Deck 8: Using Muscles and Glands

Question 1

Which of the following tissues are controlled by neurons?

A) Mammillary glands
B) Sweat glands
C) Glands that secrete hormones
D) all of the above

Answer 1

D

Question 2

Which of the following is NOT an accurate statement regarding skeletal muscle?

A) Skeletal muscle cells develop from the fusion of precursor cells and may contain multiple nuclei.
B) A single muscle fiber contains multiple myofibrils.
C) Each myofibril is an independent muscle fiber and is enclosed by the sarcolemma.
D) The extracellular solution enters the muscle fiber via the T-tubules.

Answer 2

C

Question 3

The regions of the sarcomere that appears darkest under a microscope and border each sarcomere is known as the __________________.

Answer 3

Z-lines

Question 4

Which of the following is NOT necessary for cross-bridge cycling to take place?

A) intracellular calcium must be appropriately high
B) ATP must be present
C) the muscle fiber must be able to shorten
D) ATP hydrolysis must be able to occur

Question 5

During cross-bridge cycling, the molecule ______ binds to myosin heads, allowing the myosin heads to extend and bind to ______ filaments. ATP is hydrolyzed to ______ by the removal of inorganic phosphate. As hydrolysis occurs, the myosin head pulls against actin, and they slide relative to each other. The ________________ remain bound to actin until they encounter a molecule of ATP, at which point they release actin and extend to their original conformation (shape).

Question 6

Compare and contrast white and dark meat in chickens. Give 4 differences between them and outline how each property relates to muscle function.

Question 7

Analyze Figure 8.5. In the text What can you conclude from these data?

A) No glial cells are present at the neuromuscular junction.
B) Motor neurons use ACh to communicate with muscles at the neuromuscular junction.
C) Axons from motor neurons are in close proximity to ACh receptors.
D) Motor neurons carry information from the ventral horn of the spinal cord.

Question 8

Compare and contrast the terminology used to describe muscle fibers with other terms used to describe other cell types. Which of the following statements is NOT accurate?

A) In muscle cells, the cell membrane is known as the sarcolemma, whereas in most cells it is known as the plasmalemma.
B) In both muscles and neurons, the term "motor end plate" describes the post-synaptic side of the synapse.
C) In muscle cells, a depolarization in response to a stimulus is known as an "end plate potential" whereas in neurons it is known as an "excitatory post-synaptic potential".
D) Muscle fibers (muscle cells) often contain many nuclei, whereas most cells only contain a single nucleus.

Question 9

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

Question 10

A patient is seen in at a neurology clinic, with generalized muscle weakness. Nerve conduction is normal. Based on the information presented in this chapter, the patient may have which of the following conditions?

A) Tetanus
B) Rigor mortis
C) Mysasthenia gravis
D) All of the above

Question 11

A muscle cell experiences enough stimulation that intracellular calcium cannot be restored to resting levels after the arrival of action potentials at the neuromuscular junction. This will result in which of the following?

A) tetanus
B) myosin heads having access to actin binding sites because of the movement of tropomyosin
C) sustained muscle contraction
D) all of the above

Question 12

Many insecticides and chemical weapons use organophosphates, a class of chemical compounds that inhibit the enzyme acetylcholinesterase. What would you predict would be the result to an organism that ingests or inhales an acetylcholinesterase inhibitor?

Question 13

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.

Question 14

Which of the following is an accurate statement regarding the organization of motor neurons and muscle fibers?

A) Multiple motor neurons synapse with each muscle fiber
B) A motor unit is the set of motor neurons that innervate a single muscle fiber
C) Each motor neuron synapses with only a single muscle fiber
D) None of the above are accurate statements

Question 15

Analyze figure 8.7. In the text Which of the following can be concluded from these data?

A) Each motor neuron innervates multiple muscle fibers
B) Each motor neuron innervates muscle fibers of the same type (fast, fatigable, fast, fatigue-resistant, etc.)
C) alpha-bungarotoxin leads to muscle weakness by inhibiting the detection of acetylcholine
D) motor neurons synapse at locations that may or may not contain acetylcholine receptors
E) all of the above can be concluded from these data

Question 16

Analyze figure 8.8. In the text Which of the following can be concluded from these data?

A) fast, fatigable motor units are the predominant muscle types in cats
B) fast, fatigue-resistant motor units respond to repeated stimuli with contractions that do not diminish in force even after several minutes of repetitive stimulation
C) fast, fatigable motor units respond to repeated stimuli with contractions that do not diminish in force even after several minutes of repetitive stimulation
D) slow, highly fatigue-resistant motor units respond to repeated stimuli with contractions that do not diminish in force even after 3 hours of repetitive stimulation

Question 17

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

A) Multiple motor units are equally active at any given contractile force.
B) Increasing the strength of a muscle contraction involves the recruitment of multiple motor units
C) Recruitment of additional motor units leads to greater contractile force of a muscle
D) It is possible to distinguish the activity of different motor units in humans

Question 18

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.

Question 19

In your own words, rewrite a definition of the "size principle of motor unit recruitment". Justify your definition by citing specific evidence from human studies that involve recording from shin muscle and leg muscle as described from figures 8.11 and 8.12.
In the text

Question 20

Which of the following is an accurate statement regarding the muscle fibers innervated by a single motor neuron?

A) The motor neuron, along with the muscle fibers, are known as a motor unit
B) The muscle fibers generally each express the same isoform of myosin
C) The muscle fibers are generally all of the same type (fast, fatigable; fast, fatigue-resistant, etc.)
D) all of the above

Question 21

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

A) They are a sensory structure that contains mechanosensory neurons
B) They are innervated by motor neurons that cause contraction of muscle fibers
C) They are found embedded in skeletal muscle
D) all of the above are accurate statements regarding muscle spindles

Question 22

Analyze Figure 8.14. In the text Which of the following can be concluded from these data?

A) Mechanosensory neurons that innervate muscle spindles are activated when the muscle is stretched
B) When both alpha- and gamma-motor neurons are active, mechanosensory neurons are silent during a muscle twitch
C) alpha- and gamma-motor neurons are always activated simultaneously during muscle contraction
D) all of the above are accurate statements regarding these data

Question 23

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

Question 24

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.
-___________________ attachment to tendons

Question 25

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.
-___________________ 3 cm in length

Question 26

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.
-___________________ 1 nucleus per muscle fiber

Question 27

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.
-___________________ attachment to skin

Question 28

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.
-___________________ no electrical coupling between cells

Question 29

Which of the following statements accurately describes cardiac muscle?

A) cardiac myocytes attach primarily to other myocytes
B) cardiac myocytes are electrically coupled to each other
C) cardiac muscle contracts without neural input
D) all of the above accurately describe cardiac muscle tissue

Question 30

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

A) cardiac action potentials last 100X longer than those in a neuron or skeletal muscle
B) voltage-gated sodium channels open during membrane depolarization
C) voltage-gated calcium channels open during membrane polarization
D) hyperpolarization-activated cyclic nucleotide (HCN) channels release calcium from intracellular stores

Question 31

Explain how a cardiac myocyte in the sinoatrial (SA) node can contract rhythmically. In your explanation, be sure to discuss the role of voltage-gated sodium and calcium channels, as well as hyperpolarization-activated cyclic nucleotide (HCN) channels.

Question 32

Which of the following statements does NOT accurately describe the structure and function of the heart?

A) The atrioventricular (AV) node is found in the right atrium
B) Purkinje fibers are specialized myocytes that propagate action potentials similar to axons
C) Electrical coupling between cardiac myocytes ensures that depolarization (and thus contract) occurs nearly at the same time in all the myocytes in a ventricle
D) Purkinje cells that originate in the AV node primarily uses acetylcholine (ACh) as a neurotransmitter in coordinating ventricular contraction

Question 33

Analyze Figure 8.16B. In the text Which of the following can you conclude from these data?

A) The sinoatrial (SA) node is found in the right atrium
B) neural input via cholinergic synapses can modulate the activity of SA myocytes
C) cardiac myocytes exposed to acetylcholine contract increase in their contraction frequency
D) acetylcholine exposure leads to an action potential in cardiac myocytes

Question 34

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

A) Acetylcholine is a neurotransmitter that leads to depolarization of skeletal muscle fibers and cardiac muscle fibers.
B) Cardiac muscle has an intrinsic ability to contract, whereas skeletal muscle requires neural input
C) Cardiac muscle fibers attach to each other, whereas skeletal muscle fibers attach to tendons, bone, or skin.
D) Cardiac muscle fibers generally contain metabotropic acetylcholine receptors, whereas skeletal muscle fibers generally contain ionotropic (nicotinic) acetylcholine receptors.

Question 35

Based on its role in skeletal muscle and cardiac muscle, choose whether you would rate acetylcholine as an excitatory or inhibitory neurotransmitter. If you cannot choose one or the other, how might you evaluate whether a neurotransmitter is excitatory or inhibitory?

Question 36

Which of the following is NOT an example of smooth muscle tissue?

A) muscles that control pupil diameter
B) the muscle wall of the bladder
C) muscle that enables you to move your index finger
D) muscle that surrounds blood vessels
E) muscle that causes your body hairs to stand up

Question 37

Analyze Figure 8.17C. In the text What can you conclude from this image?

A) actin and myosin are both present in smooth muscle cells (myoepithelial cells)
B) actin filaments criss-cross myoepithelial cells
C) myoepithelial cells have only one nucleus
D) all of the above

Question 38

Which of the following statements accurately describe smooth muscle?

A) actin and myosin are both present in smooth muscle cells (myoepithelial cells)
B) actin filaments criss-cross myoepithelial cells
C) myoepithelial cells have only one nucleus
D) all of the above

Question 39

Compare and contrast smooth, skeletal, and cardiac muscle. Which of the following is NOT an accurate statement?

A) action potentials can lead to contraction in smooth muscle and skeletal muscle
B) voltage-gated sodium channels are primarily responsible for the initial depolarization in both smooth muscle and cardiac myocytes.
C) contraction in smooth, skeletal, and cardiac muscle is mediated by actin and myosin sliding relative to one another.
D) smooth muscle contracts 100s of times more slowly than skeletal muscle.

Question 40

Compare and contrast the molecular events that lead to contraction in smooth and skeletal muscle cells. What is responsible for cell depolarization? What events lead to interactions between myosin and actin? Outline each process and point out similarities and differences.

Question 41

Which of the following statements is accurate regarding the effects of norepinephrine on smooth muscle?

A) It is excitatory, causing depolarization of smooth muscle cells and contraction.
B) It is inhibitory, causing hyperpolarization of smooth muscle cells and relaxation.
C) It is released from small varicosities (swellings) on axons onto the smooth muscle tissue
D) all of the above are accurate statements

Question 42

Create a Venn diagram that illustrates similarities and differences in cardiac, skeletal, and smooth muscle. You must include at least 8 features of each cell type in the diagram. Note that some of the 8 will be shared-so you do not need 8 unique features for each.

Question 43

Which of the following is true regarding muscle relaxation?

A) skeletal muscle is relaxed when antagonizing muscles pull it back to its relaxed state
B) skeletal muscle relaxes when myosin heads push backward in an ATP-driven movement
C) smooth muscle relaxes when myosin heads push backward in an ATP-driven movement
D) skeletal muscle is relaxed when the pressure increases inside fluid-filled cavities

Question 44

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 _______________________.

A) skeletal muscle cell
B) cardiac muscle cell
C) smooth muscle cell
D) skin cell

Question 45

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 _______________________.

A) skeletal muscle
B) cardiac muscle
C) smooth muscle

Question 46

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

A) Outer hair cells express large amounts of prestin, a membrane-bound protein
B) Outer hair cells are responsible for the majority of sensory innervation that arises in the cochlea
C) Outer hair cells outnumber inner hair cells 3:1
D) Outer hair cells aid in the detection of quiet sounds

Question 47

Analyze Figure b8.1. In the text Which of the following can you conclude from these data?

A) hyperpolarized cells lengthen by 1-2%
B) depolarized cells shorten by about 10%
C) the change in cell length is the same at 10 kHz as it as at 40 kHz
D) the change in cell length is the same at 10 Hz as it as at 20 Hz

Question 48

Which as an accurate statement regarding insect flight in bees and flies?

A) the frequency of wing beats is limited by the rate of neuronal firing
B) antagonistic muscle groups that control wing beats contract when stretched
C) while flying, muscle cells are in a constant state of calcium-dependent excitation
D) all of the above

Question 49

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.

Question 50

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.

Question 51

Which of the following is an accurate statement regarding effectors?

A) Examples of exocrine glands include the pituitary and adrenal glands.
B) The actions of glands are generally much faster than skeletal muscle
C) Exocrine glands secrete a variety of hormones into the blood
D) None of the above are accurate statements

Question 52

Compare and contrast the neurons that innervate the anterior and posterior pituitary. Which statement is NOT accurate?

A) Hormones released from the posterior pituitary gland are synthesized in the hypothalamus
B) Oxytocin is released from the anterior pituitary
C) Magnocellular neurons are found in the supraoptic nucleus of the hypothalamus
D) The pituitary gland is located posterior to the optic chiasm.

Question 53

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.

Question 54

Which is an accurate statement regarding oxytocin release from the posterior pituitary gland?

A) oxytocin released into the bloodstream leads to contraction of the mammary glands
B) astrocytic processes between magnocellular neurons must be present for synchronous firing to occur
C) magnocellular neurons fire action potentials in response to milk release from mammary glands
D) gap junctions between magnocellular neurons disappear shortly after a rat gives birth to a litter of pups
E) all of the above are accurate statements

Question 55

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

A) Lactating rat mothers show increased astrocytes and astrocytic processes between magnocellular neurons as compared with non-lactating rat mothers
B) Lactating rat mothers show increased gap junctions between magnocellular neurons as compared with non-lactating rat mothers
C) Bursts of action potentials that last for greater than 10 sec are required in order to stimulate milk ejection in mammary tissue
D) higher frequency stimulation of the pituitary gland leads to increased oxytocin release as compared to lower frequency stimulation
E) all of the above can be concluded from these data

Question 56

Which of the following is NOT an accurate statement about oxytocin's role in parturition (giving birth)?

A) oxytocin release is suppressed when the there is pressure on the internal side of the cervix
B) magnocellular neurons release oxytocin, which causes contraction of uterine smooth muscle
C) Pitocin is a synthetic form of oxytocin and is given to women to induce labor
D) some mechanosensory neurons increase their firing rate when pressure is applied to the cervix

Question 57

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

A) the HPA axis was activated
B) leutinizing hormone released from the anterior pituitary caused estradiol to be released from the ovaries
C) parvocellular neurons have released estradiol from the anterior pituitary
D) gonadotropin releasing hormone has acted on the ovaries to cause estradiol release

Question 58

Tumors can arise from cells in the anterior pituitary gland. Predict what types of symptoms a person might experience from a pituitary tumor, making specific reference to the affected endocrine axis.

Question 59

Several feedback loops are described in this chapter. What distinguishes a positive feedback loop from a negative feedback loop? In your answer give at least one specific examples of a positive and negative feedback loop, including the tissues and cells involved the feedback loop's function in the organism.

Question 60

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

Question 61

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

A) endocrine disrupters often mimic female sex hormones
B) developing organisms tend to be more sensitive to endocrine disrupters than older animals
C) endocrine disrupters may have effects on sexual characteristics such as reproductive tissues and fertility rates
D) endocrine disrupters may have effects on body weight
E) all of the above are accurate statements

Question 62

Examine Figure 8.26. In the text What can be concluded from these data?

A) stress hormones are important for functional spatial memory in hippocampal lesioned rats
B) metyrapone is a good drug candidate for improving memory related to test-taking anxiety in humans
C) hippocampal-lesioned rats take longer to learn a water-maze task
D) all of the above can be concluded from these data

Question 63

The end of chapter 8 states that brain regions are multifunctional. Choose 3 brain regions and design a graphic that shows at least two functions associated with each area. In your description of each function, include evidence that the function is associated with that particular area of the brain.

Question 64

Which region of the brain is associated with normal, daily fluctuations in hormone levels?

A) bed nucleus of stria terminalis
B) suprachiasmatic nucleus of the hypothalamus
C) supraoptic nucleus of the hypothalamus
D) periventricular nucleus of the hypothalamus
E) all of the above

Question 65

Construct an argument that stress impacts the ability to recall information. Justify your response with data from experiments that have investigated stress hormones and their impact on memory functions.