LS 7C - Part 1 Flashcards
What happens to a signal after it binds the receptor?
A. It stays bound until the receptor is destroyed
B. It eventually dissociates from the receptor
C. It is eventually destroyed by the receptor
D. It dissociates from the receptor when a termination signal is received
B. It eventually dissociates from the receptor
Why do the functions of many receptor kinases depend on the fluid nature of the plasma membrane?
A. The activation of enzyme pathways requires a fluid membrane.
B. Binding of ligand to the receptor requires a fluid membrane. C. The receptor monomers must move together and dimerize to be activated.
D. Phosphorylation requires a fluid membrane.
C. The receptor monomers must move together and dimerize to be activated.
A decrease in cell adhesion, by the introduction of an experimental substance to a tissue, compromises the strength of the tissue. Which cell junction would MOST likely be affected if a tissue is treated with this experimental substance?
A. adherens junctions
B. gap junctions
C. hemidesmosomes
D. tight junctions
A. adherens junctions
Which of the following junctions would you predict to be most important for the function of the bladder?
A. adherens junctions
B. gap junctions
C. hemidesmosomes
D. tight junctions
D. tight junctions
Older individuals have fragile skin that causes bed sores. The outer layer of skin can detach and blister in response to friction. Increased susceptibility to blister formation is caused by the loss of which component in the skin?
A. Skin signal pathway transducers
B. Cell cytoskeleton proteins
C. Cell adhesion molecules
D. Extracellular matrix proteins
D. Extracellular matrix proteins
True or False: The signal can only be terminated in one location in the cell.
False
Endocrine Signaling:
A. Is contact dependent
B. Signals to nearby cells through diffusion
C. Travels through the circulatory system
D. Is a type of signaling whereby the cell signals to receptors on its own cell membrane
C. Travels through the circulatory system
Name a type of signaling molecule used in Paracrine Signaling.
Usually small, water-soluble molecules such as Growth Factor
When is a time during development that Autocrine Signaling is important?
During the development of the embryo (for instance, to maintain specialization after differentiation of cell types.)
What type of change occurs in the protein at the ligand binding site?
Conformational Change
What is an example of a hydrophobic molecule?
Steroid
After a GCRP is activated, the alpha subunit attached to what protein?
Adenylyl Cyclase
What is a Kinase?
An enzyme that catalyzes the transfer of a phosphate group from ATP to a substrate.
Is a phosphorylated protein considered activated or deactivated?
Activated
Do phosphotases add or remove a phosphate group? What is this process called?
Remove. Dephosphorylation.
What is it called when two sides of a receptor kinase is activated and comes together?
Dimerization
What do Ion channels provide?
A hydrophilic pathway
What are two types of controls for Ion Channels?
Voltage-gated and Ligand-gated
What determines how long a ligand will be bound to its receptor?
Binding Affinity
What are the 3 layers of skin?
Epidermis, Basal Lamina, Dermis
What is the function of the cytoskeleton?
It determines the shape of cells.
What are 3 types of motor proteins?
Kinesin, Dynein, and Myosine
What are the subunits of Microtubules, Microfilaments and Intermediate filaments?
Tubulin dimers, Actin monomers, diverse proteins
What is a transmembrane protein called?
Cadhedrin
What allows adhesion to the extracellular matrix?
Integrins
Give several examples of the extracellular matrix.
Elastin, Collagen, Fibroblasts, Basal Lamina, Laminin
What are the 3 types of nerve cells?
Sensory neurons, interneurons, and motor neurons.
What is an astrocyte?
A star-shaped glial cell. Contributes to blood-brain barrier by surrounding blood vessels in the the brain, thus limiting the size of compounds that can diffuse from the blood to the brain.
Explain Membrane Potential.
The difference in charge between the exterior and interior of the cell membrane. Measure in volts. (Only muscle and nerve cells respond to potentials.)
At what end of the neuron does depolarization begin?
The terminal end of a dendrite.
Where must the signal be strong enough to initiate an action potential?
Axon Hillock
What type of receptors are Post-Synaptic Membrane Receptors?
Ligand-gated Ion Channels (accept neurotransmitters from the corresponding cell’s axon terminal)
Is an Excitatory Postsynaptic Potential a positive or negative change in membrane potential? What is another name for this? What principle ion(s) is involved?
Positive, depolarization, Sodium (Na+), also Potassium (K+) in lesser amounts
Is an Inhibitory Postsynaptic Potential a positive or negative change in membrane potential? What is another name for this? What principle ion(s) is involved?
Negative, hyperpolarization, Cholride (Cl-)
What are the two divisions of the Autonomic nervous system?
Sympathetic (fight/flight), Parasympathetic (rest/digest)
Is the autonomic nervous system apart of the Peripheral or Central nervous system?
Peripheral
What are the 3 major brain regions?
Hindbrain, Midbrain, Forebrain
Name the major component in the Limbic system?
Hippocampus
Name 3 major regions in the Forebrain.
Cerebral cortex, thalamus, hypothalamus
Name 3 major regions of the Hindbrain.
Pons and medulla (part of brainstem), cerebellum
What is the Cerebellum responsible for?
Complex motor tasks, integrating sensory and motor information
What is the Thalamus responsible for?
It is a relay station for sensory information. Sends information to cerebrum.
What is the Hypothalamus responsible for?
It interacts with autonomic and endocrine system to regulate general physiological state of the body.
What is the Cerebrum?
The outer left and right hemispheres of the cerebral cortex.
What is the Limbic System responsible for?
It controls physiological drives, instincts, emotions, motivation, and a sense of reward. Major component is the Hippocampus.
From anterior to posterior, name the lobes and other regions that separate the 4 major lobes.
Frontal lobe, Primary Motor Cortex, Central Sulcus, Primary Somatosensory Cortex, Occipital lobe, Visual Cortex.
What is Grey Matter composed of?
Densely packed neuron cell bodies and dendrites. Highly folded, make up cortex. Around 4mm thick.
What is White Matter composed of?
Axons of cortisol neurons in interior of the brain. White appearance due to fatty myelin produced by glial cells surrounding the axons.
What does the Central Sulcus separate?
The primary motor cortex and the primary somatosensory cortex.
What is Long-Term Potentiation?
The persistent strengthening of synapses based on recent patterns of activity.
True or False: Resting potential is generated mainly by the outward movement of K+ ions from inside the cell.
True
True or False: The voltage changes shown in the figure are measured just across the plasma membrane
True
True or False: The changes in voltage seen at #2 and #4 in the figure are caused by similar movements, in the same direction, of the same types of ions across the membranes.
False
True or False: The trace in the figure is following the voltage change as it moves down the axon.
False
True or False: The voltage change shown in the figure is an all-or-nothing response.
True
True or False: Different ion channels are responsible for generating the voltage change seen at #2 and #4 in the figure.
True
True or False: All voltage changes along the plasma membrane of an axon have the characteristic shape shown above.
True
True or False: The changes in voltage shown in the figure are due to ligand-gated ion channels opening and closing along the axon.
False
True or False: An EPSP of sufficient strength to reach threshold occurred at #1 on the figure.
True
True or False: A membrane that has no K+ channels will have a resting membrane potential that is higher than the one shown on the figure.
True
Imagine you genetically engineered a neuron to produce voltage-gated Na+ and K+ channels that opened at the same time in response to a change in voltage. How would that change the recording shown in the figure?
A. The peak voltage would be higher.
B. The peak would occur over a longer period of time.
C. Threshold values would increase.
D. The period of hyperpolarization would be longer.
E. No action potential would be generated.
E. No action potential would be generated.
Dilated pupils, inhibited digestive activity, increased respiratory rate, and release of glucose from the liver are all signs of activity of:
A. the sympathetic division of the autonomic system.
B. both divisions of the autonomic nervous system.
C. the somatic nervous system.
D. the parasympathetic division of the autonomic system.
A. the sympathetic division of the autonomic system.
What effect does the nervous system have on the heart rate?
A. Stimulation by sympathetic nerves sets the resting heart rate of the pacemaker cells in the SA node.
B. Stimulation by parasympathetic nerves causes the heart rate to slow down.
C. The nervous system does not directly affect the heart rate.
D. Stimulation by either the sympathetic or parasympathetic nerves causes pacemaker cells in the SA node to depolarize more slowly.
E. Stimulation by sympathetic nerves causes the pacemaker cells of the AV node to depolarize more rapidly than the pacemaker cells of the SA node.
B. Stimulation by parasympathetic nerves causes the heart rate to slow down.
Which of the following is an example of the effector’s role in maintaining homeostasis?
A. decrease in body temperature on a cold day
B. increased sweating on a hot summer day
C. vasodilation on a cold winter day
D. increased body temperature during a workout
B. increased sweating on a hot summer day
Imagine you created a toxin such that when a neuron fired an action potential, the toxin would bind immediately to the sodium-potassium pump at the top of the action potential, but the sodium and potassium channels would still function. What process(es) would be affected?
A. maintaining resting potential and returning to resting potential after the hyperpolarization phase of an action potential
B. the hyperpolarization phase of an action potential
C. returning to resting potential after the hyperpolarization phase of an action potential
D. maintaining resting potential
E. the depolarization phase of an action potential
A. maintaining resting potential and returning to resting potential after the hyperpolarization phase of an action potential
An interneuron may receive multiple stimuli from the same sensory neuron over a very short period of time. The firing rate of the receiving neuron is proportional to the number of signals received from the sensory neuron over time. Of which of the following is this an example?
A. action potential
B. hyperpolarization
C. spatial summation
D. temporal summation
D. temporal summation
Imagine that you are talking with one of your friends about your biology course. He states that the somatic nervous system is subdivided into sympathetic and parasympathetic components, and is responsible for involuntary responses. Is this statement correct?
A. No, the somatic nervous system is responsible for voluntary responses, and is not subdivided into sympathetic and parasympathetic components.
B. No, although the somatic nervous system does have both sympathetic and parasympathetic subdivisions, it is responsible for voluntary responses.
C. No, although the somatic nervous system controls involuntary responses, it is the autonomic nervous system that is subdivided into parasympathetic and sympathetic components.
D. Yes, this statement is correct. The somatic nervous system has both sympathetic and parasympathetic components and controls involuntary responses.
A. No, the somatic nervous system is responsible for voluntary responses, and is not subdivided into sympathetic and parasympathetic components.
What does this negative resting potential mean?
A. The inside (ICF) of the axon is more negatively charged than the outside (ECF)
B. The outside of the axon (ECF) is more negatively charged than the inside (ICF)
A. The inside (ICF) of the axon is more negatively charged than the outside (ECF)
Potential = Inside - Outside
If a membrane were freely permeable to allcharged molecules, then the resting membrane potential would be _________.
A. Positive
B. Negative
C. Zero
C. Zero
A cell with a resting membrane potential of -70 mV suddenly becomes more permeable to Ca2+ ions. This cell will
A. Hyperpolarize
B. Depolarize
C. Neither (membrane potential will not change)
B. Depolarize
What kind(s) of ion channels would you expect to find in the plasma membraneof a neuron’s dendrites?
A. Ligand-gated ion channels only
B. Voltage-gated ion channels only
C. Both of these channels
A. Ligand-gated ion channels only
Which of the following best describes what is happening during Region 1 of the action potential?
A. Hyperpolarization due to cations leaving the cell
B. Depolarization due to cations leaving the cell
C. Hyperpolarization due to cations entering the cell
D. Depolarization due to cations entering the cell
D. Depolarization due to cations entering the cell
- Sodium ions enter the cell, making the inside of the cell more positively charged than the outside
Which of the following best describes what is happening during Region 2 of the action potential?
A. Repolarization due to cations leaving the cell
B. Repolarization due to cations entering the cell
A. Repolarization due to cations leaving the cell
- Potassium ions leave the cell, making the inside of the cell more negatively charged than the outside
Which of the following best describes what is happening during Region 3 of the action potential?
A. Hyperpolarization due to cations leaving the cell
B. Depolarization due to cations leaving the cell
C. Hyperpolarization due to cations entering the cell
D. Depolarization due to cations entering the cell
A. Hyperpolarization due to cations leaving the cell
- Potassium ions continue to leave the cell, causing an overshoot of the resting membrane potential