Human anatomy
Chapter 1
Introduction to Human Anatomy
I. Introduction to Anatomy- A broad field
of science in which the body is studied at
different levels. The definition of anatomy
(morphology) is the study of human body
or science of form; physiology is the study
of body function. As you study this subject
pay attention to the theme of how
"Structure Determines Function" .
• II Anatomical Terminology- The study of anatomy will
introduce you to a large vocabulary. It is as if you were
learning a new language and mastery of this language is
essential for your success in this class.
A. Pay attention to Greek and Latin roots as you
learn the new vocabulary. At one point Latin was
the official language used in science and thus it
remains today as a way to maintain consistency
worldwide.
B. As you learn this new language it is
recommended that you create vocabulary flash
cards pertaining to each chapter to learn the correct
spelling and pronunciation (internet glossary) for
each word. Practice the new vocabulary
consistently and recognize that many different words
can be used to describe the same thing
III. Branches of Anatomy- The different levels of
organization that make up the body allow for the
study of anatomy in various branches.
Levels of organization:
Atoms form molecules
molecules form organelles (essential for cell function)
organelles form cells
a group of cells with the same structure and function forms a
tissue
two or more different tissues form an organ
two or more organs form organ systems
multiple systems form the human body.
B. Anatomy can be studied at each level of organization:
1) Gross Anatomy
2) microscopic anatomy
3)clinical anatomy
4)Developmental Anatomy
5) Embryology
6)Functional Morphology (physiology)
1. Gross Anatomy- This form of study focuses on large body structures that
can be analyzed by the naked eye, primarily through dissection. Studying
the organs can be done as part of regional anatomy (all the organs in a
body region) or systemic anatomy (all organs relating to one system).
Surface anatomy is the study or superficial body "landmarks" that reveal
underlying organs.
A. The
anatomical
position- A
stance or
position
commonly
used for
visual
reference
points.
B. Defined as
standing
erect, feet
together and
eyes, feet,
and palms
facing
forward.
B. Directional and Regional terms- These are standard terms based
on the anatomical position to precisely describe the location of a
certain body part in relation to another.
i. Directional terms are usually paired as:
superior and inferior
anterior and posterior
medial and lateral
intermediate
distal and proximal
superficial and deep.
ADD: VENTRAL/DORSAL
See page 6 table 1.4 for definition and description.
Note-- four legged animals have a different anatomical position than
humans. Thus, their ventral is on the inferior side and dorsal in on
the superior side whereas in humans ventral and anterior is the
same and so is dorsal and posterior
ii. Regional
terms are used to
describe certain body
regions, many
anatomical structures
will have names
relating to their body
region. See p 7
C. Body planes
and sections- a
plane is a flat
sectional cut
along the body
(see page 11).
There are four
planes:
Frontal (coronal)
Median (midline
or sagittal)
Transverse
(horizontal)
Oblique
(diagonal)
• STOP FOR TODAY
D. Body cavities and membranes- cavities are spaces in the body that are
filled with organs and these organs are often surrounded by membranes
i. Dorsal
body cavitya large
cavity on the
posterior
side of the
body, it
contains the
brain and
spinal cord.
It is further
divided into
the cranial
and vertebral
cavity
ii. Ventral body cavityanother large cavity that
encloses organs on the
anterior side of the body. It
is also divided into the
throracic cavity- divided
into pleural cavity,
mediastinum, and
pericardial cavity
abdominopelvic cavityabdominal and pelvic
cavity containing
organs in peritoneal
cavities
iii. Other smaller cavities may be created by membranes and are also
closed to the environment
(a) Synovial cavities- formed by fibrous layers they surround joints and
create lubricating fluids to reduce friction
(b) Serous cavities- formed by serous membranes (sora) that
surround organs and contain two membrane layers (see page 15)
1.parietal serosa- membrane layer that forms the outer part
of the cavity
2.visceral serosa- membrane layer that forms the inner part
of the cavity and is closer to the organ (viscera)
iiii. Some cavities are smaller and open to the outside environment: nasal,
oral, orbital (eye), ear cavities (see page 16).
.
E. Body quadrants
and regions. To
facility its study, the
abdominopelvic
region can also be
divided into different
regions and
quadrants. There
are four quadrants
and nine regions.
See page 17 and
master this
vocabulary, it is
essential for those
going into the health
professions.
2. Microscopic Anatomy- This
form of anatomy is better
known as histology which
is the study of tissues.
Specializes cells form
different types of tissues.
Thus different tissues do
not look or function in the
same way. Any illness or
physiological problems
experienced in the body
occur at the cellular level.
A. Light and electron
microscopy- Two types of
microscopes are used to
study tissues and each
reveals different aspects.
Light microscopes have less
magnification then electron
microscopes but show color
and texture. Specimens can
be stained to show only
certain aspects. Electron
microscopes can magnify an
image to show finer detail
than an electron microscope
but is flat and colorless.
Scanning and transmission
electron microscopes a
power and used to reveal
more detail.
B. Preparing Human Tissue for microscopy- Tissues are processed
before viewing, first they are fixed (preserved), then sectioned (thinly
sliced), and then stained (color stains or metals added). The type of stain
used depends on the type of microscope through which specimen will be
studied.
C. Scanning Electron Microscopy- This type of microscope uses electrons
to scan the surface of a
specimen with an electron beam and create
a three dimensional picture. The specimen is preserved and stain with
metal, but it is not sectioned. These images are originally in shades of
gray but can be artificially colored.
D. Artifacts- As you study specimen under the microscope or by an
unaided eye, you will notice that the structure my not strictly represent
that of a living structure. Preserving and staining the specimens alters the
tissues and may even create artifacts (distortions). As your eye is trained
to recognizes structures you will be able to distinguish the differences
between preserved and live speicimens.
3. Clinical Anatomy- includes
pathological anatomy
(study of anatomical
changes caused by
disease) and radiographic
anatomy (study of body
structures by different
forms of radiation). Clinical
anatomy relies on different
imaging techniques used
for diagnosis.
A. X Rays- this is the
traditional method of
diagnosis. X-rays that are
directed to the body may
penetrate and create a dark
image if they pass through
soft tissues, while those
that are absorbed by dense
tissues, such as bones,
leave a white image.
Contrast medium (solution
containing heavy elements
like barium) can be used to
view soft tissue organs.
1. Cineradiography is a techniques in which a fluoroscope (fluorescent screen) is
used to view an X-ray image as organs
are moving.
2. Prolonged exposure to X-rays can cause genetic defects, tissue damage, or
cancer. Other disadvantages are: it is difficult to see soft tissues, a 3D body becomes
a flatten image, denser organs block imaging of less dense organs
B. Advanced X-Ray Technique- these techniques
incorporate the use of computers for processing the xrays taken and adding color to the images.
1.CT Scan (computed tomography) or CAT Scan
(computed axial tomography)- A rotating tube and
recorder move around the person as X-rays are taken. A
computer processes the images to create a single
transverse image that reveals all organs at their best
angles with almost no blocking structures.
1.CT Scan (computed tomography) or CAT Scan (computed axial tomography)A rotating tube and
recorder move around the person as X-rays are taken. A
computer processes the images to create a single transverse image that
reveals all organs at their best angles with almost no blocking structures.
2. DSR (dynamic spatial resolution)ultra fast CT scanner are used to
assemble a series of CT pictures and
create a three dimensional image can
also be used to view in detail an organ
in motion (beating heart, blood flow)
3. Xenon CT- a CT taken in
combination with inhaled xenon (inert
gas). Absence of xenon in the picture
indicates area with blood flow is lacking.
Used primarily for identifying an area of
a stroke.
C. DSA (digital subtraction angiography)An image is taken before and after the
patient is given a contrast medium. The
computer processes the x-ray images
and subtracts the differences in the
"before" image from the "after" image.
This any blockages in blood vessels are
revealed.
D. PET ( Positron Emission
Tomography)- radioactive
isotopes are detected,
these isotopes may be
used to follow the flow of
blood to the brain and
heart. As the isotope
decays it emits a gamma
ray that is detected. There
will be a greater
concentration in areas that
are more active or are
receiving more
blood. Because of its
cause and other limitations
it is being replaced with the
MRI.
•
E. Sonography (ultra sound)- high frequency (ultrasonic) sound waves are
sent through the tissues and can reflect (echo) off the body. The echo is
processed by the computer to produce an image. The equipment is
inexpensive, the technique is safer, and it can be used to detect developing
fetuses. Ultrasound is used to study soft tissue and contrasting mediums
can also used to create better images.
F. MRI (Magnetic Resonance Imaging)- The patient lies in a
chamber
surrounded by a large magnet and is exposed to a strong magnetic field when
magnet is activated. Then the hydrogen atoms in the body's water align with
the magnet and a radio frequency is emitted to misalign them. As they realign
with the magnet a radio wave is emitted from them. Sensors detect the waves
and the computer takes these signals and produces detailed images of soft
tissues. Tissues can be distinguished on the basis of their water content. Bones
to do not block the view of an MRI because they have low water content.
F. MRI (Magnetic Resonance Imaging)- The patient lies in a
chamber surrounded by a large magnet and is exposed to a strong
magnetic field when magnet is activated. Then the hydrogen atoms in
the body's water align with the magnet and a radio frequency is emitted
to misalign them. As they realign with the magnet a radio wave is
emitted from them. Sensors detect the waves and the computer takes
these signals and produces detailed images of soft tissues. Tissues
can be distinguished on the basis of their water content. Bones to do
not block the view of an MRI because they have low water content.
4. Developmental Anatomy- focuses on the changes in body structures as
the body ages and grows.
5. Embryology- the study of organ formation and development before
birth.
6. Functional morphology- studying the function of body structures and
their design efficiency- can be related to kinesiology.
IV. The Metric System- In the science field length, volume, and weight
are measured in unit used by the metric system. This allows
consistency in measurement throughout the world. Reference
Appendix A for these measurements and prefixes.
Length is measured in kilometer, meter, centimeter, or millimeter
Volume is measured in kiloliter, liter, or milliliter
Weight is measured in kilogram, gram, or milligram.
V. Anatomical Variability- Be aware that the structures presented
in the book are largely representative of those found in every
individual. However, because of our genetic diversity every
individual is got structurally identical and sensory organs do not
perceive the environment the same either.