Cells are classified into which of the following four broad categories?
neurons, muscle, epithelial, and connective tissue
The presence of ________ chemical groups makes carbohydrates ________.
hydroxyl : polar
Which of the following accurately represents the order of complexity for the components of the body, from least to most complex?
cells, tissues, organs, organ systems
________ are molecules composed of a glycerol and three fatty acids.
Triglycerides
The amphipathic property of phospholipids can be described as a
polar region that dissolves in water and a nonpolar region that repels water.
________ are molecules that form the bilayer of cell membranes and micelles.
Phospholipids
Which of the following is NOT found in plasma membranes?
chromatin
The process whereby a complementary mRNA is produced from a DNA template is called
transcription
The initiator codon is composed of the sequence
AUG
The strand of DNA that gets transcribed to mRNA is called the
template strand
The sum of the thousands of chemical reactions that occur within the body is called
metabolism
When phosphate is added to ADP to form the energy-storing molecule ATP, this is known as ________ and, since water is also produced, this reaction is also considered a ________ reaction.
phosphorylation : condensation
During what type of reaction are electrons removed from the reactant?
oxidation
Enzymes are what class of molecule?
proteins
How do enzymes speed up chemical reactions?
by lowering the activation energy barrier
What are coenzymes?
organic molecules derived from vitamins that function in the transfer of a chemical group
Regulation of an enzyme through reversible binding of a modulator to a regulatory site on an enzyme is specifically called
allosteric regulation
Where does glycolysis occur?
cytosol
Which of the following does NOT occur in mitochondria?
conversion of pyruvate to lactate
Of the gradients listed below, which is the MOST accurate description of the force that ultimately determines the movement of ions across the membrane?
electrochemical gradient
Which of the following transport mechanisms is passive?
movement of sodium through ion channels
In facilitated diffusion, a molecule is moved
down its concentration gradient with the assistance of a protein carrier molecule, and no energy is required.
Which of the following transport mechanisms requires energy?
both primary and secondary active transport
During cotransport of glucose with sodium, sodium increases the affinity of the carrier molecule for glucose when the binding site is facing which side?
the extracellular fluid
The first step of the Na+/ K+ pump's activity involves the binding of which of the following?
3 Na+ to their binding site on the inside of the cell
In chemical communication between cells, a ________ cell secretes a chemical messenger that binds to ________ on the ________ cell.
secretory : receptors : target
Once a steroid hormone is synthesized, it is
immediately capable of diffusing across the membrane.
Which of the following statements best describes the function of tyrosine kinase?
It catalyzes the phosphorylation of a protein inside a cell.
The function of a second messenger system is to
amplify the response of the first messenger.
When the alpha subunit of the G protein is activated, it can stimulate ion channels to do what?
either open or close
Which of the following is NOT a hormone released from the anterior pituitary?
prolactin inhibiting hormone
What anterior pituitary hormone is NOT a tropic hormone?
prolactin
When carbohydrates are consumed, they can be used to produce ________ or converted to ________ for storage.
energy : glycogen
________ provide an energy storage that is used primarily in times of starvation and are not metabolized by nervous tissue.
Proteins
When amino acids are used for energy, they must be deaminated. In the process, ________ is produced, and eventually eliminated from the body in the form of ________.
ammonia : urea
Which of the following is TRUE of the absorptive state?
Energy input exceeds output and thus is stored in macromolecules.
In the postabsorptive state, what do most cells use for energy?
lipids
Which of the following accurately describes afferent neurons?
They transmit information from the periphery to the CNS.
What type of ion channels in the membrane of neurons open or close in response to a neurotransmitter binding to its receptor?
ligand-gated
Most neurons have a resting membrane potential of
-70 mV
Which of the following best describes the electrochemical forces acting on sodium and potassium ions at the resting membrane potential?
The force on sodium ions is to move into the cell, and the force on potassium ions is to move out of the cell.
Which of the following potentials can sum?
graded potentials
During the rapid depolarization phase of an action potential, the plasma membrane is more permeable to which of the following ions?
sodium (Na+)
The chemical synapse is bounded by the ________ neuron, from which neurotransmitters are released across the synaptic cleft, to the ________ neuron, where the receptors for that neurotransmitter are located.
presynaptic : postsynaptic
Synaptic vesicles store
neurotransmitter
The synaptic delay is caused by the time required for which step of neurotransmitter release?
calcium entry to trigger exocytosis
In response to stepping on a nail, the crossed-extensor reflex causes
extension of the leg opposite the side of receptor activation.
Which of the following reflexes is a monosynaptic reflex found in the human body?
muscle spindle stretch
Which of the following statements about lateral inhibition is FALSE?
Lateral inhibition results in a stronger signal coming from second-order neurons associated with the central point of stimulation.
What is a decrease in the amplitude of a receptor potential in the presence of a continuing stimulus called?
adaptation
What chemical messenger diffuses to neighboring cells to exert an effect?
paracrine
A target cell will respond to a chemical messenger once that molecule has bound to a
receptor
An amplifier enzyme catalyzes the synthesis of a second messenger
TRUE
What molecule, whose synthesis is catalyzed by phospholipase C, triggers the release of calcium from the endoplasmic reticulum?
inositol triphosphate
Secretion of hormones from the anterior pituitary is stimulated by ________ released from the ________.
tropic hormones : hypothalamus
What cells secrete epinephrine from the adrenal gland?
chromaffin cells
What is the fate of any excess glucose in the liver that is not required for energy and not stored as glycogen?
It is converted into fatty acids.
Most energy stores for the body are in the form of ________ and are stored in ________.
triglycerides : adipose tissue
The glycogen that is stored in skeletal muscle cells
can only be used by that skeletal muscle cell.
How does insulin increase cellular uptake of glucose?
causing GLUT4 to be incorporated into the plasma membrane of some cells
During the postabsorptive state, what happens to the blood levels of insulin and glucagon?
Insulin decreases, whereas blood levels of glucagon increase.
On what portion of the neuron do action potentials propagate?
axon
________ branch from the cell body and receive input from other neurons at specialized junctions called ________.
Dendrites : synapses
Which of the following determines the resistance to an ion's movement across a membrane?
ion channels within the membrane
A change in a cell's membrane potential, such that the inside of the cell becomes more positive, is referred to as a ________ whereas if it becomes more negative it is referred to as ________.
depolarization : hyperpolarization
Which of the following best describes the electrochemical forces acting on sodium and potassium ions at the resting membrane potential?
The force on sodium ions is to move into the cell, and the force on potassium ions is to move out of the cell.
The all-or-none principle, associated with the action potential, states that
once membrane potential reaches threshold, an action potential will be generated and that action potential will always be the same magnitude.
Synaptic vesicles store
neurotransmitter.
Neurotransmitters can be reused through the process of ________, where neurotransmitters are transported back across the presynaptic membrane.
reuptake
Tight junctions between capillary endothelial cells in the central nervous system create the blood-brain barrier, thereby restricting what type of movement of molecules into the brain?
diffusion of hydrophilic
What is the function of gray matter in the CNS?
neural integration and synaptic communication
Which of the following statements about sensory coding is FALSE?
The intensity of stimulus is coded for by the size of the action potential.
Proprioceptors provide the body with continuous information that changes little as a particular joint angle is maintained, and are therefore an example of ________ receptors.
tonic or slowly adapting
Of the following areas of the body, which has the greatest tactile acuity?
lips
Where do the preganglionic neurons of the sympathetic nervous system emerge from the spinal cord?
thoracic and lumbar regions
Preganglionic and postganglionic sympathetic neurons are anatomically arranged in what three patterns?
sympathetic chains, those that innervate the adrenal medulla, and collateral ganglia
What is the neurotransmitter released from motor neurons?
acetylcholine
The shortening of a skeletal muscle fiber during contraction involves which of the following?
the sarcomeres shortening
Which of the following is not part of the process whereby skeletal muscles relax?
Sarcolemmal calcium channels open to allow the efflux of calcium.
Which of the following best describes the interaction between transverse (T) tubules and the sarcoplasmic reticulum in skeletal muscle contraction?
Action potentials in T tubules are detected by DHP receptors, which are coupled to ryanodine receptors in the sarcoplasmic reticulum and open channels for calcium.
Which of the following is a property of isometric skeletal muscle contraction?
Load is greater than the force generated by the muscle.
The tension produced during skeletal muscle contraction can be increased by all of the following EXCEPT
increasing the load on the muscle.
Which of the following is NOT an accurate description of specific muscle fiber types?
Slow oxidative fibers are quick to fatigue.
Which of the following is responsible for the rapid depolarization phase of an action potential within the pacemaker cells?
an increase in Pca
If both the SA node and the AV node fail, what would be the expected outcome of impulse rate within the heart?
The rate would be 30-40 beats per minute due to the concentration of pacemaker cells in the Purkinje fibers.
Conduction through which of the following is slow to allow atria to contract before the ventricles?
AV node
Which of the following ion channels does NOT participate in the contractile cell action potential?
type T calcium channels
Blood is ejected from the left ventricle once pressure within the
ventricle is greater than pressure within the aorta.
Ejection of blood from the right ventricle will continue until
pressure in the pulmonary artery is greater than pressure in the right ventricle.
Cardiac output is determined by what two variables?
heart rate and stroke volume
In comparison to the systemic circuit, the pulmonary circuit
has lower resistance to blood flow.
In the circulatory system, the largest pressure drop occurs across which blood vessels?
arterioles
Veins functions as ________ reservoirs due to their ________ compliance.
volume : high
An increase in total peripheral resistance, in the absence of any change in cardiac output, would
elevate mean arterial pressure.
Mean arterial pressure can be increased by all of the following EXCEPT
decreasing end-diastolic volume.
Of the following choices, which has the elastic recoil of its walls during diastole, causing a continuation of blood flow throughout the cardiac cycle?
artery
Which statement best describes the function of fibrinogen?
It is the key substance in the formation of blood clots.
Some athletes, in order to gain an advantage over their competitors, participate in blood doping. This process increases the number of red blood cells in their cardiovascular systems and in turn delivers more oxygen to their metabolically active tissues.
Erythropoietin is injected stimulating more red blood cell production. An increase in red blood cells increases the hematocrit which can increase blood pressure and weaken vessels making the chances of stroke increase.
Which of the following is the first step of hemostasis?
vascular spasm
Which of the following is most abundant in the trachea and bronchi, becoming much less dense (and eventually absent) in the bronchioles?
cartilage
The transition from the conducting to the respiratory zone in the lungs occurs at the
respiratory
The difference between what two pressures drives air into and out of the lungs?
atmospheric and intra-alveolar
Which of the following is responsible for changes in airway resistance that occur in a single breath under normal conditions?
passive forces exerted on the airways
The presence of a negative intrapleural pressure at maximum expiration is responsible for which of the following?
residual volume
Which of the following measurements cannot be determined by a spirometer?
residual volume
Which of the following statements is FALSE regarding a leftward shift in the hemoglobin-oxygen dissociation curve?
It can be caused by an increase in PCO2
Which of the following increases oxygen unloading from hemoglobin?
increased carbon dioxide in the tissue
Which statement best describes why oxygen is unloaded in tissue that is highly active?
As temperature increases due to increased metabolism, the affinity of hemoglobin for oxygen is decreased.
What is the primary mechanism of carbon dioxide transport in blood?
as bicarbonate dissolved in the plasma
The Haldane effect describes the increase in the affinity of hemoglobin for CO2 in the presence of a lowered
PO2
Assuming resting conditions at sea level, what is the partial pressure of oxygen in alveoli?
100 mm Hg
What hormone is secreted by the kidneys to increase red blood cell synthesis?
erythropoietin
What two structures make up the renal corpuscle?
Bowman's capsule and glomerulus
What capillaries come off of the efferent arterioles associated with cortical nephrons?
peritubular
During myogenic regulation of glomerular filtration rate, an increase in mean arterial pressure will cause the
afferent arterioles to constrict and thereby maintain a relatively constant glomerular filtration pressure.
The glomerular capillaries are composed of a fenestrated surface that allows protein-free plasma to exit the vasculature.
TRUE
Most reabsorption occurs in the ________ and is ________.
proximal tubule : not regulated
A substance is in positive balance when
it enters plasma at a greater rate than it exits plasma.
What is the force that moves water out of the distal tubules and collecting ducts?
an osmotic gradient
The regulation of sodium and water balance in the kidneys occurs primarily through the unique action of which cells in the distal tubules and collecting ducts?
principal cells
At high concentrations of antidiuretic hormone, the extent of water reabsorption in the collecting ducts is ________, causing urine output to ________.
high : decrease
Which of the following best describes sodium movement in the proximal tubule?
Sodium is transported across the basolateral membrane by the Na+/K+ pump and across the apical membrane by secondary active transport.
Aldosterone stimulates an increase in sodium reabsorption at the same time it stimulates an increase in potassium secretion.
TRUE
The thick ascending limb of the loop of Henle is permeable to water.
FALSE