Circulatory System Flashcards
What is the Circulatory System made up of?
Blood (transport medium), heart (pump), transport vessels (arteries, veins, capillaries).
What is the function of the circulatory system?
Transports O2 and CO2 (from respiratory tract to body tissues). Distributes nutrients (digestive tract to body tissues) and transports waste (tissues to respiratory tract). Maintains body temperature and circulates hormones.
What are the two parts of the circulatory system?
Pulmonary Circuit and Systemic Circuit.
Pulmonary Circuit
(Low pressure) It carries deoxygenated blood to the lungs and oxygenated back to heart
Systemic Circuit
(High pressure) Carries oxygenated blood to the tissues and brings deoxygenated back to the heart.
What is the human blood (5L per person) made up of?
Plasma, Red Blood Cells, White Blood Cells, Platelets.
Plasma
(55%) A straw coloured fluid that allows nutrients and gases to be dissolved.
(Erythrocytes) Red Blood Cell
Made in the bone marrow, stored in spleen. Lifespan of 120 days. No nucleus and donut shaped (easier to move through blood vessels). Contains Hemoglobin (molecule that binds O2). They transport O2 and remove CO2 from the cells.
(Leukocytes) White Blood Cells
Made in bone marrow, generally larger then RBCs. They fight infection, destroy and consume invading bacteria and damaged cells. Elevated amounts of WBCs can indicate an infection.
Platelets
Small parts of other cells involved in clotting blood. Break open when they encounter damaged blood vessels, releasing clotting factors. Production of fibrin.
Fibrin
A protein mesh or clot that traps escaping blood cells and closes the wound. A scab contains fibrin, platelets and blood cells.
Diastole
Occurs when the heart is relaxed.
Systole
Occurs when the ventricles contract, expelling blood forcefully from the heart.
What is the path of blood through the pulmonary circuit?
It enters right atrium, flows through tricuspid valve to the right ventricle, through pulmonary semi-lunar valve and into pulmonary trunk, then to the lungs and back to the heart by pulmonary veins into left atrium.
What is the path of blood through the systemic circuit?
It flows from the left atrium through bicuspid(mitral) valve and into left ventricle, through aortic semi-lunar valve and into aorta, which branches into arteries which branch into arterioles that turn into capillaries which rejoin venules that join with veins which return blood through the Sup/Inf Vena Cava to right atrium.
