These inquiries have provided data to suggest that the PSLM protocol can increase a student's learning rate and ability to comprehend the relationship of adjacent anatomical structures as viewed in sections.

Systematic Search Pattern ([3], ([2])

A.  The goal of the second part of this study is to establish a systematic search pattern for sections. One overriding aspect of the strategy for mastery of sectional anatomy incorporates the PSLM approach.

B.  The establishment of a standard systematic search pattern is essential to insure the mastery of sectional anatomy.

C.  A systematic search pattern contains a prescribed sequence of steps to further insure the correct identification of structures of anatomical sections and clinical images.

A.  Identification of multi-sectional planes.

B.  Determine the origin of the section.

C.  Recognize the four tissue layers/structures in a prescribed sequence.

D.  Classify the layers/ structures of the section into 4 anatomical units.

E.  Identify fixed body landmarks.

F.  Compare anatomical sections with clinical images.

G.  Correct identification of the surface for each plane.

H.  Description of structures as seen in each plane.

I.   Recognize the relationship of adjacent structures of the section.

A.  Identification of a multi-sectional plane (Fig.10)

1. Transverse (axial) plane is perpendicular to the median.

2. The coronal plane is parallel to the midaxiallary line.

3. The sagittal plane is parallel to the median.

4. Off axis means slanted or oblique section of one of the other planes.

B.  Identification of the section's origin

1. Includes orientation lines (grids), scanograms, for both cadaver sections and clinical images.

2.  Identifying the origin of a section is to rely on the distance from a fixed reference point such as Reid's baseline (infraorbital meatal plane) in axial sections of the head, the median for sagittal sections and midaxiallary line for coronal sections.

C.  The recognition of four classes of layers ([1], ([5])

1.  These classes are very useful to focus on the main structures of the section.  The four classes of tissue layers include:

a. Somatic - layers/structures which surround cavities.  (Fig.11, Fig.12 , Fig.13, Fig.14)

b. Visceral - layers/structures found within cavities, including visceral spaces, clefts, as well as major blood vessels. (Fig.15, Fig.16, Fig.17, Fig.18, Fig.19, Fig.20, Fig.21)

c. Visceral luminal - tissue layers/structures associated with hollow organs, or organs containing a lumen  (Fig.22)

d. Visceral nonluminal - tissue layers/structures of organs possessing no lumen (Fig.23)

D. Classify the layers/structures of the section into 4 anatomical units ([6])

1. Musculoskeletal unit - skeletal muscles and bones.  (Fig.24)

2. Neurovascular unit - comprised of nerves, blood and lymph vessels. (Fig.25)

3. Visceral unit - Composed of internal organs of the section. (Fig.26)

4. Enclosing unit - such as spaces, clefts, membranes and cavities. (Fig.27)

E. Identify fixed body landmarks

1. Axial  (transverse)

(a) Infraorbital meatal plane is the fixed landmark for axial head sections.

(b) The vertebral levels are fixed landmarks for axial sections in the neck, thorax, abdomen, and pelvis.

(c) The fixed landmarks for axial sections of the limbs is the distancefrom the proximal end.

2. Coronal (frontal)

(a) The midaxillary line is the fixed landmark for coronal sections of the head, neck, thorax, abdomen, pelvis and limbs.

(b) A midcoronal section is one from the midaxillary line.

3. Sagittal

(a) The median is the fixed landmark for all sagittal sections except for the limbs.  The median of each limb serves as it's fixed landmark.

(b) A midsagittal section is a section from the median.

F. Compare anatomical sections with clinical images (This means to note similarities and differences)

1. Compare specific layer/structures of anatomical sections with comparable computer images in accordance with PSLM protocol.

2. Compare the anatomical units of sections with comparable images, in accordance with PSLM protocol.

G. Correct identification of the surface for each plane

1. Axial (transverse): The inferior surface of the section is used for identification and interpretation.

2. Coronal  (frontal): The anterior surface is used for identification and interpretation.

3. Sagittal: The left surface of the section is typically used for identification and interpretation of the section. ([9])

H. Description of structures as seen in each plane

1. Structures appear different in dissimilar planes, depending on the position/orientation of the organ.

a. Some organs are normally positioned in a vertical plane, e.g.,  trachea

b. Some organs are normally positioned in a vertical oblique plane,e.g., heart

c. Some organs are normally positioned in a transverse plane, e.g., clavicle

d. Some organs are normally positioned in a transverse oblique plane, e.g., pancreas, transverse colon

e. Some organs are normally found in a curved position, e.g., arch of the aorta

f. Some organs are normally located in a transverse and curved position, e.g., small intestines

g. Some organs are normally positioned in a circular arrangement, e.g., circle of Willis

I. Recognize the relationship of adjacent structures of the section

1. Implementation of the PSLM protocol offers itself as a useful tool in this regard because sequenced labeling provides relationships of adjacent structures.