Chapter 10: Muscle Tissue
What is the smallest contractile unit in a muscle fiber?
Sarcomere
The movement of what ion outside the cell initiates repolarization?
K+
What structure is responsible for production of cerebrospinal fluid?
choroid plexus
negative
You are sitting in a loud coffeeshop studying for your BIO245 exam. After awhile, you are no longer distracted by the noise of the coffeeshop.
What part of your brain is responsible for this?
thalamus
What protein is found in thin myofilaments?
actin
Which cell is responsible for myelination in the CNS?
oligodendrocytes
What is the only sense that does not have to be processed through the thalamus?
olfaction/smell
What is the role of Ca2+ in skeletal muscle contraction?
binds to troponin, changes its shape, reveals myosin binding site on actin
Describe what would happen if acetylcholinesterase was unavailable at the neuromuscular junction. How would skeletal muscle contraction be affected?
ACh would remain in synaptic cleft, muscles would stay contracted until the depletion of ATP
What are the components of the triad in skeletal muscle?
a transverse tubule and two terminal cisternae
What is the function of the sodium-potassium pump?
maintain resting membrane potential
limbic system
What do we call the space between a neuron and the cell it stimulates?
synaptic cleft
Multiple sclerosis is a demyelinating disease that causes damage to nerve cells in the CNS. Explain how demyelination would cause tremors in MS patients.
action potential can no longer effectively jump from node to node
slower propagation= shaky/uncontrolled movement
What converts a myosin head back to the high-energy state?
hydrolysis of ATP
Describe the difference between continuous conduction and saltatory conduction.
Saltatory: propagation of AP down myelinated axon, AP jumps between Schwann cells on Nodes of Ranvier
What three structures compose the diencephalon?
epithalamus, thalamus, hypothalamus
The occipital lobe is responsible for which sense?
vision
Explain how a drug that interferes with reuptake of neurotransmitter, such as serotonin, would affect nerve impulses.
Cells would be stimulated more often/continuously and more impulses would be initiated. With serotonin, a person would remain "happier" for longer.
Describe summation. What must occur for wave summation to progress to tetanus?
Increased frequency of stimulus will lead to tetanus.
Explain the difference between absolute refractory and relative refractory.
Absolute: no amount of stimulus can initiate a second action potential
Relative: follows absolute, AP can be initiated, more stimuli required
Name at least two protective features of the brain.
cranial bones
meninges (dura, arachnoid, pia mater)
cerebrospinal fluid
blood-brain barrier
Explain the advantage of myelinated axons.
quicker impulse transmission
Describe the types of symptoms we would expect to see in a patient who had frontal lobe damage.
trouble problem-solving, behavioral issues/impulsivity, difficulty thinking, personality changes