THE THEORY OF PHYLEMBRYOGENESIS

that include cell division and growth, and the elaboration of

differentiation programs leading to cell fate specification. 

Human developmental period

cause, the beginning + Greek allaxis from allaso – to

change, change) – phylogenesis type, is characterized by the fact that change of an initial laying of body is observed at early stages of an embryogenesis and changes the further course of ontogenesis.

made up of the vessels that carry blood and lymph

through the body. The arteries and veins carry blood throughout the body, delivering oxygen and nutrients to the body tissues and taking away tissue waste matter. The vascular system, also called the circulatory system, is made up of the vessels that carry blood and lymph through the body. The arteries and veins carry blood throughout the body, delivering oxygen and nutrients to the body tissues and taking away tissue waste matter.

system to meet the rigorous demands of running, flying, swimming,

or diving in a variety of environments, some of them extreme. Sustained high levels of activity in these environments place severe demands on the cardiovascular system to provide adequate delivery of oxygen to working vascular beds and to provide efficient removal of metabolic products. Furthermore, birds are endothermic organisms and the cardiovascular system plays a major role in conserving or removing body heat. The descriptions of the component parts of the circulatory system in this chapter illustrate that these transport requirements are met in a variety of ways in birds inhabiting particular environmental niches. This chapter describes the morphological and functional aspects of the avian heart, circulatory hemodynamics, and the vascular tree. A common thread running through this discussion is that the component parts of the circulation must function in an integrated fashion to ensure tissue oxygen delivery matches tissue demands. This is accomplished through the integrative control of circulation by autoregulatory, humoral, and neural mechanisms. Since the last edition of this book, a significant number of studies have examined the development of cardiovascular control in avian embryos which has expanded our understanding of this system throughout ontogeny.

the accumulation of lipids, macrophages and fibrous materials in the

intima. When the endothelial cell of blood vessel is damaged, it loses the ability to regulate itself. It results in inflammation as the macrophages irrupt the vessel wall. The most common vascular diseases are stroke, peripheral artery disease (PAD), abdominal aortic aneurysm (AAA), carotid artery disease (CAD), arteriovenous malformation (AVM), critical limb-threatening ischemia (CLTI), pulmonary embolism (blood clots), deep vein thrombosis (DVT), chronic venous insufficiency (CVI)

to your heart muscle. Peripheral arteries carry blood to other

tissues and organs. Both can have deposits of fat, cholesterol, and other substances on their inside walls called plaque. Over time, plaque can build up, so the vessel becomes narrow and it’s harder for blood to flow. Or a plaque could rupture, blocking blood flow.

network of your blood vessels.
This network is known as your

vascular or circulatory system. "Vascular"comes from a Latin word for hollow container. If your entire network of blood vessels were stretched end-to-end, they could circle the Earth multiple times.
Some of these vessels move blood. As your heart beats, it pumps blood with oxygen and nutrients to feed your tissues and carry off waste. Arteries move blood away from the heart. Veins return it.

Syndrome)
Raynaud's phenomenon consists of spasms of the small arteries of the fingers and

sometimes the toes, brought on by exposure to cold or stress. Certain occupational exposures bring on Raynaud's. The episodes produce a temporary lack of blood supply to the area, causing the skin to appear white or bluish and feel cold or numb. In some cases, the symptoms of Raynaud's may be related to underlying diseases such as lupus, rheumatoid arthritis, and scleroderma.

arms and legs. In Buerger's disease — also called thromboangiitis obliterans —

your blood vessels become inflamed, swell and can become blocked with blood clots (thrombi). Although no treatment can cure Buerger's disease, the most effective way to stop the disease from getting worse is to quit using all tobacco products. Even a few cigarettes a day can worsen the disease.

BUERGER’S DISEASE

weakness in the legs.
Burning or aching pain in the feet

or toes while resting.
A sore on a leg or a foot that will not heal.
One or both legs or feet feeling cold or changing color (pale, bluish, dark reddish)
Loss of hair on the legs.
Impotence. Vascular Disease Causes and Risk Factors
Vascular disease causes can include: Atherosclerosis, the buildup of plaque in your arteries. Blockage in your blood vessel by a mass of debris (embolus) or blood clot (thrombus) Inflammation, called vasculitis.