BIO304H5 Lecture Notes - Lecture 10: Sk Channel, Alpha Helix, Exocytosis

16 views2 pages

whitelouse363

1 Mar 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Lva channels: do(cid:374)"t (cid:374)eed a stro(cid:374)g depolarizatio(cid:374) to (cid:271)e(cid:272)o(cid:373)e a(cid:272)tivated. It can sense the depolarization and open up and conduct a depolarization calcium current into the neuron. Slide 19: hva, need a very strong depolarization to activate, they do(cid:374)"t (cid:373)ake the de(cid:272)isio(cid:374) to fire a(cid:374) ap, (cid:271)ut a(cid:374) ap de(cid:272)isio(cid:374) is (cid:373)ade, these guys are (cid:373)ade to do something important in the cell. Lva tend to be rich in the dendrites of neurons. Lva channels are helping driving aps, they are bringing aps closer to each other. In small mammals, they rely on lva to drive heart contractions. Slide 23: heart cells also have a lot of hva channels, calcium is still rushing into the heart cell making sure it fully contracts. Seizures occur when the ns has lost its equilibrium between excitatory and inhibitory transmission: too much t-type activity. For a calcium channel to functionally control a potassium channel, they have to be pretty close to each other.

Related Questions

Bad Fish: The Case of Tetrodotoxin

Part I â Poisoned!

One evening during a trip to Indonesia to study the recent sightings of a coelacanth, Dr. Marshall Westwood from the Montana Technical Institute sat down to a meal of pufferfish and rice. Within an hour of returning to his hotel room, he felt numbness in his lips and tongue, which quickly spread to his face and neck. Before he could call the front desk, he began to feel pains in his stomach and throat, which produced feelings of nausea and eventually severe vomiting.

Fearing he had eaten some âbad fishâ for dinner, Dr. Westwood called a local hospital to describe his condition. The numbness in his lips and face made it almost impossible for him to communicate, but the hospital staff managed to at least understand the address he gave them and they sent an ambulance in response. As Dr. Westwood was rushed to the hospital, his breathing became increasingly difficult. In addition, he began to show signs of paralysis in his upper body and arms.

By the time the ambulance reached the hospital, Dr. Westwoodâs face and mouth were completely paralyzed and he had an irregular heartbeat. The physicians helped by keeping his airway open, administering drugs to bring his heart back to a normal rhythm, and putting a mixture of charcoal into his stomach, which would help absorb any chemicals that might still be left there.

Within a few hours, Dr. Westwoodâs condition improved and he was on his way to a full recovery. After discussing his case with his physician, he learned that he had probably been the victim of a pufferfish poisoning.

The active toxin in the tissues of this fish is a chemical called tetrodotoxin. Tetrodotoxin or (TTX) is in a class of chemicals known as neurotoxins due to the fact that it has its effects on nerve cells (neurons). Specifically, tetrodotoxin blocks voltage-gated sodium ion channels.

What follows is a series of questions relating to the basic biology of this case.

Answer the following questions about the case study:

1. How many different elements are contained in a molecule of tetrodotoxin? What are the names of these elements?

2. What is a voltage-gated sodium ion channel? What is it made of? What is its function?

3. Why do sodium ions need channels in order to move into and out of cells?

4. Describe the process involved in the movement of ions through these channels.

5. When nerve cells are at rest, there is an unequal amount of positive and negative charges on either side of a nerve cell membrane. This charge difference is called an electrical potential. Describe this âpotentialâ when the neuron is at rest (resting potential).

6. What is happening to the electrical potential of a neuron when it generates an action potential? What is the function of the action potential in neurons?

7. Describe the role of sodium ions and sodium channels in the action potential.

8. What would happen to a neuron if it were exposed to tetrodotoxin? Be specific regarding its effect on the ability of a neuron to communicate.

9. Now that you have addressed some of the basic biology of this case, explain why Dr. Westwood experienced numbness after eating the pufferfish meal.

10. Paralysis is a term used to describe the loss of function of muscle. If tetrodotoxinâs effect is on neurons, why did Dr. Westwood experience paralysis?

violetferret341

Meadow voles differ from prairie voles in that they:

	a.	are not monogamous.
	b.	show preference for a single partner if the AVPR1A gene is blocked.
	c.	release vasopressin but not oxytocin.
	d.	release oxytocin but not vasopressin.

5 points

Question 2

Painful events are detected by:

	a.	Free nerve endings.
	b.	Merkel's disks.
	c.	Meissner's corpuscles.
	d.	Pacinian corpuscles.

5 points

Question 3

It has been found that:

	a.	Language memory is stored near Broca's area.
	b.	Identifying pictures of hand tools uses memories stored in the left temporal lobe and hand motor areas.
	c.	Identifying the color of an object requires memories stored in the temporal lobe.
	d.	All of the above.

5 points

Question 4

Sex is considered to be a form of ___ behavior.

	a.	chaotic
	b.	motivated
	c.	learned
	d.	innate

5 points

Question 5

A difference between Einstein's brain and the average brain is that:

	a.	It was larger in size.
	b.	It was lighter in weight.
	c.	There were more neurons.
	d.	There was no difference.

5 points

Question 6

The individual in the opening chapter vignette lost virtually all motor control because the control of our muscles and, hence, our limbs and bodies is heavily influenced by and has to be integrated with our ___.

	a.	proprioception sense
	b.	vestibular sense
	c.	skin senses
	d.	visceral sense

5 points

Question 7

Which cortical area is most important for maintaining information in working memory when a distracting stimulus is introduced?

	a.	Temporal lobe.
	b.	Parietal lobe.
	c.	Prefrontal cortex.
	d.	All of the above.

5 points

Question 8

The anxiolytics that have the highest abuse and addiction potentials are:

	a.	Barbiturates.
	b.	SNRIs.
	c.	Benzodiazepines.
	d.	Tricyclics.

5 points

Question 9

If your grandfather suffered a stroke in his left prefrontal cortex, in what ability would he likely be most impaired?

	a.	Working out a complicated math problem in his head.
	b.	Wondering what the capital city of Nevada is.
	c.	Playing the piano.
	d.	Quickly telling you the value of 3x3.

5 points

Question 10

Major depression:

	a.	Can usually be explained by exposure to prolonged stress.
	b.	Always consists of decreased physical activity.
	c.	Generally appears after midlife.
	d.	None of the above.

5 points

Question 11

According to your text, one of the reasons that some psychologists question the diagnosis of dissociative identity disorder is that:

	a.	Symptoms seem to come and go.
	b.	The symptoms are not consistent across diagnosing psychologists.
	c.	The number of diagnosed cases increased from 500 to 5000 over a period of six years.
	d.	They believe it is a popular diagnosis due to movies such as The Three Faces of Eve.

5 points

Question 12

When the differences in body size are accounted for, the average male's brain is ___ than the average female's brain.

	a.	heavier
	b.	lighter
	c.	the same size
	d.	the same ratio

5 points

Question 13

All of the following make it difficult to determine if there are gender-related differences in behavior and cognition except:

	a.	The results show evidence for strong differences, but people do not want to accept them.
	b.	Different researchers tend measure the same characteristic in different ways.
	c.	The differences that exist are relatively small.
	d.	People tend to talk to children dressed as boys or girls in different, subtle ways.

5 points

Question 14

The leading environmental cause of intellectual disability is:

	a.	Maternal alcoholism.
	b.	Rubella.
	c.	Prenatal exposure to virus.
	d.	Early infancy exposure to viruses.

5 points

Question 15

Antipsychotic medicines have come to be known as ___, which means ___.

	a.	psycholeptics; to have antipsychotic effects
	b.	neuroleptics; to have anti-neurosis effects
	c.	neuroleptics; to seize control of a neuron
	d.	psycholeptics; to seize control of a psychosis

5 points

Question 16

Using classical conditioning to pair a loud boat horn with presenting a blue slide, researchers found that with:

	a.	Hippocampus damage, conditioning occurred even though the subjects could not describe what was learned.
	b.	Amygdala damage, conditioning occurred even though the subjects could not describe what was learned.
	c.	Hippocampus damage, no conditioning occurred but subjects could describe the procedure.
	d.	None of the above.

5 points

Question 17

In the most famous case of Ablatio penis, where a young boy with XY chromosomes had his penis destroyed during a circumcision,

	a.	the child (Bruce) was born as a hermaphrodite and the decision was made to rear him as a girl (Brenda).
	b.	Money counseled the parents that by rearing the child (Bruce) as a girl, âsheâ (Brenda) would accept a female gender identity.
	c.	the child lost both testicles, which was the source for all of the male-specific hormones in âherâ body.
	d.	Money showed that the âneutral-at-birthâ position was in fact correct.

5 points

Question 18

The method of introspection is seldom used in today's research because:

	a.	Machines were developed that were more accurate.
	b.	It was found to be too subjective.
	c.	It required too much training to produce accurate results.
	d.	All of the above.

5 points

Question 19

Both Parkinson's disease and Huntington's disease produce damage to:

	a.	Declarative memory.
	b.	Nondeclarative memory.
	c.	Memory of Lincolnâs birthplace.
	d.	Memory of what you had for breakfast.

5 points

Question 20

Lucid dreamers:

	a.	Show characteristics of being both awake and asleep.
	b.	Can control the content of their dreams.
	c.	Know that they are dreaming.
	d.	All of the above.

Meadow voles differ from prairie voles in that they:

BIO304H5 Lecture Notes - Lecture 10: Sk Channel, Alpha Helix, Exocytosis

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Biology

Concepts of Biology

Essentials of Biology

Related Documents

BIO304H5 Lecture Notes - Lecture 10: Bk Channel, Sk Channel, Afterhyperpolarization

BIO304H5 Lecture Notes - Lecture 10: Tandem Pore Domain Potassium Channel, Retinal Ganglion Cell, Neural Coding

BIO304H5 Lecture Notes - Lecture 10: Bk Channel, Alpha Helix, Repolarization

Related Questions