hi let's have a talk about the cardiovascular system the cardiovascular system has four parts
to it there's the blood the heart the blood vessels or the vasculature and the lymphatic
system the cardiovascular system could be mapped throughout the body you can follow the pathway of
the vessels from the heart out to serve all of the metabolically active tissues throughout the
body the blood is our vehicle where we're able to transport nutrients gases waste products hormones
etc to these tissues and there's going to be exchanged between the cardiovascular system
and its contents and the interstitial tissues and fluids that surround metabolically active tissues
so the blood really is the vehicle for materials to flow by means of the heart through the
vasculature it transports materials it also helps to regulate acid-base homeostasis temperature it
serves a protective function in terms of it being a host to the immune system and it also helps
to regulate clotting and there are two major constituents to the blood there's the plasma
which is largely water and the formed elements such as these erythrocytes and leukocytes and
thrombocytes the heart is the pump of the cardiovascular system it is comprised of
cardiac muscle tissue surrounded and invested by connective tissue that sits within the thoracic
cavity specifically within a segment of the thoracic cavity called the mediastinum and it
is ever working from early on in development until the day that you die and perhaps even beyond if
you are an organ donor the heart is going to beat in concert with our metabolic need for oxygen and
other nutrients the vasculature where the blood vessels are the pathways by which blood moves
from the heart out to the metabolically active tissues returns back to the heart and then goes
out to the lungs and then returns back to the heart and then it goes out to the metabolically
active tissues and so on and so forth the main constituents of the vasculature are the arteries
which are vessels that deliver blood away from the heart and veins which deliver blood back
to the heart and nestled between the arteries and the veins are the capillary beds which are
the site of nutrient and gas and other material exchange between the cardiovascular system and the
interstitial tissue lymphatics are in all fairness a system unto themselves so people will frequently
refer to the lymphatics as the lymphatic system but they can just as easily be seen as a subset
of the cardiovascular system the function of the lymphatic system is varied and will be explored in
subsequent lessons but for the most part the role of the lymphatic system is to reclaim filtered
plasma that was lost in the interstitial tissue and not resorbed back into the cardiovascular
system to prevent edema or swelling the lymphatic system is also notable because it transports fatty
acids and lipid soluble vitamins from regions of the small intestine back up into blood supply and
finally the lymphatic system is a sizable host to our immune system and helps us to modulate immune
responses so we've talked a little bit about the cardiovascular system its constituents and their
functions and we'll explore these topics in greater detail in subsequent lessons thank you