[Lec] Circulatory System Flashcards
Carries oxygen and food to the cells of the body and carries CO2 and other wastes away from the cells to the excretory organs, kidneys, lungs, and skin. Aids in coagulation (clotting) process, and assists in defending the body against disease
Circulatory System
Major structure of the Circulatory system. Pump that circulates blood throughout the body. Has 4 chambers, is hollow, and slightly larger than a man’s closed fist. Walls have 3 distinct layers
Heart
What is the thin fluid-filled sac that surrounds the heart
Pericardium
Outer layer of the heart. Thin serous (watery) membrane that is continuous with the lining of the pericardium. Covers the heart and attaches to the pericardium
Epicardium
Middle layer of the heart. Thick layer of cardiac muscle. Contracts to pump blood in the arteries
Myocardium
Inner layer of the heart. Thin layer of epithelial cells that is continuous with the lining of the blood vessels. Lines the interior chambers and valves
Endocardium
Receives deoxygenated blood from the body via both the superior (upper) and inferior (lower) vena cava and pumps it into the right ventricle. Upper right chamber
Right atrium
Receives blood from the right atrium and pumps it in the pulmonary artery, which carries it to the lungs to be oxygenated
Right ventricle
Receives oxygenated blood from lungs via pulmonary veins and pumps it in the left ventricle
Left atrium
Receives blood from left atrium and pumps it to the aorta; the walls are nearly 3 times as thick as those of the right ventricle owing to the force required to pump the blood in the arterial system
Left ventricle
AKA angina pectoris. Med term for chest pain due to reduced blood flow to the heart muscle. Caused by narrowing, obstruction, or spasm of coronary arteries
Angina
Partial obstruction a coronary artery or one of its branches can reduce blood flow. Complete obstruction or prolonged ischemia leads to MI due to necrosis or death of the surrounding tissue from lack of oxygen
Myocardial infarction/heart attack
Not adequate to meet the oxygen needs of the heart muscle
Myocardial ischemia
Graphic record of the heart’s electrical activity during cardiac cycle. Produced by a machine called electrograph, which records the electrical currents corresponding to each event in heart muscle contraction
Electrocardiogram
Palpable rhythmic throbbing caused by the alternating expansion and contraction of an artery as a wave of blood passes through it. In normal individuals, pulse rate it is same as heart rate
Pulse
Force (pressure) or tension exerted by blood on the walls of blood vessels. Commonly measured in a large artery using sphygmomanometer aka blood pressure cuff
Blood pressure
Arterial pressure during contraction of ventricles
Systolic pressure
Arterial pressure during relaxation of muscles
Diastolic pressure
System of blood vessels
Vascular system
Two divisions of Vascular system
- Pulmonary circulation
- Systemic circulation
sometimes referred to as pulmonary and systemic circuits
Blood vessels that carry blood away from the heart. Have thick walls because blood that moves through them is under pressure from the contraction of the ventricles. This pressure creates a pulse that can be felt
Arteries
Blood vessels that return blood to the heart. Blood is oxygen poor and much darker and more bluish
Veins
Microscopic, one-cell-thick vessels that connect arterioles and venules. Comes from Latin capillaris meaning “hair-like”. So tiny that RBCs can only travel through them in a single file
Capillaries
Means “in front of the elbow”
Antecubital Fossa
Located near the center of the antecubital area. Preferred and first choice vein for venipuncture. Typically larger, closer to the surface, better anchored, and more stationary
Median cubital vein
Located in the lateral aspect of the antecubital area. 2nd choice for venipuncture. Often the only vein that can be palpated in obese patients
Cephalic vein
Large vein located on the medial aspect (Inner side) of the antecubital area. Last choice for venipuncture. Generally easy to palpate but is not as well anchored and rolls more easily
Basilic vein
“the river of life”. Deliver nutrients, oxygen, and other substances to the cells and transporting waste products away from the cells for elimination
Blood
Blood composition
- Mix of fluid and cells
- pH of 7.4
- 55% plasma; 45% formed elements
Fluid portion of blood
Plasma
Cellular portion of blood
Formed elements
Adult weighing 70kg (154 lb) has blood volume of
5L
Formed elements (3)
- Erythrocytes
- Leukocytes
- Thrombocytes
Formed elements that are anuclear, biconcave (indented from both sides). Mature RBCs have a lifespan of 120 days
Erythrocytes/RBCs
RBC formation is called
Erythropoiesis
Immature RBCs are called
Reticulocytes
Formed elements that contain nuclei. Have extravascular function because they can leave the bloodstream and do their job in the tissues. Neutralizes and destroys pathogens
Leukocytes/WBCs
(Granulocytes) Most numerous type of WBC. Segmented or multilobed nucleus. Fine-textured lavender staining granules
Neutrophils
- Relative % of Neutrophils in adult
- Function
- Lifespan
- 54-62%
- Destroy pathogens by phagocytosis
- 6 hours to few days
Granulocytes (segmented nucleus) (3)
NEB
- Neutrophils
- Eosinophils
- Basophils
(Granulocytes) Bead-like granules that stain bright orange-pink. 2 lobed nucleus
Eosinophils
- Relative % of Eosinophils in adult
- Function
- Lifespan
- up to 3%
- ingest and detoxify protein. Help turn off immune reactions. Increase with allergies and parasite (eg pinworm) infestations
- 8-12 days
(Granulocytes) Least numerous type of WBC. Large dark blue-black-staining granules that often obscure a typically S-shaped nucleus
Basophils
- Relative % of Basophils in adult
- Function
- Lifespan
- Less than 1%
- Release histamine and heparin, which enhance inflammatory response
- thought to live several days
Agranulocytes (2)
LM
- Lymphocytes
- Monocytes
(Agranulocytes) 2nd most numerous type of WBC. Typically has a large, round, dark-purple nucleus that occupies most of the cell and is surrounded by a thin rim of pale-blue cytoplasm
Lymphocytes
- Relative % of Lymphocytes in adult
- Function
- Lifespan
- 25-38%
- Directly attack infected cells. B lymphocytes give rise to plasma cells that produce immunoglobulins (antibodies) that are released into the bloodstream to circulate and attack foreign cells
- varies from a few hours to a no. of years
(Agranulocytes) Largest WBC. Fine, gray-blue cytoplasm and a large, dark-staining nucleus
Monocytes
- Relative % of Monocytes in adult
- Function
- Lifespan
- 3-7%
- Destroy pathogens by phagocytosis (like neutrophils). 1st line of defense in the inflammatory process
- Several months
Formed elements that are known as platelets. Smallest of formed elements. Essential to coagulation (blood-clotting)
Thrombocytes
Blood Specimens (3)
SPW
- Serum
- Plasma
- Whole blood samples
(Blood specimens) Clotted blood specimen. The remaining fluid portion and can be separated from the clot by centrifugation. A clear, pale-yellow fluid
Serum
