Anatomy, Chapter 11
Function of Microglial Cells
- act as phagocytes
Functions of Astrocytes
- anchor neurons and blood vessels - regulate the extracellular environment - facilitate the formation of the blood-brain barrier - repair damaged tissue
Functions of Ependymal Cells
- line cavities - cilia circulate fluid around brain and spinal cord - some secrete this fluid
Function of Oligodendrocytes
- myelinate certain axons in the CNS
Function of Schwann Cells
- myelinate certain axons in the PNS
Function of Satellite Cells
- surround and support cell bodies
30. The resting membrane potential of a resting neuron is approximately
-70 mV
Assume you have a membrane with only potassium leak channels. The RMP is -90mV. Predict the RMP if we add leak channels. The most likely RMP value of is __________.
-70 mV
What is the value for the resting membrane potential for most neurons?
-70 mV
What is the value for the resting membrane potential for most neurons? a) +30 mV b) -70 mV c) -90 mV
-70 mV
what is the value for the resting membrane potential for most neurons
-70mV
What is the magnitude (amplitude) of an action potential? a) 70 mV b) 30 mV c) 100 mV
100 mV
Matched 12) Epinephrine and thyroxine cause both heart rate and cardiac output to 13) An increase in vagus nerve firing causes heart rate to 14) An increase in sympathetic nervous system firing causes cardiac output to 15) A decrease in peripheral resistance causes arterial blood pressure to 16) Aldosterone causes blood volume to 17) An increase in the deposition of saturated fats in the lining of blood vessels causes arterial blood pressure to 18) Salt causes both blood volume and arterial blood pressure to A)decrease B) increase
12) B 13) A 14) B 15) A 16) B 17) B 18) B
19) These vessels carry blood capillaries away from the heart 20) These vessels return blood to 21) Superior and inferior vena cava are classified as these types of vessels 22) The aorta is classified as one of these vessels 23) These vessels have thicker walls and a heavier tunica media 24) Nutrient and gas exchange occur in these vessels 25) Blood pressure in these vessels is low 26) These vessels have thinner walls and transport oxygenpoor blood 27) Some of these larger vessels have valves to prevent backflow 28) Venules drain these tiny B) veins C) arteries the heart
19) C 20) B 21) B 22) C 23) C 24) A 25) B 26) B 27) B 28) A
Place the events involved in the propagation of an action potential in the correct order of occurrence from left to right. 1. Axon segment depolarized to threshold 2. Local current flows to axon segment 3. Influx of Na+ 4. Voltage-gated Na+ channels open 5. AP regenerated in adjacent axon segment
2, 1, 4, 3, 5
For every ATP split into an ADP and a phosphate, the Na+/K+ pump moves __________ out of the cell and __________ into the cell. a) 3 Na+; 2 K+ b) 3 K+; 2 Na+ c) 2 Na+; 3 K+ d) 2 K+; 3 Na+
3 Na+; 2 K+
Place the events involved in generation of an action potential in the correct order of occurrence from left to right. 1. Na+ channels close, K+ channels open 2. Na+ influx, depolarization 3. Hyperpolarization, K+ channels close 4. Threshold stimulus, Na+ channels open 5. K+ efflux, repolarization
4, 2, 1, 5, 3
Order each of the following events so that they occur in the proper order with respect to the function of the channels, ion permeability, and changes in membrane potential. 1. Repolarization of the membrane 2. Depolarization of the membrane to +30 mV 3. K+ ion flow out of the neuron increases 4. Na+ ion flow into the neuron increases 5. Opening of voltage-gated Na+ channels
5, 4, 2, 3, 1
26) The average heart beats about __________ times per minute.
75
Match 9) Part of the cardiac cycle when the coronary system is emptying of blood ventricular systole 10) Part of the cardiac cycle when the bicuspid and tricuspid valves are open 11) Part of the cardiac cycle when both of the semilunar valves are closed A)ventricular systole B) ventricular diastole
9) A 10) B 11) B
Which of the following types of neurons carry impulses away from the central nervous system (CNS)? A. afferent B. association C. sensory D. motor
Motor
In which type of axon will velocity of action potential conduction be the fastest?
Myelinated axons with the largest diameter
Which of the following events will cause an EPSP? a) Ca ions exit the postsynaptic cell b) K ions exit postsynaptic cell c) Cl ions enter postsynaptic cell d) Na ions enter postsynaptic cell
Na ions enter postsynaptic cell
Depolarizing local potentials are caused by an influx of: a) Na ions via leak channels b) K ions via leak channels c) K ions via gated ion channels d) Na ions via gated ion channels
Na ions via gated ion channels
The diffusion of what ion, across the neuronal membrane, is responsible for the local currents that depolarize regions of the axon to threshold?
Na+
Which of the following is most likely to move through the cell membrane by facilitated diffusion?
Na+
The concentrations of which two ions are highest outside the cell. a) Na+ and A- (negatively charged proteins) b) Na+ and Cl- c) K+ and A- (negatively charged proteins) d) K+ and Cl-
Na+ and Cl-
During the action potential of a neuron, which ion is primarily crossing the membrane during the depolarization phase, and in which direction is the ion moving?
Na+ is entering the cell.
The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped? a) K+ is pumped out of the cell and Na+ is pumped into the cell b) both Na+ and K+ are pumped into the cell c) Na+ is pumped out of the cell and K+ is pumped into the cell d) both Na+ and K+ are pumped out of the cell
Na+ is pumped out of the cell and K+ is pumped into the cell
The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped?
Na+ is pumped out of the cell and K+ is pumped into the cell.
What prevents the Na+ and K+ gradients from dissipating? a) H+-K+ ATPase b) Na+-K+ ATPase c) Na+ and K+ leaks d) Na+ cotransporter
Na+-K+ ATPase
Which of the following membrane proteins is involved in active transport? a) Na+ leak channel b) Na+/K+ pump c) K+ leak channel d) Na+ voltage-gated channel
Na+/K+ pump
What is the role of neurotransmitter at a chemical synapse?
Neurotransmitter binds to receptors on the postsynaptic cell membrane and allows ions to diffuse across the membrane.
Dark-staining clusters of RER and ribosomes in neurons are called ________. a) dendrites b) neurofibrils c) Nissl bodies d) nodes of Ranvier
Nissl bodies
The rough ER of the cell.
Nissl bodies
An exceptionally strong stimulus can trigger a response.
Relative refractory period
The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability.
Repolarization
Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS?
Schwann cells
Define: neurolemmocytes
Schwann cells (also called neurolemmocytes) surround all nerve fibers in the PNS and form myelin sheaths around the larger fibers. Myelin protects and electrically insulates nerve fibers, and it increases the transmission speed of nerve impulses.
Numerous nerve impulses arriving at a synapse at closely timed intervals exert a cumulative effect.
Temporal summation
Numerous nerve impulses arriving at a synapse at closely timed intervals exert a cumulative effect. A) Spatial summation B) Subthreshold stimulus C) Threshold stimulus D) Temporal summation
Temporal summation
Which of the following best describes the Na+ and K+ concentrations across a neuron's plasma membrane?
The Na+ concentration is higher outside the cell compared to inside. The K+ concentration is higher inside the cell compared to outside.
Imagine that the cell membrane from the previous problem becomes more permeable to . Predict how this will affect the RMP.
The RMP will be more positive.
etraethylammonium (TEA) blocks voltage-gated K+ channels such that K+ cannot pass even when the channels are open. However, TEA leaves K+ leakage channels largely unaffected. How would you expect the action potential to change if you treated a neuron with TEA?
The action potential would depolarize as usual, but the repolarization phase would take longer, causing the action potential to be more broad in time.
Why does the action potential only move away from the cell body?
The areas that have had the action potential are refractory to a new action potential.
Which of the neuroglial cell types is the most abundant in the CNS?
The astrocytes within the CNS support neurons and anchor them to their nutrient source.
The cell body of the neuron is called
The cell body of neurons are alternatively termed perikaryon or soma.
What is the central nervous system
The central nervous system, which consists of the brain and spinal cord, is the integrating and control center of the nervous system. It interprets sensory input and dictates motor output based on reflexes, current conditions, and past experience.
Destruction of which of the neuroglial cell types leads to the disease multiple scleroses (MS)?
The defects in nerve transmission associated with MS are caused by a loss of myelin within the CNS. Myelin within the CNS is primarily produced by the oligodendrocytes
On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you?
The inside surface of the plasma membrane is much more negatively charged than the outside surface.
What characterizes depolarization, the first phase of the action potential?
The membrane potential changes from a negative value to a positive value.
What event triggers the generation of an action potential?
The membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of -55 mV.
What is the function of the myelin sheath?
The myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals.
The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors.
The presence of concentration gradients and leak channels
During action potential propagation in an unmyelinated axon, why doesn't the action potential suddenly "double back" and start propagating in the opposite direction?
The previous axonal segment is in the refractory period.
In their resting state, all body cells exhibit a resting membrane potential ranging from -50 to about +50 millivolts.
The resting membrane potential is maintained by solely by passive transport processes.
Hypothetically, what would be the most immediate effect of doubling the number of Na+ leakage channels in the plasma membrane?
The resting membrane potential would become less negative (more positive).
Suppose a drug is developed that blocks K+ leakage channels. The drug prevents ions from passing through those channels. If this drug was applied to a neuron, what would be the most immediate effect on that neuron?
The resting membrane potential would become less negative (more positive).
Which of the neuroglial cell types are found in the PNS?
The satellite cell, wraps and insulates the soma of neurons within ganglia in the PNS.
Which of the following allows us to consciously control our skeletal muscles? a. the somatic nervous system b. the parasympathetic division of the autonomic nervous system c. the sympathetic division of the autonomic nervous system d. the afferent division of the nervous system
The somatic nervous system
The myelin on myelinated neurons can be degraded or destroyed in diseases such as multiple sclerosis-a process called demyelination. If a myelinated neuron was affected by demyelination, how would this affect action potentials in that neuron?
The speed of action potential propagation would be slower.
Select the correct statement regarding synapses.
The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
Select the correct statement regarding chemical synapses. A) The synaptic cleft uses the action potential to transmit a chemical signal to the post synaptic cell. B) The release of neurotransmitter molecules gives cells the property of being electrically coupled. C) Cells with gap junctions use chemical synapses. D) Neurotransmitter receptors are located on the axons terminals of cells.
The synaptic cleft uses the action potential to transmit a chemical signal to the post synaptic cell.
Describe Unipolar neuron
The unipolar neuron has a single short process that emerges from the cell body and divides into proximal and distal branches. Such neurons are found chiefly in the ganglia in the PNS where they conduct sensory information.
The plasma membrane is much more permeable to K+ than to Na+. Why?
There are many more K+ leak channels than Na+ leak channels in the plasma membrane.
Which of the following is NOT true of an electrical synapse?
They are specialized for release and reception of chemical neurotransmitters.
Which of the following is NOT a characteristic of peroxisomes?
They contain powerful enzymes called acid hydrolases.
Which of the following is not true of graded potentials?
They increase amplitude as they move away from the stimulus point.
Which of the following is not true of graded potentials? A) They increase amplitude as they move away from the stimulus point. B) They can be called postsynaptic potentials. C) They can form on receptor endings. D) They are short-lived.
They increase amplitude as they move away from the stimulus point.
The action potential is caused by permeability changes in the plasma membrane.
True
The oligodendrocytes can myelinate several axons.
True
The overlapping functions of the nervous system are sensory input, integration, and motor output.
True
True or False: Astrocytes are the most abundant and versatile glial cells
True
True or False: Motor, or efferent, neurons carry impulses away from the CNS to the effector organs (muscles and glands) of the body periphery.
True
True or False: dendrites are always nonmyelinated
True
True/False 10) The pacemaker of the heart under normal circumstances is called the sinoatrial (SA) node.
True
True/False 11) Systole means contraction of the ventricles.
True
True/False 14) Reductions in venous return cause reductions in both stroke volume and cardiac output.
True
True/False 16) Smooth muscle and elastic tissue in a blood vessel wall is found primarily in the tunica media.
True
True/False 18) Exchanges between blood and tissue cells occur in capillary beds
True
True/False 19) When precapillary sphincters are closed, blood flows through the shunts and bypasses the tissue cells.
True
True/False 2) The pulmonary arteries carry deoxygenated blood to the lungs
True
True/False 23) The common iliac vein drains blood into the inferior vena cava.
True
True/False 25) The great saphenous vein, the longest vein in the body, drains deoxygenated blood from the dorsal venous arch in the foot which then empties into the femoral vein.
True
True/False 28) The umbilical vein carries blood rich in nutrients and oxygen to the fetus.
True
True/False 31) An increase in blood vessel diameter causes arterial blood pressure to decrease
True
True/False 33) Cold temperatures have a vasoconstricting effect on blood vessels.
True
True/False 4) The tricuspid valve is located on the right side of the heart between the right atrium and right ventricle.
True
True/False 6) Arteries always carry blood away from the heart.
True
True/False 8) The coronary sulcus is also known as the atrioventricular groove.
True
True/False 9) The part of the intrinsic conduction system of the heart that directly supplies the walls of the ventricles is the Purkinje fibers.
True
Unipolar neurons have axons structurally divided into peripheral and central processes.
True
Voltage is always measured between two points and may be called the potential between these two points.
True
Which of these ions is actively transported through the cell membrane to establish a resting potential? A) Cl B) Ca C) Mg D) Na
D) Na
Receptive region of the neuron.
Dendrites
The interior of the cell becomes less negative due to an influx of sodium ions.
Depolarization
1) The thick layer of the heart wall that contains contractile cardiac muscle tissue is the: A) VISCERAL PERICARDIUM B) PARIETAL PERICARDIUM C) ENDOCARDIUM D) EPICARDIUM E) MYOCARDIUM
E
10) Which one of the following blood vessels carries oxygenated blood: A) superior vena cava B) inferior vena cava C) coronary sinus D) pulmonary artery E) pulmonary
E
14) Which one of the following represents the correct path for the transmission of an impulse in the intrinsic conduction system of the heart: A) atrioventricular (AV) node, sinoatrial (SA) node, atrioventricular (AV) bundle, right and left bundle branches, Purkinje fibers B) atrioventricular (AV) node, atrioventricular (AV) bundle, sinoatrial (SA) node, Purkinje fibers, right and left bundle branches C) sinoatrial (SA) node, atrioventricular (AV) bundle, atrioventricular (AV) node, Purkinje fibers, right and left bundle branches D) sinoatrial (SA) node, atrioventricular (AV) bundle, atrioventricular (AV) node, right and left bundle branches, Purkinje fibers E) sinoatrial (SA) node, atrioventricular (AV) node, atrioventricular (AV) bundle, right and left bundle branches, Purkinje fibers
E
21) The path of blood flow within the systemic vascular system is: A) arterioles, arteries, capillary beds, venules, veins B) arterioles, arteries, capillary beds, veins, venules C) arterioles, arteries, venules, veins, capillary beds D) arteries, arterioles, capillary beds, veins, venules E) arteries, arterioles, capillary beds, venules, veins
E
23) Which of the following reduces heart rate: A) exercise B) epinephrine C) thyroxine D) increased body temperature E) high blood pressure
E
24) Veins: A) carry blood away from the heart B) branch into smaller vessels called arterioles C) transport oxygen-rich blood D) operate under high pressure E) often have valves to prevent the backflow of blood
E
27) Which of the following blood vessels is a direct branch of the ascending aorta: A) right subclavian artery B) carotid artery C) right coronary artery D) left coronary artery E) both the right and left coronary arteries
E
34) The external iliac vein receives blood from all of the following EXCEPT: A) anterior tibial vein B) fibular vein C) popliteal vein D) femoral vein E) vertebral vein
E
Which of the neurological cell types shown are found in the peripheral nervous system (PNS)?
E
32. In a resting membrane the
ECF has a higher concentration of Na+ than the ICF
Which of the neuroglial cell types control the flow of cerebrospinal fluid within the CNS?
Ependymal cells line central cavities of the CNS. Much as the cilia of respiratory epithelium moves mucous along the surface of the tissue layer, the cilia of ependymal cells help circulate the cerebrospinal fluid that nourishes and cushions the brain and spinal cord.
Give examples of Astrocytes
Examples of their many functions include: anchoring neurons to capillaries, aiding in the exchanges between neurons and blood, guiding the migration of young neurons, and helping control the chemical environment around neurons.
27) Action potentials can be generated by virtually all cells of the body because all cells possess cell membranes.
False
A positive feedback cycle is the main force in the generation of graded potentials at receptor ends.
False
Neurons that are far away from the center of the neuron pool and that are not easily excited by an incoming stimulus are in the discharge zone.
False
Saltatory conduction occurs because of the presence of salt (NaCl) around the neuron.
False
Strong stimuli cause the amplitude of action potentials generated to increase.
False
The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place.
False
The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary.
False
The nodes of Ranvier are found only on myelinated, peripheral neuron processes.
False
The sodium-potassium pump ejects two Na+ from the cell and then transports three K+ back into the cell in order to maintain the concentration gradients for sodium and potassium.
False
The two major classes of graded potentials are transmitter potentials and receptor potentials.
False
True or False: Unmyelinated fibers conduct impulses faster than myelinated fibers.
False
True/False 12) During ventricular diastole, the bicuspid and tricuspid valves are closed.
False
True/False 13) Cardiac output is calculated by multiplying the stroke volume times the systolic blood pressure.
False
True/False 15) An increased firing of the parasympathetic nervous system causes increased cardiac output.
False
True/False 17) The larger arteries contain valves to prevent the backflow of blood.
False
True/False 20) The portion of the aorta in the abdominopelvic cavity is known as the thoracic aorta.
False
True/False 22) The superior and inferior mesenteric arteries drain blood from the intestines
False
True/False 24) Veins draining the head and arms empty into the inferior vena cava.
False
True/False 26) The circle of Willis involves blood flow through the liver.
False
True/False 27) The major vessels involved in hepatic portal circulation are the inferior and superior mesenteric arteries, the splenic artery, and the left gastric artery.
False
True/False 30) Diastolic blood pressure is the pressure in the arteries at the peak of ventricular contraction
False
True/False 32) Hypotension is diastolic blood pressure below 100 mm Hg.
False
True/False 5) The semilunar valves prevent the backflow of blood into the atria when the ventricles are contracting.
False
True/False 7) The coronary sinus on the backside of the heart drains deoxygenated blood from the wall of the heart into the left atrium.
False
21) __________ are abnormal heart sounds that are fairly common in young children with healthy hearts because their heart walls are relatively thin and vibrate with rushing blood.
Heart murmurs
28. Olm's law is
I Current= Voltage/Resistance
What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?
In facilitated diffusion, molecules only move with the aid of a protein in the membrane.
Which of the following is a difference between primary and secondary active transport?
In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated.
Which part of the neuron is responsible for generating a nerve impulse? Which part of the neuron is responsible for generating a nerve impulse? A. Chromatophilic substance B. Dendrite C. soma D. axon
Axon
11) The aortic semilunar valve is composed of: A) two cusps and opens when the left ventricle contracts B) three cusps and opens when the left ventricle contracts C) two cusps and opens when the right atrium contracts D) three cusps and opens when the right atrium contracts E) two cusps and closes when blood is filling the pulmonary circuit
B
13) The sinoatrial node is located in the: A) aorta B) right atrium C) left atrium D) right ventricle E) interventricular septum
B
15) A heart rate of over 100 beats per minute is called: A) bradycardia B) tachycardia C) ischemia D) diastole E) heart block
B
16) Which one of the following vessels receives blood during right ventricular systole: A) pulmonary veins B) pumonary trunk C) aorta D) superior vena cava E) coronary arteries
B
17) The mitral valve is normally closed: A) when the ventricle is in diastole B) when the ventricle is in systole C) when the atrium is contracting D) by the movement of blood from the atrium to the ventricle E) when the ventricle is contracting
B
29) Which of these arteries is NOT a branch of the abdominal aorta: A) renal arteries B) left common carotid artery C) inferior mesenteric artery D) common iliac arteries E) gonadal arteries
B
4) The right AV valve is known as the: A) aortic semilunar valve B) tricuspid valve C) mitral valve D) pulmonary semilunar valve E) bicuspid valve
B
7) When the ventricles contract, the bicuspid (mitral) valve prevents blood from flowing from the: A) right ventricle to the right atrium B) left ventricle to the left atrium C) left atrium to the right atrium D) right atrium to the left atrium E) left ventricle to the right ventricle
B
8) The tricuspid valve is located between the: A) right atrium and left atrium B) right atrium and right ventricle C) left ventricle and pulmonary artery D) left ventricle and aorta E) right ventricle and the pulmonary trunk
B
Which of the cell types shown helps determine capillary permeability?
B
18) A person with a heart rate of 75 beats per minute and a stroke volume of 60 mL per beat has a cardiac output of: A) 4500 mL/minute B) 1.25 mL/minute C) 0.8 mL/minute D) 6000 mL/minute E) 120 mL/minute
A
22) An increase in parasympathetic activity (primarily by the vagus nerves) causes: A) a decrease in both heart rate and cardiac output B) a decrease in heart rate and an increase in cardiac output C) an increase in both heart rate and cardiac output D) an increase in heart rate and a decrease in cardiac output E) no change in both heart rate and cardiac output
A
25) Which one of the following is caused by a decrease in venous return to the heart: A) a decrease in stroke volume and cardiac output B) a decrease in stroke volume and an increase in cardiac output C) an increase in stroke volume and cardiac output D) an increase in stroke volume and a decrease in cardiac output E) no change in stroke volume and cardiac output
A
32) Blood travels to the stomach by way of the branch of the celiac trunk called the: A) left gastric atery B) splenic artery C) common hepatic artery D) superior mesenteric artery E) inferior mesenteric artery
A
35) The brachial vein: A) drains blood from the radial and ulnar veins, then empties that blood into the axillary vein B) drains blood from the internal jugular vein, then empties that blood into the superior vena cava C) drains blood from the popliteal vein, then empties that blood into the external iliac vein D) drains blood from the axillary vein, then empties that blood into the superior vena cava E) drains blood from the popliteal vein, then empties that blood into the femoral vein
A
38) Which one of the following areas is NOT a pressure point: A) renal artery B) radial artery C) facial artery D) dorsalis pedis artery E) posterior tibial artery
A
6) What structure divides the left from the right ventricle: A) interventricular septum B) interatrial septum C) bicuspid valve D) tricuspid valve E) chordae tendineae
A
Destruction of which of the neuroglial cell types leads to the disease multiple sclerosis (MS)?
A
Which of neurological cell types shown form myelin sheaths within the CNS?
A
41. Nerve fibers fall into three groups: A, B, and C fibers
A fibers are the fastest
Which of the following is false or incorrect?
A nerve impulse occurs if the excitatory and inhibitory effects are equal.
Which of the following is false or incorrect? A) An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold. B) An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane. C) A nerve impulse occurs if the excitatory and inhibitory effects are equal.
A nerve impulse occurs if the excitatory and inhibitory effects are equal.
Which of the following is true of axons?
A neuron can have only one axon, but the axon may have occasional branches along its length.
described as multipolar neuron
A neuron that has many processes (axons and dendrites) that emerge from the cell body. Such a neuron is described as multipolar and typically functions as a motor neuron or interneuron.
Which of the following is a good example of a neuromodulator? A) acetylcholine B) nitric oxide C) any protein D) any carbohydrate
B) nitric oxide
89) Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?
A single type of channel will open, permitting simultaneous flow of sodium and potassium.
Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?
A single type of channel will open, permitting simultaneous flow of sodium and potassium.
Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? A) Sodium gates will open first, then close as potassium gates open. B) A single type of channel will open, permitting simultaneous flow of sodium and potassium. C) Specific sodium gates will open. D) Specific potassium gates will open.
A single type of channel will open, permitting simultaneous flow of sodium and potassium.
Neurons may be classified according to several characteristics. Which of the following is correct? A) Group C fibers are not capable of saltatory conduction. B) Group B fibers are highly myelinated and have the highest conduction velocities. C) Group A fibers are mostly somatic sensory and motor and are the smallest in diameter. D) A small cross-sectional area allows shorter conduction times.
A) Group C fibers are not capable of saltatory conduction.
Axon terminals release neurotransmitters. A) Secretory zone B) Conducting region C) Secretory region D) Trigger zone E) Receptive region
A) Secretory zone
Which of the following is not a function of the autonomic nervous system? A) innervation of skeletal muscle B) innervation of smooth muscle of the digestive tract C) innervation of cardiac muscle D) innervation of glands
A) innervation of skeletal muscle
Period during which the neuron cannot respond to a second stimulus, no matter how strong.
Absolute refractory period
The neuron cannot respond to a second stimulus, no matter how strong
Absolute refractory period
Also called a nerve impulse transmitted by axons.
Action potential
Adjacent Schwann cells along an axon and do not touch
Adjacent Schwann cells along an axon do not touch one another, so there are gaps in the sheath. These myelin sheath gaps, or nodes of Ranvier, occur at regular intervals (about 1 mm apart) along a myelinated axon. Axon collaterals can emerge from the axon at these gaps.
What conditions will increase the diffusion of molecules, such as neurotransmitters?
An increase in the amount of neurotransmitter exocytized by the presynaptic axon.
How is an action potential propagated along an axon?
An influx of sodium ions from the current action potential depolarizes the adjacent area.
2) The layer of the heart wall synonymous with the visceral layer of the serous pericardium is: A) myocardium B) endocardium C) epicardium D) parietal layer of the serous pericardium E) either endocardium or epicardium
C
20) The volume of blood pumped out by each ventricle with each beat of the heart is called the: A) cardiac output B) cardiac cycle C) stroke volume D) heart rate E) diastolic pressure
C
26) Which one is the correct sequence going from the outermost to the innermost layer of a blood vessel wall: A) tunica media, tunica intima, tunica externa B) tunica media, tunica externa, tunica intima C) tunica externa, tunica media, tunica intima D) tunica externa, tunica intima, tunica media E) tunica intima, tunica media, tunica externa
C
30) Which of these pathways correctly traces blood as it travels from the aortic arch to the left arm: A) aortic arch, brachiocephalic trunk, right common carotid artery B) aortic arch, left common carotid artery, left internal carotid artery C) aortic arch, left subclavian artery, left axillary artery, left brachial artery D) ascending aorta, right coronary arteries E) abdominal aorta, celiac trunk, left gastric artery
C
31) The carotid artery is located in the: A) armpit B) groin C) neck D) abdomen E) leg
C
33) The right and left renal veins empty blood from the: A) kidneys B) common iliac vein C) inferior vena cava D) hepatic portal vein E) vertebral vein
C
37) Which one of the following blood vessels in the fetus has the highest concentration of oxygen: A) umbilical arteries B) inferior vena cava C) ductus venosus D) ductus arteriosus E) left atrium
C
40) The friction blood encounters as it flows through the vessels is called: A) cardiac output B) stroke volume C) peripheral resistance D) blood pressure E) diastolic pressure
C
41) Generalized vasoconstriction occurs as a result of: A) an increase in parasympathetic nervous system firing B) a decrease in parasympathetic nervous system firing C) an increase in sympathetic nervous system firing D) a decrease in sympathetic nervous system firing E) an increase in blood pressure
C
44) Substances tend to leave the bloodstream at the arterial end of the capillary because: A) the osmotic pressure of the blood is higher at the arterial end of the capillary B) the osmotic pressure of the blood is higher at the venular end of the capillary C) blood pressure is higher at the arterial end of the capillary D) blood pressure is higher at the venular end of the capillary E) interstitial pressure is higher at the arterial end of the capillary
C
5) Pulmonary veins: A) transport oxygenated blood to the lungs B) transport blood rich in carbon dioxide to the lungs C) transport oxygenated blood to the heart D) split off the pulmonary trunk E) return blood to the right atrium of the heart
C
9) The superior vena cava empties: A) oxygenated blood into the left atrium B) oxygenated blood into the left ventricle C) deoxygenated blood into the right atrium D) deoxygenated blood into the right ventricle E) deoxygenated blood into the left atrium
C
In which area of the neuron is an action potential initially generated?
C
Which of the following membrane regions would have significant numbers of voltage-gated ion channels?
C and D
Which of the following is correct relative to Ohm's law? A) The more intense the stimulus, the more voltage changes. B) I = R / V C) Current is directly proportional to the voltage. D) R = V + I
C) Current is directly proportional to the voltage.
Select the correct statement about serial processing. A) Memories are triggered by serial processing. B) Smells are processed by serial pathways. C) Spinal reflexes are an example of serial processing. D) Input travels along several different pathways.
C) Spinal reflexes are an example of serial processing.
The part of a neuron that conducts impulses away from its cell body is called a(n) ______.
C) axon
The chemically gated channel, NMDA, allows ______ions entry into the nerve cell.
Ca2+
Which of these ions triggers exocytosis of synaptic vesicles? a) Ca2+ b) Na+ c) K+ d) Cl-
Ca2+
What is the role of calcium in synaptic activity?
Calcium influx into the synaptic terminal causes vesicle fusion.
Based on your knowledge of action potentials in neurons, what can you conclude about how they occur in cardiac muscle fibers?
Cardiac muscle fibers depolarize more quickly and spend more time depolarized than neurons do.
When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the post synaptic cell? A) Chemically gated chloride channels will open. B) Chemically gated potassium channels will open. C) Chemically gated sodium channels will open. D) Chemically gated sodium channels will be closed.
Chemically gated sodium channels will open.
60. ____ is most responsible for hyper-polarization from inhibitory receptors channels opening
Cl-
Plasma membrane exhibits voltage-gated Na+ and K+ channels. A) Secretory zone B) Conducting region C) Secretory region D) Trigger zone E) Receptive region
Conducting region
12) Which one of the following are direct branches of the left coronary artery: A) circumflex and marginal arteries B) anterior and posterior interventricular arteries C) anterior interventricular and marginal arteries D) anterior interventricular and circumflex arteries E) posterior interventricular and marginal arteries
D
19) Which one of the following is true concerning the lub-dup sounds of the heart: A) the first sound is longer and louder and is caused by closure of the tricuspid valve; the second sound is shorter and sharper and is caused by closure of the mitral valve B) the first sound is shorter and sharper and is caused by closure of the tricuspid valve; the second sound is longer and louder and is caused by closure of the mitral valve C) they are caused by contraction of the ventricles, followed by contraction of the atria D) the first sound is longer and louder and is caused by closure of the AV valves; the second sound is shorter and sharper and is caused by closure of the semilunar valves E) the first sound is shorter and sharper and is caused by closure of the semilunar valves; the second sound is longer and louder and is caused by closure of the AV valves
D
28) Which one of the following does NOT receive blood directly from the aortic arch: A) brachiocephalic artery B) left subclavian artery C) left common carotid artery D) right common carotid artery E) thoracic aorta
D
3) Which area of the heart receives blood from the systemic veins: A) right ventricle B) left ventricle C) aorta D) right atrium E) left atrium
D
36) The umbilical vein carries: A) metabolic wastes and carbon dioxide from the fetus to the placenta B) metabolic wastes and carbon dioxide from the placenta to the fetus C) oxygen and nutrients from the fetus to the placenta D) oxygen and nutrients from the placenta to the fetus E) blood from the navel into the inferior vena cava
D
39) In which one of the following blood vessels is blood pressure the highest: A) veins B) capillaries C) vena cava D) arteries E) arterioles
D
42) Which one of the following is the main function of renin and aldosterone: A) they are produced whenever blood pressure rises and ultimately cause an increase in blood volume and blood pressure B) they are produced whenever blood pressure rises and ultimately cause a decrease in blood volume and blood pressure C) they are produced when blood pressure rises and have no long-term effect on blood volume and blood pressure D) they are produced whenever blood pressure falls and ultimately cause an increase in blood volume and blood pressure E) they are produced whenever blood pressure falls and ultimately cause a decrease in blood volume and blood pressure
D
43) Which one of the following are the main functions of renin and angiotensin II: A) blood pressure rises this causes vasoconstriction and further increases blood pressure B) blood pressure rises this causes vasoconstriction and a decrease in blood pressure C) blood pressure rises this causes vasodilation and a decrease in blood pressure D) blood pressure falls this causes vasoconstriction and an increase in blood pressure E) blood pressure falls this causes vasodilation and an increase in blood pressure
D
45) Varicose veins are caused by: A) a loss of elasticity in blood vessels B) the accumulation of fatty substances within blood vessels C) excessive production of the enzyme renin D) incompetent venous valves E) orthostatic hypotension
D
Which of the cell types shown is most associated with the production and flow of the cerebrospinal fluid (CSF)?
D
What changes occur to voltage-gated Na+ and K+ channels at the peak of depolarization?
Inactivation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open.
During the hyperpolarization phase of the action potential, when the membrane potential is more negative than the resting membrane potential, what happens to voltage-gated ion channels?
K+ channels close. Na+ channels go from an inactivated state to a closed state.
During an action potential, hyperpolarization is caused by: a) K+ influx b) Na+ efflux c) K+ efflux d) Na+ influx
K+ efflux
Which of the following is the clearest example of a neuronal membrane's selective permeability?
K+ ions can diffuse across the membrane more easily than Na+ ions.
During an action potential, hyperpolarization beyond (more negative to) the resting membrane potential is primarily due to __________.
K+ ions diffusing through voltage-gated channels
The repolarization phase of the action potential, where voltage becomes more negative after the +30mV peak, is caused primarily by __________.
K+ ions leaving the cell through voltage-gated channels
Which of the following causes the hyperpolarization phase of an action potential? a) K+ outflow via voltage-gated potassium ion channels b) Na+ outflow via voltage-gated sodium ion channels c) K+ influx via voltage-gated potassium ion channels d) Na+ influx via voltage-gated sodium ion channels
K+ outflow via voltage-gated potassium ion channels
The membranes of neurons at rest are very permeable to __________ but only slightly permeable to ___________. a) K+; Cl- b) K+; Na+ c) Na+; Cl- d) Na+; K+
K+; Na+
Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?
Leak channels
Which statement best describes exocytosis?
Membrane organelles fuse with the membrane and release contents out of the cell.
Which of the following is NOT true of association neurons?
Most association neurons are confined within the peripheral nervous system (PNS).
What type of channel on the postsynaptic membrane binds neurotransmitter?
a chemically gated channel
27. A substance with low electrical resistance is called
a conductor
The neural circuit pattern in which the signal goes from several neurons to one is called _______________. a) a diverging circuit b) a stabilizing circuit c) an amplifying circuit d) a converging circuit
a converging circuit
The part of the neuron that normally receives stimuli is called ____.
a dendrite
35. A -30 mV membrane potential would be an example of
a depolarized membrane
36. The following is least likely to produce an action potential
a hyper-polarized membrane
A bundle of axons in the PNS is called _______. a) a tract b) a spinal cord c) a ganglion d) a nerve
a nerve
A postsynaptic cell can be a neuron, a muscle cell, or a secretory cell. What is an example of a presynaptic cell?
a neuron
which of the following is true of axons?
a neuron can have only one axon, but the axon may have occasional branches along its length
If a post synaptic cell is stimulated to threshold by temporal summation this implies that ________. A) the postsynaptic cell can be influenced by only one presynaptic cell B) the postsynaptic cell is sending frequent action potential C) a presynaptic neuron is sending frequent EPSP D) the presynaptic neuron is sending frequent IPSP
a presynaptic neuron is sending frequent EPSP
The velocity of the action potential is fastest in which of the following axons? a) a large unmyelinated axon b) a small unmeylinated axon c) a small myelinated axon
a small myelinated axon
42. The functional connection between neurons is called
a synapse
What is a membrane potential?
a voltage or electrical charge across the plasma membrane
If a neuron had a mutation that prevented the production of voltage-gated Na+ channels, what function would the neuron NOT be able to accomplish? a. depolarization leading to action potentials b. graded depolarization c. graded hyperpolarization d. resting membrane potentials
a. depolarization leading to action potentials
Which of the choices below describes the ANS? a. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands b. sensory and motor neurons that supply the digestive tract c. motor fibers that conduct nerve impulses from the CNS to skeletal muscles
a. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
Cranial nerve II, the optic nerve sends nerve impulses to the brain carrying information about the things we see. These nerve fibers most likely belong to which division of the nervous system? a. sensory (afferent) division b. somatic nervous system c. sympathetic division d. parasympathetic division
a. sensory (afferent) division
Which of these materials or structures would be found in greatest amounts or numbers at E? a. vesicles containing neurotransmitter b. chemically gated sodium ion channels c. chromatophilic substance (Nissl bodies) d. the nucleolus
a. vesicles containing neurotransmitter
An excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle is ________.
acetylcholine
The first identified neurotransmitter was
acetylcholine
The mechanism by which the neurotransmitter is returned to a presynaptic neuron's axon terminal is specific for each neurotransmitter. Which of the following neurotransmitters is broken down by an enzyme beofre being returned? a) acetylcholine b) glutamate
acetylcholine
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?
acetylcholine
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? A) gamma aminobutyric acid B) cholinesterase C) norepinephrine D) acetylcholine
acetylcholine
Which of the following correctly describes a graded potential?
amplitude of various sizes
Which statement best describes the all-or-none principle? a) all neurons conduct an action potential together, or none do b) all voltage-gated sodium channels will open or none will open c) an action potential happens completely, or it doesn't happen at all d) local, or graded, potentials will always become action potentials
an action potential happens completely, or it doesn't happen at all
How is an action potential propagated along in an axon? a) an influx of sodium ions from the current action potential depolarizes the adjacent area b) stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon c) an efflux of potassium from the current action potential depolarizes the adjacent area
an influx of sodium ions from the current action potential depolarizes the adjacent area
Which of the following describes the nervous system integrative function? A) responds to stimuli by gland secretion or muscle contraction B) analyzes sensory information, stores information, makes decisions C) senses changes in the environment
analyzes sensory information, stores information, makes decisions
Which of the following describes the nervous system integrative function? A. responds to stimuli by gland secretion or muscle contraction B. analyzes sensory information, stores information, makes decisions C. senses changes in the environment
analyzes sensory information, stores information, makes decisions
8) Crushing chest pain caused by oxygen deprivation of the myocardium is called __________.
angina pectoris
21. Movement away from the cell body is called
anterograde
Cold sores on the skin of the mouth occur when herpes simplex viruses that are dormant in neural ganglia become active and travel to the skin of the mouth. Which of the following is the mechanism by which these viruses travel from the ganglia (located within the head) to the skin of the mouth?
anterograde transport
12) The pointed tip of the heart that is directed toward the left hip is called the __________.
apex
Nerve cell adhesion molecules (N-CAMs) ________.
are crucial for the development of neural connections
Define: Microglial cells
are small andovoid with relatively long "thorny" processes. Their processes touch nearby neurons, monitoring their health, and when they sense that certain neurons are injured or are in other trouble, the microglial cells migrate toward them. Where invading microorganisms or dead neurons are present, the microglial cells transform into a special type of macrophage that phagocytizes the microorganisms or neuronal debris.
29) Larger blood vessels that carry blood away from the heart are called __________.
arteries
A neuron that has as its primary function the job of connecting other neurons is called a(n) _____.
association neuron
A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.
association neuron
14. The most abundant neuroglia of the CNS is
astrocytes
Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________.
astrocytes
Which neuroglia are the most abundant and versatile of the glial cells? A. ependymal cells B. astrocytes C. Schwann cells D. oligodendrocytes
astrocytes
15. What two cells are best pair functionally
astrocytes and satellite cells
During what part of the action potential do voltage-gated Na+ channels begin to inactivate (their inactivation gates close)?
at the end of the depolarization phase, as the membrane potential approaches its peak value
Where are action potentials regenerated as they propagate along a myelinated axon?
at the nodes of Ranvier
10) The two superior receiving chambers of the heart are known as the __________, while the two inferior discharging chambers of the heart are known as the __________.
atria; ventricles
11) The valves located between the atria and ventricles are known as the __________ valves.
atrioventricular (or AV)
Involuntary control of smooth and cardiac muscles and glands is provided by the __________. a) visceral sensory division b) afferent division c) autonomic nervous system d) somatic motor division
autonomic nervous system
The part of a neuron that conducts impulses away from its cell body is called a(n) ________.
axon
Which of the following is the conducting region of the neuron?
axon
which of the following is the conducting region of the neuron?
axon
18. The cone shaped area that leads into the process leaving the cell body is called the
axon hillock
Where in the neuron is an action potential initially generated? a) axon hillock b) soma and dendrites c) anywhere on the axon
axon hillock
20. The distal end of an axon is called
axon terminals and terminal boutons
40. When talking of conduction velocities of a nerve a(n)
axon with saltatory conduction is faster than continuous
Bacteria in the blood stream can be prevented entry to the fluids surrounding the brain. Which cells are most responsible for preventing bacterial from entering the fluids of the brain? a. satellite cells b. astrocytes c. Schwann cells d. oligodendrocytes
b. astrocytes
Collections of nerve cell bodies in the peripheral nervous system are called ________. a. nuclei b. ganglia c. nerves d. tracts
b. ganglia
Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensive network of rough endoplasmic reticulum and many clusters of ribosomes. These cellular features indicated all of the following EXCEPT _________. a. neurons must meet a high demand for ATP b. neurons have stable, relatively unchanging internal environments c. neurons produce many proteins d. neurons have a relatively high consumption of oxygen
b. neurons have stable, relatively unchanging internal environments
Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing, and certain motor activities (such as arm swinging when walking)? a. parallel after-discharge circuits b. reverberating circuits c. converging circuits d. diverging circuits
b. reverberating circuits
Which is the main receptive portion of the neuron? a. the synapse b. the dendrite c. the axon d. the cell body or soma
b. the dendrite
Select the correct statement regarding chemical synapses. a. Neurotransmitter receptors are located on the axons terminals of cells. b. The synaptic cleft transmits a chemical signal to the post synaptic cell through diffusion of neurotransmitters across the cleft. c. Cells with gap junctions use chemical synapses. d. The release of neurotransmitter molecules gives cells the property of being electrically coupled.
b. the synaptic cleft transmits a chemical signal to the post synaptic cell through diffusion of neurotransmitters across the cleft.
43) The pressure blood exerts against the inner walls of the blood vessels is known as __________.
blood pressure
47) Fluid tends to be forced out of a capillary bed by __________ while __________ tends to draw fluid into the capillary bed.
blood pressure; osmotic pressure
Which areas of this neuron would be classified as receptive regions?
both A and B
during depolarization, which gradient moves Na+ into the cell?
both chemical and electrical
44. Most neurons function as
both pre and post synaptic neurons
During depolarization, which gradient(s) move(s) Na+ into the cell? a) both the electrical and chemical gradients b) only the chemical gradient c) only the electrical gradient d) Na+ does not move into the cell. Na+ moves out of the cell
both the electrical and chemical gradients
38) The __________ veins join to form the superior vena cava before emptying into the right atrium.
brachiocephalic
The term central nervous system refers to the _______.
brain and spinal cord
The term central nervous system refers to the ________.
brain and spinal cord
The term central nervous system refers to the ________. A) brain and spinal cord B) sensory (afferent) nerves C) the somatic nerves D) the spinal nerves
brain and spinal cord
Which of the following are organs of the central nervous system? a) brain and cranial nerves b) spinal cord and spinal nerves c) brain and spinal cord d) brain, cranial nerves, spinal cord, and spinal nerves
brain and spinal cord
A neuromodulator is a chemical messenger released by neurons that does not cause EPSPs or IPSPs
but does affect the strength of synaptic transmission
How do neurofibrils differ from nerve fibers? a. There is no real difference, since they are both capable of impulse conduction away from a neuron. b. Neurofibrils are axon subunits that are bundled together to make up a single nerve fiber. c. Neurofibrils are cytoskeletal intermediate filaments maintaining cell shape, but they do not conduct impulses.
c. Neurofibrils are cytoskeletal intermediate filaments maintaining cell shape, but they do not conduct impulses.
Which of the following peripheral nervous system (PNS) neuroglia from the myelin sheaths around larger nerve fibers in the PNS? a. oligodendrocytes b. satellite cells c. Schwann cells d. astrocytes
c. Schwann cells
Many neurons have many short, branching extensions called dendrites. What is the benefit of these structures for a neuron? a. There is a large amount of space for myelin to form and make electrical conduction more efficient. b. There is a large area for production of chemicals used to signal other neurons c. The dendrites provide a large surface are for connections from other neurons. d. There is a large surface area to send signals to other cells
c. The dendrites provide a large surface area for connections from other neurons.
Which of the following is NOT a difference between graded action potentials and action potentials? a. Graded potentials occur along dendrites, whereas action potentials occur along axons. b. Greater stimulus intensity results in larger graded potentials, but not larger action potentials. c. The magnitude of action potentials decrease as the impulse travels further away from the start of the impulse while graded potentials do not decrease in magnitude.
c. The magnitude of action potentials decrease as the impulse travels further away from the start of the impulse while graded potentials do not decrease in magnitude.
Suppose that both stimuli seen in these graphs happened equally at the same time on a postsynaptic membrane as a result of two different synapses. Which of the following best descries the result? a. Temporal summation would occur. b. No chemically gated ion channels would open. c. There would be little or no graded potential. d. An action potential would result.
c. There would be little or no graded potential.
Ependymal cells line many open cavities in the central nervous system (CNS). Ependymal cells have cilla on the side of the cell that face these openings. What is the most likely function of these ciliated cells? a. exchange of nutrients between the circulatory system and neurons b. act as macrophage cells to destroy microorganisms or neuronal debris c. movement and circulation of cerebrospinal fluid d. create myelin sheaths for CNS cells
c. movement and circulation of cerebrospinal fluid
Which of the following stimuli caused the reaction in the graph on the left? a. opening of gated Ca2+ channels b. opening of gated K+ channels c. opening of gated Na+ channels d. opening of gated Cl- channels
c. opening of gated Na+ channels
Which of the following is NOT a function of astrocytes? a. anchor neurons to blood vessels. b. support and brace neurons. c. provide the defense for the CNS. d. control the chemical around neurons.
c. provide the defense for the CNS.
30) The smallest blood vessels known as __________ connect arterioles and venules.
capillaries
32) The amount of blood being pumped out of the heart at any time is called __________.
cardiac output
Bundles of axons known as tracts are part of the: a) ganglion b) myelin sheath c) central nervous system d) peripheral nervous system
central nervous system
What part of the nervous system performs information processing and integration?
central nervous system
Which nervous system division is responsible for the integration of sensory information? a) visceral motor division b) peripheral nervous system c) somatic motor division d) central nervous system
central nervous system
The two anatomical divisions of the nervous system are the: a) sensory division and motor division b) somatic sensory division and visceral sensory system c) central nervous system and peripheral nervous system d) visceral motor division and somatic motor division
central nervous system and peripheral nervous system
45. Two main types of synapses are
chemical and electrical
The presence of a synaptic cleft between cells is characteristic of: a) electrical synapse b) chemical synapse c) both chemical and electrical synapses d) neither chemical nor electrical synapses
chemical synapse
Which component has a role in the postsynaptic cell during synaptic activity?
chemically gated channels
Binding of a neurotransmitter to its receptors opens ___________ channels on the ____________ membrane. a) chemically gated; presynaptic b) voltage-gated; postsynaptic c) voltage-gated; presynaptic d) chemically gated; postsynaptic
chemically gated; postsynaptic
Which of the following is NOT one of the chemical classes into which neurotransmitters fall?
chlorides
14) The tiny white cords that anchor the cusps or flaps of endocardium to the walls of the ventricles are called the __________.
chordae tendineae
40) The complete circle of connecting vessels in the brain is called the __________.
circle of Willis or cerebral arterial circle
Ependymal cells: a) form myelin in the brain and spinal cord b) help form the blood-brain barrier c) serve as wandering phagocytes during brain injury d) circulate cerebrospinal fluid
circulate cerebrospinal fluid
Branches that may occur along an axon are called: a) collaterals b) dendrites c) hillocks d) telodendria
collaterals
4. What is false of the central nervous system
consist of nerves that extend from the brain/spinal cord
Action potential propagation in unmyelinated axons happens via: a) saltatory conduction b) synaptic transmission c) local potentials d) continuous conduction
continuous conduction
What type of conduction takes place in unmyelinated axons? a) saltatory conduction b) continuous conduction c) synaptic transmission d) electrical conduction
continuous conduction
18) When ventricles __________, the AV valves are closed.
contract
19) The coronary veins empty blood from the myocardium into a large vein on the posterior side of the heart known as the __________.
coronary sinus
1. The gray covering of the Cerebrum is called the
cortex
Which of the following is NOT one of the basic functions of the nervous system? a. integrate sensory input for decision making. b. Generate direct, electrical signals. c. Decode sensory information from the environment. d. Release hormones into the bloodstream to communicate with other cells in the body.
d. Release hormones into the bloodstream to communicate with other cells in the body.
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? a. cholinestrase b. norepinephrine c. gamma aminobutyric acid d. acetylcholine
d. acetylcholine
Bipolar neurons are commonly ________. a. found in ganglia b. called neuroglial cells c. motor neurons d. found in the retina of the eye
d. found in the retina of the eye
Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system? a. sensory (afferent) division b. somatic nervous system c. sympathetic division d. parasympathetic division
d. parasympathetic division
Which of the following is NOT a type of circuit? a. converging circuits b. diverging circuits c. reverberating circuits d. pre-synaptic circuits
d. pre-synaptic circuits
Which of the following statements most accurately describes the effects caused by binding of the neurotransmitter (green dots) to the structure labeled C? a. an action potential is generated b. the neurotransmitter is transported into the postsynaptic neuron c. the membrane potential of the presynaptic membrane changes d. the membrane potential of the postsynaptic membrane changes
d. the membrane potential of the postsynaptic membrane changes.
Which of the following is not characteristic of neurons? a. they have an exceptionlly high metabolic rate. b. they conduct impulses. c. the have extreme longevity. d. they are mitotic.
d. they are mitotic
Immediately after an action potential has peaked, which of the following channels will open? a. voltage gated calcium channels b. chemically gated chloride channels c. voltage gated sodium channels d. voltage gated potassium channels
d. voltage gated potassium channels
Which of the following is one of the mechanisms for termination of synaptic transmission? a) storage of neurotransmitter in vesicles b) reuptake of neurotransmitter into the postsynaptic cell c) release of neurotransmitter into the synaptic cleft d) degradation of neurotransmitter by enzyme
degradation of neurotransmitter by enzyme
Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon?
degree of myelination of the axon
Determine the direction in which and electrical signal is carried in a typical multipolar neuron. a) dendrites, cell body, axon b) cell body, axon, dendrites c) dendrites, axon, cell body d) axon, cell body, dendrites
dendrites, cell body, axon
An excitatory postsynaptic potential is a local ______________ of the postsynaptic membrane
depolarization
If a stimulus opens ligand-gated sodium ion channels, the neuron will ___________. a) remain at its resting membrane potential b) repolarize c) hyperpolarize d) depolarize
depolarize
An action potential is self-regenerating because _________. a) repolarizing currents established by the efflux of Na+ flow down the axon and trigger and action potential at the next segment b) repolarizing currents established by the efflux of K+ flow down the axon and trigger and action potential at eh next segment c) depolarizing currents established by the influx of K+ flow down the axon and trigger an action potential at the next segment d) depolarizing currents established by the influx of Na+ flow down the axon and trigger and action potential at the next segment
depolarizing currents established by the influx of Na+ flow down the axon and trigger an action potential at the next segment
an action potential is self-regenerating because...
depolarizing currents established by the influx of Na+ flow down the axon and trigger an action potential at the next segment
What is the role of acetylcholinesterase?
destroy ACh a brief period after its release by the axon endings
The role of acetylcholinesterase is to ________.
destroy ACh a brief period after its release by the axonal endings
Depolarization to threshold during action potential propagation in axons is due to: a) diffusion of K ions up to the previous segment of the axon b) diffusion of K ions down to the next segment of the axon c) diffusion of Na ions up to the previous segment of the axon d) diffusion of Na ions down to the next segment of the axon
diffusion of Na ions down to the next segment of the axon
The following are types of circuits in neuronal pools
diverging, converging, and reverberating
During the action potential, when does sodium permeability initially decrease? a) during repolarization b) during the peak of depolarization c) during hyperpolarization d) during the rising phase of depolarization
during the peak of depolarization
Bidirectional, instantaneous synaptic transmission is typical of ___________. a) electrochemical synapses b) chemical synapses c) electrical synapses d) all synapses
electrical synapses
Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone?
endorphin
Which neurotransmitter(s) is/are the body's natural pain killer?
endorphins
25. Which of the following statements is false
energy is bound when charges move towards one another
Caveolae are closely associated with all of the following except ________.
enzymes involved in cell metabolism
What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called?
ependymal cells
9) The visceral layer of the serous pericardium is actually the same layer as the __________.
epicardium
Which membrane potential occurs because of the influx of Na+ through chemically gated channels in the receptive region of a neuron?
excitatory postsynaptic potential
A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____.
exocytosis
Neurotransmitter is released from presynaptic neurons through what mechanism?
exocytosis
Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____.
facilitated diffusion
The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____.
facilitated diffusion
The all-or- none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place.
false
The sensory, or afferent, division of he peripheral nervous system carries information from the brain and spinal cord to effector organs. a) true b) false
false
True/False 1) Cardiac muscle is enclosed by a double sac of serous membrane known as the peritoneum.
false
True/False 3) The chordae tendineae anchor the semilunar valves to the walls of the ventricles.
false
36) The blood vessel that is the immediate inferior continuation of the external iliac artery is the __________.
femoral artery
42) The flaplike opening in the interatrial septum of the fetus through which blood is shunted directly from the right atrium to the left atrium is the __________.
foramen ovale
Bipolar neurons are commonly ________.
found in the retina of the eye
What does the central nervous system use to determine the strength of a stimulus? A) size of action potentials B) origin of the stimulus C) type of stimulus receptor D) frequency of action potentials
frequency of action potentials
Loss of K ions from the cytosol will have the same effect as: a) gain of Na ions b) gain of Cl ions c) gain of K ions d) loss of Cl ions
gain of Cl ions
Collections of nerve cell bodies outside the central nervous system are called _______.
ganglia
Collections of nerve cell bodies outside the central nervous system are called ________.
ganglia
Collections of nerve cell bodies outside the central nervous system are called ________. A) ganglia B) nerves C) tracts D) nuclei
ganglia
When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________.
generator potential
When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. A) action potential B) excitatory potential C) postsynaptic potential D) generator potential
generator potential
34. Change in the resting membrane potential produce 2 types of potential signals: graded or action
graded potential travel short distances
Which group of fibers spreads impulses at up to 1 meter per second?
group C fibers
27) Cardiac output is the product of __________ and __________.
heart rate (HR); stroke volume (SR)
Ependymal cells ________.
help to circulate the cerebrospinal fluid.
39) The single vessel that drains blood from the digestive tract organs to the liver is the __________.
hepatic portal vein
An inhibitory postsynaptic potential (IPSP) is associated with ________.
hyperpolarization
An inhibitory postsynaptic potential (IPSP) is associated with ________. A) lowering the threshold for an action potential to occur B) a change in sodium ion permeability C) hyperpolarization D) opening of voltage-regulated channels
hyperpolarization
The relative refractory period is caused by: a) inactivation of voltage-gated Na ion channels b) depolarization to threshold c) hyperpolarization d) inactivation of voltage-gated K ion channels
hyperpolarization
A series of measurements with a voltmeter show a neuron's membrane potential becoming more negative, from -70 mV to -85 mV. This neuron is experiencing a: a) hyperpolarization phase b) polarization phase c) repolarization phase d) depolarization phase
hyperpolarization phase
In an inhibitory synapse the membrane of the postsynaptic neuron becomes
hyperpolarized
46) A systolic blood pressure reading below 100 mm HG is called __________.
hypotension
Batrachotoxin produced by certain species of frogs is a toxin that permanently opens voltage-gated Na ion channels. The results of exposure to batrachotoxin will be: a) inability to generate action potentinals b) increased frequency of action potentials c) no depolarization d) permanent hyperpolarization
inability to generate an action potential
what changes occur to voltage gated Na+ and K+ channels at the peak of depolarization?
inactivation gates of voltage gated Na+ channels close, while activation gates of voltage gated K+ channels open
Define: Multipolar
is a structural classification that groups neurons according to the number of processes extending from their cell body. Multipolar neurons have three or more processes - one axon and multiple dendrites.
Define: axon
is the conducting region of the neuron. It generates nerve impulses (action potentials) and transmits them, typically away from the cell body, along the axolemma (cell membrane of the axon).
3. Processing and interpretation of sensory input
is the function of the integration component
11. The counterpart in the central nervous system to schwann cells in the peripheral nervous system
is the oligodendrocytes
13) Lack of adequate blood supply to the heart is called __________.
ischemia
Which of the following correctly describes a graded potential? A) it has a depolarization, repolarization and hyperpolarization phase B) it can have amplitudes of various sizes C) it is initiated by voltage changes in the membrane D) it travels long distances
it can have amplitudes of various sizes
Conduction speed will be fastest in a ____________. a) large unmyelinated axon b) small unmyelinated axon c) small myelinated axon d) large myelinated axon
large myelinated axon
Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the plasma membranes of all cells because of the presence of what type of channel? a) ligand-gated channels b) leak channels c) sodium-potassium ATPases d) voltage-gated channels
leak channels
31. The two types of ion channels in the membrane are
leakage and gated channels
24. What is true of interneurons
lie between motor and sensory neurons
Postsynaptic potentials are: a) local potentials b) action potentials c) resting potentials d) chemical potentials
local potentials
25) During diastole, the pressure in the heart is __________.
low
What is the major role of the Na+-K+ pump in maintaining the resting membrane potential?
maintaining the concentration gradients for Na+ and K+ across the cell membrane
What channels open or close in response to physical distortion of the membrane surface, such as vibrations or pressure? a) voltage-gated b) mechanically-gated c) chemically-gated d) ligand-gated
mechanically-gated
34) The flow of blood through a capillary bed is called __________.
microcirculation
Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons?
microglia
17) The bicuspid valve is also referred to as the __________ valve.
mitral
A primary active transport process is one in which __________.
molecules move through transport proteins that have been activated by ATP
22. Which is not a structural classification of neurons
monopolar
Which of the following would increase the membrane permeability to K+?
more K+ leakage channels
If the cytosol loses K+ ions through leak channels, it will become: a) less negative b) more positive c) more negative d) there will be no change in the membrane potential
more negative
Which of the choices below describes the ANS?
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
What symptoms would a nurse focus on in his or her care of a client with multiple sclerosis?
Visual disturbances, paralysis, and weakness
During the hyperpolarization phase of the action potential, voltage eventually returns to the resting membrane potential. What processes are primarily responsible for this return to the resting membrane potential?
Voltage-gated K+ channels close. K+ and Na+ diffuse through leakage channels.
What opens first in response to a threshold stimulus?
Voltage-gated Na+ channels
What is the first change to occur in response to a threshold stimulus?
Voltage-gated Na+ channels change shape, and their activation gates open.
29. Which opens and closes in response to changes in membrane potential
Voltage-gated channels
Which of the following best explains diffusion?
movement of molecules from an area of high concentration to an area of low concentration
Complete the following sentence. The operation of the ATPase pump __________.
moves 3 to the ECF and 2 to the cytoplasm
Which of the following is NOT a functional classification of neurons?
multipolar
In which type of axon will velocity of action potential conduction be the fastest? a) myelinated axons with the largest diameter b) unmyelinated axons of the shortest length c) unmyelinated axons with the largest diameter d) myelinated axons with the smallest diameters
myelinated axons with the largest diameter
Saltatory propagation occurs in _________ axons, in which action potentials __________. a) myelinated; move from one node of Ranvier to another b) unmyelinated; spread by depolarizing the adjacent region of the axon membran c) unmyelinated; move from one node of Ranvier to another d) myelinated; move continuously along the axon toward the axon hillock
myelinated; move from one node of Ranvier to another
Which of the following is an effect of myelination? a) myelination increases the speed of conduction of action potentials b) myelination increases the volume of cerebrospinal fluid in circulation c) myelination increases the rate of mitosis in damaged neurons d) myelination increases the rate at which phagocytosis occurs in the brain
myelination increases the speed of conduction of action potentials
6) The layer of the heart wall that receives the stimulus from letter E is called the __________.
myocardium
The interior surface of a neuron's plasma membrane at resting membrane potential will have a ________. A) negative charge and contains more sodium than outside of the cell B) positive charge and contains less sodium than outside of the cell C) positive charge and contains more sodium than outside of the cell D) negative charge and contains less sodium than outside of the cell
negative charge and contains less sodium than outside of the cell
In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________.
negatively charged and contains less sodium
The sheath of Schwann is also called the ________.
neurilemma
19. The neuron cell membrane is called the
neurilemma and axolemma
Which of the following are bundles of neurofilaments that are important in maintaining the shape and integrity of neurons?
neurofibrils
16. Which is not a term for the excitable cell bodies of the nervous system
neuroglia
9. Nervous system histology reveal the following as glial cells except
neurons
The discharge zone refers to
neurons closer to the incoming fiber
Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensive network of rough endoplasmic reticulum and many clusters of ribosomes. These cellular features indicate all of the following EXCEPT ________. A) neurons produce many proteins B) neurons must meet a high demand for ATP C) neurons have a relatively high consumption of oxygen D) neurons have stable, relatively unchanging internal environments
neurons have stable, relatively unchanging internal environments
A molecule that carries information across a synaptic cleft is a: a) receiving neuron b) synapse c) synaptic cleft d) neurotransmitter e) sending neuron
neurotransmitter
The substance released at axon terminals to propagate a nervous impulse is called a(n) _______.
neurotransmitter
The substance released at axon terminals to propagate a nervous impulse is called a(n) ________.
neurotransmitter
If a neuron simultaneously receives a stimulus that results in local depolarization of 10 mV and a stimulus that results in a local hyperpolarization of 10 mV, the net effect would be: a) net depolarization b) no net change in membrane potential c) neurons can only receive one incoming stimulus at a time d) net hyperpolarization
no net change in membrane potential
Which of the following are gaps found along a myelin sheath?
nodes of Ranvier
13. Non-myelinated segments along periferal nerve are called
nodes of ranvier
7. The counterpart in the central nervous system for the ganglia is the
nuclei
Which of the following is not a chemical class of neurotransmitters?
nucleic acid
Which of the following is not a chemical class of neurotransmitters? A) biogenic amine B) nucleic acid C) amino acid D) ATP and other purines
nucleic acid
schwann cells are functionally similar to...
olidendrocytes
Schwann cells are functionally similar to ________.
oligodendrocytes
Schwann cells are functionally similar to ________. A) astrocytes B) microglia C) ependymal cells D) oligodendrocytes
oligodendrocytes
Which of the following types of glial cells produces the myelin sheaths that insulate axons, or nerve fibers, in the central nervous system (CNS)?
oligodendrocytes
What characterizes repolarization, the second phase of the action potential? a) as the membrane repolarizes to a negative value, it goes beyond the resting state to a value of -80 mV b) before the membrane has a chance to reach a positive voltage, it repolarizes to its negative resting value of approximately -70 mV c) once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV d) once the membrane depolarizes to a threshold value of approximately -55 mV, it repolarizes to its resting value of -70 mV
once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV
Second messengers can
open and close ions channels, activate kinase enzymes, and phosphorylate channel proteins
Direct-acting neurotransmitters ________.
open ion channels to provoke rapid responses
The Peripheral Nervous System (PNS) is the part of the nervous system that is located_______ the CNS.
outside
20) The sinoatrial node, located in the right atrium of the heart, is often called the __________.
pacemaker
5. Spinal nerves and cranial nerves are both components of the
peripheral nervous system
6. Ganglia are a part of the
peripheral nervous system
44) The amount of friction blood encounters as it flows through the blood vessels is known as __________.
peripheral resistance
Immediately after an action potential has peaked, which cellular gates open?
potassium
During the repolarization of a neuron: a) sodium ions move out of the cell b) potassium ions move out of the cell c) potassium ions move into the cell d) sodium ions move into the cell
potassium ions move out of the cell
Which of the following is NOT a type of circuit?
pre-discharge circuits
Which best represents synaptic transmission?
presynaptic axon to synapse to dendrite or postsynaptic cell body
In a synapse, neurotransmitters are stored in vesicles located in the ____________. a) presynaptic neuron b) postsynaptic neuron c) synaptic cleft
presynaptic neuron
The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____.
primary active transport
Which of the following is not a function of astrocytes? A. anchor neurons to blood vessels B. support and brace neurons C. provide the defense for the CNS D. control the chemical environment around neurons E. guide the migration of young neurons, synapse formation, and helping to determine capillary permeability
provide the defense for the CNS
16) The circulation from the heart to the lungs and back is known as __________ circulation.
pulmonary
The sodium-potassium pump ________.
pumps three sodium ions outside the cell and two potassium ions inside.
Which of the following processes allows cells to concentrate material that is present only in very small amounts in the extracellular fluid?
receptor-mediated endocytosis
8. Autonomic nervous system consists of visceral motor nerve fibers that
regulate smooth muscle, are apart of the parasympathetic nervous system, regulate cardiac muscle
Which of the following is NOT one of the basic functions of the nervous system?
regulation of neurogenesis
Which is not a one of the basic functions of the nervous system? a. monitor changes occurring both inside & outside the body b. control the activity of muscle and glands c. regulation of neurogenesis d integration of sensory input
regulation of neurogenesis is not one of the basic functions of the nervous system
37. The down slope on an AP graph represents
repolarization phase
Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference?
resting membrane potential
Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference? a) action potential b) resting membrane potential (RMP) c) threshold potential d) positive membrane potential
resting membrane potential (RMP)
In addition to diffusion, what are two other mechanisms that terminate neurotransmitter activity?
reuptake and degragation
47. Neurotransmitter effects are terminated how
reuptake by astrocytes or axon terminal degradation by enzymes diffusion away from the synaptic cleft
A neural circuit in which a single impulse is transmitted over and over is a ________.
reverberating circuit
Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing?
reverberating circuit
neural circuit in which a single impulse is transmitted over and over is a ________.
reverberating circuit
The node-to-node "jumping" regeneration of an action potential along a myelinated axon is called __________.
salatory conduction
The type of action potential propagation in which action potentials are only generated at nodes of Ranvier is called ___________. a) saltatory conduction b) synaptic transmission c) unmyelinated conduction d) continuous conduction
saltatory conduction
10. All of the following are found in the central nervous system except
satellite cells
Cranial nerve II, the optic nerve sends nerve impulses to the brain carrying information about the things we see. These nerve fibers most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division
sensory (afferent) division
46. The synaptic cleft
separates the presynaptic from the postsynaptic neurons
Which pattern of neural processing works in a predictable, all-or-nothing manner, where reflexes are rapid and automatic responses to stimuli in which a particular stimulus always causes the same response?
serial processing
Which of the following describes the excitatory postsynaptic potential?
short distance depolarization
Which of the following describes the excitatory postsynaptic potential? A) moves membrane potential away from threshold B) opens K+ or Cl- channels C) short distance depolarization D) short distance hyperpolarization
short distance depolarization
Which of the following is controlled by the somatic motor division? a) smooth muscle b) cardiac muscle c) glands d) skeletal muscle
skeletal muscle
Hyperpolarization results from ___________. a) slow closing of voltage-gated Na+ channels b) slow closing of voltage-gated K+ channels c) fast closing of voltage-gated K+ channels
slow closing of voltage-gated K+ channels
hyperpolarization results from...
slow closing voltage gated K+ channels
Which of the following is least likely to increase the rate of diffusion?
small concentration gradient
Which of the following best characterizes depolarization?
small consecutive steps of Na+ penetration into the axon along its length
Which of the following is true about the movement of ions across excitable living membranes?
sodium gates in the membrane can open in response to electrical potential changes
Sarah sensed a mosquito land on her arm and swatted it away with her hand. Which specific PNS division was responsible for the movement of Sarah's hand? a) somatic motor division b) visceral sensory division c) somatic sensory division d) autonomic nervous system
somatic motor division
The somatic nervous system is composed of?
somatic motor nerve fibers that conduct impulses from the central nervous system to skeletal muscles. It is often referred to as the voluntary nervous system because it allows us to consciously control our skeletal muscles
Upon entering your house, you noticed the smell of cake baking in the oven. What division of the peripheral nervous system is responsible? a) somatic sensory division b) somatic motor division c) visceral motor division d) visceral sensory division
somatic sensory division
Changes in membrane potential that cancel each other are likely are result of
spacial summation of EPSP and IPSPsy
An impulse from one nerve cell is communicated to another nerve cell via the ________.
synapse
The small space between the sending neuron and the receiving neuron is the: a) vesicle b) synaptic terminal c) neurotransmitter d) calcium channel e) synaptic cleft
synaptic cleft
The time needed for neurotransmitter to release and diffuse across the synapse is called the
synaptic delay
If a signal from a sending neuron makes the receiving neuron more negative inside, a) the receiving neuron is less likely to generate an action potential b) the receiving neuron is more likely to generate an action potential c) the receiving neuron immediately generates an action potential d) the sending neuron becomes more negative inside e) the sending neuron becomes more positive inside
the receiving neuron is less likely to generate an action potential
If a signal from a sending neuron makes the receiving neuron more negative inside,
the receiving neuron is less likely to generate an action potential.
A neurotransmitter may have an excitatory or an inhibitory effect on the postsynaptic cell, depending on ____________. a) which class of neurotransmitters it belongs to b) the quantity of neurotransmitter released c) the receptor to which it binds d) the frequency of neurotransmitter release
the receptor to which it binds
During an action potential, the rapid decrease in sodium permeability and simultaneous increase in potassium permeability is responsible for __________. a) the depolarization phase b) returning to the resting membrane potential after the action potential c) the repolarization phase d) the hyperpolarization phase
the repolarization phase
33. What system stabilizes a resting membrane
the sodium potassium pump
What is the electrochemical gradient of an ion?
the sum of the electrical and concentration gradients for that ion
In the axon hillock, slow depolarization to threshold is due to ____________. a) the summation of EPSPs b) the opening of Na+ voltage-gated channels c) the opening of K+ voltage-gated channels d) the summation of IPSPs
the summation of EPSPs
During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that ________. A) the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane B) the membrane is now impermeable to all ions C) the sodium potassium pump will stop working during relative refractory D) the inactivation gates on voltage gated sodium ion channels are closed
the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane
The plasma membrane is much more permeable to K+ than to Na+. Why? a) there are many more voltage-gated K+ channels than voltage-gated Na+ channels b) ligand-gated cation channels favor a greater influx of Na+ than K+ c) there are many more K+ leak channels than Na+ leak channels in the plasma membrane d) the Na+-K+ pumps transport more K+ into cells than Na+ out of cells
there are many more K+ leak channels than Na+ leak channels in the plasma membrane
Which of the following is not characteristic of neurons?
they are mitotic
When calcium ions enter the synaptic terminal, a) they cause an action potential in the sending neuron b) the inside of the receiving neuron becomes more negative c) the inside of the receiving neuron becomes more positive d) they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron e) neurotransmitter molecules are quickly removed from the synaptic cleft
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron
When calcium ions enter the synaptic terminal,
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
35) Inflammation of varicose veins can result in a clot in that vessel; this condition is referred to as __________.
thrombophlebitis
23. Proximal processes form unipolar cells head
to the central nervous system
43. Presynaptic neurons conduct information
toward the synapse
17. which of the following is a term for a bundle of neuron processes
tracts and nerves
True/False 21) The three branches of the aortic arch are the brachiocephalic trunk, left common carotid artery, and the left subclavian artery.
true
True/False 29) In fetal circulation, blood travels directly from the right atrium to the left atrium through the foramen ovale.
true
efferent nerves may be described as motor nerve fibers.
true
31) The innermost blood vessel wall that lines the lumen and consists of cells that fit closely together to form a slick surface that decreases friction and allows blood to flow smoothly is the __________.
tunica intima
Which of the following is NOT one of the mechanisms for synaptic transmission termination? a) diffusion of neurotransmitter away b) uptake of neurotransmitter into postsynaptic neuron c) reuptake of neurotransmitter into presynaptic neuron d) degradation of neurotransmitter by enzyme
uptake of neurotransmitter into postsynaptic neuron
33) Larger veins have __________ to prevent the backflow of blood.
valves
45) The narrowing of blood vessels is known as __________.
vasoconstriction
41) The umbilical cord contains an umbilical __________ that transports oxygen and nutrientrich blood to the fetus.
vein
26. The measure of potential energy generated by separated charges is the definition of
voltage
the depolarization phase of an action potential results from the opening of which channels?
voltage gated Na+ channels
Immediately after an action potential has peaked, which of the following channels will open? A) voltage gated calcium channels B) chemically gated chloride channels C) voltage gated potassium channels D) voltage gated sodium channels
voltage gated potassium channels
An action potential releases neurotransmitter from a neuron by opening which of the following channels? a) chemically gated Ca2+ channels b) voltage-gated Ca2+ channels c) voltage-gated K+ channels d) voltage-gated Na+ channels
voltage-gated Ca2+ channels
The channels that open when the axolemma reaches threshold depolarization are the: a) voltage-gated K ion channels b) voltage-gated Na ion channels c) chemically gated K ion channels d) chemically gated Na ion channels
voltage-gated Na ion channels
The depolarization phase of an action potential results from the opening of which channels? a) voltage-gated Na+ channels b) chemically gated K+ channels c) voltage-gated K+ channels d) chemically gated Na+ channels
voltage-gated Na+ channels
what opens first in resonse to a threshold stimulus? a) voltage-gated Na+ channels b) ligand-gated cation channels c) ligand-gated Cl- channels d) voltage-gated K+ channels
voltage-gated Na+ channels
What is the first change to occur in response to a threshold stimulus? a) voltage-gated Na+ channels change shape, and their inactivation gates close b) voltage-gated K+ channels change shape, and their activation gates open c) voltage-gated Ca2+ channels change shape, and their activation gates open d) voltage-gated Na+ channels change shape, and their activation gates open
voltage-gated Na+ channels change shape, and their activation gates open
Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?
voltage-gated channel
The generation of an action potential in a neuron requires the presence of what type of membrane channels? a) voltage-gated channels b) chemically gated channels c) leakage channels d) membrane channels are not required
voltage-gated channels
When an action potential arrives at the end of the axon terminal, a series of events take place that result in the release of neurotransmitter from the presynaptic axon. Select the answer that correctly describes the primary stimulus for vesicles to move towards the cell membrane and eventually release their contents.
voltage-gated membrane channels open, and Ca+2 enters the cytoplasm, increasing intracellular calcium
59. A converging circuit is
when different sensory stimuli elicit the same memory
12. Myelin is associated with the
white matter
Myelinated axons in the CNS are known as: a) dark matter b) internodes c) gray matter d) white matter
white matter
Matching 1) Heart chamber with the 2) Superior discharging 3) Heart chamber that pumps 4) Heart chamber that contains the sinoatrial node 5) Roof of this chamber contains the bicuspid valve 6) The coronary sinus empties blood from cardiac circulation into this chamber 7) The four pulmonary veins return oxygenated blood to this chamber 8) This chamber sends blood into the aorta A) right atrium thickest wall B) right ventricle C) right atrium chamber on the left side of the heart D) left ventricle E) left atrium blood to the pulmonary trunk
1) D 2) D 3) B 4) C 5) D 6) A 7) E 8) D
Identify the sequence of events that occurs at a synapse. 1. An action potential arrives at the synaptic terminal 2. Vesicles containing neurotransmitter fuse with the plasma membrane of the sending neuron 3. Neurotransmitter molecules diffuse across the synaptic cleft 4. The neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, causing ion channels there to open 5. Calcium channels open, and calcium ions enter the synaptic terminal
1, 5, 2, 3, 4
Which of the neuroglial cell types form myelin sheaths within the CNS?
Oligodendrocytes form myelin sheaths within the white matter of the CNS
Define: Oligodendrocytes
Oligodendrocytes wrap their processes around the thicker axons in the CNS, producing an insulating covering called a myelin sheath that increases the transmission speed of nerve impulses.
What characterizes repolarization, the second phase of the action potential?
Once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV.
22) The electrocardiogram (ECG) wave that results from depolarization of the atria is the __________.
P wave
How do action potential propagation speeds compare in myelinated and unmyelinated axons?
Propagation is faster in myelinated axons.
Which of the following is true about the movement of ions across excitable living membranes? A) Ions always move actively across membranes through leakage channels. B) Sodium gates in the membrane can open in response to electrical potential changes. C) Ions always move from an area of higher concentration to an area of lower concentration. D) Ions always move passively across membranes.
Sodium gates in the membrane can open in response to electrical potential changes.
Which of the following is NOT a difference between graded potentials and action potentials?
Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.
Local anesthetics block voltage-gated Na+ channels, but they do not block mechanically gated ion channels. Sensory receptors for touch (and pressure) respond to physical deformation of the receptors, resulting in the opening of specific mechanically gated ion channels. Why does injection of a local anesthetic into a finger still cause a loss of the sensation of touch from the finger?
Touch stimulation of this sensory receptor will open the mechanically gated ion channels, but action potentials are still not initiated because propagation of an action potential requires the opening of voltage-gated Na+ channels.
Which statement best characterizes a leak channel?
Trans-membrane protein channels that are always open to allow to cross the membrane without the additional input of energy.
A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons.
True
A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane.
True
Axon diameter and degree of myelination determine nerve impulse conduction velocity.
True
Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system.
True
During depolarization, the inside of the neuron's membrane becomes less negative.
True
During depolarization, the inside of the neurons's membrane becomes LESS negative T/F
True
Efferent nerve fibers may be described as motor nerve fibers.
True
Enkephalins and endorphins are peptides that act like morphine.
True
If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them.
True
In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier.
True
Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers.
True
Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte.
True
Neurons are also called nerve cells.
True
Neurons in the CNS are organized into functional groups.
True
Opening K+ or Cl- channels in a postsynaptic membrane would produce an inhibitory postsynaptic potential (IPSP).
True
Reflexes are rapid, automatic responses to stimuli that will produce the dame effect every time.
True
Reflexes are rapid, automatic responses to stimuli.
True
Some neurotransmitters can be either excitatory or inhibitory depending upon the receptor.
True
Which of the following statements is correct regarding the polarization of a neuronal membrane and the formation of a resting membrane potential? a. As Na+ leaks across the membrane, that establishes a negative charge inside the membrane. b. Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels. c. As sodium leaks into the cell, the inside of the cell becomes more negative. d. A resting potential can be generated without the energy as an input.
b. Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels.
The period after an initial stimulus when a neuron is NOT sensitive to stimulus is the _________. a. depolarization b. absolute refractory period c. repolarization d. resting period
b. absolute refractory period
Which of the following describes the nervous system integrative function? a. senses changes in the environment b. analyzes sensory information, stores information, makes decisions c. responds to stimuli by gland secretion or muscle contraction
b. analyzes sensory information, stores information, makes decisions
Cold sores on the skin of the mouth occur when herpes simplex viruses that are dormant in neural ganglia become active and travel to the skin of the mouth. Which of the following is the mechanism by which these viruses travel from the ganglia (located within the head) to the skin of the mouth? a. transport along nerve impulses that travel down the axons b. anterograde axonal transport c. retrograde axonal transport d. travel of the viruses along neurofibrils
b. anterograde axonal transport
A neuron that has as its primary function the job of connecting other neurons is called a(n) _________. a. efferent neuron b. association neuron c. glial cell d. afferent neuron
b. association neuron
Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? a. Sodium gates will open first, then close as potassium gates open. b. Specific sodium gates will open. c. A single type of channel will open, permitting simultaneous flow of sodium and potassium. d. Specific potassium gates will open.
c. A single type of channel will open, permitting simultaneous flow of sodium and potassium.
Neurotransmitters classified by function are grouped into 2 classifications
effects or actions
Binding of the neurotransmitter to its receptor causes the membrane to _____________. a) depolarize b) either depolarize or hyperpolarize c) hyperpolarize
either depolarize or hyperpolarize
What changes occur to the voltage-gated Na+ and K+ channels at the peak of depolarization? a) inactivation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open b) activation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open c) inactivation gates of voltage-gated Na+ channels close, while inactivation gates of voltage-gated K+ channels open d) activation gates of voltage-gated Na+ channels close, while inactivation gates of voltage-gated K+ channels open
inactivation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open
15) A decrease in the elasticity of blood vessels (i.e., increase in rigidity) causes arterial blood pressure to __________.
increase
28) The hormones epinephrine and thyroxine will cause the heart rate to __________.
increase
If a drug inhibits the enzyme Acetylcholinesterase, the effect will be: a) decreased stimulation of ACh receptors b) increased ACh reuptake into presynaptic cell c) increased ACh availability in synaptic cleft d) increased levels of ACh inside synaptic vesicles
increased ACh availability in synaptic cleft
37) The vessel that drains blood from all body regions below the diaphragm muscle before emptying into the right atrium is the __________.
inferior vena cava
Where do most action potentials originate? a) axon terminal b) cell body c) Nodes of Ranvier d) initial segment
initial segment
Which of the following is not a function of the autonomic nervous system? A innervation of cardiac muscle B innervation of skeletal muscle C innervation of glands D innervation of smooth muscle of the digestive tract
innervation of skeletal muscle
What component of the reflex arc determines the response to a stimulus?
integration center
What type of neuron is found within the CNS to perform the job of information processing? a) interneurons (association neurons) b) motor (efferent) neurons c) bipolar neurons d) sensory (afferent) neurons
interneurons (association neurons)
7) The partition where the bundle branches are located is called the __________.
interventricular septum
Autonomic Nervous System (ANS) is also called the
involuntary nervous system
When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, a) vesicles in the synaptic terminal fuse to the plasma membrane of the sending neuron b) ion channels in the plasma membrane of the sending neuron open c) the receiving neuron becomes more positive inside d) the receiving neuron becomes more negative inside e) ion channels in the plasma membrane of the receiving neuron open
ion channels in the plasma membrane of the receiving neuron open
When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,
ion channels in the plasma membrane of the receiving neuron open.
Learning or memory is a result of
synaptic potentiation
24) The term that means heart contraction is __________.
systole
23) A heart rate over 100 beats per minute is referred to as __________.
tachycardia
Why does the action potential only move away from the cell body? a) the flow of the sodium ions only goes in one direction - away from the cell body b) the areas that have had the action potential are refractory to a new action potential
the ares that have had the action potential are refractory to a new action potential
which areas of the neuron would be classified as receptive regions?
the cell body and dendrites
which criterion is used to functionally classify neurons?
the direction in which the nerve impulse travels relative to the central nervous system
Imagine you changed the concentration of K+ outside a neuron such that the resting membrane potential changed to -80 mV (from the normal resting value of -70 mV). What have you changed?
the electrical gradient for K+ and the concentration gradient for K+
39. When coding for stimulus intensity
the frequency of impulses in registered in the CNS
An action potential in one segment of axon causes adjacent sections of axon membrane to reach threshold through what mechanism?
the generation of local currents
If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________.
the impulse would spread bidirectionally
If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________. A) the impulse would move to the axon terminal only, and the muscle contraction would occur B) the impulse would spread bidirectionally C) muscle contraction would occur D) the impulse would move to the axon terminal only
the impulse would spread bidirectionally
Why does regeneration of the action potential occur in one direction, rather than in two directions?
the inactivation gates of voltage gated Na+ channels close in the node, or segment that has just fired an action potential
Why does regeneration of the action potential occur in one direction, rather than in two directions? a) the activation gates of voltage-gated Na+ channels close in the node, or segment, that has just depolarized b) the inactivation gates of voltage-gated Na+ channels close in the node, or segment, that has just fired an action potential c) the activation gates of voltage-gated K+ channels open in the node, or segment, that has just depolarized d) the inactivation gates of voltage-gated K+ channels close in the node, or segment, that has just fired an action potential
the inactivation gates of voltage-gated Na+ channels close in the node, or segment, that has just fired an action potential
On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you? a) the inside surface of the plasma membrane is much more positively charged than the outside surface b) the inside surface of the plasma membrane is much more negatively charged than the outside surface c) the outside surface of the plasma membrane is much more negatively charged than the inside surface d) there is no electrical potential difference between the inside and the outside surfaces of the plasma membrane
the inside surface of the plasma membrane is much more negatively charged than the outside surface
What characterizes depolarization, the first phase of the action potential? a) the membrane potential changes to a much more negative value b) the membrane potential changes from a negative value to a positive value c) the membrane potential reaches a threshold value and returns to the resting state d) the membrane potential changes to a less negative (but not a positive) value
the membrane potential changes from a negative value to a positive value
A second nerve impulse cannot be generated until ________. A) all sodium gates are closed B) the membrane potential has been reestablished C) the Na ions have been pumped back into the cell D) proteins have been resynthesized
the membrane potential has been reestablished
What event triggers the generation of an action potential? a) the membrane potential must hyperpolarize from the resting voltage of -70 mV to the more negative value of -80 mV b) the membrane potential must return to its resting value of -70 mV from the hyperpolarized value of -80 mV c) the membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of -55 mV d) the membrane potential must depolarize from the resting voltage of -70 mV to its peak value of +30 mV
the membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of of -55 mV
Saltatory conduction is made possible by ________. A) erratic transmission of nerve impulses B) diphasic impulses C) large nerve fibers D) the myelin sheath
the myelin sheath
What is the function of the myelin sheath? a) the myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals b) the myelin sheath decreases the speed of action potential conduction from the initial segment to the axon terminals c) the myelin sheath increases the insulation along the entire length of the axon d) the myelin sheath decreases the resistance of the axonal membrane to the flow of charge
the myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals
what is the function of the myelin sheath?
the myelin sheath increases the speed of action potential from the initial segment to the axon terminals
2. The master controlling and communicating system of the body is
the nervous system
In a myelinated axon, how do the nodes of Ranvier differ from other segments of the same axon?
the nodes are more permeable to ions
the repolarization phase of an action potential results from....
the opening of voltage gated K+ channels
The repolarization phase of an action potential results from ___________. a) the closing of voltage-gated K+ channels b) the closing of voltage-gated Na+ channels c) the opening of voltage-gated K+ channels d) the opening of voltage-gated Na+ channels
the opening of voltage-gated K+ channels
38. The refractory period is
the period where another action potential cannot be produced the period of hyperpolarization
A neuron that receives neurotransmitters from another neuron is called: a) a Schwann cell b) the presynaptic neuron c) the postsynaptic neuron d) an oligodendrocyte
the postsynaptic neuron
The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors. a) the presence of concentration gradients and Na+-K+ pumps b) the presence of a resting membrane potential and leak channels c) the presence of concentration gradients and leak channels d) the presence of concentration gradients and voltage-gated channels
the presence of concentration gradients and leak channels
If a post synaptic neuron is stimulated to threshold by spatial summation this implies that ________. A) the post synaptic cell has a lower than normal threshold B) the post synaptic cell has many voltage gated ion channels C) the post synaptic cell is slow to repolarize D) the postsynaptic cells has many synapses with many presynaptic neurons
the postsynaptic cells has many synapses with many presynaptic neurons
Reflexes are rapid, automatic responses to stimuli that will produce the same effect every time.
true
An action potential is regarded as an example of a positive feedback. Which of the following examples below best illustrates the positive feedback aspect of an action potential? A) The sodium potassium pump consistently moves ions as long as ATP is available, and regardless of membrane potential changes. B) Potassium permeability is about 25 times greater than sodium ions. C) Voltage gated potassium ion channels open slowly and remain open long enough to cause hyperpolarization. D) A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels.
A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels.
Select the correct statement about synapses. A) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another. B) Neurotransmitter receptors are located on the axons of cells. C) The release of neurotransmitter molecules gives cells the property of being electrically coupled. D) Cells with interconnected cytoplasm are chemically coupled.
A) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
Conducting region of the neuron.
Axon
Neurotransmitters are released at the ________.
Axon terminal
Receives stimuli. A) Secretory zone B) Conducting region C) Secretory region D) Trigger zone E) Receptive region
Receptive region
Which of the following is true about the movement of ions across excitable living membranes? A) The bulk of the solutions inside a cell are negatively charged. B) Ions always move actively across membranes through leakage channels. C) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps. D) Sodium gates in the membrane can open in response to electrical potential changes.
C) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps.
Choose the statement that is most correct about membrane potential. A) Voltage would be measured by placing one electrode on one end of the axon and another electrode on the other end. B) Voltage would be measured by placing one electrode on the axon and grounding the other electrode. C) Voltage would be measured by placing two electrodes on the exterior of the axon. D) Voltage would be measured by placing one electrode inside the membrane and another outside the membrane.
D) Voltage would be measured by placing one electrode inside the membrane and another outside the membrane.
All of the following are true of graded potentials except that they ________. A) can be called postsynaptic potentials B) are short-lived C) can form on receptor endings D) increase amplitude as they move away from the stimulus point
D) increase amplitude as they move away from the stimulus point
Which of the following is not a structural feature of a neuron? A) Nissl bodies B) dendrites C) axon D) synaptic cleft
D) synaptic cleft
Multiple sclerosis (MS) is a disease in which the myelin sheaths are destroyed. What process does this interfere with and what would be the consequence?
Demyelination interferes with saltatory conduction, which would result in a slowing down of nerve impulse propagation.
The effect of acetylcholine can be stimulating or inhibiting. Which of the following gives the best explanation for why this is so? A) Acetylcholine has many different forms. B) Acetylcholine has a "dose effect". Larger doses are stimulating while small doses inhibit. C) Postsynaptic cells have a dynamic and changing metabolism and respond differently at different times. D) Different post synaptic cells will have different receptors.
Different post synaptic cells will have different receptors.
________ is an indolamine.
Epinephrine
The nodes of Ranvier are found only on myelinated, peripheral neural processes.
False
Plasma membrane exhibits chemically gated ion channels. A) Secretory zone B) Conducting region C) Secretory region D) Trigger zone E) Receptive region
Receptive region
Plasma membrane exhibits voltage-gated Ca2+ channels. A) Secretory zone B) Conducting region C) Secretory region D) Trigger zone E) Receptive region
Secretory region
A client was admitted for depression. What should the nurse explain to the client regarding the role of serotonin and depression?
Serotonin is a biogenic amine neurotransmitter widely distributed in the brain, where it plays a role in emotional behavior and helps to regulate the biological clock.
Stimulation of a postsynaptic neuron by many terminals at the same time.
Spatial summation
Stimulation of a postsynaptic neuron by many terminals at the same time. A) Spatial summation B) Subthreshold stimulus C) Threshold stimulus D) Temporal summation
Spatial summation
An insufficient stimulus to reach an action potential. A) Spatial summation B) Subthreshold stimulus C) Threshold stimulus D) Temporal summation
Subthreshold stimulus
An insufficient stimulus.
Subthreshold stimulus
Which of the following is not characteristic of neurons? A) They have an exceptionally high metabolic rate. B) They conduct impulses. C) They have extreme longevity. D) They are mitotic.
They are mitotic.
The depolarization phase of an action potential is punctuated by the closing of inactivation gates in the voltage gated sodium ion channels. All of the following are consequences of this inactivation except one. Choose the statement below that is not a consequence of the closing of inactivating gates. A) This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell. B) This allows for the one way transmission of action potential down the axon. C) This limits the frequency of action potentials down the axon. D) This stops the depolarization of the axon membrane.
This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell.
Any stimulus at or above this level will result in action potential. A) Spatial summation B) Subthreshold stimulus C) Threshold stimulus D) Temporal summation
Threshold stimulus
Any stimulus below this intensity will result in no response in a neuron.
Threshold stimulus
Area where nerve impulse is generated. A) Secretory zone B) Conducting region C) Secretory region D) Trigger zone E) Receptive region
Trigger zone
32) Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system.
True
A graded potential that is the result of a neurotransmitter released into the synapse between two neurons is called a postsynaptic potential.
True
A stimulus traveling toward a synapse appears to open calcium channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane.
True
A synapse formed between the axon ending of one neuron and the cell body of another neuron is called an axosomatic synapse.
True
Acetylcholine is not a biogenic amine.
True
The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. A) repolarization B) resting period C) absolute refractory period D) depolarization
absolute refractory period
Bacteria in the blood can be prevented entry to the fluids surrounding the brain. Which cells are most responsible for preventing bacteria from entering the fluids of the brain? A) satellite cells B) astrocytes C) Schwann cells D) oligodendrocytes
astrocytes
The concentration neurotransmitters in the fluid of the synaptic cleft must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for aiding in this regulation? A) satellite cells B) astrocytes C) Schwann cells D) oligodendrocytes
astrocytes
The concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for this? A) satellite cells B) astrocytes C) Schwann cells D) oligodendrocytes
astrocytes
The sympathetic and parasympathetic are subdivisions of the _____.
autonomic nervous system
A neuronal circuit that concentrates or directs a large number of incoming impulses to a rather small number of neurons is called a(n) _______.
converging circuit
Ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid are called ________.
ependymal cells
These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid ________. A) ependymal cells B) astrocytes C) oligodendrocytes D) Schwann cells
ependymal cells
Bipolar neurons are commonly ________. A) motor neurons B) called neuroglial cells C) found in the retina of the eye D) found in ganglia
found in the retina of the eye
An inhibitory postsynaptic potential (IPSP) is associated with _______.
hyperpolarization
When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the post synaptic cell? A) influx of positively charged ions into the postsynaptic cell B) opening of chemically gated sodium channels C) depolarization of the postsynaptic cell membrane D) hyperpolarization of the postsynaptic cell membrane
hyperpolarization of the postsynaptic cell membrane
Loss of function in the enzyme acetylcholine esterase would result in which of the following? A) inability to destroy and remove acetylcholine from the synaptic cleft B) stimulation of the production of acetylcholine C) amplify or enhance the effect of ACh D) inability to release acetylcholine
inability to destroy and remove acetylcholine from the synaptic cleft
Which of the following is not a function of the autonomic nervous system? A) innervation of smooth muscle of the digestive tract B) innervation of skeletal muscle C) innervation of cardiac muscle D) innervation of glands
innervation of skeletal muscle
An action potential _____.
is essential for impulse propagation
Meningitis can be caused by infection of the central nervous system by bacteria. Which cells would be most responsible for removing the infection? A) Schwann cells B) oligodendrocytes C) microglia D) satellite cells
microglia
Which of the choices below describes the ANS? A) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands B) motor fibers that conduct nerve impulses from the CNS to skeletal muscles C) sensory and motor neurons that supply the digestive tract D) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division
parasympathetic division
Nerve impulses leading to the brain carry information about cool temperatures on the skin.The nerve fibers sending these signals will most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division
sensory (afferent) division
Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division
somatic nervous system
The point at which an impulse from one nerve cell is communicated to another nerve cell is the _______.
synapse