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Chapter 1
An Introduction to
Anatomy and
Physiology
Lecture Presentation by
Lee Ann Frederick
University of Texas at Arlington
© 2015 Pearson Education, Inc.
An Introduction to Studying the Human Body
• Learning Outcomes
• 1-1 Explain the importance of studying anatomy
and physiology.
• 1-2 Define anatomy and physiology, describe
the origins of anatomical and physiological
terms, and explain the significance of
Terminologia Anatomica (International
Anatomical Terminology).
• 1-3 Explain the relationship between anatomy
and physiology, and describe various
specialties of each discipline.
© 2015 Pearson Education, Inc.
• Learning Outcomes (continued)
• 1-4 Identify the major levels of organization in
organisms, from the simplest to the most
complex, and identify major components of
each organ system.
• 1-5 Explain the concept of homeostasis.
• 1-6 Describe how negative feedback and
positive feedback are involved in homeostatic
regulation, and explain the significance of
homeostasis.
• 1-7 Use anatomical terms to describe body
regions, body sections, and relative positions.
• 1-8 Identify the major body cavities and their
subdivisions, and describe the functions
of each.
© 2015 Pearson Education, Inc.
Anatomy and Physiology Directly Affect
Your Life
• Anatomy
• Is the study of structures of the body
• Oldest medical science: 1600 BCE
• Physiology
• Is the study of how anatomical structures in living
organisms perform their vital functions
• Individual and cooperative
• Biochemical, Genetic, etc…
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Relationships between Anatomy and
Physiology
• Gross anatomy, or macroscopic anatomy,
examines large, visible structures without the use of
a microscope
• This is subdivided into:
•
•
•
•
Surface anatomy: specific surfaces of the body
Regional anatomy: specific regions of the body
Systemic anatomy: specific organ systems of the body
Comparative anatomy: anatomical differences
between different species
• Developmental anatomy: structural changes from
conception to death (egg through terminal adult form)
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• Microscopic anatomy examines cells and
molecules not visible to the naked eye,
necessitating the use of resolving equipment
(a.k.a. microscopes)
• This is subdivided into:
• Histology: study of tissues and their structures
• Light microscopes can view tissues
• Cytology: study of cells and their structures
• Light microscopes can view cells
• Electron microscopes view inside the cells
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• Physiology is a broad study of function and is
subdivided into several classes
• Cell physiology: studies processes within and
between cells
• Organ physiology: studies functions of specific
organs
• Systemic physiology: studies functions of an organ
system
• Pathological physiology: studies the effects of
diseases
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Levels of Organization
1. Atoms
2.
3.
4.
5.
6.
7.
8.
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Molecules
Organelles
Cells
Tissues
Organs
Organ System
Organism
Example of the Levels of Organization…
Cellular Level
Chemical Level
Protein filaments
Atoms in combination
Complex protein molecule
Organism
Organ system
Tissue
Cardiac muscle
tissue
Organ
The heart
The
cardiovascular
system
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Heart muscle
cell
A cursory look at the major Organ Systems
• Integumentary System
• Major Organs
•
•
•
•
Skin
Hair
Sweat glands
Nails
• Functions
• Protects against environmental hazards
• Helps regulate body temperature
• Provides sensory information
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• Skeletal System
• Major Organs
•
•
•
•
Bones
Cartilages
Associated ligaments
Bone marrow
• Functions
• Provides support and protection for other tissues
• Stores calcium and other minerals
• Forms blood cells
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• Muscular System
• Major Organs
• Skeletal muscles and associated
tendons
• Functions
• Provides movement
• Provides protection and support for
other tissues
• Generates heat that maintains body
temperature
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• Nervous System
• Major Organs
•
•
•
•
Brain
Spinal cord
Peripheral nerves
Sense organs
• Functions
• Directs immediate responses to stimuli
• Coordinates or moderates activities of other organ
systems
• Provides and interprets sensory information about
external conditions
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• Endocrine System
• Major Organs
•
•
•
•
Pituitary gland
• Thyroid gland
Pancreas
• Adrenal glands
Gonads
Endocrine tissues in other systems
• Functions
• Directs long-term changes in the activities of other
organ systems
• Adjusts metabolic activity and energy use by the body
• Controls many structural and functional changes
during development
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• Cardiovascular System
• Major Organs
• Heart
• Blood
• Blood vessels
• Functions
• Distributes blood cells, water, and
dissolved materials including nutrients, waste
products, oxygen, and carbon dioxide
• Distributes heat and assists in control of body
temperature
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• Lymphatic System
• Major Organs
•
•
•
•
•
Spleen
Thymus
Lymphatic vessels
Lymph nodes
Tonsils
• Functions
• Defends against infection and disease
• Returns tissue fluids to the bloodstream
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• Respiratory System
• Major Organs
•
•
•
•
•
•
•
Nasal cavities
Sinuses
Larynx
Trachea
Bronchi
Lungs
Alveoli
• Functions
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• Delivers air to alveoli (sites in lungs
where gas exchange occurs)
• Provides oxygen to bloodstream
• Removes carbon dioxide from
bloodstream
• Produces sounds for communication
• Digestive System
• Major Organs
•
•
•
•
•
•
•
•
•
Teeth
Tongue
Pharynx
Esophagus
Stomach
Small and Large intestines
Liver
Gallbladder
Pancreas
• Functions
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•
•
•
•
Processes and digests food
Absorbs and conserves water
Absorbs nutrients
Stores energy reserves
• Urinary System
• Major Organs
•
•
•
•
Kidneys
Ureters
Urinary bladder
Urethra
• Functions
• Excretes waste products from the blood
• Controls water balance by regulating volume of
urine produced
• Stores urine prior to voluntary elimination
• Regulates blood ion concentrations and pH
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• Reproductive System (Male or Female)
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The following is a list of several levels of organization
that make up the human body. Put them in order from
smallest to largest.
1) tissue
3) organ
5) system
2) cell
4) organelle
a. 1, 3, 4, 2, 5
b. 4, 1, 2, 5, 3
c. 5, 3, 1, 2, 4
d. 4, 2, 1, 3, 5
The following is a list of several levels of organization
that make up the human body. Put them in order from
smallest to largest.
1) tissue
3) organ
5) system
2) cell
4) organelle
a. 1, 3, 4, 2, 5
b. 4, 1, 2, 5, 3
c. 5, 3, 1, 2, 4
d. 4, 2, 1, 3, 5
What is NOT true of the lymphatic system?
a. defends against infection
b. includes the liver and the pancreas
c. returns fluids to the bloodstream
d. includes the tonsils and the thymus
What is NOT true of the lymphatic system?
a. defends against infection
b. includes the liver and the pancreas
c. returns fluids to the bloodstream
d. includes the tonsils and the thymus
Homeostasis
•Homeostasis is the ability of the body to maintain a stable
internal environment despite changing external conditions
•Organ systems respond to external and internal changes to
keep body parameters within physiological limits (involving
the nervous and endocrine systems)
•Two examples:
•Blood glucose levels are kept within narrow range
70-110mg/dl. What hormones control blood glucose
levels?
•Body temperature is maintained 37oC.
These are just set points with a range! (95% rule)
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• Homeostasis is regulated by a feedback
mechanism, involving three components
• Receptor, which senses changes in the internal
and external environment (receives the stimulus)
• Control Center, which evaluates the input and
sends out instructions (executive branch)
• Effector, which makes the required changes
(operational discipline)
Failure of homeostasis results in death!
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Negative and Positive Feedback
• Negative feedback opposes variations from
normal; it tends toward the normal range
• Homeostatic mechanism
• Slows down the process
• Positive feedback exaggerates variations from
normal; it tends toward the extreme point
• Move away from homeostasis
• Speeds up the process
Let’s look at a couple of examples…
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Negative Feedback: Control of Body Temperature.
RECEPTORS
Temperature
sensors in skin
and
hypothalamus
Normal
temperature
disturbed
Information
affects
CONTROL
CENTER
STIMULUS:
Body temperature
rises
HOMEOSTASIS
RESPONSE:
Increased heat loss,
body temperature
drops
Normal
temperature
restored
EFFECTORS
• Sweat glands
in skin increase
secretion
• Blood vessels
in skin dilate
Sends
commands
to
a Events in the regulation of body temperature, which are comparable to
those shown in Figure 1–2. A control center in the brain (the hypothalamus)
functions as a thermostat with a set point of 37C. If body temperature
exceeds 37.2C, heat loss is increased through enhanced blood flow to the
skin and increased sweating.
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Body temperature (C)
Thermoregulatory
center in brain
Normal body
temperature
Vessels
dilate,
sweating
increases
37.2
Set point
37
36.7
Vessels
constrict,
sweating
decreases
Normal
range
Time
b The thermoregulatory center
keeps body temperature fluctuating within an acceptable range,
usually between 36.7C and
37.2C.
Positive Feedback: Blood Clotting.
Clotting
accelerates
Positive
feedback
loop
Chemicals
Damaged cells in the blood
vessel wall release chemicals that begin the clotting
process.
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The chemicals start chain
reactions in which cells,
cell fragments, and soluble
proteins in the blood begin
to form a clot.
Chemicals
Blood clot
As clotting continues, each
step releases chemicals
that further accelerate the
process.
This escalating process
is a positive feedback
loop that ends with the
formation of a blood clot,
which patches the vessel
wall and stops the bleeding.
Positive Feedback: Childbirth and Oxytocin.
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The Roles of Organ Systems in Homeostatic Regulation.
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Most examples of extrinsic regulation of organ
systems in the human body will be controlled
via ________.
a. negative feedback
b. positive feedback
c. autoregulation
d. homeostasis
© 2015 Pearson Education, Inc.
Most examples of extrinsic regulation of organ
systems in the human body will be controlled
via ________.
a. negative feedback
b. positive feedback
c. autoregulation
d. homeostasis
© 2015 Pearson Education, Inc.
Anatomical Terminology
• Superficial anatomy provides anatomical
landmarks; references to palpable structures that
we can touch and see
• The commonly accepted anatomical position is
with the hands at the sides, palms facing forward,
with the feet next to each other
• Supine: lying down, face up
• Prone: lying down, face down
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Figure 1-5a Anatomical Landmarks (Part 1 of 2).
Frontal or
forehead
Nasal or nose
Ocular, orbital
or eye
Cranial
or skull
Cephalic or head
Facial
or face
Oral or mouth
Mental or chin
Buccal or cheek
Cervical or neck
Thoracic or
thorax, chest
Axillary or armpit
Mammary
or breast
Brachial
or arm
Abdominal
(abdomen)
Umbilical
or navel
Antecubital
or front of
elbow
a Anterior view
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Otic or ear
Trunk
Figure 1-5a Anatomical Landmarks (Part 2 of 2).
Antebrachial
or forearm
Pelvic
(pelvis)
Trunk
Carpal or wrist
Palmar or palm
Manual
or hand
Digits
Pollex
or thumb (phalanges)
or fingers (digital
or phalangeal)
Inguinal
or groin
Pubic
(pubis)
Patellar
or kneecap
Femoral
or thigh
Crural
or leg
Tarsal or
ankle
Digits (phalanges)
or toes (digital or
phalangeal)
Hallux or
great toe
Pedal
or foot
a Anterior view
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Figure 1-5b Anatomical Landmarks (Part 1 of 2).
Cephalic
or head
Acromial or
shoulder
Dorsal or
back
Cervical
or neck
Olecranal
or back
of elbow
Upper
limb
b Posterior view
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Figure 1-5b Anatomical Landmarks (Part 2 of 2).
Lumbar
or loin
Upper
limb
Gluteal
or buttock
Lower
limb
Popliteal or
back of knee
Sural
or calf
Calcaneal or
heal of foot
Plantar or
sole of foot
b Posterior view
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• There are also Anatomical Regions
• An example is the abdominopelvis, which
contains:
• Four Abdominopelvic quadrants
• Nine Abdominopelvic regions
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Abdominopelvic Quadrants
Right Upper
Quadrant
(RUQ)
Left Upper
Quadrant
(LUQ)
Right Lower
Quadrant
(RLQ)
Left Lower
Quadrant
(LLQ)
a Abdominopelvic quadrants. The four
abdominopelvic quadrants are formed by two
perpendicular lines that intersect at the navel. The
terms for these quadrants, or their abbreviations, are
most often used in clinical discussions.
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Abdominopelvic Regions.
Right
hypochondriac
region
Right lumbar
region
Right
inguinal
region
Epigastric
region
Left
hypochondriac
region
Umbilical
region
Left lumbar
region
Hypogastric
(pubic)
region
Left inguinal
region
b Abdominopelvic regions. The nine abdominopelvic
regions provide more precise regional descriptions.
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Abdominopelvic Quadrants and Regions.
Liver
Gallbladder
Stomach
Spleen
Large intestine
Small intestine
Appendix
Urinary
bladder
c Anatomical relationships. The relationship between
the abdominopelvic quadrants and regions and the
locations of the internal organs are shown here.
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• There are also Anatomical directions
• These are reference terms based on a subject
• Ipsilateral means the structures are on the
same side of the body.
• Contralateral means the structures are on
opposite sides of the body.
• Intermediate means one structure is between
two other structures
• Proximal is close to a pivot point; distal is far
from the pivot point
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Directional References.
Superior: Above; at a higher level (in the human body, toward the head)
Right
Superior
The head is superior to the knee.
Cranial or Cephalic
Toward the head
Left
The cranial, or cephalic, border of
the pelvis is superior to the thigh.
Proximal
Toward an
attached base
The shoulder is
proximal to the
wrist.
Lateral
Medial
Away
from the
midline
Toward
the
midline
Posterior or Dorsal
Anterior or Ventral
Posterior: The back
surface
Anterior: The front
surface
Ventral: The belly
side. (equivalent to
anterior when
referring to the human
body)
The umbilicus (navel)
is on the
anterior (or ventral)
surface of the trunk.
Dorsal: The back.
(equivalent to posterior
when referring to the
human body)
The scapula (shoulder
blade) is located
posterior
to the rib cage.
Proximal
Caudal
Distal
Toward the tail;
(coccyx in
humans)
The hips are
caudal to the
waist.
Away from an
attached base
The fingers are
distal to the
wrist.
OTHER DIRECTIONAL TERMS
Superficial
Distal
At, near, or relatively close
to the body surface
The skin is superficial to
underlying structures.
Deep
Toward the interior of the
body; farther from the surface
a Anterior view
Inferior: Below; at a lower level; toward the feet
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The bone of the thigh is deep
to the surrounding skeletal
muscles.
The knee is inferior to the hip.
b Lateral view
Inferior
• And there are Anatomical Planes and Sections
• A Plane is a three-dimensional axis (x, y, z graph)
• A Section is a slice that is parallel to a plane
• This is used to visualize the internal organization
and structure
• It is important in different radiological techniques
• MRI
• PET
• CT
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Sagittal divides the body or an
organ into left and right sides
• Midsagittal:
• Runs through the midline.
• Produces equal right and
left halves.
• Parasagittal:
• Runs away from the midline.
• Produces unequal right and
left portions.
•
Frontal or Coronal
• Divides the body into
anterior and posterior
portions
•
Transverse or Horizontal
• Divides the body into
superior and inferior portions
Summary of Sectional Planes.
Sagittal plane
Frontal or coronal
plane
Plane is oriented parallel to
long axis
Plane is oriented
parallel to long axis
A sagittal section separates
right and left portions. You
examine a sagittal section,
but you section sagittally.
A frontal, or coronal,
section separates
anterior and
posterior portions of
the body. Coronal
usually refers to
sections passing
through the skull.
In a midsagittal section, the
plane passes through the
midline. It separates the
body into equal right and
left sides.
Directional term:
frontally or coronally
Midsagittal plane
A parasagittal section
misses the midline. It
separates the body into
unequal right and left sides.
Directional term: sagittally
Transverse, or
horizontal, plane
Plane is oriented
perpendicular to long axis
Frontal plane
Transverse plane
(inferior view)
A transverse, or cross,
section separates
superior and inferior
portions of the body.
Directional term:
transversely or horizontally
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Body Cavities
• There are two essential functions of body cavities
1. They protect organs from accidental shocks
2. They permit changes in the size and shape of
internal organs (i.e. heart, lungs, etc…)
• The main example is the ventral body cavity,
which is termed the Coelom
• It is composed of the thoracic cavity and the
abdominopelvic cavity
• These cavities are separated by the diaphragm
• Another example is the dorsal body cavity, which
contains the cavities of the brain and spinal cord
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Relationships among the Subdivisions of the Body Cavities of the Trunk.
DORSAL
VENTRAL
Cranial
cavity
Pleural
cavity
Pericardial
cavity
Thoracic
cavity
Vertebral
cavity
Diaphragm
Peritoneal
cavity
Abdominal
cavity
Abdominopelvic
cavity
Pelvic
cavity
A lateral view showing the body cavities of the trunk.
The muscular diaphragm subdivides them into a
superior thoracic cavity and an inferior abdominopelvic
cavity. Four adult true body cavities are shown
Only one of the two pleural thoracic cavities can be shown in a sagittal section!
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For now, let’s focus on the
ventral body cavity
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Relationships among the Subdivisions of the Ventral Body Cavity
Ventral Body Cavity
• Provides protection
• Allows organ movement
• Linings prevent friction
Subdivides during development into
Abdominopelvic Cavity
Thoracic Cavity
Surrounded by the chest wall
and the diaphragm
Peritoneal Cavity
Right Pleural Cavity
Surrounds right lung
Mediastinum
trachea, esophagus,
thymus and major
vessels, and also…
Pericardial cavity
Surrounds heart
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Left Pleural Cavity
Surrounds left lung
Extends throughout
the abdominal cavity
and into the superior
portion of the pelvic
cavity
Abdominal Cavity
Contains many
digestive glands
and organs
Pelvic Cavity
Contains the
urinary bladder,
reproductive organs,
the end of the
digestive tract and
the rectum
Ventral body cavity divisions
You can see two pleural
cavities the the thorax in
a coronal section
THORACIC CAVITY
Right
lung
in right
pleural
cavity
Left
lung
in left
pleural
cavity
Spine
VENTRAL BODY CAVITY
Mediastinum
ABDOMINOPELVIC CAVITY
Diaphragm
THORACIC CAVITY
The abdominal cavity
contains many digestive
glands and organs
Retroperitoneal area*
Diaphragm
ABDOMINOPELVIC
CAVITY
The pelvic cavity contains
the urinary bladder,
reproductive organs, and the
last portion of the digestive tract
*The retroperitoneal space is an area posterior to the peritoneum and anterior to the
muscular body wall. It contains the pancreas, kidneys, ureters, and parts of the
digestive tract
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•Serous membranes line ventral body cavities
and secrete serous fluid into the cavity
• They consist of two continuous layers separated
by a cavity
• The visceral layer is an inner layer that covers the
organ surface
• The parietal layer is an opposing outer layer that
covers inner surface of body wall or chamber
• The cavity is the potential space between the
visceral and parietal layers
• This cavity is filled with serous fluid (lubricant)
• Allows for smooth movement of the surrounded
organ (i.e. heart, lung, digestive tract, etc…)
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Examples of Serous Membranes in Ventral Cavity
•Pericardium: Surrounds the heart
• Visceral pericardium
• Parietal pericardium
•Pleura : Surrounds each lung
• Visceral pleura
• Parietal pleura
•Peritoneum: Surrounds most of abdominopelvic cavity
• Visceral peritoneum
• Parietal peritoneum
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Relationships among the Subdivisions of the Body Cavities of the Trunk.
Visceral
pericardium
Heart
Pericardial
cavity
Parietal
pericardium
Air space
Balloon
b The heart projects into the pericardial cavity like a fist pushed
into a balloon. The attachment site, corresponding to the wrist
of the hand, lies at the connection between the heart and
major blood vessels. The width of the pericardial cavity is
exaggerated here; normally the visceral and parietal layers
are separated only by a thin layer of pericardial fluid.
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Relationships among the Subdivisions of the Body Cavities of the Trunk.
ANTERIOR
Pericardial
cavity
Parietal pleura (outside)
Pleural cavity (space)
Heart
Right
lung
Left
lung
Visceral pleura (inside)
Mediastinum
Spinal cord
POSTERIOR
c A transverse section through the thoracic cavity, showing the central
location of the pericardial cavity. The mediastinum and pericardial cavity
lie between the two pleural cavities. Note that this transverse or crosssectional view is oriented as though the observer were standing at the
subject’s feet and looking toward the subject’s head. This inferior view of
a transverse section is the standard presentation for clinical images.
Unless otherwise noted, transverse or cross-sectional views in this text
use this same orientation (see Spotlight Figure 1-10).
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Supplemental Material (look over it yourselves)
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Medical Diagnosis and Imaging Techniques
Diagnosis is the identification of disease or disorder:
• Consultation
•
•
Medical or familial history of disease
Symptoms (subjective changes) or signs (measurable or observable changes)
• Physical examination
•
•
Vital signs: temperature, pulse, blood pressure, breathing
Palpation (feel) and Auscultation (listen)
• Laboratory tests
•
urine, blood or biopsy
• Explorative Surgery
• Medical Imaging
•
•
•
•
•
•
Radiography
Computed Tomography Scanning (CT Scan)A
ngiogram & Digital Subtraction Angiography (DSA)
Positron Emission Tomography (PET)
Magnetic Resonance Imaging (MRI)
Ultrasound
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Radiography
• Uses X-rays
─ penetrate soft tissues and darken photographic
film
─ Dense tissues absorb X-rays so film remains
white
• Radiograph: picture that results; also called an Xray
• Radiopaque/contrast agents allow hollow organs to
be visualized
• Major use is osteology, chest examination,
mammography, dentistry
Disadvantages
• Radiation exposure
• Poor resolution of soft tissues and denser
structures block less dense structures
• Conventional X-rays flatten 3-D structures
into 2-D images
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Computed Tomography (CT)
• Uses X-rays
• Patient moved through cylindrical machine
• Thin images can be viewed singly or the computer
can stack them to give a three dimensional picture
• Sharper image than simple radiography
• Useful for soft tissue scanning, identification of
tumors, aneurysms, cerebral hemorrhages, kidney
stones, trauma
Disadvantages: Radiation exposure
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Angiogram
• Uses X-rays in conjunction with injected contrast
medium to produces image of blood vessels
• Digital Subtraction Angiography (DSA): Images
of vessel taken before and after injection of contrast
medium and analyzed by computer
• Used for diagnosis of aneurisms, atherosclerosis,
blocked arteries
Disadvantages: Radiation exposure
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Positron Emission Tomography (PET)
• Assesses metabolic state of tissues
• Patient injected with radioactive
isotopes including glucose
• Emitted Positrons collide with
electrons giving off Gamma rays
that are detected by sensor
• Analyzed by computer
• Used to access active brain areas
when performing tasks, oncology,
heart damage
• Disadvantages: Cost, messy
radioactive tracers, patient
discomfort.
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Cancerous
throat
tissue
A Technician monitoring the output of a PET scanner
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Magnetic Resonance Imaging (MRI)
• Patient placed in cylindrical chamber surrounded by
electromagnets
─ Body subjected to strong magnetic field which aligns
hydrogen atoms, followed by brief pulse of
radiowaves to knock out of alignment
─ When magnetic field removed, electrons realign
giving off energy.
─ Detected by sensors and analyzed by computers
─ Amount and rate of energy given off depends on
tissue type.
• Functional MRI (fMRI): used to visualize active areas
of the brain
• Better than CT scans for soft tissue. Excellent
contrast between normal/abnormal tissue.
Disadvantages
• Cost, Cannot use on patient with metal in their body,
limited use for mostly soft tissues, patient discomfort.
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Sonography (Ultrasound)
• Uses handheld device that uses highfrequency sound waves and detects
echo back from internal organs
• Avoids harmful x rays
• Used in obstetrics, cardiology
• 2nd most commonly used of the
techniques
Disadvantages
• Image quality, limited use
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