Circulatory System

The pace maker uses electrical impulses to regulate heart rate. It is used when the bodies own impulses from the brain are not able to do the job anymore.

The myocardium (middle layer)

Normal skin color is vibrant and looks healthy. The appearance of the veins in the forearm before testing should be blue and smooth-looking.

pretty much the same as any animal with the heart veins arteries and capillaries

the heart, the lungs, and the blood vessels ;D

What I have heard is that you blow through a straw into water for as long as you can. If you do it enough then you will be able to achieve circulatory breathing.

Cholesterol is a cellulite substance found in most forms of animal life. It can be divided into two groups: HDL (healthy) & LDL (unhealthy). Low density cholesterol causes formation of plaque, which clogs the vascular system & leads to stroke &/or heart attack. High density cholesterol is produced by the body in humans & aids the vascular system against LDL damage.

From the blood it is pumping, the blood pervades are organs and carries food /energy for those organs to function.

All organ systems work together in order for a body to function. The circulatory system and the excretory system work together to rid the body of wastes. As blood travels to the kidneys, unneeded materials are filtered out through the rest of the excretory system and the filtrated blood is carried away via the Renal vein. The circulatory system works with the respiratory system by providing red blood cells with oxygen. The nervous system sends messages to the heart that cause it to pump.

Hemoglobin: the oxygen-carrying pigment of red blood cells that gives them their red color and serves to convey oxygen to the tissues

The Blood stream

Your circulatory system is important because that is what carries blood to and from all areas of your body. Without your circulatory system, you wouldn't make it far.

because their body have a direct contact with the environment

The only vein that normally carries oxygen rich blood is the pulmonary vein which carries freshly oxygenated blood from the lungs back to the heart for distribution to the body. Ordinary veins can have oxygen poor blood but don't carry oxygen rich blood.

Arterial

If the carotid bodies are removed during the process the respiration rate may not increase as effectively in response to low levels of oxygen. Carotid artery disease occurs when the major arteries in your neck become narrowed or blocked.

Any type of wound can be dangerous an run the risk of infection. The most fatal type of wound is one that has punctured a major organ, or severed a major artery.

you'll get sick

...

The major organs of the circulatory system are the heart, blood, and blood vessels.

The brain does not send the electricity to the heart. The heart is myogenic which means it can contract and relax without any stimulus from the brain.

arteries

Aerobic exercises

Functionally both the respiratory and digestive system are tasked with the extraction of the requirements of metabolism (energy in the form of food, oxygen from the air). On a more superficial level there are certain morphological similarities. Both the digestive system and the lungs have invaginations or folding of the epithelial surfaces in order to maximize surface area.

The tiniest blood vessels that carry oxygen-rich blood are the capillaries. These capillaries form a bed. The arterioles that carry the blood into the bed are high in oxygen. The oxygen is released to the cells. The rest of the bed is low in oxygen and venules carry deoxygenated blood to the veins back to the heart.