Structure and function of the cardiovascular and lymphatic systems Flashcards
(9 cards)
Circulatory system
structures:
blood vessels_ complex array of tubing
heart: pump blood
function:
deliver oxyegen, nutrients and other substances to all body cells. Remove waste products
intrinsic systems regulators:
nervous and endocrine
other interactions:
digestive system: supply nutrients
respiratory system: supply oxygen, remove carbon dioxide, maintain acid-base balance
renal system: waste removal, fluid and electrolyte and acid base balance
Pulmonary and systemic circulation
Know the direction of blood of each ventricle and each vein or artery of the heart and each atrium and valve.
pulmonary circulation:
right heart: pumps deoxygenated blood to the lungs for gas exchange
systemic circulation:
left heart pumps oxygenated blood and nutrients to the rest of the body for delivery and removal of wastes and carbon dioxide
arteries: carry blood away from the heart
veins: carry blood toward the heart
lymphatics:
carry plasma from the interstitium to the heart
The heart
weighs about 1 pound, lies at an angle in the mediastinum (above diagram above in between the lungs)
Function: conduct blood to and from the heart
divided into 4 chambers
Heart wall layers : Pericardium anatomy
Double walled- membranous sac that encloses the heart
layers:
parietal pericardium: outer later of mesothelium over a thin layer of connective tissue
visceral pericardium aka epicardium: inner layer that fold back and is continuous with the parietal pericardium to allow large vessels to enter / exit the heart without breaching the layers
pericardial cavity: fluid containing space between visceral and parietal pericardium
pericardial fluid:
secreted by cells of the mesothelium to lubricate membranes and minimize friction as the hearts beats slide 10
Pericardium function
Prevents displacement of the heart during gravitational acceleration / deceleration
Provides physical barrier against infection & inflammation from the lungs & pleural space
Contains pain & mechanoreceptors that elicit reflex changes in blood pressure & heart rate
Heart wall myocardium and
Myocardium:
Cardiac muscle
Anchored to heart’s fibrous skeleton
Thickness varies from one chamber to another & is r/t amount of resistance muscle must overcome to pump blood from the different chambers
Endocardium
Internal lining composed of connective tissue & squamous cells
Continuous with the endothelium that lines arteries, capillaries & veins
Creates a continuous closed circuit
Heart Chambers
Right & left atria
Smaller with thinner walls
R = 2mm & L = 3-5 mm
Serve as storage units & conduits for blood
Offers little resistance to flow of blood into ventricles
Right & left ventricles
Thicker myocardial layer & make up bulk of heart
R = 3-5 mm L = 13-15 mm
Left ventricle is the most muscular
Must propel blood through pulmonic & circulatory systems
Mean pulmonary pressure ~15 mmHg
Mean arterial pressure ~92 mmHg
Right: shaped like a crescent or triangle & acts like a bellows to propel large volumes of blood through a very small valve into the low-pressure pulmonary circulation
Left: larger & bullet shaped & pumps blood through a large valve opening into the higher-pressure systemic circulation
Septum and valces
Interatrial septum:
Separates right & left atria
Interventricular septum:
Separates right & left ventricles
Is an extension of the fibrous skeleton of the heart
Valves:
Indentations of the endocardium
Separate the atria from the ventricles &
the ventricles from the aortic & pulmonic arteries
