Nervous System

Question 1

What is the primary function of the Nervous System?

Answer 1

Processes information and controls the body

Question 2

What are the major organs within the NS?

Answer 2

• Central Nervous System: brain and spinal cord
• Peripheral Nervous System

Question 3

What are the major cell types within the NS?

Answer 3

Neurons + Glia Cells

Question 4

What are the important molecules within the NS?

Answer 4

• ions, channels and pumps
• neurotransmitters

Question 5

Frontal Lobe

Answer 5

Deals with the following:
* olfactory bulb (processes smell)
* motor cortex (plans and implements movement)
* Maintainingattention
* Speech(esp.left)
* Decision making
* Personality, socialization
* Risk assessment

Question 6

Parietal Lobe

Answer 6

Deals with the following:
* speech
* reading
* processingtouchsensations * processingbodyorientation

Question 7

Occipital Lobe

Answer 7

Deals with the following:
* processing vision

Question 8

Temporal Lobe

Answer 8

Deals with the following:
* processing/interpretingsound
* contains hippocampus, which is involved in memory formation

Question 9

Hemispheres (Right+Left)

Answer 9

Deals with the following:
* right and left are mostly redundant
* each see and control opposite side of body

Question 10

Corpus Callosum (Split-brain)

Answer 10

Deals with the following:
* bundle of neurons connecting left and right hemispheres of cerebral cortex

Question 11

Basal Ganglia

Answer 11

• movement control
• posture
• motivation

Question 12

Thalamus

Answer 12

• receives sensory/motor input
• receives feedback from cortex
• regulates consciousness/sleep

Question 13

Hypothalamus

Answer 13

• controls endocrine system
• circadian rhythm (sleep cycles)
• ‘thermostat’ that regulates
• hunger * thirst
• body temperature

Question 14

Limbic System

Answer 14

several connected structures
* regulates emotion, fear, motivation
* amygdala- fear
* cingulate gyrus- emotions, pain (part of cerebral cortex)

Question 15

Cerebellum

Answer 15

• controls balance
• coordinates movement
• involved in learning motor tasks

Question 16

Brainstem

Answer 16

• connects brain to spinal cord
• controls some unconscious movement (breathing, heart beat, etc.)

Question 17

Spinal Cord

Answer 17

• connects to brain stem
• “information highway” between the body and the brain
• controls motor reflexes
• contained within the bones of the spinal column (bones protect)
• openings allow connections to spinal nerves (PNS)
• spinal nerves lower in spine correspond to lower body functio

Question 18

Peripheral Nervous System (PNS)

Answer 18

• Connects to the CNS via cranial nerves and spinal nerves
• cranial nerves send sensory information to the CNS and motor signals to the body
• e.g. optic nerve sends signals from eyes to brain
• e.g. oculomotor nerve sends signals from brain to eyelids
• spinal nerves transmit sensory and motor information (sensory- somatic NS) and information to body systems without conscious control (e.g. heart; autonomic NS)* unconscious control may promote
• an excited/surprised state
  (sympathetic- ‘fight or flight’)
• a relaxed/resting state (parasympathetic- ‘rest and digest’)

Question 19

Neuron Structure

Question 20

Cell Body (Soma)

Answer 20

contains normal cell structures

Question 21

Dendrites

Answer 21

tree-like extensions of the cell that receive signals from
other neurons

Question 22

Axon

Answer 22

tube that carries electrical signals away from the cell body

Question 23

Synapse

Answer 23

junction where two neurons meet and pass signal
* some cells in the cerebral cortex may synapse with 200,000 other neurons!

Question 24

Neuron Functions

Answer 24

neurons send electrical signals in the form of action potentials

Question 25

Resting membrane potential

Answer 25

- neurons have a charged membrane- a voltage difference inside vs. outside the cell

Question 26

Action Potential

Answer 26

- when sending an electrical signal, the charge is reversed

Question 27

At the cellular level, how does a neuron receive a signal? How does it ‘know’ it should transmit an electrical signal?

Answer 27

Neurons receive signals through dendrites

Question 28

What part of a neuron sends the electrical signal?

Answer 28

Axon

Question 29

At the cellular level, how is the electrical signal sent?

Question 30

Glia Cells

Answer 30

* support neurons * astrocytes (CNS) and satellite glia (PNS) provide nutrients and support to neurons * oligodendrocytes (CNS) and Schwann cells (PNS) insulate the axons of neurons * other glia produce cerebrospinal fluid, remove dead cells/invading microorganisms, help developing neurons find their destination, etc.

Question 31

Glia Cells Role as insulators

Answer 31

* role as insulators * oligodendrocyts and Schwann cells wrap the axons of some neurons in myelin (the myelin sheath) * myelin contains fats and proteins that insulate the neuron and allow the electrical signal to travel long distances (up to 1m!) * spaces in the myelin sheath (nodes of Ranvier) allow the action potential to be recharged

Question 32

Action Potential

Answer 32

* an electric current is the flow of charged particles * in a neuron, those charged particles are ions * an electric current is the flow of charged particles * at rest, the inside of the neuron carries a net negative charge* -also at rest, there is a high concentration of sodium ions outside the cell and a high concentration of potassium ions inside the cell * the membrane surrounding the cell has several key features: * the membrane itself blocks ions from going through * a protein pump constantly moves sodium out of the cell and potassium in * protein channels specifically allow sodium or potassium to pass when open * both channels are voltage gated- they open only when a specific membrane potential (voltage) is reached

Question 33

Synapse

Answer 33

* synapses are where signals pass from one neuron to another * some neurons are physically linked and action potentials can pass directly * more commonly, a small gap exists between neurons * the electrical signal triggers a chemical signal to pass to the next neuron * chemical synapses rely on a few specialized structures * voltage-gated Ca2+ channels * vesicles are cellular structures that hold things * neurotransmitters are molecules (chemicals) * ligand-gated ion channels open when a ligand binds * ligand is a general term for a molecule that binds to another molecule * these channels open when a ligand (in this case, a neurotransmitter) binds * theyallowions(e.g.Na+,Cl-)toflowthrough

Question 34

What is the difference between a ligand-gated ion channel and a voltage-gated ion channel?

Answer 34

Ligand-gated ion channels open when a chemical ligand such as a neurotransmitter binds to the protein. Voltage channels open and close in response to changes in membrane potential