New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

BIOL 1040 notes, Chapter 35

by: Sarah Stewart

BIOL 1040 notes, Chapter 35 BIOL 1040

Marketplace > Clemson University > Biology > BIOL 1040 > BIOL 1040 notes Chapter 35
Sarah Stewart
GPA 4.0

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Chapter 35 covers the nervous system of animals.
General Biology II
Dr. William Surver
Class Notes
Biology, Clemson, nervous system
25 ?




Popular in General Biology II

Popular in Biology

This 6 page Class Notes was uploaded by Sarah Stewart on Thursday January 14, 2016. The Class Notes belongs to BIOL 1040 at Clemson University taught by Dr. William Surver in Fall 2016. Since its upload, it has received 36 views. For similar materials see General Biology II in Biology at Clemson University.


Reviews for BIOL 1040 notes, Chapter 35


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 01/14/16
Chapter 35: Neurons and the Nervous System Lecture given 1/19/16 *Review membrane of a cell, diffusion, active transport Neuron – functional cell in a nervous system • Cell body (soma) • Dendrites • Axon • Myelin sheath • Synapse Glial cells – accessory cells that maintain the environment of nervous system Nervous System consists of 2 sections 1. Central nervous system (CNS) – consists of the brain and the spinal cord 2. Peripheral nervous system (PNS) – consists of nerves (bundles of neurons wrapped in connective tissue) and ganglia clusters of cell bodies The nervous system must • Obtain sensory information, sensory input • Process sensory information, integration • Send commands to effector cells (muscles/glands) that carry out responses, motor output • All of these performed by neurons, anatomically the same but carry out different tasks • Discriminates between important info and unimportant info Sensory neurons – convey signals from sensory receptors to the CNS Interneurons – located exclusively in CNS, integrate info and send to motor neurons Motor neurons - convey signals to effector cells Simple reflex arc – demonstrates the relationship between neurons and nervous system structure/function, brain excluded; how “quick reflexes” function Neuron Function • Resting potential • Action potential i) Threshold ii) Depolarization iii) Repolarization iv) Hyperpolarization Propagation – movement of action potential down a neuron; one-way chain • Propagation speeds up when a myelin sheath is present, areas not covered by sheath called nodes of ranvier Synapse – relay points between synaptic terminals of a sending neuron and a receiving neuron; receiving cell can be another neuron or an effector cell i.e. a muscle cell Resting Potential of Neurons • Concentration gradient of K+ goes from inside to outside cell membrane; outside contains more Na+ (sodium-potassium pump) • More K+ channels than Na+ channels, allows K+ to diffuse to outside membrane • Na+/K+ ions move against gradient w/ a 3:2 ratio; moves more Na+ which maintains equilibrium • Neuron must be at resting potential to be stimulated Acting Potential of Neurons • Action potential is the change of membrane voltage from resting potential, to its max level, back to its resting potential • When stimulus applied, Na+ channels open up, allows those ions to move inside cell membrane • Cell interior gains a more positive charge; this is depolarization • If stimulus great enough, will generate action potential; if not great enough, will go back to resting potential • Makes action potential a “All or Nothing” phenomenon • If it reaches action potential, K+ gates open and ions stream out of cell membrane so cell interior has a negative charge; this is hyperpolarization Ch. 35 continued… Lecture given 1/21/16 **Read last section of chapter for reference Threshold-discrimination – when the energy threshold is not reached in a neuron • If action potential is reached, the charge travels down the axon in a chain reaction • Neurons do not touch each other, there is a space the charge has to cross Chemical Synapses • The ending cell (presynaptic cell) secretes a chemical signal called a neurotransmitter, crosses the synaptic cleft, which is the space between the neurons • Vesicles are membranous sacs that contain the neurotransmitters • Begin to fuse together, move to end of axons and release the neurotransmitters into the synaptic cleft • The receiving cell (postsynaptic cell) has receptors that absorb Na+ once a neurotransmitter bind to them; causes depolarization and continuation of the action potential • Neurotransmitters can also bind to K+ channels; causes hyperpolarization and the lowering of the energy threshold Neurotransmitters E.P.S.P. – excite a receiving cell I.P.S.P. – inhibit a receiving cell • Receiving neuron’s membrane may receive these signals from different sending neurons • Summation of excitation and inhibition determines if a neuron will transmit a nerve signal or not Overview of Nervous System • Flow of info within nervous system relies on synaptic integration, or how many neurons are organized within the body • Thousands of neurons in brain, arranged in blocks that either receive excitatory or inhibitory signals • Divergent circuit neurons form connections with other blocks • Convergent circuit signals from a many blocks are relayed to a few Trends to look for (simple to complex): 1. Whole body response to more local response 2. Cephalization – the formation of a head 3. Specialized functions of sensory, integrating, and responding Most bilaterally symmetrical animals evolved: • Concentration of nervous system in head area (cephalization) • Centralization – central nervous system distinct from peripheral nervous system • Presence of ganglia • Radially symmetrical organisms have a nerve system arranged in a web of nerves called a nerve net Human Nervous System Central nervous system (CNS) • Contains the brain and the spinal cord Peripheral nervous system (PNS) • Divided into 2 components: the motor system (voluntary) and the automatic nervous system (involuntary) Motor nervous system – carries signals to and from skeletal muscles, respond mostly to external stimuli Automatic nervous system – regulates internal environment, controls smooth and cardiac muscle, organs, and glands Chapter 37: Hormones and the Endocrine System • Consists of all hormone-secreting cells, works w/ nervous system in regulating body activity • Response slower than compared to nervous system, but it lasts longer Chemical messengers: • Hormones – released by endocrine glands/some neurons into the blood stream; acts on target tissues and cells, not entire body • Neurotransmitters – end of axon • Local signaling molecules – released by assorted cells • Pheromones – secretions of exocrine glands


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Anthony Lee UC Santa Barbara

"I bought an awesome study guide, which helped me get an A in my Math 34B class this quarter!"

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.