Exam 2

Question 1

The _______ in neurons has a high abundance of voltage-gated sodium channels and determines whether an action potential will be fired.

Answer 1

axon hillock

Question 2

______________send action potentials AWAY from the central nervous system.

Answer 2

efferent neurons

Question 3

The resting membrane potential of neurons:

Answer 3

is negative.
is closer to the equilibrium potential of potassium than sodium.
is maintained by the sodium potassium pump.
can be changed in excitable cells like neurons
ALL OF THE ABOVE

Question 4

If a cell has a resting membrane potential of -70mV and the membrane potential changes to -55mV this is an example of:

Answer 4

depolarization

Question 5

If a neuron becomes permeable to sodium:

Answer 5

the neuron would depolarize.

Question 6

Graded potentials:

Answer 6

can sum temporally or spatially

Question 7

The rising or depolarization phase of an action potential is due to:

Answer 7

opening of voltage gated sodium channels.

Question 8

The falling or repolarization phase of an action potential is due to:

Answer 8

closing of voltage gated sodium channels.

opening of voltage gated potassium channels.

Question 9

The absolute refractory period of an action potential:

Answer 9

spans all of the depolarization phase and most of the repolarization phase.
is the period in which a second action cannot be fired.
is the period in which the voltage gated sodium channels are either open or inactivated.
causes the unidirectional flow of action potentials.
ALL OF THE ABOVE

Question 10

During the relative refractory period it is harder to fire another action potential because _________.

Answer 10

voltage gated potassium channels are open and the membrane is hyperpolarized.

Question 11

Unmyelinated axons:

Answer 11

have action potentials spread down the axon by contiguous conduction.

Question 12

Myelin:

Answer 12

allows for faster salutatory conduction of action potentials.

Question 13

Electrical synapses:

Answer 13

are formed when two neurons are connected by gap junctions.

Question 14

Order the following events that occur at the synapse from first to last. 1 - calcium triggers exocytosis of neurotransmitter from the presynaptic neuron 2 - neurotransmitter diffuses across the synapse and binds to a receptor on the postsynaptic cell 3 - an action potential reaches the axon terminal of the presynaptic cell 4 - neurotransmitter is removed from the synapse to terminate the response 5 - voltage gated calcium channels open on the axon terminal of the presynaptic cell 6 - the postsynaptic cell responds

Answer 14

3,5,1,2,6,4

Question 15

How are neurotransmitters removed from synapses?

Answer 15

all of the above.

Question 16

At an excitatory synapse neurotransmitter released from the presynaptic neuron may cause the:

Answer 16

opening of ligand gated non-specific cation channels on the postsynaptic cell

Question 17

What type of glial cells aid in the formation and modification of synapses?

Answer 17

astrocytes

Question 18

Which of the following is the correct order of the meninges, from neural tissue to bone?

Answer 18

Pia mater : arachnoid mater : dura mater

Question 19

Which of the following statements is correct about the solute composition of cerebrospinal fluid (CSF) compared to plasma?

Answer 19

CSF is lower in protein than plasma.

Question 20

The blood brain barrier:

Answer 20

is due to the capillary endothelial cells in the pia mater forming tight junctions with each other.

Question 21

The reticular formation in the ___________receives and integrates incoming sensory information.

Answer 21

brainstem

Question 22

The _______ SUBCONCIOUSLY coordinates muscle movement.

Answer 22

cerebellum

Question 23

Which part of the brain controls thirst and urine output, food intake, and body temperature, among other things?

Answer 23

hypothalamus

Question 24

The ________ in the diencephelon filters and refines sensory information, allowing us to direct our attention to specific external stimuli.

Answer 24

thalamus

Question 25

The ______ are pockets of grey matter in the interior of the cerebrum that help to select and maintain purposeful movement while suppressing useless or unwanted patterns of movement.

Answer 25

basal nuclei

Question 26

Which of the following characteristics is a specialization of the rleft side of the cerebrum in most individuals?

Answer 26

logic

Question 27

The ________ in the cerebral cortex deals with speaking ability and is found in the _______ lobe.

Answer 27

Broca’s area : frontal

Question 28

During an electroencephalogram (EEG) high frequency low amplitude ______ waves dominate when the patient is awake, relaxed with their eyes open.

Answer 28

beta

Question 29

Which of the following is found in the GRAY MATTER of the spinal cord?

Answer 29

efferent neuron cell bodies

Question 30

In the knee jerk reflex the quadriceps and hamstring are the________.

Answer 30

effector organs

Question 31

Most visceral organs are innervated by both the sympathetic and parasympathetic nervous systems an exception to this rule is:

Answer 31

most arterioles and veins are innervated only by the sympathetic nervous system.

Question 32

Which of the following is NOT characteristic of sympathetic pathways in the peripheral nervous system?

Answer 32

postganglionic fibers release acetylcholine

Question 33

The adrenal medulla is considered part of the sympathetic nervous system because when stimulated it secretes:

Answer 33

epinephrine

Question 34

Parasympathetic stimulation ____ heart rate and ____ the motility of the digestive tract.

Answer 34

decreases : increases

Question 35

Muscarine is a compound found in toxic mushrooms. After consumption of mushrooms containing muscarine a patient may start to excessively salivate and have a decreased heart rate. Based on these symptoms muscarine is an acetylcholine ________ at muscarinic cholinergic receptors.

Answer 35

agonist

Question 36

The neuromuscular junction is a synapse between a ________ neuron and __________.

Answer 36

motor : skeletal muscle

Question 37

The release of acetylcholine at the neuromuscular junction is always ______ due to the fact that the motor end plate has nicotinic cholinergic receptors and when acetylcholine binds to those receptors _________ channels open.

Answer 37

excitatory : nonspecific cation

Question 38

Which of the following types of receptors would the body use to detect solute levels in the blood?

Answer 38

osmoreceptors

Question 39

The hair follicle mechanoreceptors in our skin are phasic and therefore ________ to stimuli and _____ sending action potentials to the central nervous system.

Answer 39

rapidly adapt : stop

Question 40

An afferent neuron codes for the intensity of a stimulus by:

Answer 40

changing the frequency of the action potentials it sends.

Question 41

Which of the following statements about sensory coding is FALSE?

Answer 41

The ability to locate the stimulus is inhibited by lateral inhibition.

Question 42

__________ detect skin temperatures between 20-35°C while ___________ detect skin temperatures between 30-43°C, _______ detect potentially damaging temperatures

Answer 42

Cold thermoceptors : warm thermoceptors : nociceptors

Question 43

Polymodal nociceptors are ______ receptors and _______ to sustained stimuli.

Answer 43

tonic : do not adapt

Question 44

Fast pain occurs _______ is transmitted on _______ neurons and is _____ localized.

Answer 44

first : myelinated : easily

Question 45

Pain signals from visceral receptors are ‘referred’ to the body surface because:

Answer 45

nociceptors from visceral organs synapse on the same second-order neurons as nociceptors from the skin surface.

Question 46

When your pupil constricts it is because the _______ nervous system causes the ______ muscles in your iris to constrict.

Answer 46

parasympathetic : circular

Question 47

If your lens is too weak and unable to do accommodation you will be hyperopic or farsighted and need _______ eyewear.

Answer 47

convex

Question 48

Which of the following statements is true about rods?

Answer 48

Rods are more numerous in the periphery of the retina.

Question 49

When we leave a dark theater and it is bright and sunny out, the retinal and opsin molecules within the ________ must first ________ before we can see clearly without squinting.

Answer 49

rods : bleach

rods : dissociate