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Questions and Answers
What type of plane divides the body into right and left parts?
What type of plane divides the body into right and left parts?
Which section type is also referred to as a cross section?
Which section type is also referred to as a cross section?
What organ structure would be seen best in a transverse section at the level of the kidneys?
What organ structure would be seen best in a transverse section at the level of the kidneys?
What is the primary purpose of sectioning the body along different planes?
What is the primary purpose of sectioning the body along different planes?
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Which of the following correctly describes a frontal section?
Which of the following correctly describes a frontal section?
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If a sagittal cut does not divide the body into equal halves, what is this type of section called?
If a sagittal cut does not divide the body into equal halves, what is this type of section called?
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Which description does NOT accurately represent a transverse plane?
Which description does NOT accurately represent a transverse plane?
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Which plane allows you to view internal organs from the front or back perspective?
Which plane allows you to view internal organs from the front or back perspective?
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What separates the thoracic cavity from the rest of the ventral body cavity?
What separates the thoracic cavity from the rest of the ventral body cavity?
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Which of the following organs is NOT located within the cranial cavity?
Which of the following organs is NOT located within the cranial cavity?
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Which body cavity is primarily protected by the rib cage?
Which body cavity is primarily protected by the rib cage?
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Which regions are lateral to the hypogastric region?
Which regions are lateral to the hypogastric region?
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What is the central region of the abdominopelvic cavity called?
What is the central region of the abdominopelvic cavity called?
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How are the abdominopelvic organs primarily protected?
How are the abdominopelvic organs primarily protected?
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Which cavity is described as being continuous with two subdivisions?
Which cavity is described as being continuous with two subdivisions?
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What term describes the central region in the thoracic cavity that separates the lungs?
What term describes the central region in the thoracic cavity that separates the lungs?
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Which incorrectly describes the structure of the abdominopelvic cavity?
Which incorrectly describes the structure of the abdominopelvic cavity?
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What does negative feedback systems primarily regulate?
What does negative feedback systems primarily regulate?
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In which region of the abdominopelvic cavity would you find the stomach and liver?
In which region of the abdominopelvic cavity would you find the stomach and liver?
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What process allows a person to maintain balance when standing still?
What process allows a person to maintain balance when standing still?
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Which of the following is a characteristic of the ventral body cavity?
Which of the following is a characteristic of the ventral body cavity?
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Flashcards
Midsagittal Plane
Midsagittal Plane
A vertical plane dividing the body into equal right and left halves.
Frontal Plane
Frontal Plane
A vertical plane dividing the body into anterior (front) and posterior (back) parts.
Transverse Plane
Transverse Plane
A horizontal plane dividing the body into superior (top) and inferior (bottom) parts.
Sagittal Section
Sagittal Section
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Cross Section
Cross Section
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Coronal Section
Coronal Section
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Body Planes
Body Planes
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Anatomical Position
Anatomical Position
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MRI Scans
MRI Scans
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Dorsal Body Cavity
Dorsal Body Cavity
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Cranial Cavity
Cranial Cavity
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Spinal Cavity
Spinal Cavity
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Ventral Body Cavity
Ventral Body Cavity
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Thoracic Cavity
Thoracic Cavity
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Diaphragm
Diaphragm
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Mediastinum
Mediastinum
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Abdominopelvic Cavity
Abdominopelvic Cavity
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Abdominal Cavity
Abdominal Cavity
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Pelvic Cavity
Pelvic Cavity
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Quadrants of Abdominopelvic Cavity
Quadrants of Abdominopelvic Cavity
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Regions of Abdominopelvic Cavity
Regions of Abdominopelvic Cavity
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Umbilical Region
Umbilical Region
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Negative Feedback Systems
Negative Feedback Systems
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Study Notes
A Closer Look
Medical Imaging: Illuminating the Body
Y bombarding the body with en-
ergy, new scanning techniques
can reveal the structure of inter-
nal organs, and wring out informa-
tion about the private and, until
now, secret working of their mole-
cules. These new imaging tech-
niques are changing the face of
medical diagnosis.
Until about 50 years ago, the
magical but murky X ray was the only
means of peering into a living body.
What X rays did and still do best was
visualize hard, bony structures and
locate abnormally dense structures
(tumors, tuberculosis nodules) in the
lungs. The 1950s saw the birth of nu-
clear medicine, which uses radioiso-
topes to scan the body, and ultra-
sound techniques. In the 1970s, CT,
PET, and MRI scanning techniques
were introduced.
The best known of new imaging
devices is computed tomography
(CT) (formerly called computerized
axial tomography [CAT]), a refined
version of X ray. A CT scanner con-
fines its beam to a thin slice of the
body and ends the confusion result-
ing from images of overlapping struc-
tures seen in conventional X rays.
CT's clarity has all but eliminated
exploratory surgery. As the patient is
slowly moved through the doughnut-
shaped CT machine, its X-ray tube
rotates around the body. Different tis-
sues absorb the radiation in varying
amounts. The device's computer
20
translates this information into a de-
tailed, cross-sectional picture of the
body region scanned. CT scans are at
the forefront in evaluating most prob-
lems that affect the brain (see photo
a), abdomen, and calcification of the
coronary arteries in those at an ele-
vated risk for heart disease. Special
ultrafast CT scanners have produced
a technique called dynamic spatial re-
construction (DSR), which provides
three-dimensional images of body or-
gans from any angle. It also allows
their movements and changes in
their internal volumes to be observed
at normal speed, in slow motion, and
at a specific moment in time. Al-
though DSR can be used to evaluate
the lungs and certain other mobile or-
gans, its greatest value has been to
visualize the heart beating and blood
flowing through blood vessels. This
allows heart defects, constricted
blood vessels, and the status of coro-
nary bypass grafts to be assessed.
Another computer-assisted X-ray
technique is digital subtraction an-
giography (DSA) (angiography
vessel pictures). This technique
provides an unobstructed view of dis-
eased blood vessels. Conventional
radiographs are taken before and af-
ter a contrast medium is injected into
an artery. Then the computer sub-
tracts the "before" image from the
'after" image, eliminating all traces
of body structures that obscure the
vessel. DSA is often used to identify
blockages in the arteries that supply
the heart wall and the brain (photo b).
Just as the X ray spawned "new
technologies, " so did nuclear medi-
cine in the form of positron emis-
Sion tomography (PET). PET excels
in observing metabolic processes.
PET's greatest clinical value has
been its ability to provide insights
into brain activity in those affected
by mental illness, Alzheimer's dis-
ease, and epilepsy. One of its most
exciting uses is to determine which
areas of the healthy brain are most
active during certain tasks (speak-
ing, listening to music, and so on).
The patient is given an injection of
short-lived radioisotopes that have
been tagged to biological molecules
(such as glucose) and then posi-
tioned in the PET •scanner. As the
radioisotopes are absorbed by the
most active brain cells, high-energy
gamma rays are produced. The com-
puter analyzes the gamma emission
and produces a picture of the brain's
biochemical activity in vivid colors.
Ultrasound imaging, or ultra-
sonography, has distinct advantages
over the approaches described so
far: the equipment is inexpensive
and it employs high-frequency sound
waves (ultrasound) as its energy
source. Ultrasound, unlike ionizing
forms of radiation, has no harmful ef-
fects on living tissues (as far as we
know). The body is probed with
pulses of sound waves, which cause
echos when reflected and scattered
oy body tissues. The echoes are ana-
yzed by computer to construct visual
images of body organs of interest.
Because of its safety, ultrasound is
the imaging technique of choice for
obstetrics, that is, for determining
•etal age and position and locating
Zhe placenta. Because sound waves
nave very low penetrating power and
ere rapidly scattered in air, ultra-
sonography is of little value for look-
ng at air-filled structures (the lungs)
or those surrounded by bone (the
orain and spinal cord).
Another technique that depends
on nonionizing radiation is magnetic
resonance imaging (MR/), which
uses magnetic fields up to 60,000
tmes stronger than the Earth's to
cry information from the body's tis-
sues. The patient lies in a chamber
Nithin a huge magnet. Hydrogen
molecules spin like tops in the mag-
•etic field, and their energy is en-
tanced by radio waves. When the
-adio waves are turned off, the en-
ergy is released and translated by
the computer into a visual image.
MRI is immensely popular because
et can do many things a CT scan
cannot. Dense structures do not
show up in MRI, so bones of the
skull and/or vertebral column do not
Impair the view of soft tissues such
as the brain (see Figure 1.6a, p. 16).
MRI is also particularly good at de-
-.ecting degenerative disease of vari-
ous kinds. Multiple sclerosis plaques,
•or example, do not show up well in
CT scans but are dazzlingly clear in
Artery supplying
heart
(a)
Narrowing
of the artery
(b)
Two different methods for illuminating the body. (a) CT scan
showing a brain tumor (oval area on right side of brain). (b) DSA image of
arteries supplying the heart.
MRI scans. A key issue being investi-
gated by MRI studies is how brain
development and behavior change
with growth or experience.
A newer variation of MRI, called
magnetic resonance spectroscopy
(MAS), maps the distribution of ele-
ments other than hydrogen to reveal
more about how disease changes
body chemistry. In 1992, MRI tech-
nology leaped forward with the
development of the functional MRI,
which allows tracking of blood flow
into the brain in real time. Until then,
matching thoughts, deeds, and dis-
ease to corresponding brain activity
had been the sole domain of PET.
Because functional MRI does not re-
quire injections of tracer elements, it
provides another, perhaps more de-
sirable, alternative to such studies.
Despite its advantages, the powerful
magnets of the MRI present some
problems. For example they can
'suck" metal objects, such as im-
planted pacemakers and loose tooth
fillings, through the body. Also, there
is no convincing evidence that such
magnetic fields are risk free.
As you can see, modern medical
science has many remarkable tools
at its disposal. CT and PET scans ac-
count for about 25 percent of all im-
aging. Ultrasonography, because of
its safety and low cost, is the most
widespread of the new techniques.
Conventional X rays remain the work-
horse of diagnostic imaging tech-
niques and still account for more than
half of all imaging currently done.
21
22 Essentials of Human Anatomy and Physiology
SUMMARY
Media study tools that could provide you with addi-
tional help in reviewing specific key topics of Chapter 1
are referenced below.
Interactive Physiology;
= Place website.
AN OVERVIEW OF ANATOMY AND
PHYSIOLOGY
1. Anatomy is the study of structure. Observation is
used to see the sizes and relationships of body
parts.
2. Physiology is the study of how a structure (which
may be a cell, an organ, or an organ system) func-
tions or works.
3. Structure determines what functions can occur;
therefore, if the structure changes, the function
must also change.
LEVELS OF STRUCTURAL ORGANIZATION
(pp. 2-7)
1. There are six levels of structural organization.
Atoms (at the chemical level) combine, forming the
unit of life, the cell. Cells are grouped into tissues,
which in turn are arranged in specific ways to form
organs. A number of organs form an organ system
that performs a specific function for the body
(which no other organ system can do). Together, all
of the organ systems form the organism, or living
body.
Exercise: Chapter 1, Levels of Biological
Organization.
2. For a description of organ systems naming the ma-
jor organs and functions, see pp. 3—7.
MAINTAINING LIFE (pp. 7-9)
1. To sustain life, an organism must be able to main-
tain its boundaries, move, respond to stimuli, digest
ie and excrete wastes, carry on metabolism,
reproduce itself, an grow.
2. Survival needs include food, oxygen, water, appropri-
ate temperature, and normal atmospheric pressure.
Extremes of any of these factors can be harmful.
HOMEOSTASIS (pp. 9-11)
1. Body functions interact to maintain homeostasis, or
a relatively stable internal environment within the
body. Homeostasis is necessary for survival and
good health; its loss results in illness or disease.
All homeostatic control mechanisms have a receptor
that responds to environmental changes and a con-
trol center that assesses those changes and produces
a response by activating a third element, the effector.
Most homeostatic control systems are negative feed-
back systems, which act to reduce or stop the initial
stimulus.
THE LANGUAGE OF ANATOMY
(pp. 11-19)
Anatomical terminology is relative and assumes that
the body is in the anatomical position (erect, palms
facing forward).
Regional terms. Visible landmarks on the body sur-
face may be used to specifically refer to a body part
or area. See pp. 12 and 13 for terms referring to an-
terior and posterior surface anatomy.
Exercise: Chapter 1, Anatomical Terminology:
Orientation and Directional Terms.
Directional terms
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
Superior (cranial, cephalad): above something
else, toward the head.
Inferior (caudal): below something else, toward
the tail.
Anterior (ventral): toward the front of the body
or structure.
Posterior (dorsal): toward the rear or back of
the body or structure.
Medial: toward the midline of the body.
Lateral: away from the midline of the body.
Intermediate: between a more medial and a
more lateral structure.
Proximal: closer to the point of attachment.
Distal: farther from the point of attachment.
Superficial (external): at or close to the body
surface.
Deep (internal): below or away from the body
surface.
Body planes and sections
a. Sagittal section: separates the body longitudi-
nally into right and left parts.
Chapter 1: The Human Body: An Orientation 23
b.
c.
Frontal (coronal) section: separates the body on
a longitudinal plane into anterior and posterior
parts.
Transverse (cross) section: separates the body on
a horizontal plane into superior and inferior parts.
WEB Exercise: Chapter 1, Body Planes.
5. Body cavities
Anatomical terms that apply to the backside of the
body in the anatomical position include
a. ventral and anterior.
b. back and rear.
c. posterior and dorsal.
d. head and lateral.
A neurosurgeon orders a spinal tap for a patient.
a. Into what body cavity will the needle be inserted?
b.
Dorsal: well protected by bone; has two subdi-
visions.
(1) Cranial: contains the brain.
(2) Spinal: contains the spinal cord.
Ventral: less protected than dorsal cavity; has
two subdivisions.
(1) Thoracic: The superior cavity that extends
inferiorly to the diaphragm; contains heart
and lungs, which are protected by the rib
cage.
(2) Abdominopelvic: The cavity inferior to the
diaphragm that contains the digestive, uri-
nary, and reproductive organs. The abdom-
inal portion is vulnerable because it is
protected only by the trunk muscles. There
is some protection of the pelvic portion by
the bony pelvis. The abdominopelvic cavity
is often divided into four quadrants or nine
regions (see Figure 1.8).
a. Ventral
b. Thoracic
c. Dorsal
d. Cranial
e. Pelvic
Which of the following groupings of the ab-
dominopelvic regions is medial?
a.
b.
c.
d.
e.
Hypochondriac, hypogastric, umbilical
Hypochondriac, lumbar, inguinal
Hypogastric, umbilical, epigastric
Lumbar, umbilical, iliac
Iliac, umbilical, hypochondriac
SHORT ANSWER ESSAY
WEB Exercise: Chapter 1, Dorsal and Ventral Cavities.
REVIEW QUESTIONS
MULTIPLE CHOICE
-Ilore than one choice may apply.
1. Consider the following levels: (1) chemical; (2) tis-
sue; (3) organ; (4) cellular; (5) organismal; (6) sys-
temic. Which of the following choices has the levels
listed in order of increasing complexity?
a.
b. 1, 4, 2, 5, 3,6 e.
2. Which of the following
taining homeostasis?
is (are) involved in main-
Feedback
Lack of change
Define anatomy and physiology.
Why would you have a hard time trying to learn
and understand physiology if you did not also un-
derstand anatomy?
List the 11 organ systems of the body, briefly de
scribe the function of each, and then name two or-
gans in each system.
In addition to being able to metabolize, grow, di-
gest food, and excrete wastes, what functions must
an organism perform if it is to survive?
Define homeostasis.
What is the consequence of loss of homeostasis, or
homeostatic imbalance?
Describe the anatomical position.
On what body surface is each of the following 10
cated: nose, calf of leg, ears, umbilicus, fingernails?
Several pairs of structures are given next. In each case,
choose the one that meets the condition given first.
a. Effector d.
b. Control center e.
c. Receptor
3. Which is not essential to survival?
a.
b.
c.
d.
e.
Distal—the knee/the foot
Lateral—the cheekbone/the nose
Superior—the neck/the chin
Anterior—the heel/the toenails
a. External—the skin/the skeletal muscles
b.
c.
Water
Oxygen
Gravity
d. Atmospheric pressure
e. Nutrients What kind of section would have to be made to cut
the brain into anterior and posterior parts?
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the different body planes and sections, as well as the various body cavities. This quiz covers detailed anatomical definitions and locations, ensuring a comprehensive understanding of human anatomy. Perfect for students preparing for anatomy exams.
