Quantitative Physiology Final

Which of the following segments of the circulatory system has the highest velocity of blood flow a. Aorta b. Arteries c. Capillaries d. Venules e. Veins

Aorta

Which of the following statements regarding the processing of signals by a pool of neurons is correct? a. Divergence of signals can lead to amplification of the signal b. Convergence of input signals to individual neurons in the pool, each of which contributes to the same output channel, can lead to amplification of the signal c. The combination of multiple input signals from multiple sources onto a single neuron in the pool is an example of divergence d. In some instances, a sensory input to a neuronal pool causes a prolonged pause in the generation of output signals, called an afterdischarge e. The distribution of multiple input signals from a single source onto many neurons in the pool is an example of convergence

Divergence of signals can lead to amplification of the signal

Glucose uptake into skeletal muscle

Facilitated diffusion

Describe saltatory conduction in a nerve fiber. Name the physiological features that make this possible

This process in the "jumping" of signals between Noes of Ranvier down an axon and the signal is reamplified at the nodes. It is sent across the myelin to complete the action potential at the next node of Ranvier

Who are the authors of the 1972 Science article: The Fluid Mosaic Model of the Structure of the Cell Membranes?

Singer and Nicolson

Describe the Huxley model of skeletal muscle contraction. What fundamental basis separates the Huxley model from the Hill model? List at least two variables (descriptions in lieu of actual letters are acceptable) in the model that are different from variables in the Hill model.

The Huxley model accounts for cross bridges whiile the Hill model does not. Two variables: p= # of cross bridges k= spring constant of cross bridges

What is the difference between intrinsic and synaptic neuronal processing?

The difference is that intrinsic deals with a single cell and synaptic, which is an extrinsic process, deals with multiple cell interactions

The Goldman-Hodgkin-Katz (GHK) Current equation relates individual ionic currents to the ion's valence, concentrations, and membrane potential. What are the two critical steps necessary to derive the GHK Voltage equation from the GHK Current equation?

a. Calculate the total ionic current b. Set ITotal = 0

Which of the following events causes rods to hyperpolarize in response to light? a. Decrease in sodium conductance into the outer segment b. Decrease in sodium pump activity at the inner surface c. Increase in potassium conductance into the outer segment d. Increase in sodium conductance into the outer segment e. Increase in the sodium pump activity at the inner segments

a. Decrease in sodium conductance into the outer segment

Maintenance of static or constant conditions of the "milieu interieur" is referred to as: a. Homeostasis b. Hemostasis c. Differentiation d. Autonomic regulation e. Environmental control

a. Homeostasis

Which of the following statements regarding the basilar membrane is correct? a. It vibrates best at high frequency near the base of the cochlea, whereas it vibrates best at low frequency at the apex of the cochlea b. The spiral ganglion lies on its surface c. It contains basilar fibers whose diameter increases from the base of the cochlea to the apex of the cochlea d. It contains basilar fibers whose length decreases from the base of the cochlea to the apex of the cochlea e. It separates the scala media from the scala vestibuli

a. It vibrates best at high frequency near the base of the cochlea, whereas it vibrates best at low frequency at the apex of the cochlea

Intracellular, in contrast to extracellular, fluid contains higher concentrations of: a. K, Mg, and phosphate ions b. Na, Mg, and phosphate ions c. Na, Mg, Ca, and Cl ions d. Na, Ca, K, and Cl ions e. K, Ca, Mg, and Cl ions f. K, Na, and phosphate ions

a. K, Mg, and phosphate ions

What relationship details the hemodynamic effects of the vessel radius? a. Poiseuille's Law b. Reynolds' number c. Bernoulli's equation d. Stoke's Law

a. Poiseuille's Law

The membrane capacitance is not a factor of: a. The concentration of integral proteins in the membrane b. The membrane dielectric constant c. The membrane thickness d. The membrane area

a. The concentration of integral proteins in the membrane

A deficiency in which vitamin prevents the formation of an adequate quantity of retinal, eventually leading to night blindness? a. Vitamin A b. Vitamin C c. Vitamin D d. Vitamin E e. Vitamin K

a. Vitamin A

Which of the following represents the basis for transduction of a sensory stimulus into nerve impulses? a. Change in the ion permeability of the receptor membrane b. Generation of an action potential c. Inactivation of a G protein-mediated response d. protein synthesis e. Conversion of electrical energy to mechanical energy

a. change in the ion permeability of the receptor membrane

If the intracellular concentration of an electrically neutral, membrane permanent substance doubles from 10mM to 20mM and the extracellular concentration remains at 5mM, the rate of diffusion of that substance across the plasma membrane will increase by a factor of how much? a. 2 b. 3 c. 4 d. 5 e. 6

b. 3

For the eye to adapt to intense light which of the following may occur? a. Bipolar cells continuously transmit signals at the maximum rate possible b. Photochemicals in both rods and cones are reduced to retinal and opsins c. Level of rhodopsin are very high d. Pupil size increases e. Vitamin A converts into retinal

b. Photochemicals in both rods and cones are reduced to retinal and opsins

Which of the following statements regarding color vision is correct? a. The wavelength of light corresponding to white is shorter than that corresponding to blue b. The stimulation ratio of the three types of cones allows specific color perception c. When there is no stimulation of red, green, or blue cones, there is the sensation of seeing white d. Green is perceived when only green cones are stimulated e. Yellow is perceived when green and blue cones are stimulated equally

b. the stimulation ratio of the three types of cones allows specific color perception

Which one of the following statements concerning sensory neurons or their functional properties is true? a. In temporal summation, increased stimulus strength is signaled by decreasing the frequency of action potentials in the sensory fibers b. In spatial summation, increasing signal strength is transmitted by using progressively greater numbers of sensory fibers c. Increased stimulus intensity is signaled by a progressive decrease in the receptor potential d. All sensory fibers are unmyelinated e. Continuous subthreshold stimulation of a pool of sensory neurons results in disfacilitation of those neurons

b. In spatial summation, increasing signal strength is transmitted by using progressively greater numbers of sensory fibers

As the receptor potential rises higher above a threshold, which of the following best characterizes the new frequency of action potentials? a. Decreased b. Increased c. Unchanged d. Increased only when the receptor potential increases to twice the threshold level e. Unchanged until the receptor potential increases to twice the threshold level

b. Increased

Divergence

amplification

The resting potential of a myelinated nerve fiber is primarily dependent on the concentration gradient of which ion? a. Cl- b. K+ c. Na+ d. Ca++ e. HCO3-

b. K+

The ability to detect two points simultaneously applied to the skin is based on which of the following physiological mechanisms? a. Presynaptic inhibition b. Lateral inhibition c. Medial inhibition d. Feed-forward inhibition e. Feedback inhibition

b. Lateral inhibition

Which of the following first principle relationships is not used in the derivation of the electrodiffusion model: a. Fick's Law b. Maxwell's equations c. Electrophoresis d. Ohm's Law

b. Maxwell's equations

Which of the following is a consequence of myelination in large a. Increase in the energy required to maintain ion gradients across the membrane b. Increase in the nonselective diffusion of ions across the axon membrane c. Decrease in the velocity of nerve impulses along the axon d. Generation of action potentials at the nodes of Ranvier e. Increase in the membrane capacitance of the axon

d. Generation of action potentials at the nodes of Ranvier

An increase in atrial pressure results in which of the following? a. Decrease in plasma atrial natriuretic peptide b. Increase in plasma angiotensin II concentration c. Increase in plasma aldosterone concentration d. Increase in heart rate

d. Increase in heart rate

Which of the following conditions would be expected to decrease mean systemic filling pressure? a. Norepinephrine administration b. Increased blood volume c. Increased sympathetic stimulation d. Increased venous compliance e. Skeletal muscle contraction

d. Increased venous compliance

Visual contrast is enhanced due to lateral inhibition by which retinal cells? a. rods b. bipolar cells c. ganglion cells d. horizontal cells e. cones

d. horizontal cells

Which of the following best describes the concept of specificity in sensory nerve fibers that transmit only one modality of sensation? a. Singularity principle b. unity theory c. frequency coding principle d. labeled line principle e. concept of specific nerve energy

d. labeled line principle

Administration of a drug decreases the diameter of arterioles in the muscle bed of an experimental animal. What physiological changes would be expected to occur in response to the decrease in diameter, with respect to: Vascular conductance: Capillary filtration: Blood flow:

decrease; decrease; decrease

increased after-load (aortic pressure)...

decreases stroke volume

Which of the following statements concerning synaptic transmission is correct? a. A neuron is "facilitated" when its membrane potential is moved in the hyperpolarizing direction b. Even if the successive discharges of an excitatory synapse occur sufficiently close in time, they cannot temporally summate and initiate an action potential c. Dendrites do not typically propagate action potentials; they transmit post-synaptic potentials by electrotonic conduction d. When a specific population of synaptic terminals is spread over the considerable surface of a neuron, their collective effects cannot spatially summate and lead to initiation of an action potential

c. Dendrites do not typically propagate action potentials; they transmit post-synaptic potentials by electrotonic conduction

Which of the following characteristics of a biological membrane is most influenced by its cholesterol content? a. Ion permeability b. Thickness c. Fluidity d. Glycosylation e. Hydrophobicity

c. Fluidity

Which of the following retinal cells has action potentials? a. rods b. bipolar cells c. ganglion cells d. horizontal cells e. cones

c. Ganglion cells

The primary visual cortex lies primarily in which lobe of the cerebral cortex? a. frontal lobe b. limbic lobe c. Occipital lobe d. Parietal lobe e. Temporal lobe

c. Occipital lobe

Convergence

comparison/ summation

The largest portion of the arterial pressure generated during systole is dissipated at which of the following locations in the vascular tree? a. Aortic arch b. Aortic-arterial juncture c. Arterial-arteriolar juncture d. Arterial-capillary juncture e. Capillary-venular juncture

d. Arterial-capillary juncture

Which of the following is not usually associated with positive feedback? a. Generation of nerve signals b. Amplification c. Reinforcing feedback d. Vicious cycles e. Homeostatic "control systems"

e. Homeostatic "control systems

Light entering the eye passes through which retinal layer first? a. Inner nuclear layer b. Outer nuclear layer c. Outer plexiform layer d. Photoreceptor layer e. Retinal ganglion layer

e. Retinal ganglion layer

Which of the following events prompts the auditory system to interpret a sound as loud? a. fewer inner hair cells become stimulated b. fewer outer hair cells become stimulated c. Hair cells excite nerve endings at a diminished rate d. amplitude of vibration of the basilar membrane decreases e. amplitude of vibration of the basilar membrane increases

e. amplitude of vibration of the basilar membrane increases

A healthy 28-year old woman stands up from a supine position. What cardiovascular changes are most likely to occur with respect to: Total peripheral resistance: Venous hydrostatic pressure in legs: Heart rate:

increase; increase; increase

Increased contractility (sympathetic innervation) ...

increases stroke volume

Increased preload (filling)...

increases stroke volume

which fiber supports a faster action potential conduction velocity

larger diameter will result in faster action potential velocity because there is more myelin to speed up the conduction

What is the advantage of a neuron generating a "spontaneous" action potential

neurons not providing a signal is still providing information

Movement of Na+ ions into a nerve cell during the upstroke of an action potential

simple diffusion

Who is the "father of physiology" and where did he do most of his work

Claude Bernard Paris

Transport of glucose from the intestinal lumen to an intestinal epithelial cell

Co-transport

What math relationship did they employ to model this phenomenon?

Cosine tuning

Na+- dependent transport of Ca2+ from the cytosol to the extracellular fluid

Counter-transport

A pure phospholipid bilayer is most permeable to which of the following? a. Water b. Sodium c. Calcium d. Chloride e. Oxygen

Oxygen

What two specific abilities do mathematical models provide in Physiology?

Prediction Estimation

What fundamental property of a single primary motor neuron did Georgopoulos name this relationship?

Preferred Direction

When a membrane is permeable to to several different ions, the membrane potential that develops at equilibrium is dependent on four factors. Name them and discuss how they contribute to the membrane potential.

permeability, concentration, valence charge, temperature