Angiology

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Angiology

• Is a Greek word from the word angio = vessel, so angiology is a science of vessels

• THE VASCULAR system is divided for descriptive purposes into • blood vascular system, which comprises the heart and blood

vessels for the circulation of the blood; and • the lymph vascular system, consisting of lymph nodes and

lymphatic vessels, through which a colorless fluid, the lymph, circulates. It must be noted, however, that the two systems communicate with each other and are intimately associated developmentally

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Angiology…

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Angiology…• Note: the blood which circulates through the spleen, pancreas,

stomach, small intestine, and the greater part of the large intestine is not returned directly from these organs to the heart, but is conveyed by the hepatic portal vein to the liver.

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Angiology…• In the liver this vein divides, like an artery, and ultimately ends

in capillary-like vessels (sinusoids), from which the rootlets of a series of veins, called the hepatic veins, arise; these carry the blood into the inferior vena cava, whence it is conveyed to the right atrium.

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Structure of Arteries• The arteries are composed of three coats: • an internal or endothelial coat (tunica intima) lined by a single

layer of extremely flattened epithelial cells, (the endothelium); • a middle or muscular coat (tunica media); having transverse

arrangement of its fibers. In the smaller arteries it consists principally of plain muscle fibers in fine bundles, arranged in lamellæ and disposed circularly around the vessel. These lamellæ vary in number according to the size of the vessel; the smallest arteries having only a single layer, and those slightly larger three or four layers

• and an external or connective-tissue coat (tunica adventitia). consists mainly of fine and closely felted bundles of white connective tissue, but also contains elastic fibers in all but the smallest arteries

Structure of Arteries…• Some arteries have extremely thin walls in proportion

to their size; this is especially the case in those situated in the cavity of the cranium and vertebral canal, the difference depending on the thinness of the external and middle coats.

• All the larger arteries, like the other organs of the body, are supplied with blood vessels (the vasa vasorum).

• Arteries are also supplied with nerves, which are derived from the sympathetic

The Capillaries• The smaller arterial branches (excepting those of the cavernous

structure of the sexual organs, of the splenic pulp, and of the placenta) terminate in net-works of vessels which pervade nearly every tissue of the body

The Capillaries…• They are interposed between the smallest branches of the

arteries and the commencing veins, constituting a net-work, the branches of which maintain the same diameter throughout

• The wall of a capillary consists of a fine transparent endothelial layer, composed of cells joined edge to edge by an interstitial cement substance, and continuous with the endothelial cells which line the arteries and veins.

Veins• The veins, like the arteries, are composed of three coats• The main difference between the veins and the arteries is in the

comparative weakness of the middle coat. Most veins are provided with valves which serve to prevent the reflux of the blood.

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Applied anatomy (Varicose Veins)

• When the walls of veins lose their elasticity, they become weak. A weakened vein dilates under the pressure of supporting a column of blood against gravity. This results in varicose veins abnormally swollen, twisted veins most often seen in the legs

Lymphatic System• The lymphatic system drains surplus fluid from the

extracellular spaces to the bloodstream. It also functions as the body's defense system. Important components of the lymphatic system are networks of lymphatic capillaries, the lymphatic plexuses; lymphatic vessels; lymph; lymph nodes; lymphocytes; and lymphoid tissue.

• The lymphatic system provides a (relatively) predictable route for the spread of certain types of cancerous cells throughout the body. Inflammation of the lymphatic vessels and lymph nodes is an important harbinger of injury or inflammation.

The Lymphatic System

Heart

Artery

Capillaries

Vein

Cell Tissue fluid Lymphatic capillary Lymphatic vessel

Lymphatic node

Lymphatic trunk

Lymphatic duct

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Lymphatic System• The right lymphatic duct drains lymph from the body's right

upper quadrant (right side of the head, neck, and thorax plus the right upper limb). At the root of the neck, it enters the junction of the right internal jugular and right subclavian veins, called the right venous angle.

• The thoracic duct drains lymph from the remainder of the body. The lymphatic trunks draining the lower half of the body merge in the abdomen, sometimes forming a dilated collecting sac, the chyle cistern (L. cisterna chyli). From this sac (if present), or from the merger of the trunks, the thoracic duct ascends into and then through the thorax to enter the left venous angle (junction of left internal jugular and left subclavian veins).

Applied anatomy• Lymphangitis is an inflammation or an infection of the lymphatic

channels that occurs as a result of infection at a site distal to the channel.

• Lymphedema, also known as lymphatic obstruction, is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system, which normally returns interstitial fluid to the thoracic duct and then the bloodstream. The condition can be inherited or can be caused by a birth defect, though it is frequently caused by cancer treatments, and by parasitic infections.

MYOLOGY

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MYOLOGY• Myology is a scientific study of muscles. Muscles

form the bulky of tissues over the skeleton. Muscle cells, often called muscle fibers because they are long and narrow when relaxed, are specialized contractile cells.

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Skeletal muscles• Skeletal muscles are connected with the bones, cartilages,

ligaments, and skin, either directly, or through the intervention of fibrous structures called tendons or aponeuroses.

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Skeletal muscles…• There is considerable variation in the arrangement of the fibers of

certain muscles with reference to the tendons to which they are attached. • In some muscles the fibers are parallel and run directly from their origin

to their insertion

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Skeletal muscles…

• Secondly, in other muscles the fibers are convergent; arising by a broad origin, they converge to a narrow pointed insertion. This arrangement of fibers is found in the triangular muscles—e. g., the Temporalis

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Skeletal muscles…• In some muscles, which otherwise would belong to the

quadrilateral or triangular type, the origin and insertion are not in the same plane, but the plane of the line of origin intersects that of the line of insertion; such is the case in the Pectineus.

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Skeletal muscles…

• Thirdly, in some muscles (e. g., the Peronei) the fibers are oblique and converge to one side of a tendon which runs the entire length of the muscle; such muscles are termed unipennate.

• A modification of this condition is found where oblique fibers converge to both sides of a central tendon; these are called bipennate, and an example is afforded in the Rectus femoris.

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Nomenclature

• The names applied to the various muscles have been derived: 1. From their situation, as the Tibialis, Radialis, Ulnaris, Peronæus; 2. From their direction, as the Rectus abdominis, Obliqui capitis,

Transversus abdominis; 3. From their uses, as Flexors, Extensors, Abductors, etc.; 4. From their shape, as the Deltoideus, Rhomboideus; 5. From the number of their divisions, as the Biceps and Triceps; 6. From their points of attachment, as the Sternocleidomastoideus,

Sternohyoideus, Sternothyreoideus.

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Skeletal muscles…

• In order to carry out a movement a definite combination of muscles is called into play, and the individual has no power either to leave out a muscle from this combination or to add one to it.

• One (or more) muscle of the combination is the chief moving force; when this muscle passes over more than one joint other muscles (synergic muscles) come into play to inhibit the movements not required; a third set of muscles (fixation muscles) fix the limb—i. e., in the case of the limb-movements—and also prevent disturbances of the equilibrium of the body generally

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