CH. 5 Flashcards
What is the cardiovascular system?
Consists of the heart, which pumps blood, and the blood vessels, through which the blood flows
What are the functions of the cardiovascular system?
Transport, homeostasis, protection
What is the lymphatic system?
Assists the cardiovascular system, collects excess interstitial fluid and returns it to the cardiovascular syste
Describe the two parts of the cardiovascular system?
The heart, which pumps blood, and the blood vessels, which carry the blood
Summarize the functions of the cardiovascular system
Generates blood pressure, transports blood, promotes gas exchange at the capillaries, and regulates blood flow as needed
Explain how the lymphatic system interreacts with the cardiovascular system
Lymphatic vessels collect excess interstitial fluid and return it to the cardiovascular system
What is an artery?
A blood vessel that transports blood away from the heart
Describe the structure of an artery
Well suited for the transport of blood leaving heart under pressure, the arterial wall has three layers. The inner is the endothelium which is surrounded by a middle layer of smooth and elastic tissue which is surrounded by the artery’s outer layer of connective tissue.
What are arterioles?
Small arteries barely visible to the naked eye, the middle layer is mostly composed of smooth muscle, muscle fibers encircle the arteriole.
Describe arterioles functions
The constriction or dilation of arterioles controls blood pressure. When arterioles constrict, blood pressure rises. Dilation of arterioles causes blood pressure to fall
What are capillaries?
Arterioles branch into these, they are the smallest of the blood vessels. It is an extremely narrow, microscopic tube with a wall composed only of endothelium, which is formed by a single layer of epithelial cells with a basement membrane
Describe veins
Blood vessels that return blood to the heart
What are Venules
Are small veins that drain blood from the capillaries and then join to form a vein. These allow blood to flow only toward the heart when open and prevent backward flow of blood when closed.
List and describe the different types of blood vessels
Arteries carry blood from the heart to smaller vessels called arterioles. These lead to capillaries where gas exchange occurs. Venules carry blood from the capillaries to the veins, which carry blood back to the heart
Describe how each blood vessel contributes to the flow of blood in the body
Arteries have thick muscular walls that are elastic and carry blood at higher pressure. Arterioles, which have thinner walls, receive blood from arteries and the blood pressure drops. Capillaries have thin walls made up of a single layer of epithelium and carry blood at lower pressure. Venules receive blood from the capillaries and move it to the veins at low pressure blood back to the heart
Explain why the structure of the veins is different from that of the arteries
Veins carry blood at a lower pressure and therefore have thinner walls than arteries, as well as less muscle and elastic fibers. In addition, veins have valves to help move the blood back to the heart