Cardiovascular System Flashcards
What is the purpose of the cardiovascular system?
Supplies oxygen and nutrients to every living cell throughout the body by orchestrated movement of blood and lymph
What structures are part of the cardiovascular system?
Heart, blood vessels, and blood
What is the function of the heart?
Propels blood through the circulatory system
What are the different chambers of the heart? (4)
Right and left atria
Right and left ventricles
What is the function of the atria?
Receives blood returning from the heart from other areas of the body
What is the function of the ventricles?
Collects and expels blood from the heart
What separates the atria and ventricles?
Atrioventricular valves
Right: Tricuspid valve
Left: mitral valve (bicuspid valve)
What are the 3 major types of blood vessels?
Arteries
Veins
Capillaries
What are the characteristics of arteries?
Strong elastic vessels
Adapted to the high pressure of blood as it leaves the heart
What are the smaller branches of arteries called and where do they supply their blood??
Arterioles
-supplies to the smallest blood vessels called capillaries
Why do capillaries consist of just a single layer of epithelial tissue?
Allows for substances and gases to be exchanged between the blood and the cells of tissues via diffusion
What is the largest artery in the body?
Aorta
How does blood return to the heart?
From capillaries via venules (merge to form veins)
Why are veins thinner that arteries?
Veins do not have to carry blood under high pressure
What prevents the backflow of blood in veins?
Valves
What is the largest vein in the body? Function?
Inferior vena cava
-brings deoxygenated blood back to the heart
Which vein brings blood from the lungs to the heart?
Pulmonary vein
What is the function of blood?
Transports oxygen and nutrients to the tissues and removes wastes products (carbon dioxide and ammonia)
What are the 4 main components of blood?
Reb blood cells, white blood cells, platelets, and plasma
What is plasma? Components?
Liquid component of blood that account for approximately half the blood volume (55%)
-proteins and electrolytes
What is the second greatest component of blood by volume?
Red blood cells (erythrocytes)
What is the functional unit of a erythrocyte?
Hemoglobin
What is a hemoglobin?
An iron containing protein that facilitates gas exchange by binding to oxygen or carbon dioxide
What is Anemia?
Condition that occurs when hemoglobin levels are low
What would cause an anemia?
Iron deficiency
Body not producing enough RBCs
Sickle cell trait
Which blood cells are part of the body’s immune response?
White blood cells/leukocytes
What is the function of WBC/leukocytes?
Removes pathogens and foreign material from the blood
What are platelets?
Cell fragments that prevent bleeding by developing blood clots
What occurs if you have too little platelets ?
thrombocytopenia
-condition that can result in excessive external bleeding (nosebleeds, bruising due to uncontrolled bleeding under the skin)
What is the closed circulatory system?
Double loop path of the blood throughout the human body
-once in its oxygenated state on its way to the body
-once more when it is deoxygenated and on its way to the lungs
What are the two pathways of the close circulatory system?
Systemic and pulmonary circuit
Explain the function of the systemic circuit
Carries oxygenated blood away from the left ventricle of the heart and returns deoxygenated blood to the right atrium
What structures are part of the systemic circuit?
-Aorta, blood vessels leading to body tissues
-veins and venae cavae
Explain the function of the pulmonary circuit
Contains the blood vessels that carry blood to and from the lungs
What is the pathway of the pulmonary circuit?
-Deoxygenated blood flows from the right ventricle through the pulmonary arteries to the lungs, where blood picks up oxygen, then returns to the left atrium via the pulmonary vein
What is the open circulatory system also called?
Lymphatic system
What is the function of the lymphatic system?
Network of capillaries that drains toxins and waste away from he body tissues into the blood and plays a vital role in monitoring and removing foreign entities in the body
What is lymph?
Clear fluid (high in WBC) that absorbs waste products
Where is lymph filtered?
Lymph nodes
-contains high concentrations of lymphocytes
Where is lymph drained?
Subclavian veins
What is the cardiac cycle?
Period between the start of one heartbeat and the beginning of the next
Does cardiac muscle rely on neural stimulation to initiate a contraction?
No
Can cardiac muscle generate and conduct its own electrical impulses and contract on its own?
Yes
What are the 2 phases of the cardiac cycle?
Systole (contraction)
Diastole (relaxation)
What happens during systole? (Cardiovascular regulation)
Contraction forces the blood to move from the chamber either into another heart chamber or into an artery.
What happens during atrial systole?
Contraction moves blood into the relaxed ventricles
What happens during ventricular systole?
Blood pumped into the aorta or the pulmonary artery once the pressure of contraction opens the semilunar valves
What happens during diastole (cardiovascular regulation)?
The heart muscle relaxes and the chambers are passively filled with blood
What is responsible for the “lub-dub” sound of the heartbeat?
Alternating closures of the atrioventricular and semilunar valve
