ALL material final exam (ASP)
A conducting sphere has a net charge of -6.4 x 10-17 C. What is the approximate number of excess electrons on the sphere?
400
A solution with more solute (less solvent) has a ____________
A solution with more solute (less solvent) has a Higher OP
Given the following methods of measuring ICP, which technique is most reliant? A: Transcranial Doppler B: CT scan/MRI C: Ventriculostomy EVD D: Optic nerve sheath diameter
C: Ventriculostomy EVD
When a heavy metal block is supported by a cylindrical vertical post of radius R, it exerts a force F on the post. If the diameter of the post is increased to 2R, what force does the block now exert on the post?
F
A brick weighs 50.0 N, and measures 30.0 cm × 10.0 cm × 4.00 cm. What is the maximum pressure it can exert on a horizontal surface due to its weight?
Minimize area to increase the pressure, use the smallest faces of the brick for area 12.5kPa
The Stefan-Boltzmann Law of Radiation
The radiant energy Q, emitted in a time t by an object that has a Kelvin temperature T, a surface area A, and an emissivity e, is given by Q= e (sigma) T At
BMR is a measure of:
The rate at which a person's body "burns" energy, in the form of calories, while at rest - Factors that affect BMR include genetics, fitness level, body composition, health problems
One would expect the velocity of the blood to
be greater through the arterioles than the capillaries.
Fluid replacement for athletes: during exercise
• Every 20 minutes: 7 to 10 fl oz
Two imaging phase of myocardial perfusion imaging:
- resting phase images the heart when it is not under stress - stress phase images the heart after during physical/chemical stress
A tuning fork when struck resonates a closed-tube air column of length 15.0 cm. What is the frequency of the tuning fork (velocity of sound in air is 343 m/s)?
572 Hz
The conventional imaging modality that utilizes a series of x-rays to produce a cross sectional view of the abdominal cavity is described as
Computerized Tomography
The iodine isotope (Z=53) that is the most likely to undergo negatron decay is Select one: a. I-125 b. I-127 c. I-131 d. I-123
I-131
The radionuclide Tl-201 thallous chloride is able to distribute within myocardial tissue in a manner similar to
K+
Signs for vo, velocity of object
+ vo = observer moves toward source of sound - vo= observer moves away from sound
Indications for Oncology Imaging
- Prostate Cancer - Neuroendocrine Tumors - Breast Cancer - Non-Hodgkin's Lymphoma - Lymphoscintigraphy of Metastatic Disease
Gamma Knife
Uses multiple radioactive sources (eg. Co-60) to deliver photons
The number of calories a person burns in a day depends on:
• Physical activity • The amount of fat and muscle in the person's body • The person's BMR - basal metabolic rate
What is shock?
A life-threatening medical condition that occurs when the body is not getting enough blood flow.
The method of radionuclide production when charged particles are accelerated in a circular path under vacuum by means of an electromagnetic field is known as a
Cyclotron
Electromagnetic radiation that originates in the nucleus is defined as a(n)
Gamma ray
High loss of body fluids may potentially lead to
Hypovolemic shock
If a spherical concave mirror has a radius of curvature R, its focal length is
R/2
Electromagnetic waves from longer to shorter
Radio, microwaves, infrared, visible, UV, X-rays, gamma
How does vision work?
The crystalline lens of the eye takes an object and forms its image on the retina
Definition of strain in terms of wire strain gauges
The resulting change in length per unit length
Ohm's Law
V=IR; R= constant
Sound intensity is measured in
W/m2
Radiation with sufficient energy to cause ionization includes
X-rays
Volume flow rate in the circulatory system is
directly proportional to the radius to the fourth power.
If the lens in a person's eye is too highly curved, this person is suffering from
nearsightedness
Side effects of HBOT
• Seizures • Middle ear and inner ear injuries • Organ damage caused by air pressure changes • Temporary nearsightedness
How does the mass spectrometer work?
• The atoms or molecules are ionized by the ion source (one electron is removed, which results in an ion with a net positive charge +e) • The ions are accelerated through a voltage V, then they enter a region of magnetic field, where they are deflected in semicircular paths • Ions following a path of a certain radius r will be detected
ALARA applies to
• Time - direct proportionality longer exposure = higher dose • Distance - maximize distance from source "Inverse Square Law" I = 1/D2 • Shielding - high atomic number materials like lead (Pb) absorb radiation
Indicaitons for Renal Imaging:
• Visualize renal blood flow • Determine size, shape, and position of kidneys • Localize space- occupying lesions • Evaluate kidney function
Heat is removed from a substance, but its temperature does not lower. Which one of the following statements provides the best explanation for this observation?
The substance undergoes a change of phase vapor to liquid
The Sphygmomanometer is a device used to measure
blood pressure
A radiopharmaceutical that localizes at the target of interest through the use of phagocytosis based on particle size would be good for imaging the
bone marrow
Motion "toward" tends to ___________fo
increase
Arrays of billions of transistors, diodes, resistors, and capacitors on a tiny chip of silicon that measures less than 1 cm on a side are called
integrated circuit
A force pump is an example of a pump which
is a closed system.
Which nucleus is most likely to decay by positron emission? 20 F 19 F 18 F
18 F
The nucleus most likely to undergo alpha decay would be a. 3H b. 11C c. 99mTc d. 210Po
210Po
The Swan-Ganz method of hemodynamic monitoring utilizes
Pascal's principle
RV achieves the excess pressure by contraction in that it is:
Secondary pump supplies the pressure for the pulmonary circulation
The relationship between energy and mass is best described by which equation?
E=mc2
DCS is also known as
the bends, compressed air sickness, caisson disease, divers paralysis, and dysbarism
Alex's face is 20 cm in front of a concave make-up mirror having a focal length of magnitude 30 cm. How large is the image of her face?
three times as large as her face
A proton, moving east, enters a magnetic field. Because of this magnetic field the proton curves downward. We may conclude that the magnetic field must have a component
towards the south
A barometer is taken from the base to the top of a 279-m tower. Assuming the density of air is 1.29 kg/m3, what is the measured change in pressure?
3530 Pa
The diagram shows the various positions of a child in motion on a swing. Somewhere in front of the child a stationary whistle is blowing. At which position(s) will the child hear the highest frequency for the sound from the whistle?
At C moving toward D
Which one of the following statements concerning streamline flow is true?
At any given point in the fluid, the velocity is constant in time.
Very high exposure (> 50 Sv (5000 rem) or > 50 Gy (5000 rad)
Death can occur 24-48 hr
The dose of radiation with the greatest likelihood to cause death would be A. 0.5 Sv B: 3 Sv C: 12 Sv D: 30 Sv E: > 50 Sv
E: > 50 Sv
Diffusion
The process in which molecules move from an area of larger concentration to an area of lesser concentration of that type of molecule-- the net transfer of molecules is driven by random kinectic energy and the rate of diffusion increases with absolute temperature
Electric charge
• Unit for charge in SI - Coulomb (C) • Electron charge q e = -1.6 x 10-19 C • Proton charge qp = +1.6 x 10-19 C
900 meters = ______________ feet?
2952
Examples of Water-Soluble Iodinated Contrasts
- Diatriazoate Meglumine - Iodipamide Meglumine (Sinografin) - Iopromide (Ultravist) - Iodixanol (Visipaque)
A Venturi meter is a device that is used for measuring the speed of a fluid within a pipe. The drawing shows a gas flowing at speed ν2 through a horizontal section of pipe whose cross-sectional area is A2 = 0.0700 m2. The gas has a density of ρ = 1.30 kg/m3. The Venturi meter has a cross-sectional area of A1 = 0.0500 m2 and has been substituted for a section of the larger pipe. The pressure difference between the two sections is P2 - P1 = 120 Pa. Find (a) the speed ν2 of the gas in the larger, original pipe and (b) the volume flow rate Q of the gas.
14 m/s, 0.98 m3/s
Electrical shock on the body
1mA= slight tingling 5mA= slight shock-- disturbing but not painful 6-16mA= painful shock causing lock of muscle control, "let go" range or freezing current 17-99mA= extreme pain, respiratory arrest, servere muscle contractions, individual cannot let go + death is possible 100-2000mA= ventricular fibrillation, muscular contraction, and nerve damage-- death likely >2000mA= cardiac arrest, internal organ damage, and severe burns-- death probable
One ounce of a well-known breakfast cereal contains 110 Calories (1 food Calorie = 4186 J). If 2% of this energy could be converted by a weight lifter's body into work done in lifting a barbell, what is the heaviest barbell that could be lifted a distance of 2.1 m?
4.4E3 N Equation U=Q-W where U=mgh mgh= Q where Q = 2% of breakfast cereal Calories
A 13,000-N vehicle is to be lifted by a 25-cm diameter hydraulic piston. What force needs to be applied to a 5.0 cm diameter piston to accomplish this? Assume the pistons each have negligible weight.
520 N
Determine the length of a copper wire that has a resistance of 0.191 and cross-sectional area of 7.85 x 10-5 m2. The resistivity of copper is 1.72 x 10-8.
873 m
What is the minimum that the young and normal eye can see?
A young and normal eye sees between 25 cm and infinity (very far away)
The rate of heat loss due to conduction is
A= (kAdeltaT)t/L
Which one of the following statements best explains why the pressure in a static fluid increases as the depth increases?
As the depth increases, the weight of the water above a particular level increases.
During hyperpolarization of the "action potential" process of the cell,
Assures that the signal is proceeding in one direction by preventing any stimulus already sent up an axon from triggering another potential in the opposite direction.
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
Catabolism
Resonant frequencies in closed pipes
Closed pipe - pipe open at one end and closed at the other f=m(v/4L)=mf1 m=1,3,5.... is the harmonic number v= speed of sound L= l of pipe
What hinders color vision?
Color blindness occurs when one of more of these types of cones is missing or nonfunctional
Resistors in series
Current=same V= add all voltags Req= add all R
Determining the radiation risk assessment:
Evaluate stochastic effects + determistic effects
Electromagnetic radiation that originates in the nucleus is defined as a
Gamma ray
Gauge pressure
Gauge pressure is the difference between the absolute pressure and the atmospheric pressure. p(g)= p-p(atm)
• Suppose the total resistance to flow of the circulatory system is halved by vasodilatation and the blood pressure increases by 15% during exercise. By what factor must the blood flow rate increase? Discuss the effect on the heart output as well.
Heart output = 2.3 x normal
Isomeric Transition (IT)
IT is the decay of an excited energy state above the nucleus ground state Long lived states are considered metastable states Energy release from excited nuclei may be transferred to an inner shell electron resulting in ejection of a conversion electron.
Emphysema and diffusion
If the wall surface area decrease, the rate of diffusion decreases - Emphysema destroys the alveolar walls, results in a reduction in wall surface area available for diffusion, and causes breathing problems
Suppose you place an object in front of a concave mirror. Which of the following statements must be true?
If you position the object between the mirror and the focal point of the mirror, its image must be upright and virtual.
According to Wien's law, people emit
Infrared radiation
Rubidium-82 decays by positron emission to produce ___________ as the daughter nucleus.
Krypton
Pressure is at its highest as it leaves the:
LV
Vasodilator drugs
Lower blood pressure; ex.) hydralazine, minioxidil • Vasodilator drugs act directly on muscles in the blood vessel walls to dilate the blood vessels; in response to vasodilatation, the body will try to keep the blood flow rate constant by lowering the blood pressure
Electric force on a point charge due to another point charge
Magnitude given by Coulomb's law: F= k * (q1)(q2)/r2 k= 8.99E9 Nm2/C2
LV achieves the excess pressure by contraction in that it is:
Main pump supplies the pressure for the systemic circulation
Risks of MRI
Note that MRI avoids the use of ionizing radiation ("excites" nuclei, but no nuclear decay) therefore risks are minimal, but the following are risks: - Will erase magnetic credit cards - Not recommended during the first 12 weeks of pregnancy
Examples of superparamagnetic iron oxide (SPIO)
Note that these agents are not radioactive but induce changes in magnetic field *** - Ferumoxides (Feridex) - intravenous use - Ferumoxsil (GastroMARK) - oral use
Oxygen Enhancement
Note: Hydroperoxy radicals and peroxy radicals are highly damaging O2 + OH (radical) or H (radical) --> HO2(radical) + H2O R(radical) + O2 --> RO2 (radical)
Example of diffusion in the lungs and clinical application
Oxygen diffuses into the blood while carbon dioxide diffuses out from the blood through the alveoli walls - If the thickness of walls (d in Fick's Law) increases, the rate of diffusion will decrease; this is seen in a patient with cystic fibrosis where mucus build-up has increased the diameter of the alveoli walls & reduces the ability of the lung to oxygenate the blood
An electron is moving to the right, as shown in the figure. Suddenly it encounters uniform magnetic field pointing out of the page. Which one of the three paths shown will it follow in the field?
Path A
Water flows through a pipe. The diameter of the pipe at point B is larger than at point A. Where is the water pressure greatest?
Point B An increase in A corresponds to a corresponding pressure increase
Heat gained is ______________ & heat lost is _______________
Positive, negative
Resistance of objects with a uniform cross-sectional area is represented by the following equation:
R= p(resistivity, constant) x L(length) / A(area)
• During the expansion of the RV, blood flows from
RA into RV (same condition is true for the left) Think A-->V (alphabetical order when EXPANDING)
Where would the decay process represented by Scheme R occur? 99Mo --> 99mTc + B- + antineutrino
Radionuclide generator
For muscle rehabilitation, patients can be fitted with a small electrical device designed to help strengthen muscle tissue. With this device, a small electrical current is passed through the muscle tissue, stimulating muscle contraction in that region. With involuntary muscle stimulation requiring a current of about 10 mA, estimate the minimum required potential difference applied over the length of a bicep muscle needed to stimulate muscle contraction. Assume a bicep muscle has a diameter of 10 cm, a length of 25 cm and a resistivity of 150 Ohm*m.
Required potential difference= V V= IR V= 48 V
Neurons function in nerve conduction, or transmission to:
Respond to stimuli, conduct impulses (action potentials) and communicate with other neurons or muscle cells
The unit of measure used when determining the radiation field of a restricted environment, such as a dispensing laboratory in a nuclear pharmacy facility, is best described as the
Roentgen
Specific gravity
SG, ρ(substance)/ρ(water) where ρ(water)=1000kg/m^3
Circulation system
Sends blood from the heart to all the other parts of the body and back again Consists of: heart & blood vessels
Fluid replacement for athletes: post-exercise
Should be completed within two hours after exercise and should correct any fluid loss accumulated during exercise
What is hyperbaric oxygen treatment?
Specialized therapy that involves breathing pure oxygen in a pressurized chamber, to increase the amount of oxygen in the blood
Which would cause a more serious burn: 30 g of steam or 30 g of liquid water, both at 100 °C; and why is this so?
Steam, because of its latent heat of vaporization.
Calculate sweat rate
Sweat rate = preexercise body weight - post exercise body weight + fluid intake during exercise - urine produced
Causes of fluid loss
Sweat • Exhalation • Waste elimination • Vomiting • Bleeding
The blood pressure reading taken from a sphygmomanometer can be read by:
Systolic pressure over diastolic pressure Normal readings are about 95-140mmHg/60-85 mmHg
These SPECT radiotracers include:
Technetium-99m which is a metastable nuclear isomer of technetium-99, indium-111, iodine-123 and thallium-201.
EKG (normal)
The atrial depolarization (activation) make the first wave ("P wave"); the ventricular depolarization (activation) make the next wave ("QRS complex"); the final wave or "T wave" represents ventricular repolarization (relaxation)
What is a direct, one-step process?
The radiation interacts directly with the target molecule
A thin flashlight beam traveling in air strikes a glass plate at an angle of 52° with the plane of the surface of the plate. If the index of refraction of the glass is 1.4, what angle will the beam make with the normal in the glass?
Theta 1= 90 - 52 = 38 Theta 2 = Arc sin [((1.0)(sin 38))/(1.4)] Theta 2 = 26
Which of the following devices is used to measure atmospheric pressure?
barometer
Motion "away" tends to _______________ fo
decrease
Treatment for neurogenic shock:
fluids, immobilization, and sometimes surgery
If vs > v., then:
fo should be > fs
Law of reflection
the angle of incidence is equal to the angle of reflection
Discharging RC Circuit
• The larger the time constant of the RC circuit, the larger the discharging time
Specific heat
- Heat is energy in transit - The heat gained or lost by a substance that undergoes a change in temp. is represented by: Q= mc(deltaT); m=mass, c=specific heat in J/kgC & Q is measured in J
In the flashlight, the current is 0.40A and the voltage is 3.0 V. Find (a) the power delivered to the bulb and (b) the energy dissipated in the bulb in 5.5 minutes of operation.
(a) 1.2 W (b) 400 J
Define capacitor:
A device that consists of a pair of conduction plates and functions to store electrical charges by keeping positive and negative charges separated by an insulating gap.
If ρ(substance) < ρ(water), the substance will float or sink?
Float
The electric potential energy stored in the capacitor of a defibrillator is 73 J, and the capacitance of the capacitor is 120 microfarads. What is the electric potential difference between the plates of the capacitor?
V= 1.1E3 V
• The stroke volume increases with
Vasodilation and increased contraction of the heart
Sign of magnification:
m is + for an upright image m is - for an inverted image
Osmotic pressure
the osmotic pressure of a solution is the pressure required to prevent diffusion from a pure solvent into that solution across a semi-permeable membrane
Which of the following devices is used to measure blood pressure?
sphygmomanometer
Lasers & their characteristics
• Monochromatic - one color • Coherent - all waves crest (high points) and troughs (low points) are lined up • Collimated - laser light waves all travel in the same direction, exactly parallel with each other
Oncology Imaging
• Use in oncology imaging has expanded greatly in recent years • Monoclonal antibodies are created specifically to bind to antigens found on specific tumor cell types
Newton's 2nd Law
The acceleration of an object is proportional to the net force acting on the object and inversely proportional to its mass. The net force is the sum of all the individual forces acting on the object.
Angle of deinclination
The angle between the north geographic pole and north magnetic pole, approximately 13 degrees • The angle of declination is the angle that a compass needle deviates from the north geographic pole
Conditions for total internal reflection
Going from a medium of high index of refraction to a medium of low index of refraction. Angle of incidence > critical angle. Find the critical angle by: n1sinθc = n2sin90° n1 > n2 θc = critical angle
Proportion to target abundance
Water= 70% (most abundant) Lipids= 20 % Proteins= 10% DNA= 1% (most sensitive)
What is wavelengthof frequency 920 kHZ?
c/frequency (v)= 326m
Energy due to the position of an object is _____________ energy and can be expressed in mathematical form as ______________.
gravitational potential, U=mgh
Ethiodized oil (Ethiodol)-- X-Ray/CT Contrast Agent
* For use in female repro, can be injected in webbing of fingers/toes • Derivative of poppy seed oil that is occasionally utilized in the radiology for non-systemic administration. • It contains 37% organically bound iodine, has considerably reduced viscosity when compared to the triiodobenzoic acid derivatives, and is not miscible with plasma • Consists of a mixture of ethyl monoiodostearate and ethyl diiodostearate (iodinated C18 saturated fatty acid esters) • Ethiodol is indicated for use as a radio-opaque medium for hysterosalpingography and lymphography
Pulmonary imaging: 1/2 types, perfusion
- Allows the physician to visualize blood supply in the lungs - Radiopharmaceuticals provide images by being trapped by the capillaries of the lung. - Used to diagnosis pulmonary emboli, establishment of regional function for COPD, emphysema, asthma, and pulmonary hypertension. - Agent used for imaging: Tc-99m MAA
Uses of X-ray imaging
- Radiography (bone/joint disorders, dental, locate foreign objects) - Chest x-ray (pneumonia, tuberculosis, heart failure, cancer) - Angiography (evaluate blood flow, esp. atherosclerosis of coronary vessels and renal perfusion) - Intravenous Pyelogram (evaluate kidneys, ureters, & bladder) - Upper/Lower GI series (esophagus, stomach, small intestine / large intestine) - Mammography (breast tissue) - Fluoroscopy - use of real-time x-rays to guide surgical procedures
RPs in GI Imaging
- Tc-99m Sulfur Colliod - In-111 DTPA - Tc-99m sodium pertechnetate
Treatment designed to lower ICP should be initiated at pressures above _______mmHg
15-20
The closest object that a typical young person with normal vision can focus on clearly is closest to
25 cm
A 9.9 mCi vial of thallous (Tl-201) chloride arrives at the pharmacy. How many megabecquerels (MBq) is the SI equivalent? (see unit conversion chart if necessary)
366 MBq
At 8:15 AM, a Mo-99/Tc-99m generator is eluted to provide the pharmacist with 640 mCi of Tc-99m sodium pertechnetate in 5 mL of 0.9% sodium chloride. If the pharmacist uses all of the radioactivity from this generator elution to immediately prepare one vial of Tc-99m sestimibi (CardioLite), how much radioactivity will remain 45 minutes later when the pharmacist completes the preparation of the compounded radiopharmaceutical, and is ready to dispense patient doses?
587 mCi
A diverging lens always forms
An upright, virtual, diminished image. - This means that m=always positive & di(image distance)= always negative, always virtual
Anabolism
Constructive metabolism - Convert smaller molecules to larger molecules
What type of lens is used to make a magnifying glass?
Converging - Note: in a magnifying glass, you want to make the image BIGGER; a diverging lens always produces a diminished image and you would want the opposite
Which one of the following combinations of units is equivalent to the ohm?
Js/C^2
Use of the Sphygmomanometer for measuring blood pressure must be done level with the heart to get an accurate measurement because
pressure changes with an increase or decrease in elevation.
Energy stored in a capacitor can be expressed in terms of any 2 of the following:
voltage, capacitance, charge For example Uc= CV^2/2 = QV/2 = Q^2/2C; SI unit is a joule (J)
Three main parts of a Chitnis device for IOP monitoring
• 1) a hypodermic needle (30 gauge) that penetrates the sclera and establishes direct access to the eye's vitreous space • 2) capacitive pressure sensor connected to the needle back-end • 3) a flexible coil connected to the capacitor forming a parallel LC circuit whose resonant frequency is a function of IOP
Defibrillation
• A technique used to stop ventricular fibrillation and restore the normal heart rhythm - Ventricular fibrillation - the heart produces a rapid, unregulated pattern of beats • Consists of sending a shock (a very fast discharge of electrical energy) through the heart
Pressure drop depends on the flow rate and resistance to flow
• Aorta 4 mmHg • Large arteries 5 mmHg • Branch arteries 15 mmHg • Arterioles 39 mmHg capillaries 26 mmHg • Venous system 7 mmHg
Pathophysiology of cardiac temponade:
• Fluid buildup in the pericardium • Increased pericardial pressure • Increased pressure on the heart • Ventricles cannot expand properly • Reduced ventricular filling • Reduced stroke volume • Reduced cardiac output • The body does not receive enough blood
Living cells are greatly affected by osmotic pressure:
• Isotonicity - cells placed in an isotonic solution do not change in volume (for example red blood cells in 0.9% saline solution) • Hypotonicity - cells place in a hypotonic solution will swell (for example blood cells placed in water will burst) • Hypertonicity - cells placed in a hypertonic solution will shrink (for example red blood cells in 1.5% saline solution will shrivel)
Optical fibers - Applications
• Medium of choice for high quality telecommunications • Endoscopy • Arthroscopic surgery
Myoview Kits (Myocardial Perfusion Imaging)
• Radiopharmaceutical = Tc-99m Tetrofosm Package Insert Preparation: - add 240 mCi of Tc-99m NaTcO4 (use venting needle) - do not exceed a concentration of 30 mCi/mL - use between 4 - 8 mL - gently mix for 10 seconds to ensure complete dissolution of powder - incubate for 15 minutes at room temperature
Why would one insert a Swan Ganz monitor?
• Sever chronic heart failure requiring use of inotropic, vasopressor, and vasodilator drugs • Cardiogenic shock • For the differential diagnosis of pulmonary arterial hypertension • For the diagnosis and treatment of uncommon causes and complications of heart failure • Heart and lung transplantation workup
RPs for Renal Imaging
• Tc-99m DTPA • Tc-99m mertiatide (MAG3) • Tc-99m DMSA • Tc-99m Gluceptate
A proton moving with a velocity of 4.0 × 104 m/s enters a magnetic field of 0.20 T. If the angle between the velocity of the proton and the direction of the magnetic field is 60°, what is the magnitude of the magnetic force on the proton? (e = 1.60 × 10-19 C)
1.1E-15
How much heat (in joules) is required to raise the temperature of 34.0 kg of water from 15°C to 95°C? Specific heat of liquid water is 4186 J/kg °C.
1.1E7 J
An engineer is asked to design a playground slide such that the speed a child reaches at the bottom does not exceed 6.0 m/s. Determine the maximum height that the slide can be.
1.8 m
The effective area of each plate of a parallel plate capacitor is 2.1 m2. The capacitor is filled with neoprene rubber (κ = 6.4). When a 6.0-V potential difference exists across the plates of the capacitor, the capacitor stores 4.0 µC of charge. Determine the plate separation of the capacitor.
1.8 x 10-4 m
The diffusion constant of oxygen through water is 8.00 x 10-10 m2s-1. On average, how long does it take for an oxygen molecule to diffuse 1.41 mm through water?
1250 seconds
Three resistors, 4.0 Ω, 8.0 Ω, 16 Ω, are connected in parallel in a circuit. What is the equivalent resistance of this combination of resistors?
2.3 Ω
Suppose the total resistance to flow of the circulatory system is halved by vasodilatation and the blood pressure increases by 20% during exercise. By what factor must the blood flow rate increase?
2.4 * Fo
A person's near point is 25 cm, and her eye lens is 2.7 cm away from the retina. What must be the focal length of this lens for an object at the near point of the eye to focus on the retina?
2.4 cm - Memory tip: farsightedness includes two real numbers for do & di while for nearsightedness, di= real number & do=infinity; this is a farsightedness problem which includes a converging lens 1/f= 1/(0.25) + 1/(0.027)= f= 0.024 m or 2.4cm (f= + for converging lens)
A 100-kg person sits on a 5-kg bicycle. The total weight is borne equally by the two wheels of the bicycle. The tires are 2.0 cm wide and are inflated to a gauge pressure of 8.0 × 105 Pa. What length of each tire is in contact with the ground?
3.2 cm
A proton travels at a speed of 5.0 × 107 m/s through a 1.0-T magnetic field. What is the magnitude of the magnetic force on the proton if the angle between the proton's velocity and the magnetic field vector is 30°? (e = 1.60 × 10-19 C)
4.0 × 10-12 N
Consider a very small hole in the bottom of a tank that is 17.0 cm in diameter and filled with water to a height of 90.0 cm. Find the speed at which the water exits the tank through the hole.
4.20 m/s
Sound intensity level
B= (10 dB) 1og (I / Io); where Io = 1.0 × 10-12 Wm-2 and represents the threshold of hearing I= sound intensity in W/m2 and B= sound intensity level in dB
The amount of energy transported per second is called the ____________________ of the wave
Power
What type of circuit is used in a pacemaker?
RC circuit
Quality Factor
This allows doses of different types of radiation to be compared for their biological effects. For x‐rays, γ ‐rays, and β‐particles, QF = 1 and therefore rads = rems
A positive charge is moving to the right and experiences an upward magnetic force, as shown in the figure. In which direction must the magnetic field have a component?
into page
The Camino is a
is a catheter-tip transducer that relies fiber optics to measure pressure through light intensity
Voltage
• The voltage (or electric potential difference) between two points A and B is equal to the work required to move a charge q from A to B divided by the charge
ALARA
Acronym adopted by occupational workers to ensure safety-- As Low As Reasonably Achievable
Thermal neutrons initiate chain reaction processes in a
Nuclear reactor
Linear Momentum, Definition + Equation
p=mv
The arterioles are called the "resistance vessels" of the circulatory system because they can control volume flow rate
through constriction and dilation.
A barber's chair with a person in it weighs 2100 N. The output plunger of a hydraulic system begins to lift the chair when the barber's foot applies a force of 55 N to the input piston. Neglect any height difference between the plunger and the piston. What is the ratio of the radius of the plunger to the radius of the piston?
6.18
Static Equilibrium, Definition + Equation
An object is in static equilibrium when it has zero acceleration and is not in motion. F=ma=0
Blood flows through a section of a horizontal artery that is partially blocked by a deposit along the artery wall. A hemoglobin molecule moves from the narrow region into the wider region. What happens to the pressure acting on the molecule?
The pressure increases. - Explanation: Q=Av, when A increases, Q increases (direct-relationship) - In the equation p= 8nLQ/pir4, Q is directly proportional to p An increase in A corresponds to a corresponding pressure increase
Mass density=
ρ, can be solved via m/V (mass over volume)
Pure Semiconductor
• Example silicon and germanium • Not good conductor of electricity • Can increase their conductivity by doping
Calorie
- an energy unit - 1 Calorie = 1 big calorie, used by nutritionists to specify the energy content of foods - 1 calorie = 1 little calorie = 1000 calorie = 1 kcal = 1 Calorie - 1 Calorie = 4186 J "the mechanical equivalent of heat"
Dosing radiation
- assess the risk to the patient - allows a comparison of risk for the patient - determines maximum amount of administered activity for the nuclear medicine procedure note: (1) the highest radiation dose is delivered to the critical organ, (2) critical organ may or may not be the target organ
What causes decompression sickness (DCS)?
- bubbles evolving from inert gas dissolved in blood or tissues when atmospheric pressure decreases to rapidly. DSC can occur after scuba diving, ascent with flying
The electric potential difference involved in a typical lightning discharge may be up to 100 MV = 108 V. What is the gain in kinetic energy of an electron accelerated through this electric potential difference?
1.6 x 10-11 J
A proton moving eastward with a velocity of 5.0 km/s enters a magnetic field of 0.20 T pointing northward. What are the magnitude and direction of the force that the magnetic field exerts on the proton? (e = 1.60 × 10-19 C)
1.6 × 10-16 N upwards
A pole is held vertically by attaching wires at a height of 13.4 m above the ground. The other end of each wire is anchored in the ground at a distance of 9.54 m from the base of the pole. The pole makes a right angle with the ground. What is the length of each wire?
16.4
You are lying down on a bed of 3000 nails. Your body weight of 695N is evenly distributed among the nails. Each nail has a tip diameter of 1.00 mm. What is the pressure in Pascals at each nail point? What is the pressure in PSI at each nail point?
42.8PSI - Weight = evenly divided between 3000 nails; 695N/3000 = F 1.00mm --> 1.00e-3 m/2 = r = 5.00e-4 m A= pir2 P=F/A --> convert to Pascals
Magnetic field generated by a coil
Consider a circular current-carrying wire coil of N loops • The magnetic field generated by the current in the coil has magnitude
Which of the following is a statement of the first law of thermodynamics? Select one: a. The entropy of the universe is constant. b. The entropy of the universe is decreasing. c. Energy cannot be created or destroyed. d. Kinetic energy is stored energy that results from the specific arrangement of matter. e. Energy cannot be transferred or transformed.
Energy cannot be created or destroyed.
A large tank is filled with water to a depth of 15 m. A spout located 10.0 m above the bottom of the tank is then opened as shown in the drawing. With what speed will water emerge from the spout?
Equation: v= sq rt(2gh) sqrt(2(9.8)(5))= 9.9m/s
Equation for Newton's 2nd Law
Fnet=ma; Where Fnet is the net force, m is the total mass of the system, and a is the acceleration of the system.
For a convex mirror, the image is always _______________________
For a convex mirror, the image is always diminished in size and upright
Example of Gd-Containing MR Contrast Agents
Gadopentetate dimeglumine (Magnevist) - Note that no mass values are associated with the contrast agents like we would see in RP
Physiology of neurogenic shock
Imbalance between sympathetic & parasympathetic stimulation > Massive vasodilation > Decreased vascular tone > Decreased systemic vascular resistance > Inadequate cardiac output > Decreased tissue perfusion > Impaired cellular metabolism
Optical fibers
Long, thin strands of glass or plastic that can carry light for long distances without allowing the light to escape (based on tir)
Axumin (fluciclovine), or FACBC is a newly approved diagnostic imaging agent indicated for the visualization of suspected prostate cancer recurrence. The radiotracer found in Axumin is F-18 (Z=9, T1/2=110 minutes, γ-ray = 511 keV) and decays by the scheme shown below. What type of decay process occurs during this transformation? 18F --> 18O
Positron decay
The rate of heat loss (measured in Watts) from the human body by convection is
Q/t= h(convection)A(T)
Pressure is at its lowest as it enters the:
RV
The heart is two synchronous force pumps that achieve the excess pressure by contraction, which of the following statements is true? RV - secondary pump supplies the pressure for the pulmonary circulation b. RV - main pump supplies the pressure for the systemic circulation c. LV and RV - are a tertiary system supplying pressure for the systemic system d. LV - secondary pump supplies the pressure for the systemic circulation
RV - secondary pump supplies the pressure for the pulmonary circulation
What is an indirect, two-step process?
Radiation produces a change in an intermediate molecule which in turn changes a second molecule
Total Internal Reflection
The complete reflection that takes place within a substance when the angle of incidence of light striking the surface boundary is less than the critical angle - Critical angle= the angle of incidence for which the refracted ray goes along the boundary (sin=n2/n1)
Decibels
The decibel (dB) is a measurement unit used when comparing two sound intensities. Because of the way in which the human hearing mechanism responds to intensity, it is appropriate to use a logarithmic scale called the intensity level
Osmosis
The diffusion of a solvent across a semi-permeable membrane separating two solutions of different concentrations -- semi-permeable membrane is permeable to the solvent but impermeable to the solute molecules - Driven by random kinetic energy - Isotonic conditions are favored
When low energy photons (e.g. 140 keV photons from Tc-99m) interact with lead shielding (high Z number), energy is transferred to the shielding by
The photoelectric effect
Treatment for cardiogenic shock
Treatment varies with the heart condition; for heart attack, the treatment may be cardiac catheterization to unblock an artery
When water vapor touches and condenses on your skin,
When water vapor touches and condenses on your skin, a large amount of heat is released onto your skin due to the large latent heat of vaporization of water and can cause severe tissue damage
Log(1)=0 so when the intensity of the sound is equal to the threshold of hearing, intensity level is:
Zero
The step during the process of Action Potential of the human nerve cell in which the repolarization typically overshoots the rest potential preventing the neuron from receiving another stimulus is called
hyperpolarization
Complete the following statement: The transfer of heat by conduction will occur
only through molecular collisions.
Some of the advantages to using the Swan-Ganz catheter to monitor cardiac pressures, are the following for the EXCEPTION of A: able to administer medications B: monitoring is continuous C: oxygen and carbon dioxide exchange is monitored D: catheter is easily and rapidly inserted
oxygen and carbon dioxide exchange is monitored
Bernoulli's equation
p + (ρ(v^2)/2) + ρgh = constant • As the speed increases, the pressure decreases • As the height increases, the pressure decreases
Deterministic effects
severity increases with dose due to a proportional increase in damage or death to cells • early effects • organ and tissue damage, possibly death • genetic effects (in utero) • threshold dose exists: dose below no measurable effects
Assuming the same force, is applied:
the smaller the area the larger the pressure
In the sound intensity level equation, B= 10log (I/Io), B =
the sound intensity level in dB and I is the sound intensity in W/m2
The gauge pressure in each of four tires of an automobile is 240 kPa. If each tire has a "footprint" of 190 cm2 (area touching the ground), estimate the mass of the car.
~1900 kg
A hollow sphere of negligible mass and radius R is completely filled with a liquid so that its density is ρ. You now enlarge the sphere so its radius is 2R and completely fill it with the same liquid. What is the density of the enlarged sphere?
ρ
Arterioles and blood flow control
• At constant pressure, doubling the radius of the arteriole decreases the resistance by a factor of 16 and increases the volume flow rate by a factor of 16 • The ability of the arterioles to reduce the resistance of the circulatory system and therefore increase the blood flow enables the body to respond to the greater demands for blood during exercise without overworking the heart.
How can lasers be applicable?
• CD and DVD players • Bar code readers • Eye surgery (for example LASIK) • Transmission of TV and telephone signals over special cables • Cutting and welding metal • Cutting through hundreds of layers of clothes • Laser spectrometer
Farsightedness (hyperopia)
• Can see far, but not near • Correction needed for the near point • Correction done with converging lens -- Converging lens always has + f
What are the types of shock?
• Cardiogenic shock • Hypovolemic shock • Septic shock • Anaphylactic shock • Neurogenic shock
Magnets and drug administration
• Certain types of bacteria can create nanometer-sized permanent magnets inside themselves • Scientists have proposed harvesting these tiny magnets, which are just small enough to fit through a hypodermic needle, and attaching them to drug molecules • By placing a magnetic field near the site of interest, the drug molecules could be attracted and held there, which would increase the effectiveness of the drugs and reduce the side effects • Major problem - extraction of the tiny bacterial magnets • Potential danger - drug molecule could attract each other, thus clumping and potentially blocking blood flow
Magnetic field generated by a straight current
• Consider a long straight current-carrying wire • The magnetic field generated by the current in the long straight wire has magnitude
Solar Cells (PV cells)
• Convert sunlight directly to electricity • Based on p-n junction and photovoltaic effect • Electric field points from the n-type to the p-type • Sunlight ionizes some of the atoms in the p-type charge layer - electrons are ejected from the atoms • Electrons move in a direction opposite to the electric field into the n-type material • Holes move in the same direction as the electric field away from the junction toward the surface of the p-type material
Contact lenses and diffusion
• Cornea receives its oxygen via diffusion from the air • Contact lenses block the diffusion of oxygen into the cornea to a degree • Conventional contact lenses need to be removed at night so as not to deprive the cornea of oxygen
Neuron consists of _____________
• Dendrites - tree-like structures that receive signals from other neurons and from special sensory cells, convert them to electrical signals and transmit them to the cell body • Axon - transmits signals away from the cell body to other neurons or to a muscle • Cell body - contains the neuron's genetic information in the form of DNA
What does a chest x-ray show of tension pneumothorax?
• Deviation of the trachea to the contralateral side • Shift of the mediastinum to the contralateral side • Depression of the hemi-diaphram
Doppler effect
• Doppler Effect is the apparent change in frequency and wavelength of a wave as perceived by an observer moving relative to the wave's source. It is commonly heard when a vehicle sounding a siren, passes, and recedes from an observer.
The local hospital calls requesting information regarding a patient that they would like to schedule for an In-111 white blood cell (WBC) study tomorrow morning. The protocol requires at least 700 μCi of In-111 oxine to be incubated with the patient's blood in order to tag the WBCs. At 8 a.m. today, you have 1.15 mCi of In-111 oxine currently in inventory. How much activity will you have tomorrow at 8 a.m.?
898 μCi
A barking dog delivers about 1.00 mW of power. If this power is uniformly distributed in all directions, what is the sound intensity level at a distance of 5.00 m?
: 65.0 dB
Take the radius of the arteriole to be 8.0 microns and the length of the arteriole to be 2.20 mm. Take the radius of the capillary to be 3.00 microns and the length of the capillary to be 1.15 mm. Determine the ratio of the resistance to flow of a capillary to the resistance to flow of an arteriole. Hint: Use the resistance to flow equation that relates the resistance to flow to viscosity, length, and radius.
26.4
A candy shop sells a pound of chocolate for $ 10.85. What is the price of 1.50 kg of chocolate at the shop?
$36.2
Common Methods of Radiolabeling
(1) Introduction of a foreign label - chemical reaction that forms covalent or coordinate covalent bonds (2) Bifunctional chelation - link macromolecule with chelated radioisotope
• Estimate the amount by which the blood pressure in the anterior tibial artery exceeds the blood pressure in the aorta at the heart when a person is: • a) reclining horizontally and b) standing as shown in the picture. The density of blood is 1060 kg/m3 . Neglect the effects of the blood flow.
(a) 0 (b) 1.4E4 Pa
The instructions for an electric lawn mower suggest that a 20-gauge extension cord can be used for distances up to 35 m, but a thicker 16-gauge cord should be used for longer distances. The cross sectional area of a 20-gauge wire is 5.2x10-7m2, while that of a 16-gauge wire is 13x10-7m2. Determine the resistance of (a) 35 m of 20-gauge copper wire and (b) 75 m of 16-gauge copper wire.
(a) 1.2 ohm (b) 0.99 ohm
The body of a man whose weight is 690 N contains about 5.2x10-3 m3 of blood; ρ(blood)= 1060kg/m^3 (a) Find the blood's weight and (b) express it as a percentage of body weight.
(a) 54 N (b) 7.8%
(a) Compare the resistance to flow of a capillary to the resistance to flow of an arteriole by giving the ratio of the resistance to flow of a capillary to the resistance flow of an arteriole, if the capillary has a diameter of 8.0 microns and a length of 1.0 mm, and an arteriole has a diameter of 20 microns and a length of 2.0 mm. (b) Also compare the pressure drop across a capillary to the pressure drop across an arteriole.
(a) Use resistance to flow equation, manipulate to receive Rcap/Rart= Lcap/Lart x [(r(art)/r(cap))^4]= Rcap= 20Rart (b) Recall that Rart < Rcap, so part >> pcap
Pulmonary imaging: 2/2 types, ventilation
- Combined with perfusion imaging the diagnosis of lung disorders becomes more specific. - Diagnosis pulmonary emboli and evaluation of pulmonary function - Agents used for imaging: Xenon-133 gas and Tc-99m pentetate (Tc-99m DTPA)
RPs used in oncology
- F-18 FDG, Tc-99m Sestamibi (Miraluma), Tc-99m sulfur colloid, In-111 Prostascint, In-111 OctreoScan - I-131 Tositumomab (Bexxar), In-111/Y-90 Ibritumomab Tiuxetan (Zevalin)
RPs used in skeletal imaging
- Tc-99m MDP (medronate) and - Tc-99m HDP (oxidronate)
Apoptosis (programmed cell death) from radiation
- accelerated - cells die - disabled - cells become immortal (cancerous)
Radiation dose depends on
- amount of radioactivity - residence time - type and energy of radiation - distribution in organ - amount of energy absorbed by organ - organ mass
Cell death from radiation
- differentiated cells - loss of function - proliferating cells - loss of reproductive integrity
Sepsis
- happens when your body has an overwhelming immune response to a bacterial infection - chemicals released into the blood to fight the infection trigger widespread inflammation; causing blood clots & leaky blood vessels that do not allow blood flow, ultimately depriving organs of oxygen/nutrition - in severe cases, organs fail and in the worst cases, BP drops, heart weakens, and patient goes into septic shock
Symptoms of neurogenic shock
- low systemic vascular resistance - excessive parasympathetic activity - bradycardia
Radiopharmaceutical (RP) versus Radiochemical
- sterile, non-pyrogenic - radionuclide: used to tag chemical & then monitor by imaging - pharmaceutical: localization
How do direct (invasive) techniques of measuring IOP function?
- the sensor is placed inside the eye and provides an accurate representation of the true IOP
How do indirect (non-invasive) techniques of measuring IOP function?
- uses the relationship between the measured parameter (i.e. change in corneal radius of curvature) and the IOP
Signs for vs, velocity of a source
- vs = source moves toward observer + vs = source moves away from observer
High Target To Non-Target Ratio of RPs-- RPs localize in the organ of interest by:
1. passive diffusion (brain, lung) 2. ion-exchange (bone) 3. active transport (thyroid) 4. metabolic activity (heart, brain) 5. receptor binding (esp. PET brain studies) 6. Ag-Ab complexes (tumors) 7. size exclusion (block vascular capillaries) 8. phagocytosis (liver, spleen, bone marrow) 9. localization (rbc - blood pooling) 10. cell sequestration (heat damaged rbc - spleen) 11. chemotaxis (wbc - infection)
During a typical workday (eight hours), the average sound intensity arriving at Chloe's ear is 1.8 × 10±5 W/m2. If the area of Chloe's ear through which the sound passes is 2.1 × 10-3m2, what is the total energy entering each of Chloe's ears during the workday?
1.1 E -3 J
What is the acceptable range of particle sizes for Tc-99m MAA?
10 - 90 μm
The x and y components of a displacement vector are -3.00 m and +4.00 m, respectively. What angle does this vector make with the positive x axis?
127o
A roller coaster starts from rest at the top of an 18-m hill as shown. The car travels to the bottom of the hill and continues up the next hill that is 10.0 m high. How fast is the car moving at the top of the 10.0-m hill, if friction is ignored?
13 m/s
What is the temperature in oC of a 0.355-M solution of seawater having an OP of 21.6 atm? (the Van't Hoff factor is 1.8)
139
The components of vectors and are given as follows: Ax = 7.6 Bx = -5.1 Ay = -9.2 By = -6.8 What is the magnitude and direction of the resulting vector? Measure the angle from the +x axis.
16 @ 99 degrees from + x axis
When an object is 12 cm in front of a concave mirror, the image is 3.0cm in front of the mirror. What is the focal length?
2.4cm
A train moving at a constant speed is passing a stationary observer on a platform. On one of the train cars, a flute player is continually playing the note known as concert A (f = 440 Hz). After the flute has passed, the observer hears the sound with a frequency of 415 Hz. What is the speed of the train? The speed of sound in air is 343 m/s.
21 m/s
Selena uses a garden hose to fill a bucket of water. The water enters the hose through a faucet with a 6.0-cm diameter. The speed of the water at the faucet is 5 m/s. If the faucet and the nozzle are at the same height, and the water leaves the nozzle with a speed of 20 m/s, what is the diameter of the nozzle?
3.0 cm
The decibel level of a jackhammer is 125 dB relative to the threshold of hearing. Determine the sound intensity produced by the jackhammer
3.2 W/m2
A submerged diver shines a light towards the surface of a body of water at angles of incidence of 30o and 60o. Take the index of refraction of water to be 1.33. can a person on the shore see a beam of light emerging from the surface in either case? Draw picture(s)
30 degrees - Yes 60 degrees - No
The electronic flash attachment for a camera contains a capacitor for storing the energy used to produce the flash. In one such unit, the electric potential difference between the plates of an 850 microFarad capacitor is 280 V. Determine the energy that is used to produce the flash in this unit.
33.3 J
A car moving at 35 m/s approaches a stationary whistle that emits a 220 Hz sound. The speed of sound is 343 m/s. What is the speed of the sound relative to the driver of the car?
378 m/s
A cell phone is placed 40 cm in front of a converging lens with a focal length of magnitude 20 cm. How far is the image of this phone from the lens?
40 cm
Normal ICP varies with age and body posture but is generally considered to be ________mmHg in healthy adults and older children, ________mmHg in children and ________mmHg in infants
5-15 3-7 1.5-6
A dentist wants a small mirror that will produce an upright image with a magnification of 5.5 when the mirror is located 2.1 cm from the tooth. What should the radius of curvature of the mirror be? Should the mirror be concave or convex?
5.13 cm concave
F-18 Fluorodeoxyglucose (F-18 FDG) decays by positron emission to produce two 511 keV photons ~180 degrees apart. What is the wavelength (λ), in nanometers, of the 511 keV photons?
511=1.24/λ; 0.00243 nm
For how long could the amount of energy required to bring a 1.0-L pot of water at 20°C to 100°C run a 60-W light-bulb? Specific heat of liquid water is 4186 J/kg °C.
5600s
Hearing damage may occur when a person is exposed to a sound intensity level of 90.0 dB (relative to the threshold of hearing) for a period of 9.0 hours. One particular eardrum has an area of 2.0 x 10-4 m 2. How much sound energy is incident on this eardrum during this time?
6.48 x 10-3 J
On Tues, the pharmacy receives an 18 Ci Mo-99/Tc-99m generator produced with a low enriched uranium source (LEU). How many Gbq is the SI equivalent for this generator?
666 GBq
What is the fraction of I-131 remaining after 30 days of storage in a waste room?
7.5%
740 microcuries in 2.5 mLs of In-111 oxine solution is incubated for 20 minutes with WBCs in a centrifuge tube. After the 20 minutes of incubation, the cell suspension is diluted with 12 mL of 0.9% NaCl, centrifuged, and the liquid layer is decanted from the solid pellet of WBCs. The radiolabeled WBCs pellet is measured in a dose calibrator, yielding 518 microcuries. What is the percent tag (% tag) of this procedure? %tag = (final activity / original activity) x 100%
70%
Determine the length of a copper wire that has a resistance of 0.172 Ω and cross-sectional area of 7.85 × 10-5 m2. The resistivity of copper is 1.72 × 10-8 Ω m.
785 m
Which of the following is false concerning the external ventricular drainage system? A: The EVD can be used to give medications B: The EVD can be used to monitor the velocity flow rate C: The EVD can be used to drain CSF D: The EVD can be calibrated at any time
B: The EVD can be used to monitor the velocity flow rate
Capacitance is mathematically found via the following equation:
C= Q(charge)/V(volt); SI unit is a Farad (F)
The resting membrane potential acts like what electronic component?
Capacitor
Sample of whole blood
Consists of: - Plasma (46-63%) - Formed elements (37-54%)
A pure semiconductor can increase conductivity through?
Doping
Doppler Ultrasound
Doppler effect is utilized to measure blood flow, bounces high-freq. sound waves off of moving red blood cells • By convention, blood coming toward transducer appears red & moving away appears blue
The north pole of a magnet points towards ___________________________
Earth's geographic north pole
When the sum of the forces within a system is equal to zero, the system is said to be in __________________.
Equilibrium
The most damaging radical for indirect cellular effects of radiation is
HO2 radical
Sound Intensity/ Sound Intensity Level Equation
I=P/A I= the sound intensity in W/m^2 P= the sound of power that passes through a surface of area A
Point of sound source
I=P/A where A=area of circle 4pi(r^2)
The transmission of an electrical signal through the central nervous system is known as ___________________.
Nerve transmission
Your friend cannot see closer than 80.0 cm from her eyes. Assuming that contacts are to be worn, determine the lens power of the corrective lens that would enable the person to see as close as 25.0 cm from her eyes.
P= +2.75D
Which portion of the graph represents the activation of the ventricles?
QRS
A patient dose of 25 mCi of Tc-99m MDP is calibrated for 1100 today. What type of study will this radiopharmaceutical be used to image?
Skeletal Imaging
Wall tension in the aorta for a mean pressure of 100 mmHg and a radius of 0.9 cm:
T=120N/m
Effective half-life is determined mathematically by:
Te = (Tp x Tb ) / (Tp + Tb ) - physical half-life (Tp ) - biological half-life (Tb ) - effective half-life (Te )
I-123 decays by electron capture to (for I, Z = 53)
Te-123
When presented with the challenge of testing the purity of a royal gold crown, Archimedes solved the problem by determining the density of the crown and comparing it to the density of gold (19.3 x 103 kg/m3 ). He determined the density of the crown by weighing the crown in air, (7.84 N) and then while completely submerged in water (6.84 N). What should Archimedes have told the king?
The gold was f a k e
If an object is placed closer than f in a concave mirror then,
The image is virtual, upright, and enlarged
What is the neuron doing when membrane is at rest?
The neuron is, too, at rest-- it is not stimulated or conducting impulses
A rock is suspended from a string; and it accelerates downward. Which one of the following statements concerning the tension in the string is true?
The tension is less than the weight of the rock.
A person 1.70 m tall is standing 2.50 m in front of a digital camera. The camera uses a converging lens whose focal length is 0.0500 m. a) Find the image distance, the distance between the lens and the image sensor and determine whether the image is real or virtual. b) Find the magnification. c) Find the height of the image on the image sensor (absolute value only)
a) +0.0510 m 0.0510 m real b) -0.0204 c) 0.0347 m
Ex.) Scalar and Vector • A force vector has a magnitude of 575 newtons and points at an angle of 36.0° below the positive x axis. What are (a) the x scalar component and (b) the y scalar component of the vector? (c) Determine the vector quantity of each scalar quantity
a) 465 N b) 338 N c) 465 N east, 338 N south
The distance between neighboring singly charged sodium and chlorine ions in crystals of table salt (NaCl) is 2.82 x 10-10 m. a) What is the electric force that the positive sodium ion exerts on the negative chlorine ion? Draw a picture showing the ions and the force on the chlorine ion. b) What is the electric force that the negative chlorine ion exerts on the positive sodium ion? Draw a picture showing the ions and the force on the sodium ion.
a) magnitude: 2.90 x 10-9 N direction: toward the sodium ion b) magnitude: 2.90 x 10-9 N direction: toward the chlorine ion Use F= k* q1* q2/ (r^2)
Anaphylactic Shock
an acute systemic (whole-body) type of allergic reaction which occurs when a person has become sensitized to a certain substance or allergen and is again exposed to the allergen, may see (1) loss of consciousness, (2) hives, (3) swelling of tongue, (4) rapid swelling of throat
Blood speed is max. in the ____________ and min. in the ____________
aorta, capillaries represented via: F=Av - 0.328 m/s in aorta vs. 2.38E-4 m/s in capillary
Law of refraction
as light passes from less dense medium into more dense medium, it will bend towards the normal. If the light ray passes from more dense to less dense, it bends away from the normal. - equation: n1(sin(theta)1)=n2(sin(theta)2)
Which one of the following quantities can be converted to kilowatt W hours (kWh)? a. 9.6 W b. 5.8 J c. 2.0 A d. 6.2 C/V e. 8.3 V
b. 5.8 J
All of the following may lead to shock for the exception of: a. Spinal cord injury b. Severe fluid loss c. Ocular pressure imbalance d. Heart conditions
c. Ocular pressure imbalance
Some of the advantages to using the Implanted Microchip Transducers to measure ICP, are the following for the exception of: a. Excellent accuracy b. Placement: usually parenchymal c. Uses changes in light intensity to measure for accuracy d. Not dependent on a fluid column
c. Uses changes in light intensity to measure for accuracy
Complete the following statement: The space between the inner walls of a thermos bottle is evacuated to minimize heat transfer by
conduction and convection.
The fact that the sum of the currents entering any junction in an electric circuit must be equal to the sum of the currents leaving the junction is an expression of what principle?
conservation of charge
Which of the following terms describe lenses that are thicker at the center than at the edges?
converging lenses, convex lenses
Many radioactive atoms used in nuclear medicine are metals that are combined with a pharmaceutical ligand by
covalent or coordinate covalent chelation
When Albumin is lost from the blood, the OP of the blood
decreases
Catabolism
destructive metabolism; the breaking down in living organisms of more complex substances into simpler ones, with the release of energy
Sign of image distance:
di is + for an image formed to the right of the lens (real image) di is - for an image formed to the left of the lens (virtual image)
Dialysis
diffusion of several types of molecules through a selectively permeable membrane - membrane is permeable to several types of molecules
How does HBOT combat DCS?
diminishing the size of the bubbles, not simply through pressure, but also using an oxygen gradient
Wall tension in an arteriole or capillary is
directly proportional to the radius and directly proportional to the pressure.
Sign of object distance:
do is + if the object is to the left of the lens do is - if the object is to the right of the lens
An electron traveling horizontally enters a region where a uniform electric field is directed upward. What is the direction of the force exerted on the electron once it has entered the field?
downward
If a pulmonary valve were faulty and would not close completely then:
during the expansion of the RV, blood would backflow from the arterial system.
Radionuclides decaying by which process would be the most desirable for inclusion in a diagnostic radiopharmaceutical?
electron capture
Radiation Protection - Occupational Workers
external exposure to particle emitters is minimal - high energy β‐emitters (32P, 1.7 MeV) can pose a threat from external exposure
Treatment for hypovolemic shock
fluids and/or blood transfusions
Doppler effect general case
fo= fs(v(+or-)vo/v(+or-)vs) • +vo is used when the observer moves TOWARD the source • - vo is used when the observer moves AWAY the source • -vs is used when the source moves TOWARDS the observer • +vs is used when the source moves AWAY from the observer
Why is physics a required aspect of learning for many different majors?
for the simple reason it is the most fundamental of all sciences
Convex mirrors are used in stores to provide a wide angle of surveillance for a reasonable mirror size. One such mirror allows a clerk 5 m away from the mirror to survey the entire store. It has a radius of curvature of 1.20 m. If a customer is 10.0 m from the mirror, how far from the mirror surface is his image? Is the image in front or behind the mirror? If the customer is 2.00 m tall, how tall is the image?
image is 0.566 m behind the mirror image is 0.113 m tall
The human body will respond to dehydration by:
increasing heart rate and constricting the blood vessels
Diastolic pressure=
lowest pressure in the artery, when the LV is expanding/at rest
A certain physical quantity, R, is calculated using the formula: R = 4a2(b - c) where a, b, and c are distances. What is the SI unit for R?
m3
If an object is placed at the focal point of a concave mirror, then (d=f):
no image is formed
Ordinary electric current involves the flow of electrons, the action potential involves the movement
of sodium and potassium ions across the cell membrane.
A p-n junction diode is
ommonly used in rectifier circuits, which convert ac voltage into dc voltage
Through a certain cross-sectional area of a wire, one coulomb of electrons pass each second. In this case, the current through the wire is equal to which one of the following choices?
one ampere
Pressure at a depth
p= po + ρgh; where po is the pressure exerted on the surface of the fluid and ρgh is the pressure of the weight of the fluid
Stochastic effects
probability increases with dose but severity is independent of dose (e.g. 0.1 Gy versus 1.0 Gy) • usually a delayed effect • cancer (exposed individual) • genetic mutation (decendents)
One method that aids high target to non-target radiopharmaceutical accumulation of Tc-99m macroaggregated albumin (Tc-99m MAA) in the vascular capillaries of the lungs is best described as
size exclusion
Rubidium chloride (82RbCl) is produced by a specialized generator system (Cardiogen-82®) for immediate use. The radioisotope, 82Rb (Z = 37), undergoes rapid positron emission (half-life of 75 seconds). Which statement is true regarding positron emission?
the ejected positron combines with an electron to produce two 511 keV photons 180o apart
Beats are:
the periodic and repeating fluctuations heard in the intensity of a sound when two sound waves of very similar frequencies interfere with one another
In the diffusion process, the energy that accomplishes the net transfer of molecules is
the random kinetic energy of the molecules.
The use of a wire strain gauge is based on the principle
the resistance of a wire is proportional to its length.
What is Relative Biologic Effectiveness? (RBE)
use to calculate the dose equivalent in rem from rads. It is defined as the amount of standard radiation that causes certain biological damage to the amount of radiation in question that causes the same biological damage
Wien's law - example • At which peak wavelength do people radiate? Take the human body temperature to be 37 oC.
wavelength max = b/t; b=2.9E-3 mK = 9.35E-6 m
Contrast agents consisting of dense material can be used to enhance the image quality for ______ images.
x-ray and CT
How do lasers function?
• 'LASER' stands for Light Amplification by Stimulated Emission of Radiation • Based on: (1) Stimulated emission, (2) Population inversion • A population inversion between two energy levels is created by an external source of energy. • Stimulated emission: one photon in and two photons out
Parallel Plates -- electric field
• 2 metal plates with charges of equal magnitude but opposite sign separated by a distance d • The electric field between the plates is approximately uniform Demonstrated by the following: E= sigma/extinction coefficient
Fluid replacement for athletes: pre-exercise
• 2-3 hours before: 17 to 20 fl oz • 20 minutes before: 7 to 10 fl oz
Process of the action potential for a human nerve cell
• A stimulus is received by the dendrites of a nerve cell. This causes the Na + channels to open. An influx of Na + ions will occur due to its higher concentration outside the membrane. If the opening is sufficient to drive the interior potential from -70 mV up to -55 mV, the process continues (1) • Having reached the action threshold, more Na + channels (sometimes called voltage-gated channels) open. The Na + influx drives the interior of the cell membrane up to about +30 mV. This corresponds to the depolarization phase at the end of which the Na + channels close. (2) • The Na+ channels are closed and the K + channels open (3) • With the K + channels open, the membrane starts to repolarize back toward its resting position (4). • The repolarization typically overshoots the resting potential to about -90 mV. The overshoot is called hyperpolarization and it is important in the transmission of information because it prevents the neuron from receiving another stimulus during this time, or at least raises the threshold for any new stimulus. Also, it assures that the signal is proceeding in one direction by preventing any stimulus already sent up an axon from triggering another potential in the opposite direction (5). • After overshoot, the sodium-potassium pump brings the membrane back to its resting potential of -70 mV (6).
The physics of a thermos bottle
• A thermos bottle reduces the rate at which cold liquids warm up or hot liquids cool down • It minimizes heat transfer due to conduction, convection and radiation • A thermos usually consist of a glass vessel with double walls, evacuated space between the walls, silvered inner walls , gasket and stopper
Electron acceleration
• Accelerate an electron through a voltage between parallel plates • The electron's kinetic energy gain is: DeltaK= Kf- Ki= e(DeltaV) where K=mv^2/2
Hydraulic systems
• Application of Pascal's principle • They transmit and multiply the force
Transistors
• Application of transistors as switches and amplifiers • One type of transistor is the bipolar-junction transistor • 2 types of bipolar-junction transistor: pnp and npn
Integrate circuits (IC)
• Arrays of billions of transistors, diodes, resistors, and capacitors on a tiny chip of silicon that measures less than 1 cm on a side • In computers and cellular phones • Commercial CMOS products used in digital cameras are integrated circuits composed of up to millions of transistors on a rectangular piece of silicon of between 10 and 400 mm2
• Origin of the earth's magnetic field
• At present, it is not known with certainty what causes the earth's magnetic field • The earth's magnetic field seems to originate from electric currents within the liquid outer core
What is the audible range for a healthy young person?
• Audible range for a healthy young person is 20 Hz to 20 kHz
Applanation tonometry is dependent upon which principle?
• Based on the Imbert-Fick principle: "the pressure in a sphere filled with liquid and surrounded by an infinitely thin membrane is measured by the counter pressure which just flattens the membrane" (2) ways: (1) measure contact force to flatten area, (2) measure area flatted by fixed force
Electronic Ink
• Based on the law of charges - like charges repel and unlike charges attract • Consists of microcapsules sandwiched between two layers, an opaque base layer and a transparent top layer
Symptoms of shock:
• Blood pressure below normal • Rapid heart rate • Cool and clammy skin • Weak, but rapid pulse • Rapid, shallow breath
Nearsightedness AKA myopia
• Can see near, but not far • Correction needed for the far point • Correction done with diverging lens
Water-Soluble Iodinated Contrasts
• Clear, Colorless and viscous liquid • Small molecular size and low chemical reactivity with body fluids and tissues • Distribute throughout extracellular spaces and do not penetrate into intracellular spaces • Eliminated via glomerular filtration (not reabsorbed or secreted)
Faulty heart valves
• Common faults include valves with holes or valves that do not close completely • Example: if the tricuspid valve does not close completely then, during the contraction of the right ventricle blood would backflow into the venous system; fault indicated by periodic pressure in the vein. • Example: if a pulmonary valve would not close completely then, during the expansion of the RV, blood would backflow from the arterial system.
Myocardial Perfusion Imaging
• Computerized images to assess the function of the heart. • Commonly called stress tests. • The procedure differentiates normally perfused myocardium from the non-perfused myocardium. • The perfused myocardium extracts radiopharmaceuticals from the blood and will appear "hot" on the images. • Non-perfused tissue cannot extract radiotracers and appear "cold" on the images. • There are two imaging phases: rest and stress
Conduction
• Conduction is a mechanism of heat transfer by molecular collisions • Molecules in the hotter part of the material are more energetic than their neighbors; as these molecules collide with their less energetic neighbors, they transfer some of their energy to them; energy is passed this way along the material from hot to cold
Capacitive pressure sensor
• Consists of a capacitor with one rigid plate and one flexible plate • Pressure changes on the flexible plate translate into changes of the capacitance • For example, if the pressure on the flexible plate increases, that results in a decrease in the distance between the plates, which results in an increase in the capacitance • Can be coupled with an inductor to form an LC circuit - the resonant frequency depends on the pressure applied to the flexible plate
Convection
• Convection is the mechanism of heat transfer by the bulk movement of fluid • The fluid flow that carries the heat is called convection current
CCD's/photography
• Converts light to electrons based on photoelectric effect • First practical way for a light-sensitive silicone chip to store an image and then digitize it • Consists of an array of pixels, each pixel including a MOS (metal-oxide-semiconductor) capacitor • As light falls on a pixel, the photons hit the silicone of the pixel, and each photon frees an electron (photoelectric effect) • The charge (the freed electrons) stored in each pixel's capacitor corresponds to the amount of light that hit it • The charge stored in each pixel is transferred row by row and measured and turned into a digital image • Boyle and Smith came up with the idea in just one hour • For color - red green or blue color filters over each pixel
Why can't everyone float in fresh water?
• Density of the body tissue • Increase size of chest cavity...take a deep breath • Easier for people to float in saltwater than fresh water
EEG frequency bands
• EEG consists of periodic oscillations of various frequencies • EEG signals are correlated with the physiological state • Used for diagnosis of epilepsy, tumors, certain forms of drug addiction, and other brain related diseases • Absence of any EEG signal over a long period of time = death
EMG - Electromyogram
• EMG - a measure of electric potentials produced by muscle fibers • Small needle electrodes inserted into the muscle or surface electrodes • Voltages on the order of 1 millivolt for a voluntary contraction of a normal muscle • Used for diagnosis of certain neuromuscular disorders and for monitoring nerve recovery
How is cardiac temponade diagnosed?
• Echocardiography: shows an enlarged pericardium or collapsed ventricles • Chest X-ray: shows large, globular heart
Low dose = < 10 cGy (10 rads) or < 10 cSv (10 rem)
• Effects are at the cellular level: non‐lethal • Mutation frequency is a function of dose - in utero damage, carcinogenesis, cataracts - damage to sperm/egg - inherited mutation - damage to somatic cell - exposed individual
What episodes lead to cardiac temponade?
• Heart surgery • Heart wounds • Malignancy • Uremia (raised level of blood urea) • Infection - pericarditis
Physics behind HBOT
• Henry's Law - at constant temperature, more gas is dissolved into a liquid by increasing the pressure of the gas. By increasing the pressure in the HBOT chamber, more oxygen can be dissolved in the plasma. • Boyle's Law - pV = ct. it applies HBOT for treatment of decompression sickness: as the pressure increases, the volume of the bubble decreases
What is the Beck's triad of Cardiac temponade?
• Hypotension • Jugular-venous distension • Faint heart sounds
Swan-Ganz monitors
• Invasive hemodynamic monitoring • Balloon flotation flow directed pulmonary artery catheter that can be used at bedside, without fluoroscopy, for hemodynamic monitoring • Pressure transmitted through the fluid (Pascal) in the catheter to a pressure transducer that converts pressure to an electrical signal
Laws of charges
• Like charges repel -- For example, 2 protons repel each other • Unlike charges attract -- For example, one electron and one proton attract each other
Echocardiography Ultrasound Cardiac Imaging
• M-Mode (motion mode) • 2D, 3D/4D (heart motion in real time) • spectral doppler (flow analysis) • color doppler (turbulence analysis) • transthoracic echocardiography (TTE) • transesophogeal echocardiography (TEE) • intravascular ultrasound (IVUS) • rest / stress echocardiography • echocardiography with perflutren (Definity®): contrast agent = (octafluoropropane lipid microspheres)
Magnetic axis
• Measurements of the earth's magnetic field show that the earth behaves magnetically almost as if a bar magnet were located near its center • The earth's magnetic axis is the orientation of this fictitious bar magnet
What can the mass spectrometer do?
• Measures the mass of molecules
p-n junction diode
• Mobile electrons from the n-type semiconductor and mobile holes from the p-type semiconductor flow across the junction and combine • This creates positive and negative layers at the junction • Charge layers generate an electric field • Commonly used in rectifier circuits, which convert ac voltage into dc voltage
Catheter-tip transducer (Camino)
• Narrow fiberoptic catheter equipped with a flexible diaphragm; light is reflected off the diaphragm and changes in light intensity are interpreted in terms of pressure. • Placement: parenchymal, ventricular, subdural • Excellent accuracy and low long term drift (T = ct.) • Not dependent on a fluid column • Main limitation: cannot be calibrated in situ • More expensive
Pathophysiology of tension pneumonthorax
• Normal conditions: Intrapleural pressure is less than alveolar pressure & atmospheric -- allows gases to flow from high pressure to low pressure (into pleural space) until pressure gradient no longer exists - More air in pleural space --> more intrapleural pressure - Excess air causes the ipsilateral lung to collapse, shifting mediastinum to the other side. This shift can lead to the compression of the other lung & affect venous return to the heart
Skeletal Imaging
• Nuclear medicine is more sensitive than conventional x-rays for identifying the presence of bone lesions. • Radiopharmaceuticals localize in lesions during early stages of the disease process and show abnormalities before they would be apparent on routine x-ray films
Renal Imaging
• Nuclear medicine studies can provide accurate information on renal size, location, anatomy and physiology along with quantitative information about renal function. • Parameters that can be measured are renal blood flow, effective renal plasma flow (ERPF), and glomerular filtration rate (GFR)
Examples of convection
• Pot of water being heated on a gas burner • Heating units are located near the floor of a room • Heat transfer via blood flow to the skin • Rapid thermal exchange device used to treat overheated athletes
Bernoulli concepts
• Pressure = lower @ higher levels, provided area remains same • Pressure will accelerate TOWARD lower p region
Atmospheric pressure
• Pressure due to the weight of the air in the atmosphere • Atmospheric pressure at sea level is: p(atm) = 1 atm = 760 mm Hg
Components of a cardiac pacemaker
• Pulse generator - tiny computer with battery and other electronic components • Leads - one end of each lead at the generator and the other end at the heart; most pacemakers today have two leads, one stimulating the RA and one at the RV
In addiction to Beck's triad, what are the other signs of cardiac temponade?
• Pulsus paradoxus: abnormally large decrease in stroke volume, systolic blood pressure and pulse wave amplitude during inspiration. • Tachycardia: When the heart abnormally sends rapid electrical signals that make the heart rate faster
Cardiolite Kits (Myocardial Perfusion Imaging)
• Radiopharmaceutical is Tc-99m Sestamibi • Package Insert Preparation (varies): - Add 20-150 mCi of Sodium Pertechnateate Tc-99m to the vial in 1-3mL. - Boil for 10 minutes, allow vial to cool for 15 minutes. - Store at room temperature and use within 6 hours.
Clinical diagnosis
• Respiratory distress • Tachypnea (abnormal rapid breathing) • Muffled heart and lung sounds • If it is diagnosed clinically, treat immediately to save life
The indirect methods of measuring IOP are:
• Soft contact lens - continuous monitoring • Tonometry - routine test that measures the pressure inside your eyes to screen for glaucoma (non-contact tonometry & applanation tonometry)
Sphygmomanometer
• Standard method of routine blood pressure measurement • Non-invasive • Consists of an inflatable cuff connected to a mercury manometer • Measures systolic and diastolic pressures as gauge pressure
Narrowing of the arteries and blood flow
• Strong dependence of volume flow rate on radius (Poiseuille) • Narrowing of an artery can result in a dramatic decrease in blood flow • The body may try to maintain normal volume flow rate (if the demand is constant) by increasing the blood pressure • If an artery bursts or becomes blocked, the part of the body that gets its blood from that artery will be deprived of energy and oxygen
Angle of dip
• The angle of dip is the angle that the magnetic field makes with the surface at any point
The speed at which action potentials propagate is affected by:
• The diameter of the axon - large-diameter axons propagate action potentials faster than small-diameter axons • Whether the axon is myelinated - myelinated axons propagate action potentials faster than unmyelinated axons (of the same diameter) because the myelin electrically insulates the membrane, which reduces the ability of ions to leak out of the axon, and increases the distance along the axon that a current can passively flow • Temperature - increase in temperature causes an increase in the rate of diffusion of ions across the membrane
Applanation tonometry -Goldmann tonometer
• The eye doctor puts eye drops containing a numbing agent and a yellow eye dye that glows under blue light in your eyes. While you stare into a slit lamp, the eye doctor gently touches the surface of your eye with the tonometer to measure your IOP
Transistors as amplifiers
• The generator introduces small voltage changes in the forward bias across the emitter/base junction, which result in large changes in the current through the resistor R • The output voltage across R is an amplified version of the input voltage of the generator
How does HBOT heal wounds?
• The increase in atmospheric pressure allows the body to incorporate more oxygen into blood cells, blood plasma, cerebral-spinal fluid, and other body fluids which results in more oxygen being delivered to organs and tissues in the body
Doppler flow meter results
• The ultrasound from the source transducer produces Doppler shifted echoes off the moving red blood cells in the arteries • The Doppler shift depends on the speed of the blood flow
Wien's law
• The wavelength at which most emission occurs is related to the temperature • The hotter an object is, the shorter the wavelength at which it will emit most radiation • The peak emission of the Sun (with effective surface temperature of 5780 K) is 502 nm, which is (not incidentally) fairly in the middle of the most sensitive part of land animal visual spectrum acuity.
Cisternography
• To evaluate the hydrodynamics of cerebral spinal fluid (CSF), compounds must be instilled into the CSF and their course is mapped • Radionuclide cisternography is one of the most reliable tests to assess CSF
Ultrasound Imaging information
• Ultrasound - frequencies above 20 kHz • High-frequency sound pulses (1 to 15 MHz) are produced by a transmitter and directed into the body. Each time a pulse encounters a boundary between tissues or fluids of different densities, reflections occur • An image of the inner anatomy (called a sonogram) is obtained by scanning ultrasonic waves across the body and detecting the echoes generated • The minimum size of the resolved object depends upon the wavelength of the sound; the wavelength of the sound must be about the same size or smaller than the object to be located. • The higher the frequency, the higher the resolution, but the higher the frequency, the smaller the depth of penetration of the scan; so a compromise must be made between the resolution of the image and the depth of penetration of the scan. • For eye examinations - frequencies up to 15 MHz can be used • For abdominal examinations - frequencies from 1 to 3 MHz are used
What causes dark pixels?
• When a small portion of the base layer is positive, the negative white beads are attracted to it
Net Flow of Heat Radiation
The net rate of radiant heat flow from the object is given by the equation: Q/t= e(sigma)A(deltaT)
Before administering a contrast agent for a CT procedure, the technician is likely to ask the patient about allergic reactions to
Seafood/shellfish
The type of shock the body experiences due to an overwhelming immune response to a bacterial infection is
Septic Shock
Sign of focal length:
f is + for a converging lens f is - for a diverging lens
Equations:
f=c/λ f = frequency, c = speed of light, λ = wavelength E=hf=hc/λ E = energy, h = Planck's constant, f = frequency E = energy, (in kiloelectron volts), λ = wavelength (in nanometers) ex.) Tc-99m = 140keV E=1.24/λ 140=1.24/λ λ=1.24/140, λ= 0.0089nm
Mirror terminology
f=focal length do=object distance di=image distance m=magnification R = radius of curvature
Model the human ear canal as a closed pipe of length 2.54 cm. what is the fundamental frequency (the lowest sound resonance frequency) of the ear canal? Take the speed of sound in the ear canal to be 353 m/s.
f=v/4L = 353 / 4x 0.0254m= 3.47 kHz
Electric Resistance=
resistance to the flow of charge; R= V/I R= resistance, V= voltage, I= electric current SI unit for resistance is an ohm, looks like a horseshoe
A student in a resting state has a systolic pressure of 120 mmHg. He has a sudden demand for vigorous exercise (i.e. he is chased by a neighbor dog that would like the beef jerky he is carrying in his pocket), and the blood volume flow rate must increase to seven times the resting value. If there were no vasodilatation, by what factor should his blood pressure increase to provide the increased blood flow rate? Is the new pressure value physiologically reasonable? If no blood pressure increase occurred but all the blood vessels dilated by the same percentage, by what factor should the radii of the blood vessels increase to handle the demand?
7 No 1.63 - Note: F=p/R, p is directly prop. to F so 7, (7)^1/4 = 1.63
Deep ultrasonic heating is used to promote healing of torn tendons. It is produced by applying ultrasonic sound over the affected area of the body. The sound transducer (generator) is circular with a radius of 1.8 cm, and it produces a sound intensity of 5.9 x 10 3 W/m 2. How much time is required for the transducer to emit 4800 J of sound energy?
7.99 x 102 s
High doses of radiation (2-10 Sv)
Acute radiation syndrome: - Death may occur within 4-6 wks, recover or death phase possible if radiation < 10 Sv & treatment options are available - Prodromal effects (within first 24-28 hr): fatigue, anorexa, N/V/D, hair loss - Latent phase: no signs/symptoms - Manifest phase: signs return to prodromal or even worsen
ARCHIMEDES' PRINCIPLE
Any fluid applies a buoyant force to an object that is partially or completely immersed in it; the magnitude of the buoyant force equals the weight of the fluid that the object displaces: Fbuoyant(magnitude of buoyant force)=Wfluid(weight of displayed fluid) Fb= ρV g,where ρV = mass of the displaced fluid
Alpha particles (4He2+)
Are a result of spontaneous fission - the breakdown of a heavy nucleus into fragments Move left on the periodic table 2 (lose 2 protons) and lose a total of 4 mass units
What device allows current to flow in one direction?
Diode
Which of the following statements about spherical mirrors is correct?
A convex mirror always produces a virtual image. A convex mirror always produces an upright image.
Which one of the following statements concerning diodes is false? Select one: a. A diode connected to an ac source allows current to flow only in one direction. b. A diode is fabricated by forming junctions between one n-type and two p-type semiconductors or one p-type and two n-type semiconductors. c. At an n-p junction in a diode that is not connected to a battery, an electric field exists across the junction. d. A battery can be connected to a diode so that a continual flow of charge results. e. Holes move in a diode under a forward-bias condition
A diode is fabricated by forming junctions between one n-type and two p-type semiconductors or one p-type and two n-type semiconductors.
Units of Radioactivity
Disintegrations per unit time (dps or dpm) Traditional unit is the curie (Ci) Equal to decay of 1 gram of "pure" 226Ra = 3.7 x 1010 dps International System of Units (SI) has adopted the Becquerel (Bq) 1 Bq = 1 dps = 2.7 x 10-11 Ci 1 Ci = 3.7 x 1010 Bq or 37 GBq
A pressure transducer converts: ______________________ into _______________________
A pressure transducer converts pressure into an electrical signal ex.) Staham pressure transducer based on wire strain gauges that form a Wheatstone bridge circuit-- consists of a set of wires that form a Wheatstone bridge circuit. Pressure applied to the transducer results in a change in wire length which in turn results in a change in their resistance which leads to a Wheatstone bridge imbalance.
Radiation can damage many cellular components, but the most sensitive cellular target that has the greatest likelihood to eventually lead to cell death is
Double-stranded DNA
What is cardiac temponade?
Excessive accumulation of fluids in the pericardial space leads to compresion of the heart
Which one of the following statements concerning waves is false? Select one: a. A wave carries energy from one place to another. b. A wave can have both transverse and longitudinal components. c. A wave is a traveling disturbance. d. A transverse wave is one in which the disturbance is parallel to the direction of travel. e. A wave does not result in the bulk flow of the material of its medium.
A transverse wave is one in which the disturbance is parallel to the direction of travel.
Which statements about about images are correct?
A virtual image cannot be formed on a screen
Which one of the following statements is true concerning the magnitude of the electric field at a point in space?
A: the maximum potential difference between the terminals of a battery
Two people are pushing a stalled car. The mass of the car is 1850 kg. One person applies a force of 275 N, while the other applies a force of 395 N. A third force of 560 N also acts on the car, but in the opposite direction in which the people are pushing. This force arises because of friction and the extent to which the pavement opposes the motion of the tires. Find the acceleration of the car
A= 0.0595 m/s2
Proton Beam Radiation Therapy
Accelerates protons via a curved path (Synchrotron) Proton passage near electrons can cause ionizations 3D depth, energy are better controlled than high energy photons (x-rays or gamma rays) Deposition of proton energy is more discrete, controllable Fewer side effects, less damage to surrounding healthy tissue
_____________________ has applications in electric motors, electric generators, MRI machines, and door bells. It is a magnet whose magnetic field is generated by electric current in a wire.
An electromagnet
Convex lens is AKA
Converging lens
Equations related to radioactive decay and explanation
Decay is a random process The disintegration rate (disintegrations per unit time) of a radionuclide is proportional to the number of atoms at that time (a.k.a. radioactive decay law) N= number of atoms & λ= decay constant (units = reciprocal time To obtain the rate of decay for a measurable period of time, the differential equation must be integrated: The activity is directly proportional to the number of atoms present A=λN; where A = activity of the radionuclide, N = number of atoms and λ= decay constant (units = reciprocal time) Substitution of activity for the number of atoms provides At=Aoe-λt
A parallel plate capacitor has a potential difference between its plates of 1.6 V and a plate separation distance of 2.5 mm. What is the magnitude of the electric field if a material that has a dielectric constant of 3.4 is inserted between the plates?
E= [V/k]/d= 190 V/m
A completely ionized beryllium atom (net charge = +4e) is accelerated through a potential difference of 6.0 V. What is the increase in kinetic energy of the atom?
E=qV 6*4=24eV
Bioelectricity-- by definition-- is:
Electric voltages or currents produced by or occurring within living organisms --> generated by biological process and range in strength from one to a few hundred millivolt
Application of linear accelerator:
External Beam Radiotherapy (Teletherapy)-- example of LINAC Intensity-Modulated Radiation Therapy (IMRT) - radiation delivery via hundreds of segments minimizes dose to normal tissue
The acceleration of electrons with a LINAC for collision with a tungsten target creates high energy photos that are medically useful for
External beam radio therapy (teletherapy)
The figure on the next slide shows a traction device used with a foot injury. The weight of the 2.2 kg object creates a tension in the rope that passes around the pulleys. Therefore, tensions T1 and T2 are applied to the pulley on the foot. The foot pulley is kept in equilibrium because the foot also applies a force to it. This force arises in reaction to the pulling effect of the tension forces T1 and T2 . Ignoring the weight of the foot, determine the magnitude of F.
F = 35 N
The contrast agent most useful for enhancing MRI images would be
Gadopentetate dimeglumine
When the metastable isotope shown below decays to the "ground state", energy is released in the form of 99mTc --> 99Tc
Gamma ray
When you put an ice cube in a glass of warm tea, which of the following happens?
Heat flows from the tea into the ice cube.
Energy balance of the human body
Human body is an open system & thus, first law of thermodynamics - Manipulation gives us (deltaU)= Q-W+E Where E= energy gained by the body as a result of ingestion and metabolism of food
Scalar Quantity
Just magnitude, no direction Ex.) Time, mass, temp
Ultrasound Contrast Agents
Microbubbles
Faraday's Law of induciomagnetic flux
Movement of the total magnetic field which passes through a given area, measured in Webers
Out of electrons, protons, and neutrons, neutrons, rank largest particle to smallest
N > P > E
Treating tensionpneumothorax prior based on clinical symptoms
Needle thoracostomy: (e.g. 20gauge needle in the 7th or 8th intercostal space) Tube thoracostomy: if the pneumothorax comes back or is persistent
Lu-177 (Z=71, T1/2= 6.734= days) is being studied as a possible isotope for use in treating cancer due to its particle emission properties. Based on the decay scheme, what type of decay process occurs during this transformation? 177Lu --> 177 Hf
Negatron decay Proton number increased by 1
Summary of the production of radionuclides-- ways include:
Nuclear Reactor (used to make 99Mo, 131I, 133Xe) Generator (used to make 99mTc) Cyclotron (used to make 18F, 111In, 123I, 201Tl) Linear Accelerator -used to make x-rays for radiotherapy
Which isotope production process would the reaction shown below occur in? 235U + n --> 236 U --> 137 Cs + 95 Rb +4n + gamma-rays
Nuclear reactor
Florbetapir (Amyvid) is a new agent for imaging the brain of patients suspected to have Alzheimer's Disease. Based on components within florbetapir's chemical structure, the imaging technique that would utilize florbetapir (Amyvid) would be
PET
Imaging studies that inject patients with radioactive tracers to obtain anatomical +/- functional information regarding a patient's disease state is(are):
PET & SPECT
Speed of action potential for a human nerve cell (pain)
Pain is actually one of the slowest sensations our bodies can send. Smaller fibers without myelin, like the ones carrying pain information, carry signals at about 0.5-2.0 m/s (1.1-4.5 miles/hour). The fastest signals in our bodies are sent by larger, myelinated axons found in neurons that transmit the sense of touch or proprioception (the unconscious perception of movement and special orientation) at 80-120 m/s (178-268 miles/hour). Scientists believe that this reflects the evolution of these senses - pain was among the most important things to sense, and so was the first to develop through small, simple nerves
What exactly happens when a person is color blind?
People with color blindness have trouble seeing red, green, or blue or they see a different shade of that color or different color
Photoelectric effect
Photon transfers all of its energy to an electron with/without ejection of the inner shell electron (Up to 0.5 MeV for photons generally, matter= high Z)
Which law, principle, or equation can be used to determine the volume flow rate of a liquid that is forced through a hypodermic needle?
Poiseuille's law
The units of measurement used in determining the radiation field one is exposed to in their immediate environment is
Roentgen
Laplace's law explains:
The blood vessel wall tension required to withstand a given blood pressure is proportional to the radius of the vessel • For a given wall strength, a smaller vessel can withstand more pressure than a larger vessel T=PR for cylindrical vessel for spherical, PR/2; r=radius & p is measured in N/m2 which is 1:1 with Pa
Which one of the following statements concerning the buoyant force on an object submerged in a liquid is true?
The buoyant force depends on the volume of the liquid displaced.
Latent heat
The heat gained or lost by a substance that undergoes a phase change (at constant temperature) is represented by: Q= (+ or -) mL; m=mass of substance, L= latent heat of substance (J/kg)
Which of following statements about the image formed by a single diverging lens are true?
The image is always virtual., The image is always upright.
A negative magnification for a mirror means that
The image is inverted, and the mirror is concave.
When an object is blaced between c-ray and f-ray (R > do > f) in a concave mirror, then:
The image is inverted, real, and enlarged
If the magnification of a lens is negative, it means that
The image is inverted.
Which one of the following statements concerning the magnetic field inside (far from the surface) a long, current-carrying solenoid is true?
The magnetic field is non-zero and nearly uniform.
EQUATION OF CONTINUITY
The mass flow rate has the same value at every position along a tube that has a single entry and a single exit for fluid flow. ρ1A1v1=ρ2A2v2 SI Unit of Mass Flow Rate: kg/s
Nerve conduction (or transmission)
The transmission of an electrical signal (impulse, action potential, or spike) along a nerve fiber • The human nervous system transmits information in the form of electrical signals • The electrical signals are carried by nerves
When the object is placed between F and the lens of a converging lens,
The virtual image is upright and larger than the object
What is nuclear radiation?
Two types of nuclear radiation: Particulate Radiation (ENERGETIC MASS) Alpha particles Large, ex.) 4He2+ Beta particles Positron: proton decays ejection charge and mass When a proton decays by positron emission, the proton transforms into a neutron, proton # decreases by one and a nuclear transformation occurs Ex.) C11 → B Negatron: neutron decays, small portion of mass and charge is ejected in the form of a negatron Electromagnetic radiation Energy released= energetic photons Gamma rays: originate in nucleus X-rays: originate in electron cloud, result of relocations of electrons due to vacancies
How to find the work done by electrical force when a positive charge is moved from point A to point B
W(ab)= Fx delta(s, ab); where W= change in electric potential energy, F = work done by electrical force, and delta s= distance from a to b
Risks associated with CT/CAT Scans
- Exposure to ionizing radiation (x-rays) - Allergic reactions to contrast media (iodine and seafood)
Warnings & precautions: MRI
- Internalized metal components may move during procedure - Procedure occurs in a confined space • (sedatives are necessary for about 1 in 20 patients) - Patient may be restrained to avoid movement - Clothing can interfere with the procedure - May be loud (earplugs or headphones may be used) - Procedure usually takes 30-60 minutes
Conventional Imaging Modalities // Magnetic Resonance Imaging
- Uses a strong magnetic field to align a small population of magnetic nuclei (like hydrogen) with the applied magnetic field. These aligned nuclei precess (spin like a gyroscope) with a frequency in proportion to the magnetic field strength. - Precessing nuclei will absorb energy when pulsed perpendicularly with non-ionizing electromagnetic radiation (RADIO WAVES). - When the excitation pulse is removed, the nuclei release the absorbed energy as a detectable signal used to generate diagnostic images.
X-ray/CT Contrast Agents
- Water Insoluble - barium sulfate - Unsaturated fatty acids - ethiodized oil - Water Soluble - ionic and non-ionic iodinated benzoic acid derivatives
Uses for MRI:
- joint disorders (shoulder, wrist, hip , knee, ankle) - functional MRI of the brain - as an alternative to CAT/CT imaging
A proton is projected with a velocity of 7.0 km/s into a magnetic field of 0.60 T perpendicular to the motion of the proton. What is the magnitude of the magnetic force that acts on the proton? (e = 1.60 × 10-19 C)
6.7 × 10-16 N
Magnetic force on a current in a wire
• Consider a current-carrying wire in magnetic field • The magnetic force exerted by the magnetic field on the current-carrying wire has
Cardiac images from myocardial perfusion studies that utilize Tc-99m sestamibi would be collected by an instrument know as a
SPECT camera
Other solutes in the plasma composition include
Electrolytes: normal extracellular fluid ion composition essential for vital cellular activities, ions contribute to osmotic pressure of body fluids. Organic nutrients: used in ATP production, growth, and maintenance of cell; include lipids (fatty acids, cholesterol, tri-glycerides), carbohydrates (primarily glucose), and amino acids Organic wastes: carried to sites of breakdown or excretion; include urea, uric acid, creatinine, bilirubin, ammonium ions
If the amount of energy released during the nuclear transformation is 107 keV, what decay process occurs in step Z? (See periodic table if necessary, Z=32 for Ge) 68 Ge --> 68 Ga
Electron capture Emission < 1.022 MeV, 107 KeV = 0.107 MeV & proton number decreases by one
Which of the following happens when a material undergoes a phase change?
Heat flows into or out of the material.
MRI Contrast Agents
- Gadolinium-containing - Manganese-containing - Superparamagnetic iron oxide (SPIO) colloids
Gallium (Ga-67) citrate emits six photons of different energies that are useful for imaging acute inflammatory lesions as well as selected cancers. If the most abundant photon emitted during Ga-67 decay yields 93.3 KeV, what is the wavelength of this photon?
0.0133 nm E(KeV)= 1/24/wavelength in nanometers
In-111 DTPA is utilized to image the spinal cord for CBF leaks. If this RP is calibrated as 1 mCi/1.5 mL on Wednesday @ 12pm, how much In-111 activity remains 7 days later?
0.177 mCi
The hospital nuclear medicine department receives a standing order of 250 mCi of Tc-99m sodium pertechnetate (Tc-99m NaTcO4) calibrated at 12:00 noon diluted to 4 mLs total volume. If the department needs to make a stat dose of 10 mCi Tc-99m Choletec at 10:30 PM, what volume of Tc-99m sodium pertechnetate will be required to prepare the dose?
0.54 mL
Suppose the pressure acting on the back of a swimmer's hand is 1.2x105 Pa. The surface area of the back of the hand is 8.4x10-3m2. (a) Determine the magnitude of the force that acts on it. (b) Discuss the direction of the force.
1.0x10^3N downward
Suppose an electric eel touches the head and tail of a fish and applies a voltage of 600 V across it. If a current of 0.80 A results (likely killing the prey), estimate the average resistivity of the fish's flesh. Model the fish as a solid cylinder with a length of 20 cm and a cross-sectional area of 3.1 x 10-4 m 2.
1.2 Ohm.m
What is the distance between two point charges when the magnitude of the electrostatic force is 248 N/C? q1 = +1.6 x 10-19 C and q2 = -2.6 x 10-19 C
1.22 x 10-15 m
Which one of the following is the longest length? a. 102 centimeters b. 105 micrometers c. 104 millimeters d. 107 nanometers e. 100 meters
104 millimeters
At a rock concert, the sound intensity level corresponding to one band playing 100 dB. What will the sound intensity level be if seven of the same bands are playing simultaneously?
108dB
A soft-drink can contains about 0.35 kg of liquid at 5°C. Drinking this liquid can actually consume some of the fat in the body, since energy is needed to warm the liquid to body temperature (37°C). How many food Calories should the drink have so that it is in perfect balance with the heat needed to warm the liquid (essentially water)? Specific heat of liquid water is 4186 J/kg °C.
11 Cal
After eating two Granola bars (chewy, with raisins, 1.5-ounce bar), Rebecca decides to go for a run to burn off the extra energy. The Granola provides 19.03 MJ/kg, and Rebecca is able to raise her metabolic rate to 240 Watts while running. How long does she have to run? (1 ounce = 28.3 grams)
112 min 3 oz. * 28.3 g/1000 to convert to kg 19.03 MJ * 10E6 to J J * kg to determine the total amount of J burned then ratio with 240 J/s
At a birthday party, a student ate a piece of cake (400 Cal). To prevent this energy from being stored as fat, she took a stationary-bicycle workout class the next day. This exercise requires the body to do work at an average rate of 200 Watts. How long must the student bicycle to achieve her goal of "working off" the cake's energy?
140 minutes
Heat conduction to skin. Suppose 150 W of heat flows by conduction from the blood capillaries beneath the skin to the body's surface area of 1.5 m2. If the temperature difference is 0.50 °C, estimate the average distance of capillaries below the skin surface. Thermal conductivity constant for human tissue: k = 0.2 J/(sec m °C)
1E-3 m
An object is placed 10 cm from a convex lens with a focal length of magnitude 20 cm. What is the magnification?
2.0 - Remember that a convex lens is converging; converging lens has + f
An object is 1.0 m in front of a mirror. A virtual image is formed 10.0 m behind the mirror. What is the radius of curvature of the mirror?
2.2 m
A capacitor has a very large capacitance of 10 F. The capacitor is charged by placing a potential difference of 2 V between its plates. How much energy is stored in the capacitor?
20J
Nuclear Reactor
235U or 239Pu undergo spontaneous fission with the concomitant release of energy and emission of thermal neutrons Emitted neutrons initiate further chain reaction fission processes Emitted neutrons are slowed by low MW materials for use in radionuclide production by fission (n, f) or neutron capture (n, γ)reactions Fission - 235U (n, f) 236U → 131I + 102Y + 3n neutron capture - 50Cr (n, γ) 51Cr Various isotopes are separated by chemical procedures including, precipitation, extraction, ion exchange, chromatography and distillation
Take the index of refraction of diamond to be 2.42. Calculate the critical angle for the diamond to air interface. Also calculate the critical angle for the air to diamond interface.
24.4 degrees
A patient was scheduled for a thallous (Tl-201) chloride myocardial perfusion study at 10 a.m. Tuesday. A 4.2 mCi dose was delivered to the facility as requested, but the procedure was delayed due to a camera malfunction. The appointment was rescheduled for 10 a.m. on Wednesday. How much activity will remain after the delay? see decay tables or use
3.35 mCi
In a half-hour, a 65-kg jogger can generate 8.0x105J of heat. This heat is removed from the body by a variety of means, including the body's own temperature-regulating mechanisms. If the heat were not removed, how much would the body temperature increase?
3.5 C
A 4.0-kg cylinder of solid iron is supported by a string while submerged in water. What is the tension in the string? The density of iron is 7860 kg/m3 and that of water is 1000 kg/m3.
34 N
Three resistors, 50 Ω, 120 Ω, 180 Ω, are connected in series in a circuit. What is the equivalent resistance of this combination of resistors?
350 Ω
The focal length of a concave mirror has a mgnitude of 20cm, radius=?
40cm
Normal ICP for an average adult is
5 mmHg to 15 mmHg
The density of mercury is 1.36 x 104 kg/m3. What is the mass of a 4.00 x 10-4 m3 sample of mercury?
5.44 kg
Early Monday morning, a 16 Ci Mo-99/Tc-99m generator was delivered to the nuclear pharmacy. How many gigabecquerels (GBq) is the SI equivalent?
592 GBq
Basal Metabolic Rate Calculation for Women
655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)
Two students are whispering in the library. The radiated sound power from one student's mouth is 1.2 × 10±9 W; and it spreads out uniformly in all directions. What is the minimum distance the students must be away from the librarian so that she will not be able to hear them? The threshold of hearing for the librarian is 1.00 × 10±12 W/m2.
9.8m
How do the eyes focus?
Accommodation - the process in which the lens changes its focal length to focus on objects at different distances
One method to improve radiopharmaceutical accumulation at a target organ/tissue that involves exploiting specific proteins found on tumor cells would be best described as
Ag-Ab complexes
Treatment for anaphylatic shock:
Benadryl, epinephrine, steroid medications
A curtain hangs straight down in front of an open window. A sudden gust of wind blows past the window; and the curtain is pulled out of the window. Which law, principle, or equation can be used to explain this movement of the curtain?
Bernoulli's equation
0.9% saline solution is isotonic with respect to red blood cells. Red blood cells placed in 0.5 % saline solution will
Burst
The capacitance of a capacitor increases upon insertion of dielectric between the plates, this alters the equation for capacitance because:
C is representative of capacitance when dielectricity is present; however when dielectricity isn't present, capacitance is represented via KC An application of this is a stud sensor
Examples of microtransducers are:
Catheter-tip transducers (Camino) & implanted microchip transducers (Codman)
In-111 decays by electron capture
Cd-111
Concave lens is AKA
Diverging lens
Bioelectricity depends on the bioelectricity phenomena, which includes:
Fast signaling in nerves and the triggering of physical processes in muscles or glands
How does hydrostatic pressure differ from osmotic pressure?
Hydrostatic p is water being pushed by some FORCE-- if there is a lot of water in the blood vessel, it will get pushed out which causes edema Osmotic pressure is water moving from an area of [high] to [low]; too many particles in the plasma will suck water into the blood vessels and elevate bp
Direct measurement of IOP
Implantable IOP sensors - Intraocular lens: IOP sensor is coupled with an IOL implant and inserted during cataract surgery - Glaucoma drainage impact: IOP sensor coupled with a drainage implant - Choroidal surface implant: Piezo resistive IOP sensor implanted in the suprachoroidal space, risk of severe bleeding at implant site
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
It is lost to the environment.
Gadolinium (Gd) would be as a component in contrast agents for ___________ imaging.
MRI
Albumin loss from the blood:
OP of the blood decreases and the pressure different between the blood in the capillary and interstitial fluid decreases - Edema (collection of fluid in the tissues) occurs because fluid balance is shifted toward the tissues, more fluid leaves the capillaries and less returns
Osmotic pressure from an insect bite
OP of the interstitial fluid increases and the OP difference between the blood in the capillary and the interstitial fluid decreases - Rapid swelling of the bite/sting area occurs due to the fact that more fluid than normal leaves the capillaries and less returns
Negatrons (B-)
Occurs when a nucleus is neutron rich Negatrons come about when a neutron decays into a proton, negatron and antineutrino Emission of a negatron can lead to can lead to bremsstrahlung radiation (braking radiation) as x-rays
Which one of the following expressions gives the correct relationship between pressure and force?
P = F/A
Formed elements consists of
Platelets & leukocytes (01%) Erythrocytes (99%)
Which of the following statements is true as related to pressure in the circulatory system: a. Pressure is at its highest as it leaves the right ventricle b. Pressure is at its highest as it leaves the left ventricle c. Pressure is at its highest as it leaves the right atrium d. Pressure is at its highest as it leaves the left atrium
Pressure is at its highest as it leaves the left ventricle
Wave speed is:
Proportional to wave length and frequency
What is radiation?
Radiation is the emission and propagation of energy through space Involves waves Short waves are shorter in length, higher in energy and frequency Gamma & x-rays are shorter and more energetic Gamma rays originate in the nucleus of a decaying atom X-rays originate in the electron cloud Naturally occurring gamma rays are MORE energetic than naturally occurring X-rays
Pathophysiology of DCS
Rapid ascent causes a sufficient amount of nitrogen bubbles to develop in body fluids either extra or intracellularly Number & size allows the bubble to cause damage to any part of the body; for ex.) - Brain= paralysis - Nerves= paraesthesia itching, severe pain - Around joints= bends, severe pain - Pulmonary vessels= dyspnoea, and chokes - Coronary arteries= cardiac damage
First Law of Thermodynamics
Regards a closed system, energy cannot be created nor destroyed - Mathematically represented by (deltaU)= Q - W (deltaU)= the internal energy lost or gained by the system Q= the net heat transferred between the system & environment W= work done by the system on the environment
29.4
The Compton effect is the scattering of a photon by an electron in a material, the scattered photon having a smaller frequency and, hence, a smaller energy than the incident photon. Part of the photon's energy and momentum are transferred to the recoiling electron. The difference between the wavelength l9 of the scattered photon and the wavelength l of the incident photon is related by Equation 29.7 to the scattering angle u (see Figure 29.10), where m is the mass of the electron. The quantity h/(mc) is known as the Compton wavelength of the electron
If atmospheric pressure increases by an amount Δp, which statement about the pressure in a lake is true?
The absolute (total) pressure increases by Δp.
Venturi effect
The decrease in pressure that results when a fluid flowing through a pipe goes through a constricted section of the pipe is called the Venturi effect. Arteries with regions constricted by plaque can exhibit Venturi effect, i.e. a pressure reduction in those regions
A parallel plate capacitor with plates of area A and plate separation d is charged so that the potential difference between its plates is V. If the capacitor is then isolated and its plate separation is decreased to d/2, what happens to the potential difference between the plates?
The final potential difference is 0.5V.
North geographic pole
The north geographic pole is that point where the earth's axis of rotation crosses the surface in the northern hemisphere
Which one of the following statements is correct?
The north pole of a magnet points towards Earth's geographic north pole.
29.3
The photoelectric effect is the phenomenon in which light shining on a metal surface causes electrons to be ejected from the surface. The work function W0 of a metal is the minimum work that must be done to eject an electron from the metal. In accordance with the conservation of energy, the electrons ejected from a metal have a maximum kinetic energy KEmax that is related to the energy hf of the incident photon and the work function of the metal by Equation 29.3. E=hf, hf= KE(max) + Wo
When the object is placed between F and 2F in a converging lens,
The real image is inverted and larger than the object.
When the object is placed further than twice the focal length from the lens in a converging lens,
The real image is inverted and smaller than the object
The potential difference across the ends of a wire is doubled in magnitude. If Ohm's law is obeyed, which one of the following statements concerning the resistance of the wire is true?
The resistance is not changed.
A bell is ringing inside of a sealed glass jar that is connected to a vacuum pump. Initially, the jar is filled with air. What does one hear as the air is slowly removed from the jar by the pump?
The sound intensity from the bell gradually decreases.
Total Mechanical Energy, Definition and Equation
The total mechanical energy is the sum of the kinetic and potential energies. E=K+U where E is the total mechanical energy, K is the kinetic energy and U is the potential energy K=1/2 mv2 Potential E= U= Ug + Us, U=mgh, Us= 1/2kx2
Three blocks, labeled A, B, and C, are floating in water as shown in the drawing. Blocks A and B have the same mass and volume. Block C has the same volume, but is submerged to a greater depth than the other two blocks. Which one of the following statements concerning this situation is FALSE?
The volume of water displaced by block A is greater than that displaced by block B.
Electric potential is represented by what variable?
V
Electric potential is represented by
V (volts)
Resistors in parallel
Voltage= all same Currents= add all currents Req= 1/Req= 1/R+1/R..
Conservation of E
Within an isolated system, a system in which friction is not present, the total mechanical energy is conserved. E= constant or Ei=Ef
Can dehydration compromise physiologic function?
Yes • Thermal strain - increased core temperature by 0.15 to 0.20 degrees Celsius for every 1% of body weight loss • Cardiovascular strain - stroke volume reduction, heart rate increase, increased systemic vascular resistance and possibly lower cardiac output and mean arterial pressure; heart rate rises and additional 3 to 5 beats per minute for every 1% of body weight loss
If the HVL for 99mTc is 0.17 mm, how much lead is necessary to reduce exposure by essentially 100% Select one: a. 1.2 mm b. 4.8 mm c. 9.1 mm d. 1.25 cm e. 3.25 cm
a. 1.2 mm
On average, the typical annual background radiation exposure of all people from natural sources is considered to be Select one: a. 300 mrem b. 1000 rem c. 50 rem d. 5 rem
a. 300 mrem
An apple crate with a weight of 225 N accelerates along a frictionless surface as the crate is pulled with a force of 14.5 N as shown in the drawing. What is the horizontal acceleration of the crate?
a= 0.595m/s2 Rationale, W= 225N (W=ma); 225/9.8= 22.95kg F=14.5N=ma, 14.5N/22.95kg= 0.63m/s2 cos(19)=a/0.63, a= 0.595
Positive pressure, as related to a pneumothorax, means
air is flowing from the atmosphere to the pleural cavity
The type of current that flows through a refrigerator when it is plugged into a wall socket is which of the following?
alternating
Wheatstone bridge circuit can measure an unknown resistance by:
balancing the bridge (zero current through the bridge)
A beaker of water is placed on a Bunsen burner. As the lower layers of water are heated, they become less dense and rise. This permits cooler layers to move downward and be heated. Eventually, the water boils. Which method(s) of heat transfer is (are) primarily responsible for boiling the sample?
both conduction and convection
The monitoring of intraocular pressure is very important for the prevention of
glaucoma
An EEG is the recording of the
electrical signals produced by the brain
All of the following are symptoms of tension pneumothorax for the exception of: Select one: a. Muffled heart and lung sounds b. Tachypnea (abnormal rapid breathing) c. Respiratory distress d. Distension of the external Jugular vein
d. Distension of the external Jugular vein; this is a symptom of cardiac temponade
The property of F-18-fluorodeoxyglucose (FDG) that greatly improves image resolution is the drug's
decay via positron emission, producing two 511 keV photons 180 degrees from each other.
The term utilized to describe the proportional increase in damage or death to cells based on increasing amounts of radiation exposure (well above background) is known as
deterministic effect
Roentgen Equivalent Man
dose equivalent defined by the absorbed dose (rad) times the relative biological effectiveness (RBE) or quality factor of the radiation in question - units used in radiation protection to report exposures from film badges and dosimeters
The formula: (Tp x Tb) / (Tp + Tb) best describes
effective half-life
An EMG measures
electric potentials produced by muscle fibers.
Complete the following statement: Bernoulli's principle is a statement of
energy conservation in dynamic fluids.
Complete the following statement: When a substance undergoes fusion it
freezes
Which of the following choices is equivalent to the SI unit of pressure, the pascal?
kg/(m . s2)
Salt water is denser than fresh water. A ship floats in both fresh water and salt water. Compared to the fresh water, the volume of water displaced in the salt water is
less.
net transfer of solvent occurs from ___ OP to ___ OP
net transfer of solvent occurs from lower OP to high OP aka from higher [solvent] to low [solvent] (driven toward isotonic conditions)
According to Poiseuille's law, the volume flow rate is
proportional to the radius of the pipe to the 4th power
Complete the following statement: Most of the heat that is lost to space from the earth occurs by
radiation
The "P"wave of an ECG is produced by the activation of
the atria
Based on Faraday's law/electromagnetic induction, its main application is to power transmission over long distances.
transformer
Indications for Echocardiography
valvular imaging wall motion analysis post CABG / valve replacement effusion evaluation / management pulmonary pressure evaluation
An object is placed 20 cm in front of a concave spherical mirror that has a radius of curvature of 60 cm. Which one of the following phrases best describes the image?
virtual and located 60 cm from the mirror
Which one of the following units are the correct SI units for the electromotive force (emf)?
volts (V)
The average distance travelled by a molecule of type A in a space filled with type B molecules in a time t is given by:
x(rms)= (2D(ab)t)^1/2 - where D(ab) is the diffusion constant & x(rms)= distance in meters If time is the desired variable, the equation can be manipulated to show t= x^2(rms)/2D(ab)
If a calculated quantity has units of Ns/Cm that quantity could be
a magnetic field
A proton traveling due west in a region that contains only a magnetic field experiences a vertically upward force (away from the surface of the earth). What is the direction of the magnetic field?
south
Isotonic Contrast Media (ICM)
• Water-soluble, benzoic acid amide dimers • Iodixanol is an isosmolar nonionic dimer with 49% bound iodine content • It is indicated for use in angiography, excretory urography, and numerous computed tomography procedures • No vascular changes with OP
When the net force that acts on a hockey puck is 12 N, the puck accelerates at a rate of 48 m/s2. Determine the mass of the puck.
0.25kg
The specific gravity of ice is 0.917, whereas that of seawater is 1.025. What percent of an iceberg is above the surface of the water?
10.5%
A plant that is 4.1 cm tall is 10.3 cm from a converging lens. You observe that the image of this plant is virtual and 6.2 cm tall. What is the focal length of the lens?
30 cm
Basal Metabolic Rate Calculation for Men
66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years)
Treatment for septic shock:
Antibiotics
The contrast media described as an insoluble colloidal suspension in water that is administered either orally or rectally to enhance x-ray or CT images of the gastrointestinal (GI) tract is
BaSO4
Which of the following stores charge and energy?
Capacitor
The electric potential at a certain point in space is 12 V. What is the electric potential energy of a -3.0 μC charge placed at that point?
E=qV (electric potential, not within a capacitor) -36 μJ
Heart output is equal to..
F, also known as volume flow rate Heart output= heart rate x stroke volume • The heart output is the product between the number of beats per minute and the output per stroke • The stroke volume increases with vasodilatation and increased contraction of the heart muscle
If light is traveling from a higher optical density to a lower, the angle of refraction will be _________ than the angle of incidence
Greater
What is OP a measure of?
Tendency for solvent transfer into the solution across a semi-permeable membrane
Total electric potential due to two charges
V= K/r (q1+q2)
ose-dependent vomiting, seen in 5% of victims exposed to 1 Sv of radiation, increasing to 50% of victims exposed to 2 Sv of radiation, and 100% of victims exposed to 3 Sv of radiation, is best described as
a deterministic effect of radiation.
Sound waves carry:
energy that can be used to do work
Electrical field is defined as:
force per unit charge E(vector)= F(vector)/q --> F=qE
For a mean arterial pressure of 100 mmHg, pressure values are:
• 4 mmHg at the entrance of the RA • 25 mmHg as it leaves the RV • 8 mmHg as it enters LA • 120 mmHg as it leaves the LV
What is a doppler flow meter?
• A DFM is an ultrasonic scanner that makes use of the Doppler effect to locate constrictions in the vascular system
Isotonicity, hypertonicity, and hypotonicity
• A and B are isotonic if their OPs are balanced • A is hypertonic in reference to B if A has a higher OP than B (low [solute] outside cell, high [solute] inside cell) • A is hypotonic in reference to B if A has a lower OP than B (high [solute] outside, low [solute] inside]
Myocardial Perfusion Imaging
• Computerized images to assess the function of the heart. • Commonly called stress tests. • The perfused myocardium extracts radiopharmaceuticals from the blood and will appear "hot" on the images. • Non-perfused tissue cannot extract radiotracers and appear "cold" on the images.
DC motor
• Converts electrical energy into mechanical energy • Current in the coil in magnetic field leads to rotation of the coil • Based on magnetic force on a current • The magnetic field exerts forces on the current-carrying coil, which result in a torque that rotates the coil
TI-201 Thallous Chloride (Myocardial Perfusion Imaging)
• Preparation: - produced in a cyclotron, patient doses prepared from ready-touse (RTU) solution • Properties: - Biological behavior mimics potassium due to its monovalence and similar ionic radius - Half-life is 73.1 hours and decays down to Hg-201 - Imaging camera detects Hg-201 x-ray emissions at approximately 80 keV (low energy)
Indications for Skeletal Imaging
- Detect metastatic bone lesions prior to appearance on x-ray - Localize lesions prior to bone biopsy - Assess benefit of therapy on bone cancer - Diagnose osteomyelitis and Paget's disease - Diagnose Stress fractures
Thyroid Imaging uses + RPs
- Evaluate thyroid function - Detect thyroid disease or thyroid cancer - Calculate dosage of I-131 for treatment - Treatment of hyperthyroidism of thyroid cancer with our without metastasis - I-123 sodium iodide (diagnosis) - I-131 sodium iodide (diagnosis and/or treatment)
Resistance is dependent on the following factors:
- Gender= men have lower resistance - Wetness or dryness of the skin - Path that the electricity follows through the body - Voltage --> higher voltage causes body to lose resistance
The body's organs and their responsibilities for resistance
- Human body has resistance to current flow of 30-100,000 Ohms Skin= >99% Greatest resistance= in bone & fat Lowest resistance= in muscle and nerve
Application of Archimedes Principle
- Hydrometer is a glass tube of standard specific gravity that floats in a liquid whose specific gravity is to be determined. The higher the specific gravity the higher the hydrometer will float because of the higher buoyant force. - Urinometer is a specialized hydrometer used to measure the specific gravity of urine which ranges from 1.001 to 1.035.
Agents used in Brain Imaging
- Hydrophilic: Tc-99m Sodium pertechnetate, Tc-99m DTPA, Tc-99m Gluceptate, and TI-201 - Lipophilic: Tc-99m Exametazine (Ceretec or Tc-99m HMPAO), Tc-99m Bicisate (Tc-99m ECD or Neurolite) - F-18 FDG (fluorodeoxyglucose) - PET agent
Conventional Imaging Modalities // X-ray (Radiography) + CAT/CT scans
- uses ionizing electromagnetic radiation (x-rays) to penetrate tissue and expose photographic film or a digital recording plate
Gd-containing MR contrast agents
--> metal containing with magnetic properties • rely on unpaired electrons of Gd+3 to produce magnetic changes in nearby water molecules- induces localized changes in magnetic environment • positive contrast agent that brightens nearby tissues • hypertonic complexes that can produce vascular changes, nausea, and taste pervasions • nephrogenic systemic fibrosis is more likely to occur in patients with renal insufficiency (< 30 mL/min)
A nearsighted girl cannot see farther than 100m. What power contact lens must be used to correct her vision?
-1 diopters - Note: for nearsightedness, do= infinity & di= negative far point
A cup that is 6.0 cm tall is in front of a concave lens. The image of the cup is 2.5 cm tall and 7.5 cm from the lens. What is the focal length of the lens?
-13 cm
A wrench is placed at 30 cm in front of a diverging lens with a focal length of magnitude 10 cm. What is the magnification of the wrench?
0.25
During exercise, a person may give off 185 kcal of heat in 25 min by evaporation of water (at 20°C) from the skin. How much water has been lost? Heat of vaporization for the evaporation process is 2450 kJ/kg.
0.316 kg
A wave has a frequency of 58 Hz and a speed of 31 m/s. What is the wavelength of this wave?
0.53 m
At what separation will two charges, each of magnitude 6.0microC, exert a force of 0.70 N on each other?
0.68 m
A 3.0-kg cart moving to the right with a speed of 1.0 m/s has a head-on collision with a 5.0-kg cart that is initially moving to the left with a speed of 2.0 m/s. After the collision, the 3.0-kg cart is moving to the left with a speed of 1.0 m/s. What is the final velocity of the 5.0-kg cart?
0.8m/s to the left
The diffusion constant of oxygen through water is 8 x 10-10 m2s-1, on average, what distance will an oxygen molecule diffuse in 530 seconds?
0.92 mm
How many disintegrations per second (dps) are contained in 1 microcurie of radioactivity?
1 Bq= 1 dps= 2.7E-11 Ci 1 microcurie x 1 curie/ 10E6 microcurie x 1 dps/2.7E-11 Ci 3.7 x 104 dps
During a typical workday (eight hours), the average sound intensity arriving at Larry's ear is 1.8 × 10-5 W/m2. If the area of Larry's ear through which the sound passes is 2.1 × 10-3 m2, what is the total energy entering each of Larry's ears during the workday?
1.1 × 10-3 J
The membrane that surrounds a certain type of living cell has a surface area of 5.0E-9 m2 and a thickness of 1.0E-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.0. (a) The potential on the outer surface of the membrane is +60.0 mV greater than that on the inside surface. How much charge resides on the outer surface?
1.33 x 10-12C
A soft drink manufacturer claims that a new diet drink is "low Joule." The label indicates the available energy per serving is 6300 J. What is the equivalent of this energy in Calories (1 Calorie = 1000 cal)?
1.5 Cal
Helium gas is confined within a chamber that has a moveable piston. The mass of the piston is 8.7 kg; and its radius is 1.300 cm. If the system is in equilibrium, what is the pressure exerted on the piston by the gas?
1.606 × 105 Pa
A person is running at 3.00 m/s on a calm 5.00 oC day. He has a surface area of 1.70 m 2 . The outer surface of his clothing has a temperature of 9.00 oC. What is the rate of heat loss due to convection?
109W
A roller coaster starts from rest at the top of an 18-m hill as shown. The car travels to the bottom of the hill and continues up the next hill that is 10.0 m high.
13m/s
A beam of light traveling in air is incident on a vertical glass window. Take the index of refraction of glass to be 1.50. If the angle of incidence on the air to glass interface is 25.6 degrees, what is the angle of refraction?
16.7 degrees
Elaine went to her outside faucet to fill a 0.0189-m3 bucket with water to wash her car. Water exits with a speed of 0.61 m/s. The radius of the faucet is 0.0078 m. How long does it take to fill the bucket completely?
160 s
One type of keyboard is based on the idea of capacitance. Each key is mounted on one end of a plunger, and the other end is attached to a movable metal plate. The movable plate is separated form the fixed plate, the two plates forming a capacitor. When the key is pressed, the movable plate is pushed closer to the fixed plate, and the capacitance increases. Electronic circuitry enables the computer to detect the change in capacitance, thereby recognizing which key has been pressed. The separation of the plates is normally 5.00 x 10-3 m but decreases to 0.150 x 10-3 m when a key is pressed. The plate area is 9.50 x 10-5 m2 , and the capacitor is filled with a material whose dielectric constant is 3.50. determine the change in capacitance that is detected by the computer.
19.0 x 10-12 F
After eating 150 grams of yogurt, Bob decides to go for a run to burn off the extra energy. The yogurt provides 4.4 MJ/kg, and Bob is able to raise his metabolic rate to 220 Watts while running. How long does he have to run?
3.0E3 seconds = 50 minutes
A bird is flying directly toward a stationary bird-watcher and emits a frequency of 1250 Hz. The birdwatcher, however, hears a frequency of 1290 Hz. What is the speed of the bird, expressed as a percentage of the speed of sound?
3.1% v
In a classroom demonstration, a 79.2-kg physics professor lies on a "bed of nails.´The bed consists of a large number of evenly spaced, relatively sharp nails mounted in a board so that the points extend vertically outward from the board. While the professor is lying down, approximately 1950 nails make contact with his body. If the area of contact at the head of each nail is 1.26E6 m2, what is the average pressure at each contact?
3.16 × 105 Pa
The decibel level of a jackhammer is 125 dB relative to the threshold of hearing. Determine the sound intensity produced by the jackhammer.
3.2 W/m2
A bulk solution of sodium (I-131) iodid is available at 7 mCi / mL for patients unable to swallow a capsule. If the stock solution is calibrated @ 1200 on Monday, what volume of solution is necessary to provide a 20 mCi does to be administered to the patient @ 1200 on Thursday? see decay tables or use
3.7 mL
An in-ground swimming pool has the dimensions shown in the drawing. It is filled with water to a uniform depth of 3.00 m. The density of water = 1.00 × 103 kg/m3. What is the total force exerted on the bottom of the swimming pool?
3.92 × 107 N
What is the osmotic pressure of a 1.25 M solution of sucrose at 25 °C? Take the Vanµt Hoff factor to be equal to 1. Give your answer in the SI system of units.
30.6 x 105 Pa
A person is running at 3.00 m/s on a calm 5.00 oC day. He has a surface area of 1.70 m 2. The outer surface of his clothing has a temperature of 9.00 oC. What is the rate of heat loss due to radiation? Assume that the surface emissivity of the person's clothing is 1. The Stefan-Boltzmann constant is 5.670 x 10-8 W m-2 K-4.
33.9W
Bats emit a frequency of 35 Hz. If a bat is moving with a speed of 10.0 m/s toward an insect, determine frequency perceived by the insect if the insect is moving toward the bat at a speed of 7.00 m/s.
36.8 Hz
A farsighted senior citizen cannot see closer than 60.0cm. What is the focal length of lenses that would allow him to comfortably read a newspaper at a distance of 25 cm?
42.9 cm For farsightedness, di= - & do= +
A person steps out of the shower and dries off. The person's skin with an emissivity of 0.70 has a total area of 1.2 m2 and a temperature of 33 °C. What is the net rate at which energy is lost to the room through radiation by the naked person if the room temperature is 24 °C?
47 W
A hospital nuclear medicine department client orders a set of doses for a Tc-99m sestamibi myocardial perfusion study to be performed on Thursday, but the patient fails to show for the appointment. The stress dose for the study was calibrated for 45 mCi @ 1500 Thursday. How much activity remains in this unused dose when the courier returns this unused dose to the pharmacy at 0830 Friday morning?
5.96 mCi
What mass of water (at 4.0 °C) can be contained in a rectangular box whose dimensions are 10.0 cm by 5.00 cm by 1.00 cm? The density of water at 4.0 °C is 1.000 × 103 kg/m3.
50.0 g
The Kingda Ka is a giant among roller coasters. Located in Jackson Township, New Jersey, the ride includes a vertical drop of 127 m. Suppose that the coaster has a speed of 6.0 m/s at the top of the drop. Neglect friction and air resistance and find the speed of the riders at the bottom.
50.3m/s
A middle-aged man typically has poorer hearing than a middle-aged woman. In one case a woman can just begin to hear a musical tone, while a man can just begin to hear the tone only when its intensity level is increased by 7.8 dB relative to the just-audible intensity level for the woman. What is the ratio of the sound intensity just detected by the man to the sound intensity just detected by the woman?
6.0
When excessive heat is produced within the body, it must be transferred to the skin and dispersed if the temperature at the body interior is to be maintained at the normal value of 37 oC. One possible mechanism of heat transfer is conduction of heat through body fat. Suppose that the heat travels through 0.030 m of fat in reaching the skin, which has a total area of 1.70 m 2 and a temperature of 34 oC. The thermal conductivity of body fat is 0.20 J/(s m oC). Determine the amount of heat that reaches the skin in half an hour (or 1800 s).
61200 J
The regulatory limit for permissible radioactive contamination on a shipped package is 6600 dpm per 300 cm2. How many disintegrations occur in a 24 hour period for a container with a surface area of 300 cm2?
6600/1 min 24 hr=1440 min 6600/1min= xdpm/1440 min 9.50 x 106 disintegrations
Suppose the skin temperature of a naked person is 34 °C when the person is standing inside a room whose temperature is 25 °C. The skin area of the individual is 1.5 m2 . (a) Assuming the emissivity is 0.80, find the net loss of radiant power from the body. (b) Determine the number of food Calories of energy (1 food Calorie 5 4186 J) that are lost in one hour due to the net loss rate obtained in part (a). Metabolic conversion of food into energy replaces this loss.
68 Watts, 58 food Calories
Consider an optical fiber consisting of a core of index of refraction 1.49 and cladding of index of refraction 1.39. Light travelling in the core is incident on the core to cladding interface. What is the critical angle for the core to cladding interface? If the angle of incidence is 75.0 degrees, will some light escape into the cladding or will all the light be reflected back into the core?
68.9 degrees all the light will be reflected back into the core
If the kinetic energy of a charged particle is 3.32 x 10-14 J, how fast is the particle moving? (particle mass is 9.109 x 10-31 g)
8.54 x 109 m/s
A metallic sphere has a net charge of -1.43 C, what is the net number of charge particles on the surface of the charged sphere?
8.94 E18
A 220.0-g sample of steam at 100 °C loses 123200 calories of heat. What is the resulting temperature of the sample?
80 °C - Note: q=mL (.22kg* 22.6E5)=497200 - Convert calories to J then substract the heat lost due to phase change - Use Q=mcdeltaT
A 12,000-N car is raised using a hydraulic lift, which consists of a U-tube with arms of unequal areas, filled with oil and capped at both ends with tight-fitting pistons. The wider arm of the U-tube has a radius of 18.0 cm and the narrower arm has a radius of 5.00 cm. The car rests on the piston on the wider arm of the U-tube. The pistons are initially at the same level. What is the initial force that must be applied to the smaller piston in order to start lifting the car? For purposes of this problem, neglect the weight of the pistons.
926N Eq. F2= F1(A2/A1)
One end of a 56-cm-long copper rod with a diameter of 2.0 cm is kept at 460°C, and the other is immersed in water at 22°C. Calculate the heat conduction rate along the rod. Thermal conductivity constant for copper: k = 390 J/(s m °C)
93W
Two individuals are exposed to an equal quantity of large amounts of radiation due to a natural disaster. One individual develops a cancer (lymphoma) within 10 years of the event, while the other demonstrates no life-long effects. This scenario demonstrates
A possible stochastic effect of radiation exposure
Plasma proteins in the plasma consitutes:
Albumins (60%): Major contributors to osmotic pressure of plasma; transports lipids, steroid hormones Globulins (35%): Transports ions, hormones, lipids; immune functions Fibrogen (4%): Essential component of clotting system; can be converted into insoluble fibrin Regulatory proteins (<1%): Enzymes, proenzymes, hormones
The speed of the action potential is dependent on a. temperature b. whether the axon is myelinated c. diameter of the axon d. all the above
All of the above
What causes neurogenic shock?
Any factor that stimulates parasympathetic activity or inhibits the sympathetic activity of vascular smooth muscles can cause this type of shock: Ex.) - Spinal cord injury above T5 - Spinal anesthesia - Casmotor center depression (severe pain, drugs, hypoglycemia)
Definition of stress in terms of wire strain gauges
Applied force per unit area
29.1:
At a constant temperature, a perfect blackbody absorbs and reemits all the electromagnetic radiation that falls on it. Max Planck calculated the emitted radiation intensity per unit wavelength as a function of wavelength. In his theory, Planck assumed that a blackbody consists of atomic oscillators that can have only discrete, or quantized, energies. Planck's quantized energies are given by Equation 29.1, where h is Planck's constant (6.63 3 10234 J?s) and f is the vibration frequency of an oscillator. E=(n)hf; n=0,1,2,3
Which one of the following statements concerning a completely enclosed fluid is TRUE? A. Any change in the applied pressure of the fluid produces a change in pressure that depends on the direction. B: The pressure at all points within the fluid is independent of any pressure applied to it. C: Any change in applied pressure produces an equal change in pressure at all points within the fluid. D: An increase in pressure in one part of the fluid results in an equal decrease in pressure in another part. E: The pressure in the fluid is the same at all points within the fluid
C: Any change in applied pressure produces an equal change in pressure at all points within the fluid.
How does carbon monoxide harm the body?
CO binds to hemoglobin with 200 times the affinity of oxygen. CO also shifts the oxygen dissociation curve to the left, which decreases oxygen release to tissues -- Oxygen competitively displaces CO from hemoglobin so HBOT is a treatment method for CO poisoning
Match the type of radiation used with each imaging modality.
CT --> x-ray MRI --> radio PET --> gamma Sono --> sound waves Radiography --> x-ray SPECT --> gamma rays
Which of the following is a life-threatening condition caused by the excessive accumulation of fluids in the pericardial space?
Cardiac tamponade
What causes a balloon to stick to a wall?
Charge must be applied -- most of the time, it is via friction - Through friction, a balloon acquires negative charge and when it comes in contain with the wall, the wall becomes polarized - Separation of charges in the wall with the positive charges closer to the negatively-charged balloon
Linear Accelerator
Charged particles are accelerated in a linear path Higher energy particles can be produced Incident particles irradiate the target nuclei depositing energy with or without mass from the incident particles The newly formed excited nucleus disposes energy by emission of nucleons and gamma rays
Sweat rate varies between individuals and depends on many factors for the EXCEPTION of: A: Work rate B: Temperature and humidity of the surroundings C: Acclimatization state D: Caloric intake E: Baseline hydration level
D. Caloric intakes
HBOT is used to treat all of the following for the exception of A: burns B: carbon monoxide poisoning C: anemia (severe) D: excessive loss of fluids
D: excessive loss of fluids
DNA and radiation effects
DNA= most sensitive - single strand breaks - high probability of repair - double strand breaks - low probability of repair
Electric current
Definition: charge flow per unit time through a surface (for example the cross sectional area of a wire); I= q/t and is measured in Ampere (A) - Flows from + to -
Direction of motion/solvent transfer/flow for osmosis
Desire to flow toward equilibrium • More solvent --> less solvent • Less solute --> more solute • Lower OP --> higher OP • Hypotonic --> hypertonic
The term utilized to describe the proportional increase in damage or death to cells based on increasing amounts of radiation exposure (well above background) is known as the __________________ effect.
Deterministic effect
Uses of Doppler Ultrasound
Diagnose blood clots, peripheral artery disease, aneurysms, stenosis
Examples of High-Osmolar Contrast Media (HOMC)
Diatriazoate Meglumine & Iodipamide Maglumine
Diffusion is represented by ________ Law
Diffusion is represented by Fick's Law- gas transport across a membrane rate of diffusion= AD/d (P1-P2) • A is the surface area of the membrane • D is the diffusion constant • d is the thickness of the membrane • P1 and P 2 are partial pressures of the gas on each side of the membrane
Semiconductor devices
Diodes and transistors
Which one of the following statements best explains why semiconductors in transistors are doped?
Doping increases the conductive properties of the semiconductors.
____________________ is the apparent change in frequency of a wave as perceived by an observer moving relative to the wave's source.
Doppler effect is the apparent change in frequency of a wave as perceived by an observer moving relative to the wave's source.
More on Electron Orbitals
Electrons are bound to their shell by a binding energy Nuclear forces are directed inward that hold nucleons together-- in opposition to repulsive, electrostatic forces which are essentially the charges on all the protons in the nucleus are pulling outward When forced out > forces in, nucleus can transform likewise can occur if < K-shell has the highest binding energy, then L, M, etc, If an inner shell electron is removed, the vacancy is filled by an outer shell electron releasing the energy difference (e- from outer → inner) e.g. K shell filled by L shell = 59 keV x-ray (kiloelectron volts) An X-ray's energy may be transferred to an outer shell electron which is ejected as an Auger Electron that has energy equal to the X-ray's energy minus the electron's binding energy (inner → outer) Auger occurs when an x-ray bumps into an electron in a higher orbital. Upon striking, it can transfer E to the electron. If x-ray exceeds binding energy → electron becomes kinetic e.g. 59 keV x-ray ejects a 56.5 keV Auger electron from the M shell
Magnetic force on a current in a wire, equation:
Fm = I L B sin (theta) where I= current (A) L= length (m) B= magnitude of magnetic field (T) Theta= angle between the magnetic field and the current
The equation for the magnetic force on a moving charge (measured in N)
Fm= |q| v B sin(theta) q= charge v= speed B= magnitude of magnetic field (in Tesla) theta= angle between the magnetic field and the velocity
Spherical mirrors
Have centers and radii of curvature as well as focal points • Concave mirror - converging • Convex mirror - diverging
The pressure in a sphere filled with liquid and surrounded by an infinitely thin membrane is measured by the counter pressure which just flattens the membrane is a statement of
Imbert-Fick law
Bernoulli's equation (incompressible fluid)
In steady flow of a nonviscous, incompressible fluid, the pressure, the fluid speed, and the elevation at two points are related by: P1 + 1/2pv1^2+pgy1= P2+ 1/2pv2^2+ pgy2
Which one of the following is not an example of convection? Select one: a. An eagle soars on an updraft of wind. b. Inside of the car warms up on a warm sunny day. c. An electric heater warms a room. d. Smoke rises above a fire. e. Spaghetti is cooked in water
Inside of the car warms up on a warm sunny day.
What is the relationship between distance from a radioactive source and minimizing one's exposure?
Inverse square law
Intravenous iodinated contrast agents can be classified as high osmolar (HOMC), low osmolar (LOMC), or isotonic (ICM) contrast agents. The contrast agent that could be classified as a low osmolar (LOMC) is
Iopromide
A physics student adds two displacement vectors with magnitudes of 8.0 km and 6.0 km. Which one of the following statements is true concerning the magnitude of the resultant displacement? a. No conclusion can be reached without knowing the directions of the vectors. b. It could have any value between 2.0 km and 14.0 km depending on how the vectors are oriented. c. It must be 10.0 km. d. It could be equal to zero kilometers, depending on how the vectors are oriented. e. It must be 14.0 km.
It could have any value between 2.0 km and 14.0 km depending on how the vectors are oriented.
How is the direction of current flow defined in a conductor?
It is in the direction that positively-charged particles would move.
In a dental X-ray machine, electrons are accelerated between two parallel plates through electrical potential differences (voltages) of 2.5 x 10 4 V. When the electrons hit the positive plate, their kinetic energy is converted into high energy particles called X-ray photons. Assume that the electric field is uniform in the area between the two plates. If the kinetic energy of one of the electrons when it leaves the negative plate is zero, what is its kinetic energy and speed when it reaches the positive plate? Take the electron mass to be 9.109 x 10-31 kg
K = 4.0 x 10-15 J, speed = 9.371 x 10 7 m/s
Light enters glass from air. The angle of refraction will be
Less than angle of incidence LOD --> HOP I > R
In this device, an alternating current in the voice coil interacts with the magnetic field to generate an alternating force that pushes and pulls on the voice coil and the attached cone.
Loud speaker
What is the mass spectrometer based on?
Magnetic force of a moving charge
Vector Quantity
Magnitude & direction + and - as related to the 'x' axis Velocity, force, acceleration, and displacement are a few examples
Example of Mn-Containing MR Contrast Agents
Mangafodipir trisodium (Teslascan)
Which of the following is true of metabolism in its entirety in all organisms?
Metabolism consists of all the energy transformation reactions in an organism
A technologist phones the pharmacy requesting both a 10 mCi as well as a 30 mCi dose of Tc-99m Tetrofosmin, to be delivered as soon as possible to her facility for a patient that was added to the imaging department's schedule overnight. What imaging study would this radiopharmaceutical be used for at the technologist's facility?
Myocardial Perfusion Imaging
Bioelectricity references which topics?
Nerve conduction Medical diagnostic techniques (ECG/EKG, EEG, EMG) TENS Cardiac pacemaker Defibrillator
Raft is made of solid square pinewood. Determine whether raft floats and if so, how much of the raft is below the surface? Density of pine=550kg/m3
Note: if a raft can displace the weight in the fluid, it can float - Fb= 47000 N and Wraft= 26000, 26000<47000, raft floats - Wraft(26000)= (1000(density of H2O)x(4x4xh)x9.8) h=0.16m
Structure of the Atom
Nucleons Protons= Z (atomic number) Neutrons= N Mass number: A= Z + N For element X, Isotopes= same atomic number (amount of protons) but a different mass number (Z) or neutron number (N) Z= same, different A & N An isotope with an ODD number of protons, neutrons, or both is magnetic Nucleus contains protons and neutrons, electrons are located in orbitals surrounding the nucleus Orbital closest to nucleus to K, next L, etc.
Electron Capture
Occurs when a nucleus is proton rich A proton combines with a shell electron to form a neutron and a neutrino EC usually occurs when the energy emission is < 1.022 MeV No particulate decay occurs but excited daughter nuclei may emit electromagnetic radiation (gamma ray or x-ray) Mass stays the same
Positron (B+)
Occurs when a nucleus is proton rich Decrease proton # by 1 Positrons come about when a proton decays into a neutron, positron and a neutrino Emission of a positron leads to combination with an electron and annihilation radiations Two 511 keV photons emitted 180o from each other
Cardiogenic shock
Occurs when your heart cannot pump enough blood and oxygen to the brain, kidneys, and other vital organs
Which one of the following statements concerning spherical mirrors is correct?
Only a concave mirror can produce an enlarged image, provided the object distance is less than the radius of curvature
Match particle with its charge:
P 1+ N 0 E 1-
Pascal's Principle
P2=P1+ρg(0m) ρgh=0 and can cancel out; knowing that P=F/A, we can set P2 and P1 equal to one another and solve for one if desired F2/A2=F1/A1, F2=F1(A2/A1)
A nearsighted person has a far point located only 400 cm from the eye. Assuming that contacts are to be worn, determine the lens power of the corrective lens that would enable the person to see distant objects.
P= -0.25 D
What enables color vision?
People usually have three types of cones cells in the eye. Each type senses either red, green or blue light. You see different colors when your cone cells sense different amounts of these three basic colors
Compton scatter
Photon changes direction upon interacting with an electron - The amount of energy transferred increases with an increasing angle of interaction (180o = "backscatter") -- Generally for photons up to 1.5 MeV, matter= low Z
Plasma consists of
Plasma proteins (7%) Other solutes (1%) Water (92%)
Pascal's principle
Pressure applied to an enclosed incompressible fluid is transmitted undiminished to every point in the fluid and to the container walls.
Water radiolysis
Produces electrons, hydroxyl radicals and hydrogen free radicals H2O --> H2O+ + e- H2O+ --> H+ OH(radical) e+ + H2O --> H2O- --> H(radical) + OH- (if any biomolecule=RH, then: RH + OH(radical) or H(radical)--> R(radical) + H2O
The acceleration of charged particles by a synchrotron creates high energy particles that are medically useful for
Proton beam therapy
A viscous fluid is flowing through two horizontal pipes. The pressure difference P2 - P1 between the ends of each pipe is the same. The pipes have the same radius, although one is twice as long as the other. How does the volume flow rate QB in the longer pipe compare with the rate QA in the shorter pipe?
QB is one-half as large as QA.
The conventional unit of radiation used to describe a patient¶s exposure to a radiation dose of a radiopharmaceutical such as Tc-99m sestamibi is known as a
Rad
What does the RAD stand for and what does it measure?
Radiation Absorbed Dose (rad): defined as the energy deposited per unit mass of any material by any type of radiation - measures of the amount of energy absorbed in a defined quantity of matter - estimate organ dose from an administered pharmaceutical or the therapeutic application of radiation by any means
An artificial pacemaker is a medical device implanted in the heart that uses tiny electrical impulses to regulate the beating of the heart; one of the electrodes of the pacemaker is placed in the
Right ventricle, Right atrium
The use of a leaded glass barrier between an occupational worker and a radioactive source is part of which ALARA principle?
Shielding
The ___________________ is defined by the power that passes perpendicularly through a surface divided by the area of that surface
Sound intensity
Sound intensity definition
Sound waves carry energy that can be used to do work The amount of energy transported per second is called the power of the wave. The sound intensity is defined as the power that passes perpendicularly through a surface divided by the area of that surface.
Fluids are lost through the following bodily functions for the exception of: a. Blood loss b. Static shock c. Respiration d. Vomiting
Static shock
12x10-5W of sound power passed through the surfaces labeled 1 and 2. The areas of these surfaces are 4.0m2 and 12m2. Determine the sound intensity at each surface
Surface (1): I= 3.0E-5 W/m2 Surface (2): I= 1.0E-5 W/m2
A solid block of mass m is suspended in a liquid by a thread. The density of the block is greater than that of the liquid. Initially, the fluid level is such that the block is at a depth d and the tension in the thread is T. Then, the fluid level is decreased such that the depth is 0.5d. What is the tension in the thread when the block is at the new depth?
T
Impedance (resistance) plethysmography
Technique to diagnose blood clotting (deep vein thrombosis) manipulate R=pL/A to get R=px(L^2)/V • The cuff is inflated until it cuts the venous flow but not the arterial flow, so the Vcalf increases and R decreases • The cuff is then deflated and the calf volume and resistance return to normal values; slow return indicates clotting
OP varies w _________________ and can be represented by the equation:
Temperature pi= iMRT where i= Van't Hoff factor M= molarity (mol/L) R= 0.08206 Latm/molK T= absolute temperature in K
What is a method to test color vision?
The Ishihara test for color blindness
As a rock sinks deeper and deeper into water of constant density, what happens to the buoyant force on it if it started below the surface of the water?
The buoyant force keeps increasing steadily. Explanation: The volume of rock and its density remains constant. The density of water also remains constant. The acceleration due to gravity remains constant. And hence the buoyant force remains constant
When correcting nearsightedness,
The corrective lens should take a object at the far point of the normal eye and place its image at the far point fir the nearsighted eye
Radiotherapy for the treatment of cancer utilizes focused beams of energetic photons to destroy cancerous tissue. The amount of radiation to be administered to the patient is prescribed in Grays (GY). This SI unit of measure describes
The energy deposited per gram of the affected tissue.
Two objects are made of the same material, but they have different masses and temperatures. If the objects are brought into thermal contact, which one will have the greater temperature change? Select one: a. The one with the lesser mass. b. The one with the higher specific heat. c. The one with the lower initial temperature. d. The one with the higher initial temperature. e. The one with the greater mass.
The one with the lesser mass
A rock is suspended from a string and moves downward at constant acceleration. Which statement is TRUE concerning the tension in the string if air resistance is ignored?
The tension is less than the weight of the rock.
Half-Life
The time required to reduce the initial activity to one half of the original amount T1/2= 0.693/λ; λ= decay constant Half-life may be able to be determined directly from a semi-log plot of activity versus time or calculated from the slope of the line (slope = λ)
Measuring radiation -- Roentgen (R)
The units of measurement used in determining the radiation field one is exposed to in their immediate environment - Defined as the quantity of x- or gamma-rays that produces one electrostatic unit of charge (positive or negative) in 1 cm3 of air at 0o C and 760 mm Hg (STP). It is equal to 2.58 x 10‐4 C/kg of air. (C = coulomb)
Which of the following statements concerning resistors that are wired in parallel is true? a. The equivalent resistance for the resistors in the circuit is the average of the individual resistances. b. The equivalent resistance for the resistors in the circuit is the sum of the individual resistances. c. The voltage across each resistor is necessarily the same. d. The current through each resistor is necessarily the same. e. The equivalent resistance for the resistors in the circuit is the product of the individual resistances.
The voltage across each resistor is necessarily the same.
A boy is playing in the bathtub with a toy boat floating on the surface of the water. His favorite rock is the cargo on the boat. If the boy takes the rock from the boat and drops it into the water, how will the water level of the bathtub change, if at all?
The water level will fall.
Which of the following statements is true concerning catabolic pathways?
They supply energy, primarily in the form of ATP, for the cell's work
The critical angle for a beam of light passing from water into air is 48.8°. This means that all light rays with an angle of incidence in the water that is greater than 48.8° will be
Totally reflected
Applications of Doppler Ultrasound
Transthoracic echocardiogram (TTE): transducer is placed on chest or abdomen to obtain images Transesophogeal echocardiogram (TEE): transducer is passed down esophogus to obtain images (blockages can be a problem)
Parallel plate capacitors
Two parallel metal plates Capacitance of a parallel plate capacitor is expressed in terms of geometry C (no dielectric)= eA/d where e = 8.854e-12 F/m C (with dielectric)= KC= keA/d
Which of the following actions would significantly reduce the risk of fire when using an electric heater connected to a wall outlet using an extension cord?
Use an extension cord with smaller-gauge wires
Magnetic Resonance Imaging: MRI
Used for: soft tissue + join problems • Uses a strong magnetic field and pulses of radio waves to "excite" nuclei to absorb and then emit the energy from the radio waves • Can provide information that cannot be obtained from x-rays, CT or ultrasound • Very useful for soft tissues and joint problems (used extensively for sports-related injuries) • Contrast agents may be useful for blood flow and localization of tumors or inflammation • Watch pacemaker, metal implants, surgical staples (in less than 6 weeks), braces ("tuning problems") etc.
For tests using a ballistocardiograph, a patient lies on a horizontal platform that is supported on jets of air. Because of the air jets, the friction impeding the horizontal motion of the platform is negligible. Each time the heart beats, blood is pushed out of the heart in a direction that is nearly parallel to the platform. Since momentum must be conserved, the body and the platform recoil, and this recoil can be detected to provide information about the heart. For each beat, suppose that 0.050 kg of blood is pushed out of the heart with a velocity of +0.25 m/s and that the mass of the patient and platform is 85 kg. Assuming that the patient does not slip with respect to the platform, and that the patient and platform start from rest, determine the recoil velocity
V= -1.47e-4 m/s - Using p=mv equation, m1v1=m2v2, pnet=0
A quantity represented using an arrow and having both magnitude and direction and is called a __________________ quantity.
Vector
The 'Gold Standard' treatment for ICP is
Ventriculostomy EVD
The SI unit of power is the watt. Which of the following units are equivalent to the watt?
V∙A
The most abundant target for direct ionization by photons generated from the nuclear decay transformation of Tc-99m is Select one: a. Proteins b. Lipids c. water d. DNA
Water
30.7
X-rays are electromagnetic waves emitted when high-energy electrons strike a metal target contained within an evacuated glass tube. The emitted X-ray spectrum of wavelengths consists of sharp "peaks" or "lines," called characteristic X-rays, superimposed on a broad continuous range of wavelengths called Bremsstrahlung. The Ka characteristic X-ray is emitted when an electron in the n 5 2 level (L shell) drops into a vacancy in the n 5 1 level (K shell). Similarly, the Kb characteristic X-ray is emitted when an electron in the n 5 3 level (M shell) drops into a vacancy in the n 5 1 level (K shell). The minimum wavelength, or cutoff wavelength l0, of the Bremsstrahlung is determined by the kinetic energy of the electrons striking the target in the X-ray tube, according to Equation 30.17, where h is Planck's constant, c is the speed of light in a vacuum, e is the magnitude of the charge on an electron, and V is the potential difference applied across the X-ray tube.
Suppose you are sitting next to a fire burning in a fireplace. One end of a metal poker has been left in the fire. Which one of the following statements concerning this situation is true?
You can feel the heat of the fire primarily because of radiation.
Sometimes when you look into a curved mirror you see a magnified image (a great big you) andsometimes you see a diminished image (a little you). If you look at the bottom (convex) side of ashiny spoon, what will you see?
You will see a little you, right side up
Gallium-68 (Ga 68, Z = 31) decays with a half-life of 68 minutes to stable daughter nucleus, ________. The following transformations occur during Ga-68 decay. 89% through positron emission with a mean energy of 836 keV followed by emission of two 511 keV annihilation photons (178%), 10% through orbital electron capture (with associated X-ray or Auger emissions), and 3% through 13 gamma transitions from 5 excited levels of the daughter nucleus. The most probable prompt gamma emission is a 1088 keV gamma with a 3.2% per decay probability. Based on this information, what is the daughter nucleus?
Zn-68
Take x and y axis in the plane of the page with +x to the right and +y up. Take z perpendicular to the plane of the page with +z coming out of the page (toward you). An electron initially moving vertically downward in the plane of the page (in the -y direction) enters a region of magnetic field directed out of the page (+z direction). The electron's speed as it enters the field is 7.50 x 103 m/s and the magnitude of the magnetic field is 1.45 T. Draw a picture including the axis +x, +y, +z, the electron's initial velocity and the magnetic field (all labeled). a) What is the magnetic force exerted by the magnetic field on the electron? Draw and label the magnetic force on the picture. If you use any right hand rules, describe them briefly. b) Derive the radius of the circular path that the electron follows in magnetic field. Draw the circular path that the electron follows in magnetic field.
a) magnitude: 17.4 x 10-16 N direction: +x (to the right) b) 2.944 x 10-8 m = 2.94 x 10-8 m
Which one of the following equations is not a valid expression for electric power P? Note: I is the current in a circuit as a result of a voltage V and R is the electrical resistance of the circuit. a. P = I2R/V b. P = I2R c. P = V2/R d. P = IV
a. P = I2R/V
All of the following are symptoms of Cardiac Tamponade for the exception of: a. A weak pulse b. Bluish skin that is cool to the touch c. Feeling energetic d. A rapid heart rate.
c. Feeling energetic
Pressure in the circulatory system can be demonstrated by this equation
chance in p=FR; where p=pressure, F= flow rate, and R= resistance to flow p(art) > p(cap) r(art) < r(cap) F(art) >> F(cap)
Uses for CT/CAT Scans
chest, abdomen, pelvis, head
Which of the following is false concerning the external ventricular drainage system? a. The EVD can be used to drain CSF b. The EVD can be used to give medications c. The EVD can be calibrated at any time d. The EVD can be used to monitor patient respiration
d. The EVD can be used to monitor patient respiration
Tree-like structures that receive signals from other neurons and from special sensory cells, convert them to electrical signals and transmit them to the cell body are called ______.
dendrites
If you were to cut a small permanent bar magnet in half,
each piece would in itself be a smaller bar magnet with both north and south poles
The acceleration of electrons with a LINAC for collision with a tungsten target creates high energy photons that are medically useful for
external beam radiotherapy.
This compound would be used when collecting MRI images
gadopentetate dimeglumine
The number one cause of blindness through disease is
glaucoma
Light enters air from water. The angle of refraction will be
greater than the angle of incidence.
The index of refraction of a type of glass is 1.50, and the index of refraction of water is 1.33. If light enters water from this glass, the angle of refraction will be
greater than the angle of incidence.
The skateboarder in the drawing starts down the left side of the ramp with an initial speed of 5.4 m/s. Neglect nonconservative forces, such as friction and air resistance, and find the height h of the highest point reached by the skateboarder on the right side of the ramp.
h=1.5m
A fiber optic line is composed of a core with an index of refraction of 1.51 and cladding with an index of 1.40. Which one of the following relations best describes angles of incidence, i, that will result in total internal reflection within the fiber optic line?
i > 68°
In the fabrication of an electrical extension cord, the manufacturer wants to reduce the overall resistance of the wires in the extension cord. Which of the following changes would result in the lowest resistance?
increase the diameter of the wires
Energy due to the motion of an object is _____________ energy and can be expressed in mathematical form as ______________
kinetic, K=(1/2)mv2
Mo-99/Tc-99m Generator
long-lived parent nuclide (Mo-99, t1/2 = 66 hours) is produced by nuclear reactor methods described above Short-lived daughter (Tc-99m , t1/2 = 6 hours) is produced by decay of parent nuclide Chemical separation of the isotopes provides daughter nuclide 99Mo remains bound to column as molybdate ions (Mo7O24-6) 99mTc elutes from column as sodium pertechnetate (NaTcO4)
Systolic pressure=
maximum pressure in the artery, when the LV contracts
A nerve cell is also called
neuron
Pair Production
photons > 1.022 MeV create electron/positron pairs where excess energy is shared by the particles - generally for photons > 1.022 MeV up to 10 MeV, matter = any Z
Why is Sn+2 important for the introduction of Tc-99m into radiopharmaceuticals? Sn+2 is required to
reduce NaTcO4- to the proper oxidation state for covalent bonding and/or chelation to the ligand(s)
Complete the following statement: In the laser-based medical procedure known as photorefractive keratectomy (PRK), nearsightedness and farsightedness can be treated using the laser to
remove small amounts of tissue from the cornea and change its curvature.
Which one of the following materials would be in an n-type semiconductor? Select one: a. germanium doped with boron b. germanium doped with gallium c. silicon doped with gallium d. silicon doped with phosphorus e. silicon doped with boron
silicon doped with phosphorus
Blood pressure is measured as gauge pressure; two values of blood pressure are measured: 1-the maximum pressure when the heart is pumping and 2- the pressure when the heart is in the resting portion of the cycle. The gauge pressure measured when the ventricles are contracting is called __________________.
systolic pressure
Charging an RC circuit
the capacitor is considered fully charged after several time constraints (say 5) have passed; the voltage across a capacitor can be expressed after 5 time constraints of battery voltage --> larger time constraint of RC circuit, larger charging time • mathematically represented by: time constraint= RC
Complete the following statement: The first law of thermodynamics states that
the change in the internal energy of a system is given by Q-W
The pressure at a point in a fluid in static equilibrium depends on which of the following?
the depth of the given point
Radiopharmaceuticals (RPs) are also know as radiotracers because
the extremely low quantity of an administered RP is unable to produce a pharmacological or biological effect.
Complete the following statement: The term heat most accurately describes
the flow of energy due to a temperature difference.
Wire strain gauges are based on the fact that:
the resistance of a wire is proportional to its length. If you apply stress to a wire, strain will result and the resistance of the wire will change
Radiopharmaceutical is also known as:
tracer, radiotracer, radiodiagnostic agent • >95% used for diagnostic - minimal pharmacological effect on patient • <5% therapeutic use via tissue damage
Two hoses are connected to the same outlet using a Y-connector, as the drawing shows. The hoses A and B have the same length, but hose B has the larger radius. Each is open to the atmosphere at the end where the water exits. Water flows through both hoses as a viscous fluid, and Poiseuille's law [Q = πR4(P2 - P1)/(8nL)] applies to each. In this law, P2 is the pressure upstream, P1 is the pressure downstream, and Q is the volume flow rate. The ratio of the radius of hose B to the radius of hose A is RB/RA = 1.50. Find the ratio of the speed of the water in hose B to the speed in hose A.
vB/vA= R2B/R2A
A 50.0-kg person has a core temperature of 37.0 °C. The onset of mild hypothermia occurs at a core body temperature of about 35 °C. The specific heat of the human tissue is 3500 J/kg K. He is losing heat at a rate of 300 W to his surroundings, and he will be exposed to this environment for four hours. Will he get hypothermia if he is walking? What is his core body temperature after four hours? (scroll as needed) Activities which increase core temperature: sitting still metabolic rate = 100 W walking metabolic rate = 250 W running metabolic rate = 600 W
walking: hypothermic 32.9 °C
What does a doppler flow meter consist of?
• A DFM consists of 2 transducers, the source transducer that converts an electrical signal into ultrasound, and the receiving transducer that converts ultrasound into an electron signal
Summary of doppler flow meter
• A DFM os am ultrasonic scanner that makes use of the Doppler effect to locate constrictions in the vascular system • Using Doppler effect, speed of blood flow is measured; increased blood speed indicates a constricted area • A DFM consists of 2 transducers, the source transducer that converts an electrical signal into ultrasound, and the receiving transducer that converts ultrasound to an electrical signal • The ultrasound from the source transducer produces Doppler shifted echoes off the moving red blood cells in the arteries • The Doppler shift depends on the speed of the blood flow
How does a capacitor function?
• A capacitor can store charge and energy • A capacitor releases its energy quickly • Charged by connecting to a battery/power supply
X-ray imaging: the process
• A machine generates the x-ray photons that are directed through the body • A computer or special film is used to record the images that are created. • dense materials (bones) appear white, soft tissue appears gray, and air appears black
Evaporative cooling from the human body
• A mechanism that the body uses to loose excess heat and prevent its temperature from rising to dangerous levels • It involves removal of heat from the body by perspiration • Takes advantage of the large latent heat of vaporization of water • Sweat glands produce sweat (mostly water with some salts) on the skin surface • As the sweat (water) evaporates, it removes heat from the body • The less the humidity, the more sweat evaporates • Typically about 600 g/day of moisture lost through the skin
n-type Semiconductor
• A semiconductor doped with an impurity that contributes mobile electrons • Example - silicon (4 outer-shell electrons)
p-type Semiconductor
• A semiconductor doped with an impurity that contributes to mobile positive holes • Example - silicon (4 outer-shell electrons) doped with boron (3 outer-shell electrons)
Metabolism
• A series of chemical reactions that convert food into the energy the body needs • All E transformation reactions in an organism • Our metabolism influences how easily our bodies gain or lose weight
How is the resting membrane potential maintained?
• A sodium-potassium pump pumps Na ions out of the cell and K ions into the cell, which creates a higher concentration of Na ions on the outside and a higher concentration of K ions on the inside • The cell membrane is much more permeable to K than to Na, therefore more positive charges leak out than come in. As a result, the outside of the membrane has more positive charges than the inside, therefore the inside of the membrane is negative relative to the outside of the membrane
Soft contact lens, indirect measurement of IOP
• A soft contact lens equipped with a sensing mechanism to measure changes in corneal biomechanics related to IOP • Continuous monitoring of IOP • Leonardi et al: a microstrain gauge embedded in a soft contact lens which allows measurement of changes in corneal curvature • Relies upon the assumed correlation between the corneal curvature and IOP, which is not universally accepted: the corneal radius of curvature changes by 3 microns for every 1 mmHg change in IOP • Not widely accepted in clinical practice
Transcutaneous Electrical Nerve Stimulation (TENS)
• AC current is passed between 2 electrodes attached to the body and inhibits the transmission of pain-related nerve impulses • Uses weak AC electricity with frequency in the range between 40 and 150 Hz • TENS works by affecting the "gates" in a nerve cell that control the passage of sodium ions into and out of the cell
Non-contact tonometry (NCT)
• Also called "puff-of-air" test • Routine glaucoma test that measures IOP • It is completely painless and the tonometer does not touch your eye • Based on your eye's resistance to the puff of air, the machine calculates your IOP • High IOP indicates glaucoma or risk of glaucoma
MRI
• An MRI machine is essentially a large solenoid; the patient goes inside the solenoid • The solenoid is typically made of superconducting wire • Large magnetic fields of about 1.5 T are used • In the presence of the magnetic field, the hydrogen nuclei of the human body behave as tiny radio transmitters and emit radio waves • A magnetic resonance image is obtained
Action potential for a human nerve cell
• An action potential is a very rapid change in membrane potential that takes place in response to stimuli. The change in membrane potential from resting potential of -70 mV to some positive value of +30 mV occurs over just a few milliseconds • The duration of a typical nerve axon action potential is 1-4 milliseconds • Unlike ordinary electric current, which involves the flow of electrons, the action potential involves the movement of sodium and potassium ions across the cell membrane
Cardiac pacemaker
• An artificial pacemaker is a medical device implanted in the heart that uses tiny electrical impulses to regulate the beating of the heart (it keeps the heart from beating to slow) • The electrical impulses are delivered through electrodes that contact the heart muscle (electrodes are placed in right atrium and right ventricle) • It replaces the activity of the natural pacemaker, the SA node, when the SA node fails to function properly • Fixed-rate pacemakers - pace at 60-70beats/min
Electromagnet
• An electromagnet is a magnet whose magnetic field is generated by electric current in a wire • Applications: electric motors, electric generators, loudspeakers, door bells, hard disks, MRI machines, picking up and moving heavy iron objects • Examples: iron-core electromagnet (soft-ironcore solenoid), air-core electromagnet (air-core solenoid), superconducting electromagnet (the wire is made of a superconducting material) • The magnetic field of an electromagnet can be turned on and off by turning the current on and off. • The magnetic field of an electromagnet can be reversed by reversing the direction of the current
More info. on CT/X-Ray Contrast Agents
• Any agent or compound administered to a patient to improve the visualization of an organ or tissue • Contrast agents can be classified as negative or positive. • An agent that increases the radiographic opacity of an organ or tissue is a positive contrast agent. • The majority of contrast agents used in diagnostic radiology are positive contrast agents. • Air and other gases are negative contrast agents because they render a structure, such as the gut, more translucent.
Ground fault interrupter (GFI)
• Application of Faraday's law • A safety device that protects against electrical shock from an appliance • Consists of a circuit breaker and a sensing coil • The circuit breaker stops the current when there is induced emf in the coil • When the appliance operates normally, the currents in the 2 wires are equal in magnitude and opposite in direction, so the net magnetic field is zero; therefore the change in flux through the coil is zero and there is no induced emf; the circuit breaker does not get triggered • When the appliance malfunctions (say a wire contacts the metal case) and if a person touches the case, some of the current begins to pass through the person's body; the currents in the 2 wires are no longer equal in magnitude, so the net magnetic field is no longer zero and changes with time, since the current is AC; therefore the magnetic flux through the coil changes with time, which results in an induced emf; the circuit breaker gets triggered and stops the current before it reaches dangerous levels • GFI work fast to turn off the current (in less than a millisecond)
Magnetic Flashlight
• Based on Faraday's law • Main components - coil, magnet, capacitor, LED • As you shake the flashlight, the magnet moves in and out of the coil, which results in a change in magnetic flux through the coil • According to Faraday's law, the change in magnetic flux through the coil results in an induced current, which charges the capacitor • When the switch is closed (flashlight ON), the capacitor discharges through the LED
Transformers
• Based on Faraday's law/electromagnetic induction • Main components - primary coil, secondary coil, iron core • AC current in the primary coil results in a variable magnetic field that induces a variable magnetic field in the iron; variable magnetic field in the secondary coil means there is a change in magnetic flux through the secondary coil, which leads to an induced voltage in the secondary coil • Step-up and step-down transformers
Cell Phones and Brain Tumors
• Cell phones are low power radio devices that emit and receive microwave radiation • Microwave radiation is nonionizing radiation (at the low energy end of the spectrum) • Nonionizing radiation can warm cells, boil water and stimulate chemical reactions, but cannot strip electrons away from atoms or directly damage DNA • Because cell phone radiation is nonionizing radiation, it is unlikely for cell phones to cause cancer
External ventricular drainage, EVD: gold standard ***
• Consists of a fluid coupled system using ventricular catheter and an external transducer • Excellent accuracy • The external transducer can be calibrated against a reference point at any time • Cost effective • Can also be used for CSF drainage and medicine administration • For narrow or displaced ventricles, EVD placement may be difficult
Implanted microchip transducers (Codman)
• Consists of a miniature solid state pressure sensor whose tip contains a silicon microchip • The gauges are connected by wires form a Wheatstone bridge circuit. Applied pressure results in a small deflection in the silicon diaphragm, which induces a strain • The resulting resistance change is reflected in the form of differential voltage which is then converted to pressure. • Placement: usually parenchymal • Excellent accuracy • Not dependent on a fluid column • Main limitation: cannot be calibrated in situ
Superparamagnetic iron oxide (SPIO)
• Contain a crystalline core composed of iron oxide complexes • The core may be coated with dextran, siloxanes, or another large polysaccharide • The particles vary in size from 1 and 10 μm, and their biological characteristics can be altered by changing their coating. • Intravenous administration allows large particles accumulate in the liver and spleen, while smaller particles remain in the circulation longer and tend to aggregate in lymph nodes. • The particles are not absorbed upon oral administration and allow for visualization of the entire GI tract
AC generator
• Converts mechanical energy into electrical energy • Based on Faraday's law • A simple AC generator consists of a coil rotated in magnetic field by some mechanical means • The rotation of the coil in magnetic field results in a change in magnetic flux through the coil • The change in magnetic flux through the coil results in an induced emf and an induced current
Photovoltaic effect
• Creation of voltage or current in a material as a result of exposure of the material to light • When light is incident on the material, electrons in the valence band absorb energy and are transferred to the conduction band and become free • Electrons are attracted to the positive electrode resulting in voltage buildup between the electrodes • Photovoltaic effect is related to the photoelectric effect
What does hyperbaric oxygen treatment (HBOT) treat?
• Decompression sickness (can occur after scuba diving) • Arterial air embolism (bubbles of air in the blood vessels) • CO poisoning • A wound that won't heal • Thermal burns • Severe anemia • Compromised skin grafts and flaps • Radiation injury • Sports injury
Drug-induced ototoxicity
• Drug-induced ototoxicity usually refers to hearing loss or tinnitus due to ototoxic drugs • Ototoxic drug - any drug with the potential to cause toxic reactions to structures of the inner ear, including the cochlea, vestibule, semicircular canals and otoliths. • Examples of ototoxic drugs: aminoglycosides and other antibiotics, platinum-based antineoplastic agents, salicylates, quinine, and loop diuretics
How does the body regulate volume flow rate?
• During exercise, the body has greater demand for blood • The blood supply is increased by increasing the volume flow rate of the blood • The circulatory system uses blood pressure and radii for short-term control of volume flow rate
Pulmonary circulation
• During the expansion of the RV, blood flows from RA into RV • During the contraction of the RV, blood flows out of RV through the pulmonary artery to the lungs and back to the heart where it enters through the LA
ECG (EKG) - Electrocardiogram
• ECG is a test that measures the electrical activity of the heart; with each heart beat, an electrical impulse (or "wave") travels through the heart, which causes the muscle to squeeze and pump blood from the heart • The variation of the electric potential difference between any two points on the body with heart muscle activity provides the basis for ECG • In a conventional 12-lead ECG, ten electrodes are placed on the patient's chest and limbs. The overall magnitude of the heart's electrical potential is then measured from 12 different angles ("leads") and is recorded over a period of time (usually a few minutes) • ECG - the plot of the recorded electric potential differences as a function of time • A standard ECG can record an abnormal heart rhythm only if it happens during the test • An ECG can show evidence of a previous heart attack or one that is in progress. • Voltages measured are on the order of a millivolt
Electric dipole - in an external electric field
• Electric dipole - a pair of charges of equal magnitude but opposite sign separated by a distance d • An electric dipole placed in an external uniform electric field will experience a torque that will align the dipole with the field
Electron shielding
• Electric field is zero inside a conductor in electrostatic equilibrium: electric field is zero inside a cavity within a conductor as well, principle behind electric shielding • Stray electric fields from electrical appliances can interfere with the operation of sensitive electronic circuits • Electronic circuits are often external fields by placing them within metal boxes
Lithotripsy
• Extracorporeal Shock Wave Lithotripsy (ESWL) is the medical procedure by which acoustic shock waves, generated outside the body, are focused onto a kidney stone in the kidney or ureter causing the stone to fragment. • EWSL - a successful technique - approximately 70% of patients with stones can be treated with EAWL alone • There is no agreement in the community as to the mechanism by which the stone fails • The two major hypotheses for the mechanism by which the stone fails (spallation, cavitation)
Facial Thermography
• Facial recognition is an automated method to record the special geometry of distinguishing features of the face. • Facial thermography is an alternative to facial recognition • Facial thermography is facial identification that employs the use of an infrared camera to capture the emission of heat patterns that are generated by the vascular system of the face. Heat that passes through facial tissue of a human produces a unique and repeatable pattern (aura). The captured aura is converted into data and then compared to stored auras of authorized individuals, at which point possible matches are generated along with probability percentages. The facial print does not change over time. • Facial thermography is more accurate than facial geometry identification technologies.
Quantitative method for fluid replacement
• Fluid intake of 1.0 to 1.5 mL for each kilocalorie that is expended is considered optimal • Example: an athlete who expends 5000 calories a day needs 5000 to 7500 mL (5-7.5 L) of fluid intake a day to maintain fluid balance and prevent dehydration
PET Imaging - F-18 FDG
• Frequently used to detect cancer, cardiovascular function and brain function • Rapid decay requires production near imaging facility - F-18 physical t1/2 = 110 minutes • Benefits: Study of body function including alterations in biochemical function • Precautions: Blood glucose variations can alter test results
Heart
• Function: receives blood from the venous system and raises its pressure to push it out into the arteries by ventricular contraction • Two synchronous force pumps (LV & RV) that achieve xs pressure by contraction
Microbubbles
• Gases efficiently reflect sound waves. • Octafluoropropane (perflutren) is encapsulated as a protein or lipid microsphere that is generated when a solution of protein or lipids is agitated with the gas immediately prior to use • The milky-white suspension of microspheres must be injected shortly after activation for maximal contrast enhancement. • Protein shells consist primarily of human albumin associated with small amounts of N-acetyltryptophan and caprylic acid. • Lipid shells consist of a polyethylene glycol (PEG) - phospholipid mixture • Perflutren microshperes (Definity) are indicated in suboptimal echocardiograms to improve the delineation of left ventricular borders.
Chitnis devise for IOP monitoring
• Implantable device for continuous wireless monitoring of intraocular pressure (IOP) • Based on Pascal's principle and LC circuits • Minimally invasive as most components sit externally on the sclera • Designed to make insertion/retrieval surgery simple • Measures the true IOP through direct hydraulic contact with the intraocular space (Pascal's principle) • 1-mmHG resolution • Successful one month in vivo implants in rabbits
Ultrasound Imaging is used for:
• In obstetrics to examine the developing fetus • To detect tumors in the liver, kidney, brain and pancreas • To detect gallbladder stones
What does a CT scan show of tension pneumothorax?
• Increased pleural space (black) at the expense of the lung on the left side • Shift of the mediastinum to contralateral side (left side) • The mediastinum shift results in the compression of the right lung
Which diagnostic imaging procedures utilize RPs?
• Infection / Inflammation Imaging • Cardiovascular • Skeletal Imaging • Liver / Gall Bladder Imaging • GI Imaging • Thyroid Imaging • Renal Imaging • Pulmonary Imaging • Oncology Imaging • Brain Imaging • Cisternography
Barium Sulfate (BaSO4)-- X-Ray/CT Contrast Agent
• Insoluble white powder that is a colloidal suspension in water • Given orally or rectally • Ideal contrast agent for oral and rectal studies of the GI tract (esophagus, stomach, duodenum, small bowel, colon and entire bowel) • Imaging can be done right after taking the contrast (upper GI) or is done after several hours (lower GI) • Produces metal like density on radiological studies, is inexpensive, minimal patient morbidity and mortality • Flavoring agents, suspending agents and other excipients my be utilized in preparing these products
Magnetic field line rules
• Magnetic field lines go from the north pole to the south pole • Magnetic field at any point is tangent to the magnetic field line at that point
Loudspeaker
• Most loudspeakers are based on the principle that a magnetic field exerts a force on a current-carrying wire • Consists of a cone, voice coil and a permanent magnet • The cone can vibrate back and forth; when vibrating, the cone pushes and pulls on the air in front of it and therefore creates sound waves. • The alternating current in the voice coil interacts with the magnetic field to generate an alternating force that pushes and pulls on the voice coil and the attached cone.
Dehydration
• Occurs when water intake is less than water loss; can pose a risk to health • Key signs: rapid heart rate and low blood pressure • When one is dehydrated, there is a smaller volume of blood circulating through their body. That results in a decrease of the amount of blood that the heart pumps with each beat and the body's needs for oxygen are not met. -- Body's solution: body will try to maintain cardiac output, blood pressure and blood flow to the vital organs by increasing the heart rate and constricting the blood vessels, can restrict blood flow from skin to internal organs
GI Imaging
• One of the first nuclear imaging procedures preformed • There is little concern over toxicity in GI Imaging • Indications: - Evaluate gastric emptying and gastroesophageal reflux - Detect GI bleeding (radiolabel red blood cells) - Localize Meckel's diverticulum
Liver / Gall Bladder Imaging
• One of the first nuclear imaging procedures to be performed • There is little concern of radiopharmaceuticals toxicity during Liver imaging • Most common indication: - Evaluate obstruction of the hepatobiliary system • Tc-99m Mebrofenin (Choletec), Tc-99m Disofenin (Hepatolite)
Treatment for cardiac temponade
• Oxygen • Volume expansion • Pericardiocentesis: procedure that uses a needle to remove fluid from the pericardial sac • Swan-Ganz - continuous monitoring of hemodynamics -- Cause for tamponade must be identified and treated -- Repeat echocardiogram and repeat chest X-ray
Rate-responsive pacemakers
• Pace at a variable rate, depending on your activity; the more active you are, the faster the pacemaker will pace your heart • They determine the optimal heart rate by measuring the activity sensor or by measuring the breathing rate with a breathing sensor
What is tension pneumothorax?
• Positive pressure in the pleural space due to air entering but not leaving the pleural space
What is the main application of a transformer?
• Power transmission over long distances • Power losses in the transmission lines are reduced by stepping up the voltage for transmission
Real image versus virtual image
• Real image - image that you can capture on a screen; image that is formed at the intersection of the actual rays of light • Virtual image - image that you cannot capture on a screen; image that is formed at the intersection of the extensions of the rays of light
What is the revised physiology model?
• Reddy and Curtiss revised the original Reddy model • Phase 1: RV and LV pressures rise but do not equilibrate the pericardial pressure • Phase 2: Pericardial pressure equilibrates with RV but not LV filling pressure • Phase 3: Both LV and RV pressures equilibrate with pericardial pressure • Cardiac tamponade - continuum of hemodynamic abnormalities
Specific Gravity & Density
• SG is defined as the ratio of the density ofa substance to the density of water • Water has a specific gravity of 1.0 • Any object w/ a specific gravity < 1.0 will float in water and anything greater than 1.0 will sink • The human body has a density slightly less than that of water (~0.974, a lean person is ~ 1.1, fat mass ~ 0.9) and therefore, floats with some exceptions
Computerized Tomography (CT Scan) Computerized Axial Tomography (CAT Scan): Overview
• Series of x-rays that produce a cross section of the body • Provides detailed views of the anatomy, especially the chest and abdomen, but also the head and spine • Contrast agents may be used to help differentiate tissues • Images may be taken before and/or after contrast agents • Patient must remain still for the procedure • May take 5-30 minutes or longer
The treatments from this chapter are applicable for the following 4 conditions:
• Shock • Cardiac tamponade • Tension Pneumothorax • Hyperbaric oxygen treatment
Management: dehydration
• The first priority is to restore intravascular volume and stabilize the vital signs by replacing fluid deficit with 0.9% saline. • Once the vital signs have been stabilized, maintenance fluid also needs to be administered with D5 0.18% saline. - Step (1) 200mL 0.9% over 10-30min - Step (2) 0-8 hrs. • Deficit: 300 mL of 0.9% saline • Maintenance: 333 mL of D5% 0.18% saline - 9-24 hrs. • Deficit: 500 mL of 0.9% saline • Maintenance: 666 mL of D5% 0.18% saline
Sensitivity of human ear
• The human ear is not equally sensitive to all frequencies • Each curve represents the intensity levels at which sounds of various frequencies have the same loudness • Lowest curve: 0 dB at 1000-Hz has the same loudness as 37 dB at 100-Hz, which means that the ear is more sensitive to a 1000-Hz sound than to a 100-Hz sound • The curve labeled "60" corresponds to sounds that have the same loudness as a 60 dB sound at 1000-Hz • The human ear is most sensitive in the 1- 5 kHz range
Parallel Plates -- voltage and electric field
• The magnitude of the voltage between the plates is proportional to the magnitude of the electric field between the plates • The relationship below is true for the uniform electric field between parallel plates and is true in general for uniform electric fields DeltaV= Ed or E= V/d
Resting membrane potential
• The membrane acts like a capacitor with negative charges on the inner side of the membrane and positive charges on the outside • Resting membrane potential is equal to the electric potential difference across the membrane due to the separation of charges • Typically measures -70 mV • During the resting membrane potential there are: • More sodium ions outside than inside the neuron • More potassium ions inside than outside the neuron
North magnetic pole
• The north magnetic pole is the location at which the magnetic axis crosses the surface in the northern hemisphere • The north magnetic pole is so named because it is the location toward which the north end of a compass needle points • The north magnetic pole does not coincide with the north geographic pole • The north magnetic pole moves over time
Thermography
• Thermography is a technique used for the diagnosis of tumors • Radiation is measured at different points on the human body • Points of high radiation indicate high temperature, which in turn would indicate the presence of a tumor or inflammation • This is like taking a photograph, only in the infrared part of the electromagnetic spectrum. The thermogram shows the temperature variation - the new blood vessels that form around a developing malignancy light up in red, yellow or white, and the normal tissue or benign tumors show up in green or blue. • No radiation and no touch is applied
Indications for Cisternography & Agents
• To evaluate the hydrodynamics of cerebral spinal fluid (CSF), compounds must be instilled into the CSF and their course is mapped • Radionuclide cisternography is one of the most reliable tests to assess CSF Agent: In-111(Indium Pentetate - DTPA)
The non-invasive techniques of measuring ICP are:
• Transcranial Doppler • Tympanic membrane displacement • Optic nerve sheath diameter • CT scan/MRI • Fundoscopy
Active transport
• Transport across living membranes in the direction opposite to that dictated by diffusion probability. • The energy for transport is provided by the membranes, which have a source of energy • Example: active transport is (in part) responsible for Na transfer from the kidney tubules
Ultrasonic cleaning
• Ultrasonic cleaning removes soil by cavitation and implosion in which waves of acoustic energy are propagated in aqueous solutions to disrupt the bonds that hold particulate matter to surfaces. • Lower frequency ultrasound in the range from 20 to 40 kHz is used in ultrasonic cleaning devices • Ultrasound in water produces large numbers of tiny bubbles in a process called "cavitation" • Cavitation is a very effective for cleaning surgical instruments • Ultrasonic cleaning removes soil by cavitation and implosion in which waves of acoustic energy are propagated in aqueous solutions to disrupt the bonds that hold particulate matter to surfaces. • Lower frequency ultrasound in the range from 20 to 40 kHz is used in ultrasonic cleaning devices • Ultrasound in water produces large numbers of tiny bubbles in a process called "cavitation" • Cavitation is a very effective for cleaning surgical instruments
Diodes
• Unidirectional device (carries current in only one direction) used in rectifier circuits • A diode is a device with two terminals, between which it allows the flow of current in one direction only • Most diodes are made of silicon • One type of diode is the p-n junction diode (n-type + p-type semiconductor)
Ultrasound (sonography)
• Use of high frequency sound waves • Reflected echoes are detected and displayed in real time • Useful in obstetrics, imaging various internal organs including blood vessels (Doppler ultrasound) and heart valves (TTE or TEE) • Painless, fast and easy • Gel is applied to skin, transducer is guided over the skin (pressure my cause mild discomfort, especially if the bladder is full) • Intestinal gas can prevent visualization of deeper structures • Obese patients are difficult to image
Brain Imaging
• Use of nuclear medicine in brain imaging has declined due to the use of conventional imaging modalities (CIM) • Using nuclear medicine has advantage over CIM in that SPECT/PET imaging allows the viewing of deep brain structures and provides a better anatomical view of the brain. • Radiopharmaceuticals used in nuclear medicine provide physiologic information about cerebral pathology which can strongly influence treatment decisions • Used to determine if a patient is legally brain dead (primary clinical use), evaluation of cerebrovascular disease, intracranial injury due to trauma, neuropsychiatric disorders, convulsive disorders and to assess cognitive functions
How does a doppler flow meter work?
• Using Doppler effect, speed of blood flow is measured; increased blood speed indicates a constricted area
How fo vasopressor drugs work?
• Vasopressor drugs make blood vessels smaller and tighter; the body will raise the blood pressure in response to vasoconstriction to keep the blood volume flow rate constant; they are used for short periods of time under close supervision - Increase BP, ex.) phenylephrine, dopamine
Output phase (blood output from ventricle) of cardiac cycle
• Ventricular contraction (systole) • The aortic and pulmonary valves close at the end of the contraction (second sound: dub)
Input phase (blood input into ventricle) of cardiac cycle
• Ventricular expansion (diastole) • The atrioventricular valves close at the end of expansion (first sound: lub)
The invasive techniques of measuring ICP are:
• Ventriculostomy EVD *** gold standard • Microtransducers - Most accurate but introduce risks such as hemorrhaging and infection
What causes light pixels?
• When a small portion of the base layer is negative, the negative white beads are repelled away from it to the upper layer
Sweat varies based on these factors:
• Work rate • Temperature and humidity of the surroundings • Acclimatization state • Baseline hydration level
Ideal properties of a radiopharmaceutical
• easily produced, inexpensive, readily available • has a short effective half-life • particle emission versus photon emission - α- and β-particle emitters are usually therapeutic (μCi), but can be diagnostic (μCi) if able to image associated photons - photon emitters (mostly γ-ray) are diagnostic - EC or IT without IC is most desirable decay properties - γ-ray energies of 30-300 keV are efficiently detected by SPECT cameras. 150 keV is optimal for cameras with a collimator - PET cameras detect 511keV photons
Effective decay
• effective decay = physical decay + biological decay - lung imaging may have absorption losses to the circulation
99mTc macroaggregated albumin (MAA)
• prepare using a commercial kit • must be checked for particle size by a hemocytometer • > 95% of particles must be: 10 μm < x < 90 μm • < 10 μm will be removed by the liver • > 150 μm will clog arterioles • primarily used for lung perfusion studies
A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field. If the particle were traveling twice as fast, the radius of the circular path would be
2R
Areas of fluoroscopy (a use of x-ray imaging):
- Note: fluoroscopy - use of real-time x-rays to guide surgical procedures • Angiography (evaluate blood flow, esp. atherosclerosis of coronary vessels, stent placement, renal perfusion) • Cystourethrogram (bladder) • Hysterosalpingography (uterus & fallopian tubes)
If light is traveling from a lesser optical density to a higher, the angle of refraction will be _________ than the angle of incidence
Less
Precautions + Warnings: CT/CAT Scans
- Patients with heart failure, diabetes, and renal disorders can delay elimination of contrast media - Drink lots of liquids and urinate frequently following the test (may utilize IV hydration) - Nursing moms should wait 24 hours for contrast agents to clear - Procedure occurs in a confined space (sedatives may be necessary for some patients) - Clothing can interfere with the procedure
EEG (electroencephalogram)
- Recording of electrical signals produced by the brain • Electrodes are placed at specific locations on the head and electric potential differences that characterize brain behavior are measured and recorded • EEG - plot of electric potential difference verses time • Voltages measured are of the order of 50 microvolts
What causes hypovolemic shock?
- Severe burns - Excessive diarrhea - Excessive/relentless vomiting - Excessive sweating
When a flower petal is 4.0 cm in front of a converging lens, the inverted image is half the height of the petal. What is the focal length of this lens?
1.3 cm
Infection/Inflammation Imaging with RPs
- Primarily used for bacterial infections rather than fungal or parasitic due to a higher leukocyte response - Chronic infections respond better to In-111 oxine - Acute infections respond better to Tc-99m exametazime (Ceretec or Tc-99m HMPAO) - Acute soft tissue abscesses (for diabetic patients) - Suspected prosthetic graft infections - Osteomyelitis - Inflammatory bowel disease - Fever of unknown origin
Arterioles are called
"resistance vessels" because they are surrounded by muscle cells that can produce large changes in the vessel radii, which in turn produce large changes in the resistance to flow
Advantages of Swan-Ganz monitors
- Quick and easy, can even be used on critically ill patients - Monitors continously, doesn't require fluoroscopy - Can administer drugs through catheter - Measures the pressures of RA, PA, PC wedge **** KNOW THIS - Can determine cardiac output and oxygen saturation in the right heart chambers
Radiation
- Radiation is the process in which energy is transferred by means of electromagnetic waves. - A material that is a good absorber is also a good emitter. - A material that absorbs completely is called a perfect blackbody.
Ideal properties of X-Ray/CT Contrast Agents
- Readily available - Inexpensive - Excellent x-ray absorption characteristics at the x-ray energies used in diagnostic radiology - Minimal toxicity - Patient acceptance - Chemical stability - High water solubility with low viscosity and no significant osmotic effects - The ability to be administered for selective tissue uptake and excretion
An in-ground swimming pool has the dimensions shown in the drawing. It is filled with water to a uniform depth of 3.00 m. The density of water = 1.00 × 103 kg/m3. What is the total pressure exerted on the bottom of the swimming pool?
1.31 × 105 Pa
Weight density=
d, can be solved bia W/V; where W=(m)(g)
P is:
the lens power (in diopters)
Mn-Containing MR Contrast Agents
• rely on unpaired electrons of Mn+2 to produce magnetic changes in nearby water molecules • positive contrast agent that brighten nearby tissues • delivered to tissues with active metabolism such as liver, pancreas, kidney, heart, and adrenals
Colloids and Labeled Particles
• solutions - compound is dissolved: molecular size ~1 nm • emulsions/suspensions - visible to the naked eye or under a microscope: molecular size is usually > 1 m • colloids - somewhere in between - usually considered 10 nm - 1 μm - stabilizing agents (gelatin, PVP, CMC, etc.) may be added to prevent aggregation of colloids into larger particles - "microaggregates" - 0.5 μm - 5.0 μm (99mTc sulfur colloid) - "macraggregates" - 15 μm - 100 μm 99mTc-MAA
Low-Osmolar Contrast Media (LOMC)
• water soluble, benzoic acid amide monomers • iopromide is a low osmolar, nonionic monomer with 48% bound iodine content-- hydroxyl groups on iopromide improve water solubility
High-Osmolar Contrast Media (HOMC)-- oldest media
• water soluble, benzoic acid monomer or dimers - Diatriazoate is commercially available as the meglumine salt, sodium salt, or as fixed combinations of the two salt forms • triiodobenzoic acid salts contain ~50% organically bound iodine • amides allow for polarity & transport in vasculature • Ionization present, ex.) NaCl= Higher OPP than glucose