Bio: Chapter 28

The diagrams show the sequence of events that occur as an action potential is conducted along an axon.

1. Action potential begins as sodium channels open here. 2. Sodium ions spread from their point of entry. 3. Action potential is conducted "downstream" as the next sodium channels open. 4. Resting potential is restored here as sodium channels close and potassium channels open.

The diagrams below show the sequence of events that occur during an action potential.

1.When a neuron is at its resting potential, the inside of the cell has a negative charge relative to the outside. 2..A stimulus begins to change the distribution of charge across the membrane. 3.During an action potential,sodium channels open and sodium ions move into the cell.The inside of cell becomes positively charged relative to outside. 4.Sodium channels close and potassium channels open, and potassium ions move out of the cell. 5.The original charge difference is re established across the membrane and the cell returns to its resting potential.

Open the site in your browser and play the podcast. Think about whether you believe the information presented or whether you have doubts about some of it.

2-4 (somewhat trustworthy; want to check some things)

Finally, how can you use your assessment of the authority, motivation, and reliability of the information to evaluate this web site relative to other sources? Use the scales below to assign a numerical score to this source.

5 to 6

Which of the following situations best represents the function of the amygdala?

Dana was riding the subway when she suddenly started remembering how she went to the theater as a child; this memory was probably triggered because the woman standing next to her wore the same perfume that Dana's mother used to wear when they went out.

If you touch a hot stove,________ in your fingertip sense the dangerous heat and convert this stimulus into an electrical signal. This signal leaves your fingertip via nerve cells called _______ . These nerves are part of an anatomical division of the nervous system called the__________ . The signal travels along these nerves, and then to the spinal cord and brain. These two structures make up an anatomical division called the_________ . Within this part of the nervous system, specialized nerves called ___________ integrate this information, formulate a response, and then communicate these instructions as nerve impulses to ___________. These neurons bring the message to the muscles in your arm to pull your hand away.

If you touch a hot stove, sensory receptors in your fingertip sense the dangerous heat and convert this stimulus into an electrical signal. This signal leaves your fingertip via nerve cells called sensory neurons. These nerves are part of an anatomical division of the nervous system called the peripheral nervous system. The signal travels along these nerves, and then to the spinal cord and brain. These two structures make up an anatomical division called the central nervous system. Within this part of the nervous system, specialized nerves called interneurons integrate this information, formulate a response, and then communicate these instructions as nerve impulses to motor neurons. These neurons bring the message to the muscles in your arm to pull your hand away.

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

Ion channels in the plasma membrane of the receiving neuron open

What type of cell makes up the myelin sheath of a motor neuron?

Schwann cells

Which of the following events is the first to occur during an action potential?

Sodium channels open.

What causes an action potential to be conducted along a neuron's axon?

The change in charge difference across the membrane spreads from open sodium channels, causing sodium channels farther along the axon to open.

If a signal from a sending neuron makes the receiving neuron more negative inside,

The receiving neuron is less likely to generate an action potential

When calcium ions enter the synaptic terminal,

They cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron

Now, search for similar information on at least two other web sites, including Mayo Clinic (mayoclinic.org) and WebMD (webmd.com).

Yes, the information on causes and symptoms of brain injuries is consistent.

Which of the following is characteristic of vertebrate nervous systems?

a distinct central nervous system consisting of a brain and spinal cord

How can you know if the person or organization providing the information has the credentials and knowledge to speak on this topic? One clue is the type of web site it is--the domain name ".gov" tells you that this is a government web site.

a researcher from the National Centers for Disease Control and Prevention

Can you identify synapse structures? Drag the labels onto the diagram to identify the various synapse structures.

a- vesicle b- neurotransmitter c- calcium channel d- synaptic terminal e- synaptic cleft f- receptor for neurotransmitter.

Can you identify the functions associated with each of the human brain structures shown here?

a.) serves as sophisticated center of integration and control b.)Controls the left side of the body c.) allows communication between cerebral hemispheres d.) Coordinates the body movements e.) Controls basic functioning like breathing and circulation f.) Conducts communication between brain and rest of body.

Studies of brain activity during sleep reveal that activity _____.

alternates between periods of rapid, irregular waves and periods of regular, slower waves

Which of these causes the release of neurotransmitter molecules?

an action potential reaching the end of the axon

A nerve impulse moves away from a neuron's cell body along _____.

axons

A neuron's nucleus is located in its _____.

cell body

As you start to pick up your biology book, you suddenly realize that it is much heavier than you thought it would be. Which of the following brain regions is responsible for the rapid adjustment of muscle force that allows you to pick up the book smoothly?

cerebellum

What part of the human brain accounts for about 80% of the brain mass?

cerebral cortex

A nerve impulse moves toward a neuron's cell body along _____.

dendrites

Action potentials are generated along a neuron because _____.

depolarization of the membrane at one point causes an increase of permeability to sodium at the next point

Effectors include __________.

endocrine glands

Schizophrenia, bipolar disorder, and depression all seem to be the result of _____.

genetics and environment

The medulla, pons, and cerebellum in the adult brain develop from this part of the early embryonic brain.

hindbrain

Some neurotransmitters may also function as __________ in a different body system.

horomones

How can you know if the information is based on scientifically collected data and if it's corroborated by other sources? On the CDC page, click the Transcript button to see the text of the interview. Scroll down to the link that Dr. Taylor gives for more information on traumatic brain injury. Follow that link.

hospital statistics medical research

A man is admitted to the hospital suffering from an abnormally low body temperature, a loss of appetite, and extreme thirst. A brain scan shows a tumor located in the _____.

hypothalamus

A physician friend of yours tells you about a patient with a head injury who suddenly stopped breathing during the examination. What portion of the brain was probably injured?

medulla oblongata

Axons insulated by a(n) _____ are able to conduct impulses faster that those not so insulated.

myelin sheath

Which of the following would be present in an animal with a nerve net?

neurons

Complex fire/don't fire "decision making" by neurons is most directly a result of the fact that __________.

neurons receive a combination of signals from both excitatory and inhibitory synapses

A molecule that carries information across a synaptic cleft is a

neurotransmitter

An impulse relayed along a myelinated axon "jumps" from _____ to _____.

node of Ranvier ... node of Ranvier

Which of the following categories includes all the others?

peripheral nervous system (PNS)

Some __________are open, allowing certain ions to move out of the cell through them.

potassium channels

The concentration of ____________is higher inside the cell than outside.

potassium ions

In humans, making more serotonin available to brain cells typically _____.

produces an effect on mood

Sodium-potassium pumps

restore the distribution of ions inside and outside a neuron's membrane following an action potential.

After a stroke, Bill can feel his left leg but is unable to move it. His neurologists suspect damage to the __________.

right frontal lobe

Sarah turns quickly and sees the soccer ball hurtling toward her face. She blinks and ducks for cover. During this reaction, Sarah perceived the ball, decided what to do, and then blinked. Which choice lists the cells that were involved in this process from first to last?

sensory neurons (part of the PNS), interneurons (part of the CNS), and motor neurons (part of the PNS)

The __________are closed, preventing certain ions from entering the cell through them.

sodium channels

The concentration of _________is higher outside the cell than inside.

sodium ions

Using energy from ATP ________, actively transport ions in both directions across the membrane.

sodium-potassium pumps

It is your turn to do your presentation. You have worried about this moment all month long. Are you prepared? Will someone spot that ring of sweat forming under your arms? Because of the activity of your __________ nervous system, your __________.

sympathetic; lunch suddenly does not agree with you and epinephrine shoots through your body

The small space between the sending neuron and the receiving neuron is the

synaptic cleft

The space between an axon of one neuron and the dendrite of another neuron is called a(n) _____.

synaptic cleft

What part of a neuron relays signals from one neuron to another neuron or to an effector?

synaptic terminal

Neurons store neurotransmitter molecules in vesicles located within _____.

synaptic terminals

During an action potential

the inside of the neuron becomes positively charged relative to the outside.

When a neuron is at its resting potential

there are more potassium ions inside the neuron than outside.

Next, can you identify what the source is trying to accomplish by providing this information? As you listen to the podcast, think about what the doctor's agenda might be with regard to head injuries.

to inform the public about brain injuries