Medical Physics ABR Part 1 Clinical

Rate the body systems in order of decreasing radio-sensitivity.
1. Hematopoietic, Reproductive (2-5 Gy)
2. Skin, cornea, lens of eyes, GI organs (10 Gy)
3. Bone and cartilage
4. Lungs, kidneys, Liver, Pancreas
5. Muscle, brain, nerves, spinal cord (20 Gy)
a. What are the components of the cell cycle & their order?
b. What is the relative radio-sensitivity of each?
Mitosis (M), Gap 1 (G1), Synthesis (S), Gap 2 (G2)
a. M -> G1 -> S -> G2
b. M > G2 > G1 > S
a. Function
b. Location
a. Motor control, balance
b. Directly posterior to the brain stem.
a. Function and properties
b. Divisions
a. Higher functions: thought, action.
b. 4 lobes: frontal (anterior), parietal (superior), occipital (posterior), temporal (lateral x 2).
Cerebral cortex
Sheet of neural tissue outermost to the cerebrum. Grey matter
Brain steam function
Basic vital life functions (breathing, heartbeat, etc.
Corpus callosum
Connects the two parts of the cerebrum.
{Lets the two hemispheres talk to each other, i.e. “call” each other}
a. Location
b. Function
a. Lungs
b. Air-lung interface. Diffusion of O2, CO2.
Hiatal hernia
a. Describe condition
b. Imaging modality to diagnose?
a. Part of the stomach sticks upward into the chest through opening in the diaphragm.
b. UGI x-ray after ingestion of barium.
Upper gastrointestinal.
UGI. Esophagus, stomach, and duodenum
Lower gastrointestinal
LGI. Small and Large intestine. Stool.
US transducers:
a. What is the angle of orientation of the two surfaces?
b. How thick are the transducers in terms of the wavelength?
c. Are the pressure waves and voltage in phase or out of phase?
a. 180 degrees.
b. lambda/2
c. pressure: in phase. Voltage: out of phase.
a. Describe
b. Effects
a. sudden loss of consciousness resulting when the rupture or occlusion of a blood vessel leads to oxygen lack in the brain
b. Loss of brain function, ischemia, hemorrhage
Insufficient blood flow to an area
Flow of blood from a ruptured blood vessels.
Transurethral resection
Small pieces of tissue from a nearby structure (typically prostate) are removed through the wall of the urethra.
Foramen magnum
A large hole in the occipital bone (base of skull) for the passage of nerves into the spinal cord.
Liver cirrhosis
a. Describe
b. Causes
c. Effects
a. Cells are progressively destroyed and replaced by fatty and fibrous tissue that surrounds the intrahepatic blood vessels and biliary radicles, impeding the circulation of blood through the liver.
b. Caused by chronic alcohol abuse (alcoholism); hepatitis B, C, and D (causes liver inflammation and injury leading to cirrhosis); and ingestion of poisons.
c. Hypertension, intestine bleeding.
Chronic inflammatory disease in which small nodules (granulomas) develop in lungs, lymph nodes, and other organs
a. Describe
b. Result
a. Describe
b. Result
a. Cell division that produces reproductive cells in sexually reproducing organisms
b. 4 haploid cells
Haploid cells
A cell containing only one set of chromosomes.
Cell having two sets of chromosomes or twice the haploid number.
How many essential minerals to human health. List them.
7 major: Calcium, Sodium, Chloride, Magnesium…
Phosphorus, Sulfur, Potassium.

10 trace: Manganese, Chromium, Copper, Selenium…
Zinc, Iodine, Fluoride, Molybdenum.

{Sing Mexican Hat Dance. Iodine = “EyeDine”}

How many and what are the major elements of the body?
H (63%)
O (26%)
C (9%)
N (1%)
Number of Cranial (CNS) nerves
12 types (but are paired, so 24 total)
Oh Once One Takes The Anatomy Final Very Good Vacations Are Here.
What are the thresholds for whole body acute radiation (rem/rad or Sv/Gy) for given symptoms?
rem rad; Sv Gy
50 rem (0.5 Sv): Blood count change
100 rem (1 Sv): Vomiting
150 rem (1.5 Sv): Death threshold
350 rem (3.5 Sv): LD 50/60 with minimal care
500 (5 Sv): LD 50/60 with supportive medical care
1000 (10 Sv): LD 50/60 with intensive medical care (bone marrow transplant)
*LD 50/60 is the lethal dose at which 50% of those exposed die within 60 days.
At what vertebral level is the Umbilicus?
Liver function
Stores glycogen;
manufactures and secretes bile; manufactures blood proteins;
destroys old red blood cells;
detoxifies harmful substances
Gallbladder function
Store & concentrate bile produced by the liver until it is needed in the small intestine
A benign epithelial tumor of glandular origin.
Common for pituitary.
A benign tumor (adenoma) of the pituitary gland that causes it to produce too much prolactin
Vertebral level of the Larynx
A tumor arising in the meninges, the structure surrounding the brain and spinal cord
Hydrolysis produces what?
H+, OH-. Leads to H2O2 (relatively stable). OH- highly oxidizing/damaging.
Lens dose equivalent
The external exposure dose equivalent to the lens of the eye at a tissue depth of 0.3 centimeters (300 mg/cm2).
Transport index
Max dose equivalent rate at one meter from the surface of a package containing radioactive material.
4 Rs of Radiobiology.
Used to justify fractionation.
. Redistribution
. Repair
. Reoxygenation
. Repopulation
. (Radiosensitivity)
What is the effect of ionizing radiation on the cellular level.
Damage to DNA.
Blood vessels of the liver
Hepatic Artery (oxygenated blood from heart)
Hepatic Portal Vein (Neutrient rich blood from GI tract)
Gleason score pertains to which cancer?
Small intestine function and division.
Duodenum – Digestion
Jejenum – Absorption of carbs and proteins
Ileum – Absorption of bile salts, fats.
Pineal gland
A small endocrine gland in the center of the brain near the brain stem that secretes melatonin and serotonin
{Pinae -> Pinay -> Phillipinos are happy and get lots of sun -> Secretes seretonin and melatonin}
Choroid plexus
A highly vascular portion of the lining of the ventricles in the brain that secretes cerebrospinal fluid (CSF) which cushions brain and spinal cord.
Optic Chiasm
Optic Chiasm
The crossing of the optic nerves from the two eyes at the base of the brain.
Below the hypothalamus.
What systems are responsible for equilibrium?
Vestibular system (inner ear) and Cerebellum
Synovial fluid
Lubricates, nourishes, and keeps the joint moveable
Single Hit Theory (Equation and variable definitions)
S = N/N0 = e^(-D/D0)
S: Survival fraction
N: Cells remaining
N0: Initial # of cells
D: Given dose
D0: Mean lethal dose
Spread of cancer cells beyond their original site in the body
Sestamibi Scan
Tc99m is injected intravenously and traced to heart muscle or thyroid to observe function. Emits 140 keV gamma rays (same as standard x-ray equipment).
Double-layered membrane surrounding the abdominal organs.
A disorder (usually of unknown origin) of the heart muscle (myocardium)
Cardiac dysrhythmia
Abnormality of heart rhythm
Ligaments of the knee
Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)
Transverse ligament
Meniscofemoral ligaments
Meniscotibial ligaments
Patellar ligament
Medial collateral ligament (MCL)
Oblique popliteal ligament
Arcuate popliteal ligament
Vertebral level of the caudal end of the spinal cord?
Number of each type of vertebrae
Number of each type of vertebrae
Cervical (7)
Thoracic (12)
Lumbar (5)
Sacrum (1, *5)
Coccyx (1, *4)
a. What is Multiple Sclerosis
b. Best technique for imaging Multiple Sclerosis? Why?
a.CNS disease. The body’s own defense system attacks myelin.
b. MRI
a. Which cancer has the shortest latency period?
b. How long?
c. How relates to others?
a. Leukemia
b. 2-15 yrs
c. Others 10-30 yrs
Radiation equivalent man Severt conversion
100 rem = 1 Sv
What is the prob. of genetic defects to offspring as a function of dose?
Approx. 1/10,000 at 10 mSv
Or 1% per Sv.
Risks of radiation exposure at stages of gestation (weeks)?
Risks of radiation exposure at stages of gestation (weeks)?
1 week: Lethality
2-7 weeks: Gross malformations, Growth retardation, general neuropathology
8-15 weeks: Mental Retardation most, but also Growth retardation, Sterility
16-25 weeks: lower risk of all above except lethality.
Present at birth but not necessarily hereditary
Parasympathetic vs. Sympathetic control
Parasympathetic vs. Sympathetic control
Part of the autonomic nervous system.
Oppose each other (complementary).
Sympathetic : police (quick response) :: parasympathetic : courts (regulated activity)
Nerves move voluntary muscles through which process?
Reflex arc.
Gray vs. Sievert
Absorbed dose (by matter) = Gray.
Equivalent dose (by biological tissues) = Sv
Sv = (Quality Factor) * Gy
Effects of 1 Gy whole body radiation?
Nausea and vomiting.
Stereotactic radiosurgery is best used for what?
Tumors of the brain.
Abnormal narrowing of a bodily canal or passageway
{A stent will prevent stenosis}
What is the primary mechanism for damage by LET photons?
Hydrolysis. 2/3 of damage to DNA by hydroxyl radical.
Medical term for mouth.
Buccal cavity.
Vena cava
Either of two large veins that return oxygen-depleted blood to the right atrium of the heart.
Pulmonary artery
One of two arteries that carry venous blood from the heart to the lungs
What is a barium scan used for?
Contrast for visualization of the GI tract via x-ray.
Committed dose equivalent
Dose to a specific organ or tissue that is received from an intake of radioactive material by an individual during the 50-year period following the intake.
Circle of Willis
A circle of arteries at the base of the brain that supply blood to the brain.
Surrounds the pituitary.
What does “radiation leakage” generally refer to?
Radiation going out through the x-ray tube housing in all directions rather than that of the useful beam.
Vocal cords
folds of tissue within larynx that vibrate and produce sounds
Increase in cancer risk as a fn of dose (Sv, rem)
Acute: 10%/Sv (10%/100rem)
Chronic: 5%/Sv (1%/100 rem)
What is used by nerve cells to stimulate skeletal muscles?
Pituitary gland:
a. nickname
b. functions
Located in the brain
a. The master gland of the endocrine system.
b. Growth hormone, Thyroid-stimulating hormone, Prolactin, etc.
What type of scans can be used to stage lung cancer.
A person with Radium exposure: where will radon be detected.
Breath. Radon is a heavy element so if it enters the lungs it will sink to the bottom and linger.
a. Embolus b. embolism
a. An abnormal particle (e.g. an air bubble or part of a clot) circulating in the blood.
b. occlusion of a blood vessel by an embolus (a loose clot or air bubble or other particle)
What is the defining characteristics of MTFs?
Better preservation of resolution => higher MTF per spacial frequency.
Usually MTF (on y axis) vs. Spacial Freq. (on x asis)
a. Telangiectasia = ?
b. How long after radiation does it develop?
Describes capillaries that have been damaged and are now larger; or distended blood vessels. Commonly called couperose skin.
What is the lower limit of detection for radio-contamination?
μCi or 10^4 Bq
Ci to Bq conversion
1 Ci = 3.7 x 10^10 Bq
Shallow-Dose Equivalent
(SDE).The external exposure dose equivalent to the skin or an extremity at a tissue depth of 0.007 centimeters (7 mg/cm2) averaged over an area of 1 square centimeter.
Point at which the trachea bifurcates (divides) into the left and right mainstem bronchi.
{Car => Driving a car => see forks in the road => Fork in trachea}
Chart of chromosome-type aberrations.
Chart of chromosome-type aberrations.
Chart of chromatid-type aberrations.
Chart of chromatid-type aberrations.
Asymmetrical rejoining
Chrom-atids, -osomes re-join in such a way that an acentric fragment is always formed.
What does symmetrical rejoining refer to?
Chrom-atids, -osomes
100 Gy acute dose. Result?
CNS death.
1 Gy to gonads. Result?
Temporary sterility/infertility.
Recommended safe dose limit to fetus?
0.5 rem (5 mSv) for entire gestation period.
Recommended safe dose limit for non-radiological workers?
0.100 rem (1 mSv) per year.
Approx dose limits per year for:
a. Extremities
b. Skin and organs
c. Lens of eye
a. 0.5 SV
b. 0.5 SV
c. 0.15 SV
Approx. safe whole body chronic dose limit per year?
5 mSv per year.
Average size of normal prostate?
35 cc
Cardiac catheterization
Introduction of a catheter through a vein or artery into the heart. Often to inject contrast media for fluoroscopic radiography (x-rays). Often includes interventional procedures such as angioplasty and atherectomy.
rad Grey conversion
1 Gy = 100 rad
Dose to trigger a sentinel event for fluoroscopy?
a. 15 Gy cumulative dose for a single field in a prolonged imaging session.
b. Any delivery to the wrong region
c. >25% above the planned dose.
Max. allowable fluoroscopy exposure output rate for standard patient?
0.05 Gy/min (5 rad/min)
Effective whole body doses from typical CT scans Sv?
a. Head
b. Screening Mammography
c. Chest
d. Angiogram
e. Abdomen
f. Chest, abdomen, pelvis
g. Barium enema
a. head: 2 mSv
b. mammo: 1 mSv
c. chest: 5 mSv
d. angio: 10 mSv
e. abdomen: 8 mSv
f. Chest, abd, pelvis: 10 mSv
g. Barium enema: 15 mSv
Define the parameters of the radiobiology multi-target survival curve.
n = exp (Dq/D0)
D0[Gy] (reciprocal of final slope): Dose requried to reduce the survival at the right part of the curve. ***
D1[Gy] (reciprocal of initial slope): Dose required to reduce the survival at the left part of the curve. ***
n[1] (extrapolation #): width of the shoulder; Small => radiosensitive.
Dq[Gy] (quasi threshold dose): Dose below which there is “minimal or no effect”.
*** These are reduced to 0.37 ( 1/e ) of initial value.
Define the parameters of the linear-quadratic model.
SF = exp(-αD – GβD^2)
Alpha: damage from a single hit.
Beta: damage from a double hit.
alpha-beta ratio: dose where the linear component and quadratic component intersect.
G: time factor. =1 for single faction.
The linear-quadratic and Dq survival curves.
The linear-quadratic and Dq survival curves.
Film directions. Side and A/P determined by?
Patient side closer to _film_
Where are the Islets of Langerhans and what do they produce?
Pancreas; Glucogyn, Insulin, Somatostatin
What is the substrate for metabolism for the brain?
What is the most sensitive part of the eye?
What part of the eye responds to light?
What can Doppler ultrasound be used to see.
Moving things, especially flows of liquid.
Benign Prostate Hyperplasm = Enlarged prostate.
Abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium
Radiation damage to the parotid leads to what condition?
Dry mouth (xerostomia)
Abnormal dryness of the mouth resulting from decreased secretion of saliva
Rate the radiosensitivity of the different blood cells in decreasing order.
1. Lymphocytes
Red blood cells.
White blood cells.
Blood platelets
What part of the inner ear is responsible for balance?
Vestibular apparatus
Which is more posterior: Trachea or Esophagus?
Which is more posterior: Trachea or Esophagus?
In what quadrant is breast cancer most likely?
Upper outer
What are the Hounsfield Unit (CT#) for air, lung, fat, muscle, and bone if water is 0?
Air = -1000
Lung = -700
Fat = -100
Muscle = 40
Bone = 700-3000
What is the result of radiation damage to the optic chiasm?
Loss of vision. Crossing of optic nerves allows each half of the brain to process only the opposite visual field. So the nerves from the inner side of each retina cross over to the other side of the brain.
Where are platelets produced?
Bone marrow
What is the vertebral level of the Iliac Crest.
Stochastic effect
A effect that has an increased probability of occurrence as a function of dose received without a threshold (generally linear)
Nonstochastic effect
Somatic effects that have a threshold; effects increase in severity with increasing absorbed does. Ex: erythema, loss of hair, cataracts, and decreased fertility.
Background radiation scattered off the atmosphere into the treatment vault.
Lacrimal gland
Any of the glands in the eyes that secrete tears.
Precision localization of a specific area of the body (most commonly the brain) using 3D coordinates for biopsy, dissection or radiosurgery
Organ on the left side of the body between the stomach and the diaphragm that removes blood cells.
Filters Iron.
Acts like a lymph node.
Adrenal gland
Tissue located on top of the kidneys that releases adrenaline and cortisol during states of emotional arousal.
The branch of biology concerned with the development of malformations or serious deviations from the normal type of organism.
Name the classic Acute Radiation Syndromes.
Bone Marrow Syndrome (1-10 Gy): Death 30-60 days
Gastrointestinal Syndrome (10 Gy): Death in 3-10 days
Cardiovascular/Central Nervous System Syndrome (50 Gy): Death within hours
Spinous process
Spinous process
Waste product of muscle metabolism, filtered out of the blood by the kidneys and excreted in urine
Pleural effusion
Accumulation of fluid within the pleural cavity (space that contains the lungs).
Which lymph nodes are first involved in the metastasis of breast cancer?
A type of cell death in which the cell uses specialized cellular machinery to kill itself
Oxygen enhancement ratio
A measure of the increased radiosensitivity of tissue in the presence of oxygen
What are the units of LET?
Linear Energy Transfer = dE/dx
High CT number = _____ density?
Grey matter
The portions of the central nervous system that are abundant in cell bodies of neurons rather than axons. The colour appears grey relative to white matter.
What is relative the RBE of
X-rays : gamma rays : beta particles : alpha particles?
The working units of the kidney that filter the blood
{Glo => Vampires glow => drink blood => kinda like filtering…yes a stretch}
A graphical record of electrical activity of the brain
excision, removal
The most common forms of breast cancer begin in which two types of cells?
Ductal (ducts that carry milk to nipple) and
Lobular (glandular, glands that produce milk)
What is the first visible effect of radiation?
Erythema (skin reddening)
Abnormal redness of the skin resulting from dilation of blood vessels (as in sunburn or inflammation)
Either of two muscles of the abdomen and pelvis that flex the trunk and rotate the thigh (T12-L5)
Identify the parts and flow of the heart.
Identify the parts and flow of the heart.
A depression or fissure where vessels or nerves or ducts enter a bodily organ. Kidney. Also: spleen, lung, and lymph.
T1 vs T2 properties (image)
T1 vs T2 properties (image)
What is dark and what is light on a T1 MRI?
Dark: Grey matter, Vitreous humor, optic nerve
Light: Bone, White matter
The ratio of the volume occupied by packed red blood cells to the volume of the whole blood. Typically 45%
Where are red blood cells produced?
Red bone marrow
What is a neoplasm that does not spread called?
Benign (In-situ)
abnormal development (of organs or cells) or an abnormal structure resulting from such growth
Abnormal condition of a joint.
a natural or surgical joining of parts or branches of tubular structures so as to make or become continuous
drooping of the upper eyelid caused by muscle paralysis and weakness.
{p,tos => when you pee, your eyes are looking at your toes}
Which nodes are most often removed in a mastectomy?
What is the vertebral level of the
a. Clavicle
b. Spinous process of scapula
c. Inferior angle of scapula
d. Iliac crest?
a. C7
b. T3
c. T7
d. L4
An EEG measures?
Electrical activity along the scalp.
Infection transmitted by inhalation or ingestion of tubercle bacilli and manifested in fever and small lesions (usually in the lungs but in various other parts of the body in acute stages)
Highest occurring cancer in men/women?
star-shaped tumor that usually develops in the cerebrum; frequently in people younger than 20 years old
any bone of the hand between the wrist and fingers
Is the corpus callosum white matter or dark matter?
Vitreous humor
Soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball
Where is the visual cortex located?
Occipital lobe
Creatinine test is acquired before a contrast study to _____?
Evaluate the function of the kidneys.
Cauda equina
The bundle of nerve roots that occupy the vertebral canal from L2 to S5.
Vertebral level of the:
a. Liver
b. Spleen
c. Pancreas
d. stomach
e. kidney
f. gallbladder
g. navel
h. bladder
a. T9-L2 Liver
b. T9 Spleen
c. T10-L1 Pancreas
d. T12 stomach
e. L1 kidney
f. L1 gallbladder
g. L4 navel
h. S5 bladder
Brain structure that acts as a control center for recognition and analysis of hunger, thirst, fatigue, anger and body temperature.
{“hypo” => low => body low on something => hungry, thirsty, …}
What dose is generally enough to produce erythema?
2 Gy
What is a common cancer for a child if irradiated during fetal stage?
What secondary cancer will show up earliest due to radiation treatment?
A usually malignant tumor arising from connective tissue (bone or muscle etc.)
Brachial Plexus
A network of nerves formed by cervical and thoracic spinal nerves and supplying the arm and parts of the shoulder. 1 per side of the body.
When does organogenesis occur?
Week 2-7.
How many spinal nerves?
31. One for each vertebra, but C7 has one nerve above it, 7th spinal nerve, and one nerve below it 8th.
Conus Medularis
End of spinal cord.
Plasma volume?
55% of blood.
~3 of the 5 Liters
Bones of the
a. forearm
b. upper arm
c. lower leg
d. upper leg
e. skull
f. kneecap
a. radius, ulna
b. humerus
c. tibia, fibula
d. femur
e. frontal, occipital (back), perietal (top), temporal (side), sephenoid (base)
f. patellar
How many lobes of the lungs?
Right: 3
Left: 2
The rounded bony protuberance on each side of the ankle.
iron-containing protein in red blood cells that carries oxygen for delivery to cells
Cell division that produces reproductive cells in sexually reproducing organisms
sex cells
the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery
the widening of the chambers of the heart between two contractions when the chambers fill with blood
Ejection fraction
Stroke volume / End diastolic volume
What is Thallium given for?
Myocardia Ischemia. Used as contrast in cells with good blood uptake.
{Chol => “Ghol”}
What modality would be used to image the gallbladder?
Functions of the pancreas
Digestive enzyme production.
Hormones (insulin)
What organ produces estrogen?
What imaging modality is used for lung cancer staging.
The dome-like superior portion of the cranium
{Ca => Cap => Skull cap}
Innominate bone
large flaring bone forming one half of the pelvis (hip bone)
Most common secondary cancers for people with AIDS?
1. Kaposi sarcoma
2. non-Hodgkin lymphoma
a neoplasm of lymph tissue that is usually malignant
A substance produced by the liver, secreted by gallbladder that breaks up fat particles
a U-shaped bone at the base of the tongue that supports the tongue muscles
{Hyoid helps you say Hi!}
the stirrup-shaped ossicle (bone) that transmits sound from the incus to the cochlea.
{Stapes lets you hear your tapes!}
Sebaceous gland
oil gland
{Sebace => Seabass => fish => fish oil}
the part of the human body between the neck and the diaphragm or the corresponding part in other vertebrates
Iliac artery
one of the large arteries supplying blood to the pelvis and legs
a small endocrine gland in the brain
the main (mid) section of a long bone
medullary cavity
cavity within the shaft of the long bones filled with bone marrow
Vital capacity
the maximum amount of air that can be exhaled after a maximum inhalation
part of the endocrine system that produces hormones that regulate metabolism
Exocrine system
The collection of ducted glands that secrete products to the body’s surface or into body cavities
Endocrine system
the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
Image of vertebral level of organs.
Image of vertebral level of organs.
Identify. pancreas, intestines, rib, left adrenal gland, aorta, spine, right kidney, liver, gallbladder. T12
Identify. pancreas, intestines, rib, left adrenal gland, aorta, spine, right kidney, liver, gallbladder. T12
Define the BED in the linear quadratic model
En = (αD+βD^2)
BED = E/α = nD (1 + (Dβ/α))
n: number of fractions
R, Rad, Rem
R: Roentgen (Exposure)
Rad: Radiation Absorbed Dose (Dose): Gy
Rem: Roentgen Equivalent Man (Dose with biological weighting): Sv
a. What are examples of densely ionizing particles?
b. How do they behave on the survival curve log-linear plots?
a. neutrons, alpha particles
b. linear (only one slope, D0); (Dq = 0; n = 1)
Bystander effect
Induction of biologic effects in cells that were not directly traversed by a radiation, but are in close proximity to cells that were.
What are the three lethal chromosomal aberrations/re-arrangements?
Dicentric (chromosome-level, re-replication): From dual break, one in each pre-replica chromosome. Two-centormere chromosome is formed.
Ring (chromosome-level, pre-replication): Dual break, one in each arm of a single chromatid.
Anaphase bridge (chromatid-level, post-repication): Break in each chromatid. Leads to them pairing, swapping, or deleting.
Average annual natural and extra-natural exposures.
Average annual natural and extra-natural exposures.
Functions of each lobe of cerebrum?
Frontal: Thinking, speaking, emotions
Parietal: Perception (temp, pain, touch)
Temporal: Hearing, memory (with hippocampus)
Occipital: Vision
Threshold dose to fetus to see deleterious effects?
10 rem (0.1 Sv)