain Power
Group lab handout –
Reflex lab (fastest one
in group)
Action Potential notes
Pick up:
Analyzing the Change in
Impulse wkst
4 different colored
pencils
Homework:
1.
2.
3.
Reflex Lab Abstract
(5I) – Fri, 1/24
Syn. Pot. & NT
Review wkst – Fri,
1/24
Action Potential Quiz
– Fri, 1/24
Warm-up: Intro to NS
Review
• What organs are
included in the CNS?
• What are the 3 main
parts of a neuron?
• What is the function of
the dendrites? Cell
body? Axon?
• What does SNS stand for
& what kind of tissue
does it control?
• Are reflexes controlled
by the SNS
monosynaptic or
polysynaptic?
BIOLOGY REVIEW:
What is the process of
Diffusion?
• When it comes to understanding
how neurons communicate
(Action Potential or Nerve
Impulse), you must understand
how the process of diffusion
works!
• Diffusion Animation
• Particles move down their
concentration gradients (from
high to low)
• Is it an active or passive form of
transporting dissolves nutrients?
• Passive – NO ATP REQUIRED!
• Also known as “Nerve Impulses”
• Self-regenerating wave of
electrochemical activity that allows
neurons to carry a signal over a
distance (“game of telephone”)
• Pulse-like waves of voltage that
travel along several types of cell
membranes
• Analogy – assume students are POSITIVELY-CHARGED
Na & K IONS!
• Initiation/Resting Stage:
• Outside the classrooms (neuron) vs. inside classrooms (neuron)
• At 7:20 a.m., more students are arriving to school than are sitting
in a “0” hr class
• So the inside of the classrooms (neurons) have a “negative”
polarity.
• Initiation/Resting Stage:
▫ Some K+ channels are open: K+ diffusion occurring (out)
▫ Initiated by stimulus above a certain intensity or threshold
(~-70mV – resting potential)
▫ Could be a pin prick, light, heat, sound or an electrical disturbance
in another part of the neuron (“telephone call”)
▫ Electrical signal rises from changes in permeability of the
neuron’s axon membranes to
specific ions (Na+ & K+)
• Analogy – assume students are POSITIVELY-CHARGED Na & K
IONS!
 **Depolarization (Rising Phase):
• Outside the classrooms vs. inside classrooms
• First bell rings & students move from the
into the classrooms
• This gives the inside of the classroom
more “positive” polarity.
• Depolarization: Becoming less negative
• (closer to 0 from -70 or “negative polarity”
halls
(neuron) a
 **Depolarization (Rising Phase)
 K+ Channel gates are closed
 Stimulus causes gate in the Na+ Channel to open
 High concentration of Na+ outside, Na+ diffuses into neuron
 Electrical potential changes to ~ +40 mV
• Analogy – assume students are POSITIVELY-CHARGED
Na & K IONS!
 **Repolarization (Falling Phase):
• Outside the classrooms vs. inside classrooms
• Dismissal bell rings & students leave the
classroom & enter the halls
• This gives the inside of the classroom
(neuron) a “negative” polarity again.
• Repolarization: Restoring to original state
of voltage
 Repolarization (Falling Phase)
 Depolarization causes K+ Channel gates to immediately open &
Na+ Channels close
 K+ diffuses out of neuron
 Reestablishment of initial electrical potential
of ~-60 mV
 Refractory Period (Recovery Phase)
 Na+ & K+ Channels cannot be opened by a
stimulus
 Na+/K+ Pump actively (ATP required) pumps
Na+ out of & K+ into neuron (against/up their
concentration gradients)
 Reestablishment of ion distribution of
resting neuron
 This AP acts as stimulus to neighboring proteins
within neuron membrane & initiates AP in
another part of neuron
 Wave of APs travel from dendrites to axon
terminals
 At axon terminal, electrical impulse is converted
to a chemical signal (neurotransmitter)
The End
Action Potential
animation
Pushing the Limits – Brain Power
• Title your paper “Pushing the Limits:
Brain Power Facts” paper & have out a
pen/pencil.
• Identify & explain at least 10 new
concepts/ideas/facts you learn
about the human brain/mind from
the video.
• Add these to your paper!
Week #3 (1/19 – 1/22)
Warm Up – Fri, 1/22:
- Action Potential Review
Anatomy Fun Fact:
An action potential (nerve impulse) is very quick &
has the ability of transmitting impulses at the
speed of 100 meters/second. The speed of
message transmission to the brain can be as high
as 180 mph.
Pick up:
Ch. 14 Tour
Turn in:
Reflex Lab Abstract
(5I)
Have out:
Syn. Pot. & NT Review
wkst
Action Potential notes
Homework:
1.
Agenda:
1.
2.
Finish Action Potential notes
Finish Pushing the Limits: Brain Power video
2.
3.
Syn. Pot. & NT
Review wkst - Wed,
1/29 & Thurs, 1/30
(MOVED)
Action Potential Quiz
- Wed, 1/29 & Thurs,
1/30 (MOVED)
Ch. 14 Tour – Wed,
1/29 & Thurs, 1/30
• Getting the message
across (the synapse)?
• At axon terminal, chemical
signal (NT) crosses synapse
between adjacent neurons
• Starts AP on this neuron
• This activates Ca2+ channel to open
• Ca2+ diffuses into neuron
• Causes NT vesicles to move to end & fuse with cell membrane
• Through exocytosis, NTs are released into synapse
• NTs diffuse across synapse & bind to NT receptors on
another neuron
• Causes Na+ channels to open & AP is initiated in next neuron
Let’s Review…
How do neurons communicate?
• Action potential animation (~3 mins)
• What is another name for the nerve impulse that travels from the
cell body down the axon to the axon terminal?
• What happens in the Rising Phase/
Depolarization?
• Falling Phase/Repolarization?
• Recovery Phase/Refractory Phase?
• Once the AP has reached the axon
terminal, what ion entering the
instigates the movement of
synaptic vesicles to the cell
membrane?
• What do the vesicles release into
the synapse?
neuron
Pushing the Limits – Brain Power
• Title your paper “Pushing the Limits:
Brain Power Facts” paper & have out a
pen/pencil.
• Identify & explain at least 10 new
concepts/ideas/facts you learn
about the human brain/mind from
the video.
• Add these to your paper!