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central dogma of molecular biology
DNA transcription mRNA transcript translation protein
amino acid derivatives
binding to its receptor sometimes produces a slow response and sometimes a fast response
steroids
binding to its receptor almost always produces a slow response
peptides
binding to its receptor produces a fast response
Which of the four organic biomolecules is pictured here?
nucleic acid
Which of the following hormones would bind with a receptor inside the cell?
steriods
paracrine signals
Paracrine signals communicate with adjacent cells. Autocrine signals are often also paracrine signals.
The role of oxygen in cells is to?
act as an electron acceptor
enzymes
metabolic catalysts lower activation energy proteins
What is the extracellular matrix of blood called?
Plasma
Which of the four major classes of organic biomolecules has up to three different folded structures?
proteins
When a catecholamine or peptide hormone binds to receptors on the surface of a cell...
second messengers are activated
What catabolic pathways in the body produce ATP?
glycolysis (2 ATP), citric acid cycle (2 ATP), and the electron transport chain (26-28 ATP)
Which of the following glial cells is found in the peripheral nervous system?
Schwann cells
The conduction of an action potential along an axon...
is not faster for a strong stimulus than a weak stimulus is not faster along unmyelinated nerve fibers does not decrease in amplitude as it is propagated along the axon
If GABA binds receptors on a post-synaptic cell body, what will likely happen to the membrane potential?
hyperpolarization
Where are synapses primarily located?
in grey matter
Which is least likely to diffuse across the blood brain barrier?
lipophobic molecule
If fluid taken from a lumbar puncture is not clear and colorless, this could indicate:
either an infection or a brain hemorrhage depending on the color
Which component(s) of the central nervous system is/are responsible for the basic functions of life (e.g., involuntary breathing and heart rate, relaying of sensory and motor signals)?
brain stem spinal cord
dorsal root and horns
receive afferent signals
ventral root and horns
project efferent signals
parasympathetic division
dominates during the "resting and digesting" time and its ganglia are on or near the target organs
"dual innervation"
organ receiving both sympathetic and parasympathetic nerves
Imagine a scenario where a presynaptic neuron's voltage-gated Ca+ channels failed to open in response to the neuron's depolarization. Which of the following would result from this situation?
neurotransmitter would not bind to the receptors on the the postsynaptic neuron
protection of the brain
cranium dura matter subarachnoid space cerebrospinal fluid (CSF)
During the rising phase of the action potential...
Na+ moves down both a concentration and electrical gradient.
A presynaptic neuron releases excitatory neurotransmitter into the synaptic cleft twice in a span of milliseconds. The resulting graded potential in the postsynaptic neuron reaches threshold and fires an action potential. This is an example of?
temporal summation
During a dissection, you observe a motor neuron that exits the spinal column at the level of thoracic vertebrae #3. It reaches its autonomic ganglion almost immediately upon exiting the spinal column. This must be a:
sympathetic pathway
central nervous system
brain and spinal cord
myelin sheath
does not cover the entirety of the axon increases the speed of an action potential composed of neuroglial cells
A neuron releases acetylcholine into the synaptic cleft at its target tissue. The acetylcholine binds muscarinic receptors initiating a response in the target tissue. Which autonomic pathway is this?
parasympathetic
secondary endocrine disorder
too much or too little hormone form the anterior pituitary
Considering a neuron with excitatory post-synaptic potential, you would predict that a drug binding and inactivating the breakdown enzyme for its neurotransmitter would result in...
more post-synaptic action potentials
Which statement accurately describes why a graded potential loses amplitude as it moves away from its stimulus?
Charged ions leak out of the membrane before reaching the trigger zone.
The nervous system's ability to communicate is primarily dependent on the movement of…
charged particles
blood-brain barrier
can be comprised of tight junctions between endothelial cells permeable to small, nonpolar, or lipophilic molecules helps protect the brain from pathogens
Successful recovery from a brain injury, like that seen in the case of Phineas Gage, likely requires the re-wiring of neuronal connections and possibly even the formation of new neurons. This type of reorganization is called...
neural plasticity
In a complex endocrine pathway, long-loop negative feedback inhibits...
the hypothalamus and/or the pituitary
During sexual intercourse, secretion and lubrication of the vagina is accomplished via parasympathetic innervation to the uterus, while contraction of the uterus (and/or vagina) is accomplished via sympathetic innervation. Similar to the male orgasm, these are best described as _________.
synergistic (or cooperative) effects
If the white matter of the spinal cord is damaged, what symptoms would you expect?
impaired sensory relay impaired movement
How does electroencephalography (EEG) detect brain activity?
free electrons in the metal electrodes respond to the flow of ions in and out of neurons
The brain is mostly composed of…
Which is used for rapid signaling over long distances?
action potentials
neurotransmitters that hyperpolarizes the cell will...
decrease the probability that the cell will produce an action potential makes the cell body more negative
In order for an action potential to be propagated, the threshold membrane potential in the cell body must be reached…
once, at the axon hillock
somatosensory cortex
processes general sensory information and the size of the area dedicated to each part of the body is correlated with receptor concentraction
sodium-potassium (NaK) pump
uses active transport binding of potassium (K+) triggers the pump to change shape when the pump is open to the intracellular fluid its shape proves binding sites for sodium (Na+)
A neuronal pathway emerging from the cranial region that slows the heart rate must be a...
parasympathetic pathway
Neurotransmitter is stored and released from...
axon terminals
agonistic effects on the primary endocrine gland will...
increase production of the primary hormone decrease production of releasing hormone from the hypothalamus decrease production of tropic hormone from the anterior pituitary
afferent neurons
transmits information coming into the central nervous system
Both the cell body and the axon have Na+ channels. Are these channels the same or different? If so, how?
different, cell body has chemically-gated channels and axon has voltage-gated channels
action potential sequence
Na-K pump establishes resting membrane potential
stimulus causes a graded potential
graded potential reaches threshold at the axon hillock
voltage gated Na channels open near the axon hillock
additional voltage-gated Na channels open along the axon
Na-K pump re-establishes resting membrane potential
Which of the following is secreted by neurons AND acts via diffusion across a synapse?
neurotransmitters
What is the primary event causing the voltage change indicated by #4 on this image?
opening of voltage-gated sodium channels
What is located in the medulla oblongata?
centers for respiratory control (breathing) pyramids, where tracts cross to the opposite side of the body centers for vomiting control
Which neurocrine behaves as a neurohormone in the PNS and as a neurotransmitter in the CNS?
epinephrine
peripheral nervous system (PNS)
consists of all sensory and motor neurons outside of the CNS contains components of the autonomic and somatic nervous system
limbic system
center for emotions
spatial summation
can be excitatory or inhibitory
The total amount of neurotransmitter released at the axon terminal is directly related to the…
total number of action potentials
charge distribution across a neuron's membrane
extracellular fluid = positive intraceullar fluid = negative
Which of the following is true about efferent information in the central nervous system?
can be carried from the CNS by motor neurons
A person with defective rods will have trouble...
distinguishing shapes at the periphery of the visual field seeing well in the dark
A blind spot in the retina occurs where...
the optic nerve leaves the eye
iris
controls diameter of the pupil
rhodopsin
light receptor
tectorial membrane
stimulates hair cells
cristae in ampullae
senses rotational movement
otoliths in maculae
senses lateral movement
The primary purpose of the middle ear bony structures (maleus, incus and stapes) is to...
amplify the vibration as it conducts to cochlea
You work at the Tabasco factory in Louisiana. You spend your workday blending barrels of fermented chili peppers with vinegar and bottling hot sauce. The smells do not bother you, because...
Olfactory receptors are phasic, they quickly adapt to constant stimulus.
skeletal muscle contraction
starts when the muscle fiber depolarizes due to the release of calcium into the cytoplasm
Why does rigor mortis occur after death?
myosin is tightly bound to actin there is no ATP available to bind to myosin
Which is a potential energy source for an athlete sprinting the 40-yard dash?
phosphocreatine
smooth muscle contraction
Ca2+ initiates the contraction uses actin-myosin crossbridges to create force contraction can occur without a change in membrane potential
As a protective mechanism, stretching a skeletal muscle fiber causes sensory neurons (i.e. proprioceptors) to ______ their rate of firing.
increase
troponin and tropomyosin in skeletal muscle contraction
they inhibit the bindings necessary for contraction
Most reflex movements are integrated by…
the spinal cord
Which is a characteristic of slow-twitch oxidative skeletal muscle fibers?
long contraction duration AND many mitochondria
Stretching a muscle spindle causes…
reflex contraction of that muscle.
Which of the following represents a somatic motor pathway?
Figure A
In the human eye, if the ________ focuses the light anywhere but the ________ then vision is imperfect.
lens, fovea
Bob fell off a ladder trying to clean out his gutters. His wife rushed him to the emergency room. The doctor tested his knee-jerk reflex and found it was normal. These results suggest that?
Bob has no damage to his spinal cord.
A person with defective rods will have trouble...
distinguishing shapes at the periphery of the visual field seeing well in the dark
If you were floating in outer space experiencing zero gravity, the weightlessness would cause the otoliths in your macula to lose their reference point. Which of these sensations might you expect to have difficulty perceiving?
head position linear acceleration
The neurons of the special senses each carry information to cortexes in the brain that are specific to each sense. However, general sensation information is all carried to the…
somatosensory cortex
In smooth muscle, the Ca2+ necessary for contraction can come from…
the sarcoplasmic reticulum the extracellular fluid
feedforward control
allows the body to anticipate a stimulus and begin a movement
negative feedback
generally result in the cessation of that movement
If glutamate is normally an excitatory neurotransmitter, why are some bipolar cells turned ON by light and some OFF by light?
different receptors
chemoreceptor
surcrose solution
mechanoreceptor
muscle tension
thermoreceptor
temperature
Sweet, bitter, and umami signals are communicated through a G-protein coupled ______ which can amplify the signal sent to the primary sensory neuron.
second-messenger system
After an injury, Jodie has difficulty recognizing and interpreting certain sounds. These symptoms imply damage to the…
auditory cortex
During crossbridge cycling, the binding of ATP to the myosin head…
releases the myosin head from actin
M line
C
Z line
A
Note
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