Heart and Immunity Flashcards
3 functions of the circulatory system?
Transport, Homeostasis, Protection
3 blood vessels?
Arteries, veins, capillaries
Arteries?
Carry blood away from the heart (oxygen rich blood). Contract and relax (pulse) as blood surges from the heart.
Artery structure?
Thick, muscular, elastic walls that maintain blood pressure between pump cycles.
Arterioles?
Small arteries, 2 functions.
Vasoconstriction?
Nervous system causes arterioles to contract in times of emergencies which increases blood pressure in some parts of the body while restricting it in others.
Vasodilation?
Nervous system arterioles to relax.
Atherosclerosis?
plaque buildup.
Veins structure?
Thin walls with a large inner circumference. Not muscular or elastic meaning that they cannot contract like arteries but can dilate to become wide.
Veins?
Carry blood towards the heart (oxygen poor). Have one way valves to avoid back flow of blood-no pressure. Blood is moved through the veins by contraction & relaxation of skeletal muscles around the vein.
Varicose veins?
Valves disfunction and venues burst. Pooling & back pressure of blood causes damage to surrounding tissues. Cause: age, obesity, poor nutrition & posture.
Capillaries?
One cell thick. Site of gas, nutrients (oxygen, monosaccharides, amino acids, fatty acids, hormones), waste (CO2, urea, ammonia). Bruise: capillaries get damage, blood/plasma rush to site.
Heart functions?
Pumps blood to lungs (pulmonary circulation) and to body (systemic circulation). Keeps oxygen rich and oxygen poor blood separated. Ensures blood flows in one direction. Contractions are limited and involuntary. Has valves so blood flows in one direction.
Heart consists of?
Walls made of cardiac muscle. 4 chambers, 2 atria (top, collects) blood returning to heart, 2 ventricles (bottom, pumps) sends blood out of heart.
Atria?
Collects blood coming back from the lungs (left atrium), or from the body (right atrium).
Ventricles?
Receive blood from the atria and pump it to the lungs (right ventricle) or the body (left ventricle).
Superior vena cava?
Collects deoxygenated blood from the head, chest & arms and dumps it into the right atrium.
Inferior vena cava?
Collects deoxygenated blood from the central & lower body and dumps it into the right atrium.
Pulmonary arteries?
Blood vessels that carry blood from the right ventricles to the lungs.
Pulmonary veins?
Blood vessels that carry blood from the lungs to the left ventricle.
Aorta?
Largest blood vessel in the body. Leaves the left ventricle carrying oxygenated blood to the body.
Tricuspid valve?
Has three valves that separate the right atrium from the right ventricle.
Bicuspid valve?
two valves that separate the left atrium form the left ventricle.
Semilunar valve?
Half-moon shape, found in the aorta and the pulmonary trunk.
Pathways of circulatory system?
Pulmonary pathway and systemic pathway.
Pulmonary pathway?
To and from the lungs. Deoxygenated blood pumped to the lungs, picks up O2 and gives away CO2, oxygenated blood brought back to the heart.
Systemic pathway?
To and from the rest of the body. Oxygenated blood pumped to the body cells, gives away O2 and picks up CO, deoxygenated blood returns to the heart.
Blood’s journey through the heart?
Deoxygenated blood enters the right atrium through eh vena cava. Then it flows to the right ventricle through the tricuspid valve. Blood id pumped from the right ventricle past the pulmonary semilunar valve into the pulmonary trunk that splits into the right & left pulmonary arteries. Blood returns from the lungs from the right & left pulmonary veins. Blood enters the left atrium after returning from the lungs and flows past the bicuspid valves as it enters the left ventricle which pumps blood out past the aortic semilunar valve into the aorta.
Beating heart?
Stimulus for a heartbeat is an electrical signal originating in the heart.