The professor’s purpose is to introduce the topic of cardiac muscle, which the rest of the lecture develops. The professor answers her own question by saying It’s possible because of the specialized type of muscle—cardiac muscle—that makes up the heart tissue…. (2.3)
The professor’s purpose is to review material the class has already studied. The professor says …let’s back up a bit, indicating that what she says next will review something that they have already discussed. (2.3)
* Skeletal muscle: These muscles are connected to the bones, which move when the muscles contract: Skeletal muscles are attached to the bones, and they the bones by contracting.
* Cardiac muscle: When this type of muscle contracts, blood moves throughout the body: …a series of contractions in the cardiac muscle. When the heart’s walls contract, they force blood out of the chambers and into the next chamber or the large blood vessels that lead to the rest of your body,
* Skeletal muscle: To contract, this type of muscle must be stimulated by a motor neuron: A skeletal muscle contracts only when it s stimulated by a motor neuron,
* Cardiac muscle: These muscle cells can generate electrical impulses without input from the nervous system: Cardiac muscle cells can generate impulses on their own, without any input from the nervous system.
* Cardiac muscle: This muscle cannot stop to rest without serious consequences for the body: …your cardiac muscle can never stop and take a rest. If your heart stops beating, you have very little time— only a matter of minutes—for it to start up again before all your other body systems are permanently damaged or stop functioning altogether. (2.5)
The professor says …an electrical impulse generated in one part of the heart will spread to all the cardiac muscle cells. Thus, the whole heart will contract. (2.2)
The professor says Electrically, they’re set up so, so that sodium and calcium—positive ions—change places with potassium—a negative ion—across the cell membrane; When sodium, calcium, and potassium ions move into or out of a cardiac cell, it causes the muscle to contract. You can infer that the contraction of cardiac muscle depends on the action of sodium, calcium, and potassium. (2.4)
TOEFL IBT Listening Practice Test 08 From Delta’s Key TOEFL Test Solution & Transcripts
Questions 1 through 5.
Listen to a conversation in a college office.
M: Excuse me. Is this where I can get a student ID?
W: Yes, we do make ID cards here actually downstairs in the photo shop but this is where you start.
M: I need to, um, replace my old one. You’ll never believe it, but my dog ate it.
W: You’re kidding! I’ve never heard that one before! Usually dogs prefer homework.
M: Well, not my dog. He’s particular about his food.
W: I hope it didn’t hurt him. Did he swallow it whole?
M: Nah, he’s all right. He just chewed it up. So, I thought I’d better get a new one so I can keep riding the bus for free.
W: There’s a twenty–dollar fee for a replacement ID.
M: OK. Where do I pay?
W: At the cashier’s office. But first you need to fill out this form. And I need to see your driver’s license or some other form of ID.
M: OK, so I just fill out this form and give it back to you?
W: Yeah, and then I have to check your status in the database so I can order the ID. It only takes a minute or so. Then you go up to the cashier to pay. After that, you take your receipt down to the photo shop, and they’ll take your picture and make your new card.
M: OK. Oh, by the way, is it possible to get a copy of my transcript?
W: Sure. If you want an unofficial transcript, you can use the computers in the information center to get a printout. You could also do that through our Web site. But if you want an official transcript, you need to fill out a request form and pay five dollars for each copy you want. It takes about five days to process your request.
M: What’s the difference between official and unofficial?
W: An unofficial transcript is, like, if you just wanted it for your own use, or if it doesn’t have to be in a sealed envelope. Unofficial is free. An official transcript is in a sealed envelope with the college seal. If you need a transcript to transfer to another school, or to, uh, apply for a scholarship, then you need an official transcript.
M: I’m applying for a scholarship, so could I have the form for an official transcript? Looks like I’d better fill that out, too.
W: Here you go.