DA QUESTA SEZIONE SI ACCEDE
ALL'ANATOMIA DELLA GABBIA TORACICA E DEL SUO CONTENUTO
Surface Anatomy: Thorax
Anatomical Position
Before studying anatomy, a student should become aware
of some of the vocabulary that is used to describe various aspects of the human
body. If everyone uses the same terminology, then it is easier to understand
what each of us is trying to say. So, before learning the particulars about the
anatomy of a region, we will take a look at some of the terminology.
For the purpose of description, the body is considered
as being in what is called the. "anatomical position". We will use a skeleton to
describe this position. In this Anatomical Position, the body is assumed to be
standing, the feet together, the arms to the side, and the head and eyes and
palms of the hands facing forwards. To ensure consistency of description it is
important to keep the anatomical position constantly in mind. This last point is
an important one, since in a normal relaxed position of the body, the thumb
points anteriorly. In anatomical parlance, the thumb is a lateral structure, not
an anterior one. Here's the Anatomical Position as shown by a skeleton:
Anatomical Planes of the Body
Second, you will consider the planes of the body. Understanding these will
facilitate learning terms related to position of structures relative to each
other and movement of various parts of the body.
Anatomical Position
|
FRONTAL (or coronal) separates the body
into Anterior and Posterior parts
MEDIAN (or midsagittal) separates body into
Right and Left parts
HORIZONTAL separates the body into Superior and
Inferior parts
SAGITTAL any plane parallel to the median plane |
 |
After taking a look at the Anatomical Planes, you can
then view some of the terms related to the planes. These are listed in the
following tables. You will notice that most of these are in pairs of opposites.
Terms of relation or position
| Aditus |
an entrance or opening |
| Ala |
a wing-like process |
| Alveolus |
a deep narrow pit, such as a tooth-socket |
| Ampulla |
used to describe the dilated part of a duct. |
| Ansa |
a loop, usually referring to a nerve |
| Antrum |
a cavity |
| Aponeurosis |
a glistening sheet of fibrous connective tissue from
which muscle fibers arise or into which they run |
| Artery |
a blood vessel which conducts blood from the heart |
| Bone |
a special form of connective tissue in which calcium
salts are deposited and which provides a framework, or skeleton, for the
other tissues of the body. |
| Bursa |
a membranous sac containing a small amount of viscous
fluid. A bursa is usually found in tissues where friction develops, such as
where a tendon crosses a bony prominence. A bursa may form synovial
sheaths to surround tendons as they cross other tendons or bone. |
| Canal |
a tubular and relatively narrow channel, or tunnel,
often through a bone. A canaliculus is a smaller canal. |
| Capsule |
a fibrous or membranous envelope surrounding an organ.
An articular capsule surrounds each synovial joint, being
attached to the bones just beyond the limits of the joint cavity. |
| Cartilage |
a firm white tissue, from which most parts of the bony
skeleton are formed and which persists to protect the surfaces of bones and
joints. |
| Caruncle |
a small fleshy eminence |
| Cauda |
tail |
| Cavity |
a hollow space (or potential space) within the body or
its organs. |
| Cervix |
means neck and is applied to the neck like portion of
an organ (e.g. cervix of uterus) |
| Chiasma |
a crossing of fibers in the form of an X. Used
primarily to describe nerve fibers. |
| Commissure |
a band of fibers which join corresponding right and
left parts of a structure across the median plane. |
| Corpus |
means body |
| Cortex |
outer part, or rind, or some organs as distinguished
from their inner part, or core usually called a medulla. |
| Crest |
a projecting ridge, especially one which on a bone |
| Crus |
means a leg and is applied to a structure that
resembles a leg or stalk |
| Decussation |
same as a chiasma. A crossing of fibers in the form of
an X. |
| Digitation |
a finger like process of a muscle |
| Disc |
a flat round structure usually applied to plates of
cartilage in joints. |
| Duct |
a tube for the passage of fluid, especially secretions
of glands. A ductule is a small duct. |
| Epithelium |
a layer of cells which forms the external surface of
the skin, or which lines the cavities of the digestive, respiratory and
urogenital organs, serous cavities, inner coats of blood and lymphatic
vessels, gland and cavities within the brain. The epithelium of the skin is
the epidermis. The epithelium of the digestive, respiratory
and urogenital organs is moistened by a film of mucus and is known as the
mucous coat. The epithelium lining bloods vessels is known
as the endothelium. Serous cavities are lined by epithelium called
mesothelium. |
| Fascia |
tissue which lies immediately deep to the skin known
as subcutaneous tissue. It usually consists of a layer of connective tissue
which contains fat, and of a deep and more fibrous layer which adheres to
the surface of the underlying muscle and vessels. These layers are known as
superficial and deep fascia respectively. Fascia surrounds every muscle,
organ, vessel and nerve in the body. |
| Fasciculus |
a small bundle. A term that is usually applied to
collections of nerve fibers. |
| Filum |
literally mean a "thread". This name is given to
several thread-like structures such as the filum terminale,
the lower extension of the pia mater of the spinal cord. |
| Fold |
a ridge formed where a membrane doubles back on itself |
| Folium |
mean leaf. The plural "folia" is applied to the folds
of the cortex of the cerebellum. |
| Foramen |
a hole, often in a bone or between adjacent bones. |
| Fossa |
a "ditch", usually referring to a shallow depression
or cavity. |
| Fovea |
a small pit or fossa |
| Frenulum |
a small fold of the mucous coat which limits the
movement of the structure to which it is attached |
| Fundus |
used to denote the widest part of a hollow organ |
| Ganglion |
a swelling on the course of a nerve. Usually
corresponds to a collection of nerve cells. |
| Genu |
mean knee. Geniculum is sometimes
applied to a bent part of a structure. |
| Gyrus |
a fold or convolution of the cerebral cortex. |
| Hilum |
a depression or notch where blood vessels enter or
leave an organ. |
| Humor |
applied to fluids of the eye |
| Infundibulum |
a funnel-shaped passage |
| Interdigitate |
an interlocking of structures by finger-like processes,
as when the fingers of the two hands are interposed. |
| Invaginate |
a process when part of a wall of a structure is pushed
inwards to that the structure which invaginates the membrane becomes partly
ensheathed by it. |
| Isthmus |
a narrow part of a duct or other passage, or a narrow
strip of tissue connecting two wider parts of an organ |
Joints
places where bones meet each other (articulate). Where bones are connected
by fibrous tissue, the joint is known as a fibrous joint
(i.e. suture of skull). Where bones are united by cartilaginous tissue, the
joint is know as a cartilaginous joint (i.e. symphysis
pubis). Where a space intervenes between the articulating ends of bones, the
joint is called a synovial joint (i.e. most of the joints
of the body). In these joints, there is an articular capsule
the encloses the joint. This capsule is lined by a synovial membrane
which secretes a lubricating fluid. |
 |
| Labium |
lip |
| Lamina |
A thin plate of bone or cartilage or a thin layer of
softer tissues. A stratum is also used to denote a layer |
| Ligament |
a band of fibrous connective tissue by which bones are
connected to each other. Sometimes bands of connective tissue which support
the viscera or the thorax or abdomen are also known as ligaments. |
| Lobe |
a part of an organ, often separated from the rest by a
fissure. A lobule is a small lobe |
| Meatus |
a passage or opening |
| Muscle |
these structures vary in shape and size, but always
consist of masses of special contractile cells which are under nervous
control. It is usual to describe a muscle as possessing an origin
and insertion, in the sense that when the muscle contracts,
the insertion moves toward the origin. It is probably more useful to regard
a muscle as possessing attachments which are approximated when the whole
muscle contracts. The original of a muscle is sometimes called the
head and the contractile part the belly. |
ganglion. This ganglion
contains the cells bodies of the sensory nerve fibers. The ventral root
consists of motor (efferent) nerve fibers.
The nerve trunk formed by the mergence of the two roots splits immediately
into a dorsal ramus and a ventral ramus.
The dorsal ramus supplies the deeper muscles of the back the their overlying
skin. The ventral ramus supplies muscles and skin on the lateral and ventral
aspects of the body. The nerve supply of the limbs is derived entirely from
the ventral rami of the spinal nerves. |
Nerves
the nerves of the body can be divided into twelve pairs of cranial
nerves, which arise from the brain and brainstem, 31-33 pairs of
spinal nerves which arise from the spinal cord in segmental
series (8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1-3 coccygeal). The
spinal nerves emerge from the intervertebral foramina which
lie along side of adjacent vertebrae. The pass laterally into the neck or
trunk.
A typical spinal nerve is formed by the union of a dorsal root,
which arises from the dorsal aspect of the spinal cord and a ventral
root which arises from the ventral aspect of the spinal cord. The
dorsal root consists of sensory (afferent) fibers and contains a swelling
called the dorsal root
 |
| Sympathetic nerves |
Just at the point where the 12 thoracic and first 2
lumbar spinal nerve trunks split into a dorsal and ventral ramus, two
branches leave the trunk that connect to the sympathetic chain
ganglia, and these are called the communicating rami.
The gray communicating ramus usually comes off first and connects to the
ganglion in the sympathetic chain. It carries post ganglionic neurons from
the ganglion back to the spinal nerve trunk and thence to its branches. The
white communicating ramus arises a little more distal than the gray one and
also connects to the sympathetic chain and its ganglia. This connection
carries pre ganglionic neurons from the spinal cord to the sympathetic chain
where synapses may occur at that level or past the sympathetic ganglia into
other sympathetic ganglia. |
| Neuron |
The neuron or nerve cell is the functional unit of the
nervous system. Each is composed of a cell body (perikaryon) where the
nucleus of the cell is located, and one or more processes. One of the
processes, called the axon, is different from the others,
which are called dendrites. The dendrites and body are the
receiving part of the neuron and the axon is the distribution part of the
neuron. |
| Node |
a swelling or protuberance. A nodule
is a small node. |
| Notch |
an indentation or depression, usually on the border of
a bone. |
| Nucleus |
literally means a kernel or nut. In anatomy, nucleus
is most often used to describe an aggregation or cluster of nerve cells. |
| Papilla |
a small nipple-shaped elevation |
| Periosteum |
the fibrous covering of a bone. |
| Plexus |
a network of nerve or vessel processes |
| Pouch |
pockets of peritoneum in the abdomen |
| Process |
an appendage or projection from the main part of a
bone or organ |
| Punctum |
a minute opening |
| Ramus |
a branch, which, when translated, is used to describe
smaller arteries, veins and nerves arising from their parent vessels or
nerves. |
| Raphe |
a seam where two similar sheets of tissue unite. |
| Rete |
a network, used to describe plexuses of small canals,
nerves or vessels |
| Retinaculum |
a band of connective tissue, usually connected at both
ends to bone, which keeps tendons or other structures in place |
| Rima |
a cleft or fissure that refers to a narrow oval or
oblong opening |
| Root |
the part of a nerve or organ which arises from another
structure |
| Sac |
a bag-like cavity or pouch |
| Septum |
a dividing wall or partition |
| Sinus |
a recess, a cavity or hollow space, a dilated channel
for venous blood or a small tunnel |
| Space |
a clearly demarcated segment of tissue or potential
cavity |
| Spine |
a small, sharp-pointed projection from a bone |
| Stria |
a streak or stripe, sometimes slightly elevated |
| Stroma |
supporting fibrous framework of tissue |
| Substantia |
means substance or matter |
| Sulcus |
a groove |
| Taenia |
a flat band or tape, applied to a narrow strip of
muscle |
| Tegmen |
roof |
| Tela |
means a web and describes a thin web-like membrane.
Loosely translated, it can mean tissue |
| Tendon |
a cord of connective tissue into which muscles fibers
end by which a muscle is attached to bone or other structures |
| Trabecula |
means a beam or bar. |
| Tract |
a bundle of fibers, often nerve fibers, having similar
origins and terminations |
| Trigonum |
a triangular space or area |
| Trochlea |
pulley |
| Tuber |
an enlargement or swelling |
| Tubercle |
an eminence on a bone, usually smoother than a
tuberosity |
| Tuberosity |
a rough eminence on a bone |
| Tunica |
a covering or coat around muscle or hollow viscera |
| Uvula |
means little grape, usually referring to the small
fleshy appendage that hangs from the soft palate. |
| Vallecula |
a wide depression, furrow or valley |
| Valve |
a fold in an artery, vein or duct which prevents
reflux of its contents |
| Vas |
a tubular structure |
| Velum |
means a veil or curtain. |
| Veins |
vessels that return blood from capillaries to the
heart |
| Viscus |
any organ of the digestive, respiratory or urogenital
systems, or ductless gland. Viscera is the plural. |
Potete
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