Exam 8: Using Muscles and Glands

Which of the following is an accurate statement regarding endocrine disruptors?

You observe the structure and function of a muscle fiber in the lab. You find that membrane depolarization is not always necessary in order to cause contraction, and that actin filaments are not arranged longitudinally along the length of the fiber. Most likely you are observing a _______________________.

The three main types of muscle (cardiac, skeletal, smooth) function in a coordinated way in humans and other vertebrates. Propose a hypothesis as to which type arose earliest over evolutionary time. In other words, do you think ancient organisms evolved something most similar to smooth, cardiac, or skeletal muscle first? Justify your proposal by stating the selective advantage that these early muscle cells would have conferred on an organism.

Compare and contrast skeletal muscle and cardiac muscle. Which of the following does NOT accurately describe these tissues?

You observe the structure and function of a muscle in the lab. You find that the cells requires tropomyosin displacement in order for myosin heads to bind actin, and that there is a great deal of electrical coupling between adjacent cells. Most likely you are observing _______________________.

Which of the following tissues are controlled by neurons?

Which of the following is NOT an accurate statement regarding the structure and function of outer hair cells?

Gap junctions and electrical coupling allow neurons to fire synchronously. Outline 3 examples of when this occurs in the nervous system, comparing and contrasting the role of each in organismal function.

Make a diagram that shows why an animal experiences rigor mortis after death. Your diagram should have 2 panels that show cellular processes inside a muscle fiber. In the first panel, draw the state of the muscle at the time of death. The second should depict the state of the muscle about 4 hours after death of the tissue. Your diagram should include the role of calcium and ATP, actin filaments, and myosin.

Create a flow chart that depicts a powerful muscle contraction that first involves a few muscle fibers and then involves many muscle fibers. Your flow chart should depict the involvement of at least 3 motor units, and include details about the number of muscle fibers involved for each and the size of action potentials and motor neurons.

Which of the following is an accurate statement regarding muscle spindles?

In a research study, you monitor a patients blood at 15 min intervals over the course of an hour. You find that estradiol increases. One explanation might be that

Which of the following statements accurately describe smooth muscle?

Analyze Figures 8.22 and 8.23. In the text Which of the following can you conclude from these data?

Analyze figure 8.10. In the text Which of the following can NOT be concluded from these data?

Place the following events in the order they occur to cause and carry out a muscle contraction. ____ sodium and other cations flow into the cell ____ ACh is released from a motor neuron ____ ACh binds receptors on the motor end plate ____ voltage-sensing ryanodine receptors allow an influx of calcium ions ____ high intracellular calcium levels allow tropomyosin to move out of the way of myosin binding sites ____ calcium is released from intracellular storage in the sarcoplasmic reticulum ____ myosin heads bind actin and muscle contraction ensues if ATP levels are adequate

Place the following events in order that describe the HPG axis. ____ testes secrete testosterone ____ parvocellular neurons fire action potentials ____ leutinizing hormone is secreted ____ gonadotropin releasing hormone secreted

Many plant- and animal-derived toxin have effects on the neuromuscular junction. Compose an argument as to why the neuromuscular junction is a widespread target for toxins.

Which of the following statements does NOT accurately describe electrical signaling in cardiac myocytes?

Discriminate between the different types of muscle tissue described in Chapter 8. Choose which muscle type is most consistent with each statement below, and write one of the following in each blank: skeletal muscle, cardiac muscle, smooth muscle. -___________________ calmodulin regulates the binding of myosin heads to actin filaments