Circulatory System Flashcards
the blood circulatory system, the lymphatic system, and pathologies of the cardiovascular system
What are the 5 main functions of blood?
- Transportation: carries water, oxygen, food and secretions to all cells
- Waste Elimination: carries away CO2 and waste products to be eliminated through the lungs, skin, kidneys and large intestine
- Heat regulation: helps equalize body temp, avg. human body temp is 37 degrees Celsius. protects from extreme heat and cold
- Fights disease: white blood cells aid in protecting the body from harmful bacteria and infections
- Clotting: forms clots that close injured blood vessels and prevent blood loss
Define hematology
the study of blood
what makes up the blood?
plasma-fluid, red corpuscles, white corpuscles and platelets
describe plasma fluid and its function
- formed from digested food and water
- straw-coloured, fluid part of the blood
- consists of protein, salt minerals and 90% water.
function: transports waste
describe red corpuscles and their function
- AKA red blood cells or erythrocytes
- contains hemoglobin protein that binds to oxygen (oxyhemoglobin), also causes red colour
- carries CO2 back to lungs
- formed in red bone marrow
function: circulation–carries oxygen to all cells and CO2 back to the lungs
describe white corpuscles and their function
- AKA white blood cells or leukocytes
- colourless and much larger than red blood cells
- produced in yellow marrow of long bones, the spleen and lymph glands
function: protect the body against disease by fighting harmful bacteria and infection
decribe blood platelets and their function
- AKA thrombocytes
- colourless, irregular bodies much smaller than red blood cells
function: clotting of blood
what organs make up the circulatory system?
heart, blood, blood vessels, lymph and lymphatic vessels
how many divisions does the vascular system have? name them.
2
- blood vascular system
- lymph vascular/lymphatic system
describe the blood vascular system
Comprised of the heart and blood vessels for the circulation of blood through the arteries capillaries and veins
describe the lymphatic system
consisting of lymph gland vessels that circulate lymph
describe the heart
a cardiac muscle pump located in the chest cavity.
in which direction does oxygenated blood flow?
away from the heart
in which direction does deoxygenated blood flow?
towards the heart
pericardium
- a triple layered, fluid-filled sac that encloses the heart
- rests on & attached to the diaphragm
- produces a lubricating fluid called serous/pericardial fluid
pericardial/serous fluid
- produced by the membranes of the pericardium
- allows the heart to beat easily in a relatively frictionless environment
what three layers comprise the heart’s walls? describe them
- Epicardium (superficial)
- both part of the pericardium and the heart wall - Myocardium (middle)
- cardiac muscle tissue, making up the bulk of the heart
- responsible for pumping blood through the body - Endocardium (deep)
- thin layer of endothelium overlaying a thin layer of connective tissue
- provides a smooth lining for the inside of the heart
how many chambers does the heart of have? describe them
4
- 2 atria (sing.atrium), receiving chambers
- 2 ventricles, discharging chambers
normal heartbeat: 2 atria contract and two ventricles relax, 2 ventricles contract and 2 atria relax
right atrium and ventricle (right heart) = pulmonary circuit, pumping blood to the lungs
left atrium and ventricle (left heart) = systemic circuit, pumping blood to the rest of the body
how many valves does the heart have? describe them
4
- bicuspid/mitral valve, consists of two cusps or flaps
- tricuspid valve has three cusps
- pulmonary and aortic semilunar valves guard the bases of 2 large arteries leaving the ventricular chambers
define systole and diastole
systole: a phase of contraction
diastole: a phase of relaxation
what is the septum?
muscle tissue that divides the heart longitudinally, separating it into the left and right chambers
what is coronary circulation?
the process through which the heart is nourished with oxygen and nutrients by the right and left coronary arteries and drained by the cardiac veins
describe pulmonary circulation
blood is pumped by the heart to the lungs where it is purified then pumped back to the heart.
-Gas exchange:
inhalation = oxygen absorbed, exhalation = CO2 expelled
CO2 blood enters right atrium via inferior & superior cava > CO2 blood exits right ventricle via pulmonary semi-lunar valve > pulmonary arteries > lungs for oxygenation
Oxygenated blood exits lungs via pulmonary veins > left atrium > systemic circulation
describe general/systemic circulation
Oxygenated blood exits left atrium via bicuspid/mitral valve > left ventricle > oxygenated blood exits left ventricle via aortic semi-lunar valve > aorta > oxygenated blood distributed to every organ and tissue
describe the path blood travels throughout the body during circulation
heart > arteries > arterioles > capillaries > venule > vein > heart
arteries
- thick-walled, muscular and elastic vessels that carry oxygenated blood from the heart to arterioles
- 2 important functional properties: elasticity and contractibility
- oxygenated blood in arteries appears red
arterioles
- very small, almost microscopic arteries that deliver blood to capillaries
- regulate blood flow from arteries into capillaries
capillaries
- microscopic vessels that branch off arterioles and connect them to venules
- one-celled epithelial tissue that services all tissues of the body
*anastomosis occurs here
anastomosis
the exchange of nutrients, chemicals, oxygen, and waste products at the union of the capillaries that lead to the venules
the venous system
a complex network of veins and venules through which blood returns to the heart and lungs for a recharge of oxygen
venule
- when several capillaries unite into a small vein
- collect deoxygenated blood containing waste products from the capillaries and drain into veins
vein
- a vessel that transports deoxygenated blood away from the tissues and organs and back toward the heart (except pulmonary vein)
- consist of thin walls with no elastic, larger in diameter and closer to the surface than arteries
vena cava inferior
the main vein draining the blood from the lower portion of the body
vena cava superior
the main vein draining the blood from the upper portion of the body
what are some of the functions of the lymphatic system? (name its primary function + 3 more)
primary function: drain lymphatic fluid, produce, maintain and distribute lymphocytes
- drain excess interstitial fluid
- transports lipids and lipid-soluble vitamins absorbed by the gastrointestinal tract to the blood
- carries out immune responses
- maintain blood volume by returning the interstitial fluid seeping out of the capillary walls back to the circulatory system
- carry nourishment from blood to cells
- remove waste from blood and cells
- creates a sutable fluid environment for cells
- reduce swelling, inflammation, and accumulations in the blood vessels
what are the major organs of the lymphatic system?
lymph nodes, thymus, spleen, tonsils, bone marrow
lymph nodes
small structures that purify lymph, removing antigens and toxins, before it returns to circulation
where are the major lymph nodes located?
base of the neck, axillae (armpits), groin, and abdomen
-filter lymph from head, arms, legs, and intestinal tract
thymus gland
- main organ of the lymphatic system
- main function: promotes the development of T-lymphocytes
- produces hormones that promote growth and maturation
t-lymphocytes
- responsible for an immune response that involves the activation of certain immune cells to fight infection (cell-mediated-immunity)
- develop and mature in the thymus and are transported via blood vessels to the lymph nodes and spleen
spleen
- primary function: filters damaged cells, cellular debris and pathogens out of the blood
- houses and aids in the maturation of lymphocytes
- largest organ of the lymphatic system
tonsils
- help prevent foreign objects from slipping into the throat
- produce antibodies to prevent pathogens from entering the respiratory and digestive system
bone marrow
- soft flexible tissue found inside bone that produces red blood cells, white blood cells and platelets
- bone marrow stem cells generate certain types of lymphocytes, aiding in immunity
atherosclerosis
- hardening of the arteries resulting from fibro-fatty lesions in the arteries
- aggravated by cigarette smoking, high blood pressure and diabetes, which may result in blood clots, organ damage and death
aneurysm
- a localized dilation of the blood vessel that can occur in arteries and veins
- can rupture, causing an interruption in blood flow which may lead to a stroke
varicose veins
- enlarged, swollen, twisted veins that occur when the valves in these veins become weak, damaged, or cease to function, resulting in the vein dilating and blood pooling in the vein
- almost always seen in the legs and feet
- main causes are heredity, obesity, pregnancy, and constantly being on your feet
- do not massage over a varicose vein
venous thrombosis (thrombophlebitis)
- the presence of a thrombus (clot) in a vein and the accompanying inflammatory response in the veins walls
- most common in the calf
- often painful and tender, may feel heat, however if the the affected vein is deep enough in the leg there may be no obvious symptoms
- no massage of any kind should be performed if thrombosis is suspected
hypertension
- AKA high blood pressure, a condition in which the pressure of the blood against the walls of the arteries is higher than normal
- the leading factor for cardiovascular disorders, uncontrolled hypertension produces increased strain on the heart, leading to hardening of the arteries, kidney disease etc.
- no heat should be applied to clients with hypertension. stay away from saunas, steam and heat packs
hypotension
- postural hypostension is an abnormal drop in blood pressure when a person gets up from lying down. assist and support the client while they are rising
- hypotension can be caused by pregnancy, certain medications, certain health conditions, etc.
angina
-chest pain associated with deficiency of blood going to the heart, usually caused by blockages of the arteries to the heart and may be brought on by exertion or stress. often mistaken for indigestion
myocardial infarction (heart attack)
occurs when the heart is completely deprived of blood. cardiac muscles die and damage occurs, and the person may not survive the attack if not treated promptly
cardiovascular accident (stroke)
an acute, local neurological deficit from an interruption of blood flow in a blood vessel in the brain, causing brain cell death
