EKG Flashcards
Closed two layer sac that surrounds the heart
Pericardium
The atrioventricular groove that surrounds the outside of the heart and divides the atria from the ventricles
Coronary sulcus
Inflammation of serous pericardium
Pericarditis
The smooth outer surface of the heart
Epicardium
The thick layer of the heart composed primarily of cardiac muscle cells and responsible for the hearts ability to contract. Middle layer
Myocardium
The innermost layer of the heart; composed of thin connective tissue
Endocardium
Valve with three cusps located between the right atrium and the right ventricle
Tricuspid valve
Fine chords of dense tissue that attach to papillary muscles in the wall of the ventricles
Chordae tendineae
Valve with two cusps located between the left atria and left ventricle
Mitral valve
Serve to prevent back flow of blood into the ventricles, each valve contains three cusps
Semilunar valves
Semilunar valve located between the right ventricle and pulmonary artery
Pulmonic valve
Semilunar valve located between the left ventricle and the trunk of the aorta
Aortic valve
Thick walled and muscular blood vessels that function under high pressure to convey blood from the heart out to the body
Arteries
The two main arteries that arise from the trunk of the aorta and function to carry oxygenated blood throughout the myocardium
Coronary arteries
The process by which oxygenated blood is distributed throughout the heart muscle
Coronary circulation
A short trunk that serves to receive deoxygenated blood from the veins of the myocardium
Coronary sinus
Blood vessels that carry blood back to the heart, operate under low pressure, and are relatively thin walled
Veins
Drains blood from the head and neck
Superior vena cava
Collects blood from the rest of the body
Inferior vena cava
Tiny blood vessels that allow for exchange of oxygen, nutrients, and waste products
Capillaries
Movement through a course that leads back to the initial point
Circulation
When blood leaves through the right ventricle and travels into the pulmonary artery
Pulmonary circulation
Arteries that leave the right ventricle to the lungs
Pulmonary arteries
Refers to gas exchange within the alveolar capillary membranes in the lungs
Tissue perfusion
The circulation of blood as it leaves the left ventricle and travels through the arteries, and veins of the entire body system and back to the primary receptacle of the heart (right atrium)
Systemic circulation
Blood flows through the heart
Right atrium, through tricuspid valve, into right ventricle, through pulmonic valve, pulmonary arteries, lungs, pulmonary alveolar capillary network, pulmonary veins, left atrium, mitral valve, left ventricle, aortic valve
The actual time sequence between ventricular contraction and ventricular relaxation
Cardiac cycle
Consistent with the simultaneous contraction of the ventricles
Systole, or ventricular systole
Synonymous with ventricular relaxation
Diastole
The volume of blood pumped out of one ventricle of the heart in a single contraction
Stroke volume
The number of contractions of the heart per minute
Heart rate
The amount of blood pumped by the left ventricle in one minute
Cardiac output
Cardiac output =
Stroke volume x heart rate
The pressure in the ventricles at the end of diastole
Preload
The resistance against which the heart must pump
After load
The more the myocardial fibers are stretched, up to a certain point, the more forceful the subsequent contraction will be
Starling’s law of the heart
The amount of opposition to blood flow offered by the arteries
Peripheral vascular resistance
Blood pressure=
Cardiac output x peripheral vascular resistance
Regulates functions of the body that are involuntary, or not under conscious control
Autonomic nervous system
Congestive heart failure, myocardial infarction, or shock may be indicated by signs?
Shortness of breath, dizziness, decreased blood pressure, chest pain, cool and clammy skin
Responsible for preparation of the body for physical activity
Sympathetic nervous system
Regulates the calmer functions
Parasympathetic nervous system
The chemical neurotransmitter for the sympathetic nervous system
Norepinephrine
The chemical neurotransmitter for the parasympathetic nervous system
Acetylcholine
Pertaining to the sympathetic nerve fibers of the ANS that use epinephrine or epinephrine like substances (norepinephrine) as Neurotransmitters
Adrenergic
Reactive site on cell surface or within the cell that combines with drug molecule to produce a physiological effect
Receptor
Pertaining to the parasympathetic nerve fibers in the ANS that use acetylcholine as the neurotransmitter
Cholinergic
Alpha receptors
Vasoconstriction and increase blood pressure
Beta 1 receptors
Increase heart rate and increase contractility
Beta 2 receptors
Bronchial dilation, and vasodilation
The heart is affected by what receptors
Alpha, and Beta 1
The lungs are affected by what receptors
Beta 2
Vessels are affected by what receptors
Alpha and Beta 2
