circulatory system Flashcards
what cavity is heart in?
thoracic cavity in mediastinum
what is the apex?
inferior part of heart
what is the base?
posterior part of heart
what is the heart enclosed in?
pericardium
what is the fibrous pericardium and its function?
outermost layer, dense connective tissue
function: prevents heart from overfilling and restricts heart movements
what is the serous pericardium?
folds back on itself to create two specific layers parietal and visceral
what is the parietal layer?
adheres to the fibrous pericardium
what is the visceral layer?
adheres to heart wall
what is the pericardial cavity?
contains serous fluid
what is the pericardial effusion?
too much fluid in the pericardial cavity that causes the heart to squeeze and prevents blood flow
what is the endocardium?
contains endothelium covering a CT layer and lines inside of heart and covers valves
what is myocardium?
cardiac muscle thickest layer
what is epicardium?
visceral layer of the serous pericardium, thin serous flat serous membrane
what is cardiac muscle?
only in heart, short, cylindrical cells, one or two centrally located nuclei, intercalated discs, striations
what is the coronary sulcus?
groove that separates the atria from the ventricles
what is myocardial infarction?
heart attack, death of heart wall due to prolonged lack of blood supply
what is the interventricular sulcus?
Groove that separates left and right ventricles
what are the chordae tendinea and its function?
from the papillary muscle to the 3 flaps of the right atrioventricular valve
function: prevents flap from everting into atrium
what is plasma?
extracellular matrix, dissolved protein fibers and watery ground substance
erythrocytes
biconcave discs, anucleate, filled with hemoglobin, transports oxygen to cells and carbon dioxide away from cells
what are neutrophils?
most numerous, cytoplasm has fine pale granules, phagocytize pathogens
what are lymphocytes?
cytoplasm lacks granules, located in lymphoid tissues, has three cells
what are T-lymphocytes?
coordinate immune activity
what are B-lymphocytes?
produce antibodies
what are natural killer cells?
attack pathogens and abnormal affected/ infected cells
what are monocytes?
largest leukocytes, cytoplasm lacks granules, phagocytize pathogens, cellular debris and dead cells
what are eosinophils?
cytoplasm contains prominent granules that stain red, nucleus is bi-lobed, phagocytizes allergens and destroys parasitic worms
what are basophils?
Make up less than one percent of leukocytes, contains big granules that stain blue, bi-lobed nucleus, releases histamine and heparin during inflammatory or allergic reactions
what are platelets?
cytoplastic fragments from larger cell, anucleate, very small, assist with blood clotting
what are veins and its function?
take blood to the heart, transport blood in low oxygen and high in carbon dioxide, has very thin walls and collapsible, low blood pressure, lumens larger than in arteries
what are arteries and what do they do?
carry blood away from heart to other tissues, transport blood high in oxygen, relatively thick. springy wall, higher blood pressure than in veins
what are capillaries?
tiny vessels that connect the smallest arteries to veins, gas exchange happens here, slightly larger than erythrocytes, have only a tunica intima
what is the tunica media?
middle layer, circularly arranged smooth muscle fibers, largest layer in arteries, sympathetic innervation typically vasoconstriction
pathway of blood?
heart, elastic arteries, muscular arteries, arterioles, capillaries, venules, vein, heart
what is the tunica externa?
outermost layer, largest layer in viens, contains areolar connective tissue
what is the tunica intima?
innermost layer, endothelium (simple squamous epithelium), and areolar connective tissue
what are elastic arteries?
vessel wall contains large amount of elastic protein fibers
what are muscular arteries?
less elastic than elastic arteries, more smooth muscle in the tunica media
what are venules function?
Collect blood from capillaries
what are arterioles?
tunica media consists of 6 or fewer layers of smooth muscle
what are veins and their function?
formed when venules unite, most have valves, prevents backflow
what is a skeletal muscle pump?
helps blood be pushed in veins toward heart
what is autorhythmicity?
the heart itself is responsible for beating itself
what is the sinoatrial node?
its in the upper wall of right atrium and its responsible for initiating the heartbeat
where is the atrioventricular node?
floor of right atrium
what is the atrioventricular bundle?
a bundle of conducing fibers that runs through interventricular septum
what are purkinje fibers?
specialized conduction muscle cells, larger than cardiac muscle fibers, and extends through ventricle walls
what is commotio cordis?
causes ventricles to flutter and no blood flow
