Anatomy I Exam 3

For the presynaptic vesicles to fuse with the presynaptic membrane and release a neurotransmitter into the synaptic area,________ ions have to be present in the axoplasm.

Calcium -Calcium ions diffuse into the cell through voltage gated Ca channels which causes the synaptic vesicles to fuse with the pre-synaptic membrane and release the neurotransmitter into the synaptic cleft.

In a nerve cell, where is action potential propagated along the axon?

At the node of Ranvier

The digestive tract is innervated by which subsection of the nervous system?

Autonomic

___ cells "teach" ____ cells how to recognize pathogens or infected cells so that they can be destroyed.

B; T

In the image below, why do we find no ascending or descending tracts in the gray matter (butterfly)?

Because myelin is white

Which of the following statements about bioelectrical properties of cell membranes is NOT true?

Bioelectricity is not found in muscle cells.

The midbrain forms a major part of the _______.

Brainstem

TRUE or FALSE: A post synaptic cell can interpret simultaneous EPSPs and IPSPs.

TRUE

The somatosensory cortex is part of the parietal lobe whereas the motor cortex is part of the frontal lobe.

TRUE

The 'all-or-nothing law' for action potential in a nerve cell means which of the following?

That the strength of the stimulus must reach a certain threshold level

Which of the following descriptions of the spinal nerve gross anatomy is correct?

The first spinal nerve leaves between foramen magnum and atlas. -The foramen magnum is the opening in occipital bone for spinal cord and first cervical vertebrae is the atlas.

What is the role of Ca in a chemical synapse?

To trigger neurotransmitter release when the concentration of Ca2+ inside the presynaptic neuron increases

Fill in the blank. Motor neurons exit the spinal cord through the ______.

Ventral root

In addition to meninges, fluid-filled spaces help protect the brain nervous tissue. The subarachnoid space would be found between which two meninges?

arachnoid and pia mater -The pia mater is internal, directly against the nervous tissue without a space and subarachnoid means it is below the arachnoid mater.

axon hillock

area between the axon and somas 1st voltage gated channels( sodium channel)

Which of the following central nervous system cells regulate ions, regulate the uptake and/or breakdown of some neurotransmitters, and contribute to the formation of the blood-brain barrier?

astrocytes

The nerve impulse travels down a(n) ,__________ away from the cell body.

axon

Which part of the neuron converts electrical potential to chemical stimuli for other neurons or target effector?

axon -At the axon synaptic terminal vesicles will release a chemical messenger across synapse in response to action potential reaching the axon terminal.

Which part of the neuron sends output to "effector"?

axon -If threshold is reached at cell body this carries the action potential to its synaptic terminal to stimulate another neuron or effector.

Which part of the neuron has plasma membrane proteins that will initiate an action potential a long distance away toward its target, if the signal reaches a strong enough level called the threshold?

axon -The axon hillock will initiate an action potential that travels away from cell body if threshold is reached.

The two vertebral arteries merge to form the ___ artery.

basilar

When we measure membrane potential, one probe detects the charge on the outside of the cell, and another detects the charge on the inside of the cell. Which probe tells us what the membrane potential is?

both; membrane potential is the difference in reading of the inside and outside probes.

The radial nerve arises from the ______ plexus

brachial

How can a specific neurotransmitter, such as norepinephrine, excite one type of cell in the body causing increased metabolic activity, but inhibit another cell elsewhere in the body at the same time?

by binding to receptors that cause different effect in cell -As with the muscarinic and nicotinic cholinergic receptors, there are different alpha and beta adrenergic receptors for norepinephrine on different effector cells and they can have either excitatory or inhibitory effects at the effector cell.

Which part of the neuron has most of the typical cellular organelles and the nucleus?

cell body (soma) -Even though it can receive input directly from other neurons, the cell body functions for cell metabolism and integration of signals for propagation if threshold is reached.

Which part of the neuron conducts electrical impulses?

cell body (soma) -This would get the electrical input from one or more cell extensions that converted chemical input to electrical.

All parts of the hindbrain and midbrain include both gray and white matter. Which part when sectioned would have a distinctive tree-branching shaped white matter pathway extending into folded gray matter cortex with increased surface area to quickly coordinate signals into and out of this brain part?

cerebellum -The myelinated white matter of the cerebellum is arranged in the arbor vitae, which means "tree of life" .

voltage = potential=

charge difference across the membrane

Electrical signals are relayed from neuron to neuron through ____.

chemical synapses

The special arterial structure at the base of the brain that helps to preserve continuous blood supply to the brain is called __.

circle of willis

Spinal nerves are ____.

combined sensory and motor axons

Which types of fibers travel through the corpus collosum?

commissural fibers

what causes local concentration differences in salatory conduction?

compression waves

Association fiber:

connects different parts of the cerebral cortex -pathway to same side of brain different place

Commissural fiber:

connects left and right hemispheres -pathway through corpus collosum (contains 90% of commissural fibers)

The main difference between oligodendrocytes and Schwann cells is...

their location -Oligodendrocytes are exclusively in the central nervous system and Schwann cells are exclusively in peripheral nervous system.

Why is the cerebral cortex foliated?

to allow head size to remain small while the amount of gray matter increases

What is the purpose of myelin?

to increase the speed of the action potential

salatory conduction =

fast

Are nuclei white matter or gray matter?

gray

butterfly shape in spinal cord is the

gray matter (cell bodies)

Satellite cells would most often be associated with what structural type of neuron?

unipolar -Unipolar sensory neuron cell bodies are surrounded by satellite cells in the ganglia while Schwann cells surround their dendrite/axon branches.

Which of the following is true about action potentials, but not graded potentials?

uses voltage-gated channels -The trigger zone has many voltage-gated channels that can start the action potential and they are also involved in the propagation of action potential on axon.

limbic system

hypothalamus, amygdala, hippocampus

Membrane potential is measured in ___.

millivolts (mV)

An IPSP causes the membrane potential to become ____

more negative

Projection fiber:

motor pathway leading out of the cerebrum -carries information out of the cerebrum

The pathologist, Robert Carswell, published this drawing in 1838 of a dissected CNS with lesions from multiple sclerosis. Notice that much of the tissue is white. The lesions are brown. What is missing from this nervous tissue that would contribute to the change in color?

myelin

Fill in the blanks. The charge of a nerve cell membrane that is not propagating a nerve impulse is ______; when it is depolarized to propagate an action potential, its charge is ______.

negative inside and positive outside; positive inside and negative outside

Which of the following would not be associated with formation of the Node of Ranvier?

neuronal cell bodies -Neither the soma nor synapses would be myelinated.

B-cells circulate in the blood. Do they normally encounter CNS myelin? Discuss why or why not in your groups.

no

visceral sensory division

not conscious -internal sensory experience -EX: BP in vessels; autonomic

When the membrane is depolarizing, K+ ions are ____

not flowing across the membrane (in significant quantities)

Which part of the cerebral cortex contains the visual center?

occipital lobe -The visual sensory region is located in this posterior lobe.

Name the CNS counterpart of Schwann cells.

oligodendrocytes

When you stand, blood pressure in your head drops due to the force of gravity. The ____ reflex prevents you from passing out when you stand.

orthostatic reflex

In which type of neural circuit does the output cell receive the same signal (generated by the input cell) at several different times in order to provide continuity even during input signal disruption?

parallel-after discharge

Which activities are under control of the anterior lobe?

planning/practicing/ learning complex movements posture/locomotion/fine motor coordination

Some spinal nerves reorganize into a systemic nerve at a structure called a

plexus/nerve plexus

Fill in the blanks. When a neurotransmitter binds to a ______on the dendrite, a______ ion channel opens up to allow certain ions to flow in, depending on the channel.

receptor; ligand-gated

Which of the following is NOT a function of the nervous system?

release chemicals into the bloodstream for distribution throughout the body -This is a function of the endocrine system, not the nervous system. Those chemicals are called hormones.

continuous conduction =

slow

potassium channels take longer to open than

sodium channels

What type of summation achieves an action potential in a neuron resulting from simultaneous input of multiple other neurons?

spatial summation -the input from Multiple neurons at different locations on the postsynaptic neuron with receptors can add up to cause an action potential.

Which of the following is part of the forebrain but not part of the cerebrum?

thalamus -This is part of the diencephalon, deep to the cerebrum.

mylein sheaths help

the action potential travel faster -130 meters/sec

Membrane potential is ____.

the charge difference across the membrane

Myelination allows an action potential to travel faster down the axon by/through ____.

the creation of compression waves of cations that travel under the myelin sheaths

A synapse is the space between

the presynaptic neuron and the post synaptic neuron

Spinal nerves are part of the _.

PNS

how may neurons are in the cerebellum

100 billion

resting membrane potential

-70mV

An excitatory post synaptic potential (EPSP) is (Select all that apply):

-Depolarizing -Graded

Which cell type(s) produce(s) myelin?

-Schwann cells -oligodendrocytes

In a membrane potential (mV) versus time (ms) graph, what happens at the peak? Select all that apply.

-Sodium (Na+) ion channels are inactive. -Potassium (K+) ion voltage-gated ion channels are open. -Sodium (Na+)/Potassium (K+) ion channels are open.

Which statements are true? Select all that apply.

-There is a higher concentration of potassium ions (K+) inside of the cell than outside at resting membrane potential. -There is a higher concentration of chloride ions (Cl-) outide of the cell than inside at resting membrane potential. -The sodium-potassium ion (Na+/ K+) pump uses ATP to move 3 Na+ ions out of the cell for every 2 K+ ions that move into the cell. -K+ ions cannot freely diffuse across the phospholipid bilayer membrane.

Which behavior(s) is/are likely to depend heavily on the anterior lateral hemispheres of the cerebellum?

-extending arm and finger to touch a small target -remaining upright while sitting

The purpose of the absolute refractory period is to _____. (Select all that apply)

-help give the membrane time to repolarize -prevent an action potential from flowing backwards

Demyelination can be caused by which of the following? (Select all that apply)

-infections -vitamin deficiencies -genetic mutations

Which arteries directly supply oxygenated blood to the Circle of Willis?

-internal carotid -vertebral

Which of the following could generate an IPSP? Select ALL correct answers.

-opening of K+ channels -opening of Cl- channels

In which situation(s) would you expect to see more activity (more action potentials) occurring in the brain? Select ALL correct responses.

-the presence of more glutamate -the presence of more acetylcholine -the presence of less GABA

The refractory period is the 'rest period' before an ion channel on a nerve cell membrane can re-open again. How many milliseconds does this rest period last?

2

About how many neurons are involved in a reflex arc?

2-5

Fill in the blanks. The sodium potassium pump actively transports ______ sodium ions from inside to outside the cell and ______ potassium ions from outside to inside the cell.

3; 2

A strong stimulus will result in which of the following?

A large number of action potentials

inhibitory postsynaptic potentials (IPSPs)

A net influx of negative charge.

excitatory postsynaptic potentials (EPSPs)

A net influx of positive charge.

What is the difference between a fissure and a sulcus?

A sulcus is a small inward fold and a fissure is a deep groove.

We call the _______ zone of the parietal lobes the somatosensory cortex.

Anterior

The _______ is the primary structure connecting the two hemispheres of the brain.

Corpus callosum

Which of the following statements is true of cranial nerve VI?

Cranial nerve VI is the abducens, which moves the eye from side to side.

Which of the following statements is true of cranial nerve X?

Cranial nerve X is the vagus, involved in the swallowing reflex.

Which of these cranial nerves are involved in taste?

Facial, Glossopharyngeal, and Vagus -All three carry sensory signals from part of tongue or pharynx for taste.

The _______ includes areas in the brain such as the thalamus, the cerebrum, and the hypothalamus.

Forebrain

Which of the following is found in a chemical synapse?

Gap junction connections between the presynaptic and postsynaptic membrane

Bundles of nerve cell bodies are known as which of the following?

Gray matter

Which of the following is required for neuronal signaling?

High levels of sodium outside the cell

Which of the following is true of binding of the neurotransmitter, released from the presynaptic neuron of a chemical synapse, to the membrane of the postsynaptic neuron?

It results in ion channels of the postsynaptic membrane to open or close.

Which cells act as immune cells in the nervous system of healthy tissue?

Microglia

What do sodium innactivation plugs cause

Na+ channels to be unable to respond to another depolarization

Which lobe of the brain is located at the very back of the head?

Occipital

Are the cranial nerves part of the PNS or CNS?

PNS

Which area of the body is affected by the T4 spinal nerve?

Pectorals

The hindbrain includes which of the following structures?

Pons,Medulla oblongata, Cerebellum

We call the posterior zone of the parietal lobes the _______ cortex.

Posterior parietal

Structures of the _______ provide control of skeletal muscles.

Somatic nervous system

If anti-myelin antibodies are present in the blood, what do you think might also be happening? (look back to questions 1 and 5 to figure it out)?

T-cells may be destroying oligodendrocytes.

Which is the BEST explanation of HOW a Purkinje cell interprets incoming information?

The likelihood of an action potential in the Purkinje cell depends on the number and strength of incoming EPSPs and IPSPs.

The cerebellar cortex is highly foliated. This dramatically increases total surface area of the cerebellum. While the cerebral cortex is also foliated, the degree of foliation is much less. Which difference can we infer based on the degree of foliation in the cerebral cortex vs. the cerebellar cortex?

The ratio of gray matter to white matter is higher in the cerebellum.

Which of the following is NOT the reason why there is a gap between the presynaptic membrane of one nerve and the postsynaptic membrane of the next nerve?

There cannot be direct contact between two nerves

Which of the following statements is true of the neurotransmitters at neuromuscular junctions?

They are always acetylcholine.

Why would "active" regions of the brain contain more of the metabolized marker?

active neurons need to produce more ATP

What part of the neuron is responsible for bringing the signal into the cell?

dendrite

Which part of the neuron has plasma membrane proteins that convert stimuli to electrical potential?

dendrite -This acts as the receptor for the cell, responding to some chemical or other stimuli and sending resulting electrical signal toward cell body.

Which part of the neuron receives chemical input, either serving as or associated with a "receptor"?

dendrite -This would send information toward the cell body.

Habituation

desensitized to stimuli

All four of the central nervous system glial cells protect the neurons in one way or another. Which pair of them is involved in the protecting by maintaining chemical barriers and fluid balance?

ependymal and astrocytes -Both create a barrier of sorts controlling what fluids and chemicals are able to reach the neurons in the tissue from the blood or cerebrospinal fluid.

Which of the following is not important for creating the Blood-brain barrier (BBB)?

ependymal cilia -While ependymal cells have cilia to help move CSF among the fluid-filled spaces, it does not contribute to the selective permeability that protects neurons from potentially harmful substances in the blood.

All but one of the lobes of the cerebrum can be seen from the outside. Which lobe is found deep to two other lobes?

insula -This lobe is typically only seen if the temporal lobe is reflected or with a para-sagittal section of the brain.

Because they are embedded within the membrane, ion channels are examples of _______

integral proteins

Spinal nerves T2 - T11 do not reorganize in a plexus, but give rise directly to the ____.

intercostal nerves

Which of the following is correct description of a chemical synapse, our most common type of synapse in the body?

it allows integration of multiple excitatory and inhibitory signals -It uses chemical messages from several presynaptic neurons to determine reaction of postsynaptic neuron.

Which part of the brain has noticeable superior and lateral gyri (folds) that increase surface area for cortical gray matter?

left and right hemispheres -These parts of the cerebrum have the gyri and sulci on the surface and even extending down either side of the medial deep longitudinal fissure between hemispheres.

Binding of a neurotransmitter to the post-synaptic membrane opens which type of channel?

ligand gated -Neurotransmitter is the ligand.

Which part of the forebrain includes the hippocampus and amygdala involved in emotions and memory?

limbic system -This cortical region around the corpus callosum and thalamus is involved in smell, memory and emotions, especially strong emotions such as anger or fear.

Which process do neurons spend the most energy on?

maintaining/re-establishing resting membrane potential

Which is NOT part of the limbic system?

medulla oblongata