A synapse can occur only between an axon and:

a cell body. another axon. a dendrite.

What mechanism quickly terminates the action of a neurotransmitter once it binds to its postsynaptic receptor?

Neurotransmitter molecules are transported back into synaptic knobs. Neurotransmitter molecules are metabolized into inactive compounds. Neurotransmitter molecules are transported into nearby glial cells.

The mechanisms that produce and maintain the resting membrane potential do so by producing a

slight excess of positive ions on the outer surface of the plasma membrane.

The difference between sodium and potassium in the generation of action potential is that:

sodium causes depolarization of the cell membrane, and potassium causes repolarization of the cell membrane.

Which neuron could transmit a nerve impulse the fastest?

A large-diameter neuron with myelin

Which is true of a neuron with a resting potential?

The sodium pump has moved Na+ to the outside of the plasma membrane.

For a neurotransmitter to produce an inhibitory postsynaptic potential, which of the following channels must open?

Potassium and/or chloride channels

Which is true of an action potential?

The outside of the plasma membrane is negatively charged, and the inside is positively charged.

Which of the following is true of spatial summation?

Neurotransmitters released simultaneously from several presynaptic knobs converge on one postsynaptic neuron.

No impulse can be sent through a neuron:

during the absolute refractory period.

Acetylcholine is in the same class of neurotransmitters as:

serotonin. histamine. dopamine.

The first event to occur when an adequate stimulus is applied to a neuron is:

some of the sodium channels at the point of stimulation open.

Within the nervous system, coding for the strength of a stimulus is accomplished through:

the frequency of nerve impulses.

When an impulse reaches a synapse:

chemical transmitters are released.

During a relative refractory period:

the action potential can be initiated with a strong stimulus.

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Week 14: StudyStack

Week 14- StudyStack Set 2

Question	Answer
A membrane that exhibits a membrane potential is said to be	polarized.
The magnitude of the action potential peaks when the sodium channels close.	True
The speed of a nerve impulse depends on the neuron’s resting potential.	False
The active transport mechanism in the plasma membrane that transports sodium and potassium ions in opposite directions and at different rates is the	sodium-potassium pump.
If the threshold potential is surpassed, the full peak of the action potential is always reached.	True
There are two types of synapses—the electrical synapse and the __________ synapse	chemical
When neurotransmitters from synaptic knobs stimulate a postsynaptic neuron in rapid succession, their effect can add up over a brief period to produce an action potential. This is called	temporal summation.
If the magnitude of the local depolarization surpasses a limit called the _____, voltage-gated Na+ channels are stimulated to open.	threshold potential
Movement of the membrane potential away from zero (below the usual RMP) is called	hyperpolarization.
A term commonly used as a synonym for action potential is	nerve impulse.
In depolarization the membrane potential moves toward zero, whereas in hyperpolarization the membrane potential moves away from zero.	True
In a myelinated neuron, the impulse can travel under the myelin between nodes of Ranvier.	True
The membrane potential maintained by a nonconducting neuron’s plasma membrane is called the _____ membrane potential.	resting
When a neuron is resting, the inner surface of its plasma membrane is slightly positive compared with its outer surface.	False
The sodium-potassium pump actively pumps three potassium ions out of the neuron and two sodium ions into the neuron.	False
The action potential seems to “leap” from node to node along a myelinated fiber. This type of impulse regeneration is called __________ conduction.	saltatory
A synapse can occur only between an axon and:	a cell body. another axon. a dendrite.
A neurologist is using a voltmeter to measure potential. The membrane potential of a neuron was recorded at +30 mV. This is what type of membrane potential?	Action
Which chemicals allow neurons to communicate with one another?	neurotransmitters
The tiny bulge at the end of a terminal branch of a presynaptic neuron’s axon is called a(n)	synaptic knob.
Which membrane receptor acts to directly change ion permeability when stimulated?	Gated-channel receptor
What mechanism quickly terminates the action of a neurotransmitter once it binds to its postsynaptic receptor?	Neurotransmitter molecules are transported back into synaptic knobs. Neurotransmitter molecules are metabolized into inactive compounds. Neurotransmitter molecules are transported into nearby glial cells.
The brief period during which a local area of an axon's membrane resists re-stimulation is called the __________ period.	refractory
The mechanisms that produce and maintain the resting membrane potential do so by producing a	slight excess of positive ions on the outer surface of the plasma membrane.
Neurons are the only living cells that maintain a difference in the concentration of ions across their membranes.	False
The difference between sodium and potassium in the generation of action potential is that:	sodium causes depolarization of the cell membrane, and potassium causes repolarization of the cell membrane.
An ion channel that opens in response to a sensory stimulus is a(n)	stimulus-gated channel.
Whether an impulse is continued through the neuron depends on the magnitude of the voltage in the axon hillock.	True
The difference in electrical charge between the inside and outside of a membrane is called the membrane potential.	True
In a myelinated fiber, the action potential jumps from one node of Ranvier to the next.	True
The fastest nerve fibers in the body can conduct an impulse that is how much faster than the slowest fibers in the body?	Almost 300 times faster
When current leaps across an insulating myelin sheath from node to node, the type of impulse conduction is called:	saltatory conduction.
Which neuron could transmit a nerve impulse the fastest?	A large-diameter neuron with myelin
A slight shift away from the resting membrane potentials in a specific region of the plasma membrane is called a _____ potential.	local
Which is true of a neuron with a resting potential?	The sodium pump has moved Na+ to the outside of the plasma membrane.
For a neurotransmitter to produce an inhibitory postsynaptic potential, which of the following channels must open?	Potassium and/or chloride channels
Which is true of an action potential?	The outside of the plasma membrane is negatively charged, and the inside is positively charged.
Which of the following is true of spatial summation?	Neurotransmitters released simultaneously from several presynaptic knobs converge on one postsynaptic neuron.
Compared with the outside of the neuron, the inside has a(n) ____ charge.	negative
A synaptic knob would be located on a(n):	axon.
No impulse can be sent through a neuron:	during the absolute refractory period.
The neurotransmitter(s) that inhibit(s) the conduction of pain impulses is(are):	enkephalins.
Excitatory neurotransmitters are most likely to:	initiate an action potential.
Acetylcholine is in the same class of neurotransmitters as:	serotonin. histamine. dopamine.
The first event to occur when an adequate stimulus is applied to a neuron is:	some of the sodium channels at the point of stimulation open.
The only ion(s) that can diffuse across a neuron’s membrane when the neuron is at rest is (are):	potassium.
Within the nervous system, coding for the strength of a stimulus is accomplished through:	the frequency of nerve impulses.
Serotonin is an example of a(n):	amine neurotransmitter.
When an impulse reaches a synapse:	chemical transmitters are released.
During a relative refractory period:	the action potential can be initiated with a strong stimulus.
The fastest nerve fibers in the body can conduct impulses up to approximately _____ meters per second.	130
Which of the following statements about amino acid neurotransmitters is incorrect?	They are all inhibitory neurotransmitters.
Dopamine, epinephrine, and norepinephrine are classified as:	catecholamines.
Which of the following is not one of the main chemical classes of neurotransmitters?	Triglycerides
Neurotransmitters are released in a synapse and bind to:	receptors on the postsynaptic neuron.
Severe depression can be caused by a deficit in certain brain synapses of:	amines.
Which of the following antidepressants acts by blocking the action of monoamine oxidase (MAO)?	Phenelzine
A synapse consists of:	a synaptic knob. a synaptic cleft. the plasma membrane of a postsynaptic neuron.
Stimulus-gated channels open in response to:	sensory stimuli.
Which of the following is not used by the body as a neurotransmitter?	Nitric oxide. Acetylcholine. Carbon monoxide
Many cerebral functions have typical locations. This fact is known as	cerebral localization.
The two main types of adrenergic receptors are	alpha and beta.
A reflex consists of either a muscle contraction or a	glandular secretion.
The _____ is an extension of the great toe, with or without fanning of the other toes, in response to stimulation of the outer margin of the sole of the foot.	Babinski sign
Which cranial nerve is responsible for the sense of smell?	olfactory
The groove between the frontal and parietal lobes of the cerebral cortex is the	central sulcus.
A _____ is a skeletal muscle or group of muscles that receives motor axons from a given spinal nerve.	myotome
The reticular activating system maintains	consciousness.
Both sympathetic and parasympathetic divisions are tonically active, which means they	continually conduct impulses to autonomic effectors.
Mixed cranial nerves contain axons of	sensory and motor neurons.
Tongue movement is controlled by which cranial nerve?	hypoglossal
Axon terminals of autonomic neurons release either of two neurotransmitters,	norepinephrine and acetylcholine.
Which of the following is NOT correct?	Sympathetic preganglionic axons pass along the dorsal root of certain spinal nerves.
If the center of a reflex arc is the brain, the response it mediates is called a	cranial reflex.
The effect of sympathetic stimulation on the urinary bladder is	relaxation.
“Fight or flight” physiological changes include all of the following EXCEPT	constriction of respiratory airways.
Another name for the parasympathetic nervous system is the nervous system.	craniosacral
Which of the following is NOT an example of sympathetic stimulation?	constriction of the bronchioles
The _____ consists of several structures that lie beneath the thalamus and form the floor of the third ventricle and the lower part of its lateral walls.	hypothalamus
Which region of the brain plays a part in the mechanism responsible for emotions by associating sensory impulses with feelings of pleasantness and unpleasantness?	thalamus
The set of coordinated commands that control the programmed muscle activity mediated by extrapyramidal pathways is called the	motor program.
The cortex is capable of storing and retrieving information from both short-term and long-term	memory.
The action of acetylcholine is quickly terminated by its being hydrolyzed by the enzyme	acetylcholinesterase.
The _____ nerve transmits impulses that result in sensations of equilibrium.	vestibular
Each skin surface area supplied by sensory fibers of a given spinal nerve is a	dermatome.
The somatic motor system includes all the _____ motor pathways _____ the CNS.	voluntary; outside
The second largest part of the brain, located just below the posterior portion of the cerebrum, is the	cerebellum.
Acetylcholine binds to _____ receptors.	cholinergic
The most numerous cerebral tracts are the	association tracts.
The limbic system integrates	emotion.
Cerebrospinal fluid is formed by filtration of blood in the:	choroid plexuses.
The part of the brain that assists in the maintenance of balance is the:	cerebellum.
Acetylcholine can stimulate _____ receptors.	nicotinic
Normal infants will show the Babinski reflex up to the age of _____ years	1.5-2
Damage to the _____ nerve could make the diaphragm unable to function.	phrenic
If the dorsal root ganglia of the spinal nerve were destroyed, a person would lose _____ related to that pathway.	sensory perception
Afferent nerves or fibers are found only in the _____ nervous system.	sensory , autonomic
The preganglionic neurons of both the sympathetic and the parasympathetic divisions are cholinergic.	True
The cerebellum acts with the _____ to produce skilled movement.	cerebrum
Somatic motor and autonomic pathways share all of the following characteristics except:	number of neurons between central nervous system (CNS) and effector.
Which of the following statements is not true?	The major function of the parasympathetic division is to serve as an “emergency” system.
Which of the following is not associated with the oculomotor nerve?	Closing and opening of the eye (blink reflex)
The vomiting reflex is mediated by the:	medulla.
A child was frightened by a large dog. The pupils of the child’s eyes became dilated, and the heart and respiratory rates increased. These symptoms were caused by stimulation of:	the sympathetic nervous system.
Propranolol is an example of a:	beta blocker. drug used to treat irregular heartbeats. drug used to treat hypertension.
Which of the following is a correct statement?	There are 5 lumbar nerve pairs.
If the ventral nerve root of a spinal nerve were destroyed, a person would lose _____ related to that pathway.	willed movement
Norepinephrine is liberated at:	most sympathetic postganglionic nerve endings.
A mixed nerve is one that:	carries both sensory and motor fibers.
The knee jerk can be classified as a segmental reflex because:	impulses that mediate it enter and leave the same segment of the cord.
Nerves that innervate the floor of the pelvic cavity and some of the surrounding areas are found in the _____ plexus.	coccygeal
Impulses sent over which of the following tracts could result in voluntary movement, especially of the hands, fingers, feet, and toes of the opposite side?	Lateral corticospinal
Which of the following is a description of the principle of autonomic antagonism as it relates to the autonomic nervous system?	If sympathetic impulses tend to stimulate an effector, parasympathetic impulses tend to inhibit it.
Which of the following is not a function of the hypothalamus?	Regulation of motor activity
Nerve impulses over the _____ nerve cause increased peristalsis and decreased heart rate.	vagus
Impulses from the _____ play a part in arousing or alerting the cerebrum.	thalamus
Which is not true of the dorsal nerve root?	It is also called the posterior root. It includes the spinal ganglion. It includes sensory fibers.
The cerebellum performs all of the following functions except:	controls cardiac function.
The parasympathetic and sympathetic divisions always act with a cooperative influence, and through summation of the impulses, the effect can be increased.	False
Tic douloureux is a painful neuralgia of the _____ nerve.	trigeminal
Most effectors of the autonomic nervous system are dually innervated by sympathetic and parasympathetic neurons.	True
Which of the following is not true of the knee jerk reflex?	It is a flexor reflex.
Cerebrospinal fluid circulates through the ventricles, into the central canal and _____, and is absorbed back into the blood.	subarachnoid space
The spinal tract that is located in the side of the cord, originates in the brain, and terminates in the spinal cord is the _____ tract.	lateral corticospinal
Once inside the sympathetic chain ganglion, the preganglionic fiber may:	synapse with a sympathetic postganglionic neuron. send ascending and/or descending branches through the sympathetic trunk to synapse with postganglionic neurons in other chain ganglia.pass through one or more ganglia without synapsing.
Which of the following is not true?	One bundle of nerve fibers (nerve roots) projects from each side of the spinal cord.
How does a dually innervated autonomic effector differ from a singly innervated autonomic effector?	A dually innervated effector receives input from both sympathetic and parasympathetic pathways. A singly innervated autonomic effector receives input from only the sympathetic division.
Sympathetic responses generally have widespread effects on the body because:	preganglionic fibers synapse with several postsynaptic fibers.
Which is(are) the neurotransmitter(s) in a somatic motor pathway?	Acetylcholine
Audition is a function of the _____ lobe.	temporal
Which of the following is not an example of sympathetic stimulation?	Constriction of the bronchioles
All of the following are examples of parasympathetic stimulation except:	increased heart rate.
Which is the only plexus that contains fibers from the thoracic region of the spinal cord?	Brachial
The part of the brain that can directly influence or inhibit the release of hormones from the pituitary is the:	hypothalamus.
All of the following cranial nerves are involved in proprioception except the:	vagus
Visit this link (Links to an external site.) to watch an animation of the events that occur when a hormone binds to a cell membrane receptor. A small molecule binds to a G protein, preventing its activation. What direct effect will this have on signaling	. Adenylyl cyclase will not be activated.
Visit this link (Links to an external site.) to watch an animation showing the role of the hypothalamus and the pituitary gland. Which hormone is released by the pituitary to stimulate the thyroid gland?	thyrotropin
Visit this link (Links to an external site.) to view an animation describing the location and function of the adrenal glands. Which hormone produced by the adrenal glands is responsible for mobilization of energy stores?	Cortisol
Visit this link (Links to an external site.) to view an animation describing the function of the hormone melatonin. What should you avoid doing in the middle of your sleep cycle that would lower melatonin?	turning on the lights
Visit this link (Links to an external site.) to view an animation describing the location and function of the pancreas. What goes wrong in the function of insulin in type 2 diabetes?	the cells don't respond to insulin like they should
Watch this video (Links to an external site.) to learn more about how the structures of the ear convert sound waves into a neural signal by moving the “hairs,” or stereocilia, of the cochlear duct. Specific locations along the length of the duct encode sp	The ossicles
Watch this animation (Links to an external site.) to learn more about the inner ear and to see the cochlea unroll, with the base at the back of the image and the apex at the front. Specific wavelengths of sound cause specific regions of the basilar membra	the apex of the cochlea . between the base and the apex of the cochlea
Watch this video (Links to an external site.) to learn more about a transverse section through the brain that depicts the visual pathway from the eye to the occipital cortex. The first half of the pathway is the projection from the RGCs through the optic	electrical signals
Watch this video (Links to an external site.) to learn more about how the brain perceives 3-D motion. Similar to how retinal disparity offers 3-D moviegoers a way to extract 3-D information from the two-dimensional visual field projected onto the retina,	right eye
Watch this video (Links to an external site.) to learn more about the reflex arc of the corneal reflex. When the right cornea senses a tactile stimulus, what happens to the left eye?	blinks
The olfactory tract carries impulses associated with:	smell.
The major hormone produced by the corpus luteum is:	progesterone.
The type of cells that secrete ACTH are:	corticotrophs.
Sensory impulses ending in what part of the CNS trigger imprecise or “crude” sensation awareness?	Thalamus
When a small amount of one hormone allows a second hormone to have its full effect, the phenomenon is called:	permissiveness.
The somatic senses enable us to detect sensations, including:	pain. temperature. touch.
Accommodation for near vision necessitates	an increase in the curvature of the lens. constriction of the pupils. convergence of the two eyes.
In comparison with the nervous system, the regulatory effects of the endocrine system are:	slow to appear but long-lasting.
The last step in the nonsteroid hormone mechanism of action is:	protein kinases activate other enzymes.
Dynamic equilibrium depends on the functioning of the	crista ampullaris.
The immediate effect of a steroid hormone on a cell is the:	transcription of RNA.
Which of the following is a function of glucagon?	Tends to increase blood glucose concentrations
The two-point discrimination test can be used to measure:	the sensitivity of the skin in various parts of the body.
When you are looking at a large green field, which cones would be sending the green wavelength to the brain?	M
All of the following are nonsteroid hormones except:	cortisol.
The clear and potassium-rich fluid that fills the labyrinth is	endolymph.
Which of the following statements is not true of the pineal gland?	Melatonin is stimulated by the presence of sunlight.
Which of the following is true about pain receptors?	Alpha fibers are associated with sharp, localized pain.
Visceroceptors are located in which of the following?	Internal organs
The sequence of auditory ossicles in the middle ear starting at the tympanic membrane and ending at the oval window is:	malleus, incus, and stapes.
Clearness or sharpness of visual perception is known as:	visual acuity
The production of thyroid hormone is stimulated by another hormone from the:	anterior pituitary.
All of the following are true statements except:	aspirin produces some of its effects by increasing PGE synthesis.
If you slammed your finger in a car door, it would stimulate _____ pain fibers.	acute
Which of the following is not a characteristic of the endocrine system?	Chemical messenger travels a short distance.
Which is not true of the hormone somatostatin?	It stimulates the secretion of insulin.
Movement of hair cells in the organ of Corti against the _____ membrane can stimulate nerve impulse condition.	tectorial
The receptors responsible for sensing crude and persistent touch are the:	Ruffini corpuscles.
Which of the following is not true of a receptor potential?	It follows the all-or-none law.
One of the few hormones that functions on a positive-feedback loop is:	oxytocin
Fluid shift is when...	thenbody's fluids move between the fluid compartments.
The second step of hemostasis occurs when additional coagulation factors beyond factor VII respond in a cascade to form fibrin strands. Fibrin stands strengthen what?	platelet plug
Pulmonary circulation is the portion of the circulatory system which carries ____________ blood away from the right ventricle, to the lungs, and returns ____________blood to the left atrium and ventricle of the heart.	deoxygenated; oxygenated
In an electrocardiogram the T wave represents	repolrization of the ventricles.
What causes the ventricles to contract?	The inpulse to the Perkinje Fiber
Veins from our digestive organs send blood to the Hepatic Portal Vein in order for	nutrients and toxins can be extracted from digested contents..
(Links to an external site.)The foramen ovale allows blood to move from the right atrium to the left atrium	bypassing pulmonary circulation.
The greatest pressure drop is in the ____________ which has muscle fibers that expand and contract change diameters.	arterioles
The amount of water that moves into the blood from the interstitial fluid depends on the concentration of	plasma protein.
The process of red cells are production in the marrow of certain bones is referred to as	Erythropoiesis
Which of the following is(are) involved in determining a person’s total blood volume?	Age. Body type. Sex
What is the functional significance of large areas of cardiac muscle being electrically coupled to form a single functional syncytium?	Because they form a syncytium, muscle cells can pass an action potential along a large area of the heart wall, stimulating contraction in each muscle fiber of the syncytium.
The heart begins beating in the fetus at about what stage of development?	After about 4 weeks
Which of the following is not true of ventricles?	They are the pumping chambers of the heart. The myocardium of the ventricles is thicker than that of the atria. The myocardium of the left ventricle is thicker than that of the right ventricle.
Erythrocytes begin their maturation sequence in red bone marrow from nucleated cells known as:	hematopoietic stem cells.
Which are the two baroreceptors that are located near the heart?	aortic baroreceptors and carotid baroreceptors
A hematocrit of 56% would be an indication of:	polycythemia.
_____ is used to determine the volume percentage of red blood cells in whole blood.	Hematocrit
All of the following are components critical to coagulation except	none of the above; all of these components are critical to coagulation.
Blood volume per kilogram of body weight varies inversely with:	body fat.
_____, a natural constituent of blood, acts as an antithrombin and prevents clots from forming in vessels.	Heparin
In the extrinsic pathway of stage 1 of the clotting mechanism, chemicals released from damaged tissues trigger the cascade of events that ultimately result in the formation of	prothrombin activator.
The localized pressure gradient needed to maintain blood flow in a tissue is called	perfusion pressure.
Inhibition of sympathetic vasoconstrictor impulses is considered a major mechanism of	vasodilation.
Starling’s law of the heart states that, within limits, the longer, or more stretched, the heart fibers are at the beginning of the contraction, the	stronger the contraction.
The vagus is said to act as a “brake” on the heart. This situation is called	vagal inhibition.
Which of the following is a powerful poison that acts directly on any cell and quickly kills it?	lymphotoxin
Which organ has several functions, including defense, hematopoiesis, red blood cell and platelet destruction, and blood reservoir?	spleen
_____ refers to a phenomenon in which the genetic characteristics common to a particular kind of organism provide defense against certain pathogens.	Species resistance
During their residence in the thymus, pre-T cells develop into _____, cells that proliferate as rapidly as any in the body.	thymocytes
Masses of lymphoid tissue located in a protective ring under the mucous membranes in the mouth and the back of the throat are called	tonsils.
The ingestion and destruction of microorganisms or other small particles is called	phagocytosis.
The internal environment of the human body is protected by the _____, which is(are) referred to as the first line of defense.	skin
The functions of the lymph nodes are	defense and hematopoiesis.
Activities that result in central movement or flow of lymph are called	lymphokinetic activities.
Which of these substances operate(s) immune mechanisms?	sebum. mucus. enzymes. hydrochloric acid in gastric mucosa
Molecules formed by the reactions of the complement cascade assemble themselves on the enemy cell’s surface, which results in	cytolysis.
Which antibody is synthesized by immature B cells and then inserted into their plasma membranes?	immunoglobulin M
The lymphatic system serves various functions in the body. The two most important functions of this system are	fluid balance and immunity.
Because T cells attack pathogens more directly, T-cell immune mechanisms are classified as _____ immunity.	cell-mediated
Lymphocytes that kill many types of tumor cells and cells infected by different kinds of viruses are known as	natural killer cells.
What is the function of the spleen?	tissue repair. hematopoiesis. red blood cell and platelet destruction. blood reservoir
Each cortical nodule is composed of packed lymphocytes that surround a less dense area called a	germinal center.
Which protein interferes with the ability of viruses to cause disease?	interferon
The body’s defense mechanisms can be organized into one of two major categories of immune mechanisms; these are	innate and adaptive immunity.
Chemotaxis is the process by which a cell navigates toward the source of the chemotactic factor by way of	detecting and then moving toward higher concentrations of the factor.
Bean-shaped structures located at certain intervals along the lymphatic system are	lymph nodes.
The _____ postulates that when an antigen enters the body, it selects the clone whose cells are committed to synthesizing its specific antibody and stimulates these cells to proliferate and to thereby produce more antibodies.	clonal selection theory
The primary organ of the lymphatic system is the	thymus.
The movement of phagocytes from blood vessels to an inflammation site is called	diapedesis.
Recognition of antigens by antibodies occurs when an	antigen’s epitopes fit into and bind to an antigen molecule’s antigen-binding site.
Adaptive immunity, part of the body’s third line of defense, is orchestrated by two different classes of a type of white blood cell called the	lymphocyte.
Antibodies are proteins of the family called	immunoglobulins.
Pyrogen molecules trigger the fever response by promoting the production of	prostaglandins.
The presentation of an antigen by an antigen-presenting cell activates the T cell. The cell then divides repeatedly to form a clone of identical sensitized T cells that form	effector T cells and memory cells.
Lymphatics in the villi of the small intestines are called	lacteals.
Oxygen enters blood from alveolar air because the partial pressure of alveolar air is	greater than the partial pressure of incoming blood.
Which structural feature facilitates oxygen diffusion from the alveolar air into the blood in lung capillaries?	The alveolar and capillary walls are both very thin. The alveolar and capillary surfaces are both extremely large. The lung capillaries accommodate a large amount of blood at one time. Each red blood cell comes close to alveolar air.
The _____ represents the largest volume of air an individual can move in and out of the lungs.	vital capacity
The basic rhythm of the respiratory cycle of inspiration and expiration seems to be generated by the	medullary rhythmicity area.
_____ law states that the volume of a gas is inversely proportional to its pressure.	Boyle’s
In what form does oxygen travel in the blood?	dissolved oxygen in the plasma. associated with hemoglobin
The exit of the bicarbonate ion from the red blood cell is balanced by the inward transport of another negative ion, chloride. This countertransport of negative ions is often called the _____ shift.	chloride
During inspiration, as the size of the thorax increases, the	intrapleural and alveolar pressures decrease.
The exact amount of oxygen in blood depends mainly on the amount of	hemoglobin.
Hyperpnea means a(n)	increase in breathing.
Spirometry is used to measure all of the following EXCEPT:	Total lung capacity
The sensors that provide feedback information to the medullary rhythmicity area are the	central chemoreceptors and peripheral chemoreceptors.
The compound formed when carbon dioxide combines with hemoglobin is	carbaminohemoglobin.
An obstructive lung disorder that is characterized by recurring spasms of the smooth muscles in the wall of the bronchial air passages is	asthma.
The amount of oxygen that diffuses into blood each minute depends on which factor?	oxygen pressure gradient between alveolar air and incoming pulmonary blood. total functional surface area of the respiratory membrane. respiratory minute volume. alveolar ventilation
An increase in carbon dioxide in the blood causes	a drop in pH in the blood.
The forced expiratory volume test can determine the presence of respiratory obstruction by measuring the	volume of air expired per second during forced expiration.
The ability of the lungs and thorax to stretch is referred to as	compliance.
According to the law of partial pressures, the partial pressure of gas in a mixture of gases is	directly related to the concentration of that gas in the mixture and to the total pressure of the mixture.
During the respiratory cycle, intrapleural pressure is always less than alveolar pressure. This difference is called	transpulmonary pressure.
A right shift of the oxygen-hemoglobin dissociation curve due to increased partial pressure of carbon dioxide is also known as	the Bohr effect.
Which term refers to the volume of inspired air that actually reaches, or “ventilates,” the alveoli?	alveolar ventilation
More than two-thirds of the carbon dioxide carried by blood is carried in the form of	bicarbonate ions.
Which oxygen-binding protein helps move oxygen out of the blood and into muscle cells?	myoglobin
When carbon dioxide dissolves in water, some of the carbon dioxide molecules associate with water to form	carbonic acid.
The apparatus used to measure the volume of air exchanged in breathing is called a(n)	spirometer.
What variations exist in the body to temporarily store or carry oxygen?	neuroglobin. myoglobin. fetal hemoglobin
The mechanism that produces pulmonary ventilation is one that establishes a gas pressure gradient between the	atmosphere and the alveolar air.
The volume of air exhaled normally after a typical inspiration is called _____ volume.	tidal
Pressure gradients are established by changes in the	thoracic cavity.
Which of the following is not a regulated process associated with the functioning of the respiratory system?	Control of cell metabolism rate
If the tidal volume of a given individual is 500 ml, then the anatomical dead space is approximately _____ ml.	150
Which of the following helps determine the amount of oxygen that diffuses into the blood each minute?	All of the above help determine the amount of oxygen that diffuses into the blood each minute.
Excessive fluid in the pleural cavity would be most likely to cause:	decreased vital capacity.
The vital capacity is equal to the sum of the:	inspiratory reserve volume, tidal volume, and expiratory reserve volume.
The major form by which carbon dioxide is transported in the circulatory system is:	as bicarbonate ions.
Which of the following would have the greatest accelerating effect on the dissociation of oxygen from hemoglobin?	Decreased PO2 and increased PCO2
Normal, quiet breathing is known as:	eupnea.
When the pressure in the lung is greater than atmospheric pressure:	expiration occurs.
About 98.5% of the oxygen carried by systemic arterial blood is attached to:	hemoglobin.
A type of breathing characterized by gradually increasing tidal volume for several breaths followed by several breaths with gradually decreasing tidal volume is:	Cheyne-Stokes respiration.
If a person were skiing high up in the mountains, she might feel that she is having trouble breathing (getting enough oxygen in her blood). This is because the:	lower atmospheric pressure lowers the PO2 and the diffusion gradient between the blood and the atmosphere is less.
During inspiration, the expansion of the lungs causes:	a decrease in alveolar pressure.
Vital capacity is defined as the:	maximum volume of air that can be moved into and out of the lungs during forced respiration.
Boyle’s law states that the volume of a gas varies _____ with pressure at a _____ temperature.	inversely; constant
Which of the following is not a means of transporting oxygen in the blood?	Combined with the bicarbonate ion (HCO3–)
The approximate partial pressure of oxygen at standard atmospheric pressure is about _____ mm Hg.	160
Which of the following constitutes total lung volume?	Residual volume and vital capacity
Standard atmospheric pressure is _____ mm Hg.	760
The symbol HbNCOOH– is used for:	carbaminohemoglobin.
A drop in the body’s production of carbonic anhydrase would hinder the formation of:	carbonic acid.
By the time the blood leaves the lung capillaries to return to the heart, what percentage of the blood’s hemoglobin has united with oxygen?	97%
Dalton law states that the partial pressure of a gas in a mixture of gases is _____ to the total pressure of the mixture.	directly related to the concentration of that gas in the mixture and
Which muscles are used for forced expiration?	Abdominal muscles and internal intercostals
The PCO2 in the atmosphere is:	less than in the alveolar air.
Carbon dioxide is carried in three forms in the blood. Ranking them from greatest to least amount carried, the sequence would be:	bicarbonate ion, carbaminohemoglobin, and dissolved in plasma.
The PCO2 in alveolar air is _____ blood.	less than in the systemic venous. equal to the systemic arterial
The term used to describe the volume of air exchanged during normal inspiration and expiration is:	tidal volume.
Which type of breathing is characterized by repeated sequences of deep gasps and apnea, and is usually seen in people with increased intracranial pressure?	Biot’s breathing
One hundred milliliters of arterial blood contains approximately what volume percent of oxygen?	20%
Pepsinogen is converted to pepsin by hydrochloric acid, which is produced by the _____ of the gastric glands.	parietal cells
CCK is an intestinal hormone that	causes the pancreas to increase secretion of exocrine high in enzymatic content. opposes the influence of gastrin on gastric parietal cells. stimulates contraction of the gallbladder so that bile can pass into the duodenum.
The chemical process in which a compound unites with water and then splits into simpler compounds is called	hydrolysis.
The ejection of bile from the gallbladder is controlled by which hormones?	CCK and secretin
During which stage of swallowing is there a risk of food entering respiratory pathways?	Oropharyngeal
The act of expelling feces is called	defecation.
Stimulation of gastric juice secretion occurs in all of the following phases except the _____ phase.	digestive
Saliva contains the enzyme	amylase.
Because fats are insoluble in water, they must be	emulsified.
Peristalsis is regulated in part by the intrinsic stretch reflexes. It is also thought to be stimulated by the hormone	cholecystokinin (CCK)
The final step in lipid transport by the intestines is the formation of	chylomicrons.
_____ is the passage of substances through the intestinal mucosa into the blood or lymph.	Absorption
The wave-like ripple of the muscle layer of the GI tract is called	peristalsis.
The process of deglutition includes all of the following except the _____ stage.	laryngeal
Fats and other nutrients in the duodenum stimulate the intestinal mucosa to release a hormone called	gastric inhibitory peptide.
What percentage of this blood flow comes from the hepatic portal system?	80%
Chemical digestion requires the secretion of _____ into the lumen of the GI tract.	digestive enzymes and bile
Which of the following is a disaccharide?	Sucrose
Which blood vessel carries absorbed food from the GI tract to the liver?	Portal vein
Hydrolysis refers to:	using water to split larger compounds into smaller ones.
The sodium cotransport or coupled transport acts to transport sodium ions and glucose molecules _____ the GI lumen.	passively out of
Which step of deglutition is under voluntary control?	Oral stage
The major site for the absorption of the end products of digestion is the:	small intestine.
The hormone that stimulates the release of bicarbonate substance from the pancreas is:	secretin.
The hormone that stimulates the gallbladder to release bile is:	cholecystokinin.
The final product of carbohydrate digestion is a:	monosaccharide.
Polysaccharides are hydrolyzed into disaccharides by enzymes known as:	amylase.
Bicarbonates are useful in the GI tract to:	neutralize hydrochloric acid.
When classified according to the kind of chemical reactions catalyzed, digestive enzymes are referred to as _____ enzymes.	hydrolyzing
Which of the following is not true of enzymes?	They change chemically and are in the end products of the reaction.
Which of these is not an example of mechanical digestion?	Moistening the food
Which phase(s) of gastric secretion is(are) stimulated by the sight, taste, and smell of food?	Intestinal phase . Cephalic phase. Gastric phase
The intestinal hormone cholecystokinin:	causes the pancreas to increase exocrine secretions high in enzyme content. opposes the influence of gastrin on gastric parietal cells. Stimulates the contraction of the gallbladder.
Which of the following is not one of the openings that must be blocked when food moves from the pharynx into the esophagus?	Oropharynx
The purpose of peristalsis is to:	propel food forward along the GI tract.
Glucose moves from the GI tract into the circulatory system by the process of:	cotransport.
Which of the processes of mechanical digestion involves the esophagus?	Deglutition. Peristalsis .
The enterogastric reflex causes:	inhibition of gastric peristalsis.
The hormone that inhibits gastric muscle, slowing passage of food into the duodenum, is called:	gastric inhibitory peptide.
The enzyme pepsin begins the digestion of:	protein.
Cellulose is a residue of digestion that comes from:	carbohydrates.
The process of fat emulsification consists of:	breaking fats into small droplets.
Rotavirus can cause what life-threatening condition in infants?	Diarrhea
An end product of fat digestion is:	glycerol.
The process of swallowing is known as:	deglutition.
The substances absorbed into the lymph capillaries are:	glycerol and fatty acids.
The hormone thought to be a messenger causing release of digestive enzymes from the intestinal mucosa is:	vasoactive intestinal peptide.

Created by: madridcindy1

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