This document discusses the role of pathology in diagnosis and provides an overview of myology and splanchnology. It begins by explaining how pathology helps establish diagnoses through the examination of specimens and use of special techniques. It then provides introductions and overviews of the topics of myology, which is the study of muscles, and splanchnology, which is the study of viscera. Key aspects of muscle and visceral anatomy are summarized such as muscle types, layers of the gastrointestinal tract wall, and reference lines used to describe abdominal regions.

1. No. 3
1. Introduction of Myology
2. Introduction of Splanchnology

2. THE ROLE OF PATHOLOGY IN DIAGNOSTIC
PROCESS: FROM CLINICAL REASONING TO
MOLECULAR BIOLOGY.
 patients present with symptoms and
clinical examination reveals signs
which suggest a diagnosis
 -examination of various specimens in
pathology laboratories helps to
establish and confirm diagnosis, and
monitor the treatment
 Diagnosis is the act of identifying a
disease in an individual patient and is
based on clinical history, physical
examination and pathology
investigation

3. Diagnosis
 Diagnosis involves skills and laboratory tests
 Special pathology techniques are used
 Special stains, immunohistochemistry and molecular
biology techniques are routinely used

4. The role of pathologist:
 Looking at samples of tissues
(biopsies)
 Using the range of special laboratory
techniques
 Histology
 Autopsy
 Special stains
 Immunohistochemistry
 Electron microscopy
 Molecular biology techniques

5. Chapter 3
Myology

6. Section 1 Introduction
 Muscle tissue constitutes almost one-half of
the total body weight. Much of the body’s form
is due to the numerous muscles that attach to
the skeleton and underlie the skin. Other
muscles are located within the walls of hollow
organs and blood vessels.
 Muscle types:
The body contains three types of muscles--
skeletal muscle,
smooth muscle,
cardiac muscle.
 Muscles can be further classified as voluntary
and involuntary, on the basis of the type of
control exercised over their activity.

7.  Voluntary muscles: The contractions of
voluntary muscles are normally under the
conscious control of the individual. Voluntary
muscles are controlled by the portion of the
nervous system known as the somatic nervous
system.
 Involuntary muscles: The contractions of
involuntary muscles are generally not under
the conscious control of the individual. Rather,
they are governed by the portion of the
nervous system known as the autonomic
nervous system, as well as by hormones and
by factors intrinsic to the muscles themselves.

8. Skeletal muscles:
The muscles of locomotor apparatus are the
skeletal (or striated) muscles. All of them are
attached by at least one end to some part of
the skeleton.
The skeletal muscle is voluntary muscle
because its contraction is under the voluntary
control. About 40% of the body weight is
shared by the skeletal muscle.
Each skeletal muscle possesses a definite
shape, structure, location and accessory
apparatus, and is supplied by abundant blood
vessels, lymphatics and nerves, so that, it can
be regarded as an organ.

10.  Smooth muscles: Smooth muscle is so named
because its cells lack the striations evident in
skeletal muscle cells. It is also called visceral
muscle because it is found in the walls of
hollow organs and tubes such as the stomach,
intestines, and blood vessels.
Smooth muscle is involuntary muscle, and its
contractions govern the movement of
materials through the organ systems of the
body.
 Cardiac muscles: Cardiac muscle is a
specialized type of muscle that forms the wall
of the heart. It is involuntary, like smooth
muscle, and stiated, like skeletal muscle.

11. Ⅰ. The Morphology of Skeletal Muscle
 Muscle fiber: Each muscle is composed of a collection of muscle fibers
(cells).
 The muscle fiber, bundle of muscle fibers and the muscle are wrapped by
connective tissue.

12. 1. Connective-tissue
coverings
 Muscle fibers are held together by thin
sheets of fibrous connective-tissue
membranes called fascia. The fascia that
envelops an entire muscle is called the
epimysium. Fascia also penetrates
muscle, separating the muscle fibers into
bundles called the perimysium. We can
say that the perimysium is the connective
tissue that surrounds each bundle of
muscle fibers. The endomysium envelops
the cell membrane of each muscle fiber.

14. 2. Belly and tendon
 The fleshy part of a muscle is often called the
belly. At each end of a skeletal muscle the
connective tissue blends with the strong
collagen bundles to form the tendon that
anchors it to the bone, cartilage or articular
capsule.
 The muscles vary extremely in their shape. It
may be long, short, broad and circular band-
like (sphincter).
 Some muscles have more than one belly or
one origin. The fibers of some muscles are
oblique to the long axis of the muscle.
Because of their resemblance to feathers,
they are called pinnate muscles.

17. Ⅱ. The Origin, Insertion and Action of
Skeletal Muscle
1. Origin and Insertion:
Most of muscles are attached either directly or by
means of their tendons of aponeuroses to bones,
cartilages, ligaments, fasciae or to some combination
of these. Some muscles are attached to organs, such as
the eyeball, and some are attached to skin or mucous
membrane.
When a muscle contracts and becomes short, one of its
attachments usually remains fixed and the other one
moves.
The fixed attachment is called the origin, the movable
one the insertion.

18. In the limbs, the more distal parts are
usually mobile. Therefore the distal
attachment is usually called the insertion.
However, the terms origin and insertion are
convenient merely for purposes of
description.
Sometimes the anatomical insertion
remains fixed and the origin moves.
Sometimes both ends remain fixed, the
muscle then stabilizes a joint.

19. 2. Prime movers (agonists) and antagonist, synergist and
fixators:
 During movements of the body, certain principal muscles are
called into action. These muscles, called prime movers or
agonists, contract actively (shorten and thicken) and
produce the desired movement.
 A muscle that opposes the action of a prime mover is called
an antagonist.
 The muscles which cooperate in performing an action are
called synergist.
 Other muscles, called fixators, steady the proximal parts of
a limb while movements are occurring in distal parts.
A muscle may act as a prime mover, antagonist, synergist or
fixator under different conditions.

20. Ⅲ. The Nomenclature of
Muscle
The names of muscles usually indicated some
structural or functional feature.
 A name may indicate shape, e.g., rhomboid,
trapezius, or gracilis.
 A name may refer to location, e.g., tibialis
posterior.
 The number of heads of origin is indicated by the
terms biceps, triceps, and quadriceps.
 The names of some muscles, such as levator
scapulae and extensor digitorum, depend on their
actions.
 Action and shape are combined in the term
pronator quadratus,.
 The action and location are combined in the term
flexor digitorum profundus.

21. Ⅳ. The Supplementary Structures
of Muscles
Ⅰ) The Fascia
 It is formed by connective tissue and can be divided, from where it is
found, into two groups, superficial and deep.

22. 1. The superficial fascia
It is found immediately beneath the cutis,
covering almost the entire body.
It is a layer of loose connective tissue
containing fat in varying quantity. The
superficial fascia varies in thickness in
different individuals and different parts of
the body. It is very dense in the scalp, in the
palm of hand and the sole of foot. In the
groin it is so thick that is capable of being
subdivided into several laminae. Beneath the
fatty layer of the superficial fascia, there is
generally another layer of the same structure,
comparatively devoid of adipose (fatty) tissue,
in which the trunks of the subcutaneous
vessels and nerves, the superficial lymph
nodes, the mammary gland and certain
cutaneous muscles are found.

24. 2. The deep fascia (proper
fascia)
 It is a dense, inelastic fibrous membrane,
forming a strong investment, which not only
binds down collectively the muscles in each
region, but also gives a separate sheath to
each, as well as to the vessels and nerves.
 In the limbs, the fasciae give off septa which
separate the groups of muscle and attached
to the periosteum. These prolongations of
fasciae are usually called the intermuscular
septa. In certain situations the deep fascia
affords attachment for muscles. It is
thickened at the wrist and ankle to form the
retinaculum that maintains its underlying
tendons.

25. Ⅱ) The Synovial Bursa
 It is a connetive tissue sac with a slippery inner surface, and filled with
synovial fluid. Bursa presents in the place where tendon rubs against bone,
ligament, or other tendon, or where skin moves over a body prominence.

26. Ⅲ) The Tendinous Sheath
 The tendinous sheath is usually located
in the hand and foot in which the tendon
runs. It constitutes fibrous layer (fibrous
sheath of tendon) and synovial layer
(synovial sheath of tendon).
 Synovial sheath of tendon is a double
layered synovial sheath. The outer layer
is parietal layer and the inner layer is
visceral layer. The mesotendom forms
the continuity between the inner and
outer synovial layers and carries blood
vessels to the tendon. The inner layer of
the synovial sheath is fused with the
tendon. The fluid in the cavity of the
sheath is similar to synovial fluid of the
joint cavity and facilitates movement by
minimizing friction.

27. Ⅳ) The Sesamoid Bones
 They are developed in those tendons exert a great amount of pressure
upon the part over which they glide. They minimize the friction, change
the direction of pulling force and stengthen the force of the muscle.

28. PART Ⅱ
SPLANCHNOLOGY

29. Chapter 1 Introduction
Viscera and Splanchnology:
 Viscera are the organs that are mainly
situated in the thoracic, abdominal and pelvic
cavities and fulfill the metabolism and
maintain the life of the species.
They are associated with the pleura and
peritoneum.
According to the functions which they perform,
the viscera can be arranged in the
alimentary system, respiratory system,
urinary system and genital system.
 Splanchnology means the study of viscera.

30. Functions:
The main functions of the viscera are to fulfill the
metabolism and maintain the life of the species.
 The alimentary system is adapted to ingest foods, to
secrete enzymes that modify the sizes of food molecules, to
absorb the products of this digestive action, and to eliminate
the unused residues.
 The respiratory system is to carry out the gas exchanges-
supply of oxygen for the living cells and remove of carbon
dioxide resulting from cell metabolism.
 The primary function of the urinary system is to keep the
body in homeostasis by removing and restoring selected
amount of water and solutes. It also excretes selected
amount of various wastes.
 The functions of the genital system are to produce germ
cells and to secrete some hormones.

31. Ⅰ. General Structure of
Viscera
 According to their general structures, in each of the
three chief subdivisions, the alimentary, respiratory and
the urogenital system, two principal constituents may
be recognized, i.e., a tubular canal and a series of non-
tubular so called parenchymatous organs.

32. Ⅰ) The Tubular Viscus
 The basic arrangement of tissue layers in the wall of tube of viscera is
best seen in the alimentary system.

33. The wall of the alimentary tract, particularly those
from the esophagus to the anal canal, consists of:
 Mucous membrane (mucosa): possessing the functions
of secreting and absorbing.
 Submucosa: external to the mucosa, consisting of
areolar tissue.
 Muscular coat: outside the submucosa, with two
muscular coats—an outer longitudinal one and an inner
circular one.
 Serosa (adventitia): It is the outermost coat of the
tract and is composed of a thin layer of connective
tissue and a mesothelium on those organs that lie in the
abdominal and pelvic cavities.

34.  The respiratory tract consists mainly of the mucosa,
submucosa and outermost coat, the latter is composed
of cartilages and connective tissue.
 The wall of the urogenital tract consists of three layers
of tissues—the mucous coat, the muscular coat, and the
fibrous coat.

35. Ⅱ) The Parenchymatous
Organ
 The parenchymatous organ is encased in a
thin, fibrous capsule from which fibrous
partitions pass into the interior to divide
the organ into units known as lobules.
 There is a somewhat depression or slit on
the surface of the viscus named the hilum
or porta, such as the hilum of lung, the
porta hepatis and the hilum of kidney,
where the structures which form the root
of the viscus enter and leave the viscus.

36. Ⅱ. Reference Lines and Abdominal
Regions
 In order to observe the relative locations and the arrangements of internal
organs, it is necessary to mark reference lines on the surface of thorax
and to subdivide abdomen into regions.

37. Ⅰ) The Common Used
Reference Lines of the Thorax
1. The anterior median line
A vertical line through the median of the sternum.
2. The sternal line
A vertical line through the two sides of the
sternum.
3. The midclavicular line
It extends downward vertically from the midpoint
of the clavicle and usually coincides with the
mammary line in male.
4. The parasternal line:
It extends downward vertically through the
midway between the sternal line and
midclavicular line.

38. 5. The anterior axillary line
A vertical line downward from the anterior axillary fold.
6. The midaxillary line
A vertical line midway between anterior and posterior
axillary line.
7. The posterior axillary line
A vertical line downward from the posterior axillary fold.
8. The scapular line
A vertical line through the inferior angle of the scapula.
9. The posterior median line (vertebral line)
A vertical line through the spines of the thoracic vertebrae.

39. Ⅱ) The Abdominal Regions
To make it easier to describe the location of the
organs of the abdomen, the abdominal cavity is
divided into nine regions by 4 imaginary lines,
two horizontal and two vertical.
 two vertical lines bisect the inguinal ligaments;
 two horizontal lines: one passes along the
lower edge of the rib cage and another that
runs across the upper edges of the hip bones
(iliac crests).

40. These regions are:
 Umbilical: located centrally, surrounding the umbilicus
(navel).
 Lumbar: the regions to the right and left of the umbilical
region.
 Epigastric: (epi-means on or above; gastric-refers to the
stomach).
The midline region superior to the umbilical region. As the
name implies, most of the stomach is located in this region.
 Hypochondriac: (hypo-means beneath or under; chondral
refers to cartilage)
The regions to the right and left of the epigastric region.
The name indicates that the hypochondriac regions are
located beneath the cartilage of the rib cage.

41.  Hypogastric: the midline region directly inferior to the
umbilical region,
 Iliac: the regions on either side of the hypogastric
region. The name is derived from the iliac (hip) bones,
which form the lateral boundaries of the regions. These
areas are also referred to as the inguinal regions .
In practice, it is more common to divide the
abdominopelvic cavity into four quadrants by means of
two intersecting lines; an imaginary horizontal line and
a vertical line that pass through the umbilicus. These
two intersecting lines (planes) divide the
abdominopelvic cavity into a right upper quadrant; a
right lower quadrant; a left upper quadrant, and a left
lower quadrant.