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The infamous box jellyfish developed its frighteningly powerful venom to instantly stun or kill prey, like fish and shrimp, so their struggle to escape wouldn’t damage its delicate tentacles.
Their venom is considered to be among the most deadly in the world, containing toxins that attack the heart, nervous system, and skin cells. It is so overpoweringly painful, human victims have been known to go into shock and drown or die of heart failure before even reaching shore. Survivors can experience considerable pain for weeks and often have significant scarring where the tentacles made contact.
Box jellies, also called sea wasps and marine stingers, live primarily in coastal waters off Northern Australia and throughout the IndoPacific. They are pale blue and transparent in color and get their name from the cubelike shape of their bell.
Warm Up Clickers
Do you think that the jellyfish have a nervous system? Explain.
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AP Biology Agenda1. WarmUp 52. Review Immune System Reading 53. Immune System Question 55. Nervous System Notes 405. Nervous System Questions 306. Nervous System/Genetics Activity 25
Announcements
Due Today: Immune System Reading/Answers and Week 11 Spring Assignments
Due Friday, May 2: Week 12 Assignments
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Immune System NotesReleased freeresponse test item
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes: Nervous System
I. Cells of the Nervous SystemA. ____________ ‐ Nerve cells that transport informaon
1. Diagram: Figure 48.2
2. 3 Types: Sensory, _________________, Motor
3. Main Parts:a) ____________‐ Receive info.b) Cell Body‐ Contains Nucleus (Located in CNS)c) Axon Hillock‐ Where impulse is generatedd) ____________‐ Transmits acon potenale) Synapc Terminals‐ Release Neurotransmiers
4. Neurons have variety of shapes suited to a variety of funcons
B. Supporng Cells (AKA _________ Cells) *Lots of these1. ______________‐ Encircle Brain Capillaries
2. ______________________‐ Form insulang myelin sheaths around axons in the CNS
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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II. Transmission of Electrical Signals
A. Origin of Electric Membrane Potential (Figure 48.7)1. Inside of Cell is more neg. than outside‐
Gradient across membrane = ____________ Potential
2. An unstimulated neuron’s potential is called ___________ potential (‐70 mV)
3. *Remember‐Ions go in/out via channels
4. Neurons have more ____ channels than ___channelsà K+ goes out fast (_______________ pumps put K+ back in cell w/ ATP)
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Chapter 48 Notes
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B. The Action Potential (Figure 48.9)1. In neurons, ________________‐gated ion channels allow cell to change
membrane potential in response to stimuli *Graded= Larger stimulus opens more _______ channels*Example of __________ feedbackà Na+ causes more channels to open
2. If ______________‐ reaches a threshold, an _____________ action potential (AP) results
3. A steep, repolarizing phase follows depolarization where a refractory period makes the neuron insensitive to depolarization (_____ channels are closed, but ________ channels are still open)
4. New APs are generated along the axon from cell to cell
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Chapter 48 Notes
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Chapter 48 Notes
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III. The _________ (Junction Between Neurons)
A. Electrical = Direct Via ______ Junctions (intercellular channels)
B. Chemical (Figure 48.12) *More Common A narrow gap (synaptic cleft) separates pre‐ and post‐ synaptic cells
1. Synaptic vesicles hold neurotransmitters. NTs released when __________ rushes in during depolarization. Then vesicles fuse with the pre‐synaptic membrane.
2. Specific receptors on postsynaptic membrane pick up NTà opening of _______ channels à AP (sometimes, sometimes inhibits)
3. __________ break the NT down quickly
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Chapter 48 Noteshttp://shapeoflife.org/video/scientist/ianlawnneurobiologistanemonenervoussystem
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Chapter 48 Notes
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Chapter 48 Notes
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Chapter 48 Notes
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Mr. Anderson Video Nervous System
https://www.youtube.com/watch?v=UabDiuTtU0M
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The diagram above depicts the response to a pinprick (stimulus) on the tip of a human finger. The arrows show the direction of impulse transmission along the labeled axons. If axon II was damaged before the pinprick, which of the following is most likely?
(A) The person will not feel the pinprick.(B) The person can no longer feel pain.(C) The person’s finger will not withdraw reflexively.(D) The person cannot transmit nerve impulses to the brain.
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Question 34: C
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The illustration above depicts a neuromuscular junction of a patient with an autoimmune disorder. Acetylcholine is a stimulatory neurotransmitter. Which of the following would be the most likely result of the continued presence of the antibody?
(A) An increase in action potentials in the motor neuron and constant nerve pain(B) A decrease in action potentials in the muscle, causing muscle weakness and fatigue(C) A decrease in the opening of sodiumgated channels in the muscle, causing less sodium to be released from the muscle(D) An increase in the opening of sodiumgated channels in the motor neuron because of the accumulation of acetylcholine in the junction
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Observation of the direction of the nerve impulse supports the conclusion that fiber X is(A) an axon(B) a dendrite(C) an effector(D) a ganglion(E) a synapse
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Which of the following statements is true about the neurotransmitter used to transmit the impulse at the synapse?
(A) It is constantly released by fiber X.
(B) It is constantly released by fiber Z.
(C) It is released by fiber X when an impulse travels the length of fiber X.
(D) It is released by fiber Z after an impulse travels across Y.
(E) It is passed from fiber Z to fiber X by way of Y.
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Taste Lab
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Exit Question
Reminders
What are the two parts of your peripheral nervous system?
Due Today: Immune System Reading/Answers and Week 11 Spring Assignments
Due Friday, May 2: Week 12 Assignments