Please enable JavaScript.
Coggle requires JavaScript to display documents.
Cardiovascular system (structural and functional differences between blood…
Cardiovascular system
structural and functional differences between blood vessel types
arteries
Carries blood away from heart
arterioles
found between arteries and capillaries
capillaries
smallest of blood vessels and sites of gax exchange between blood and tissue cells
venules
connects capillaries and veins
veins
return blood toward the heart
differences between blood types
arteries
thickest layer; small lumen, carry high pressure blood, and blood moved by pumpina action of the heart
Veins
thinner tunica media; larger lumen, carry low pressure blood, blood moved "miliking" action of muscles to heap move blood, and contain many minivalves to prevent backflow
Capillary beds
vascular shunt-directly connects an arteriole to a venule
true capillaries- gas exchange by diffusion (high to low concentration
Blood vessel Anatomy
Tunica intima
Endoynelium ( inner lining of blood vessels)
Tunica media
middle, smooth muscle; controls (sympathetic nervous system) diameter of blood vessels
Tunica externa
outermost, fibrous connective tissue
ECG disorders of the cardiovascular system
Pericarditis- inflammation of pericardium
May be commonly caused by viral infections which causes build up of fluid in the pericardial cavity and prevents the heart from expanding and contracting to pump blood
Angina pectoris- crushing chest pain from lack of blood to heart muscles
may be an indication of myocardial infarction or pain during exercise or exertion; also may be due to sore chest muscles
Myocardial infarction (heart attack)- heart muscles cells die due to lack of blood to heart muscles
caused by atheroscierosis of the coronary arteries; symptoms include chest pain, pain down the left arm, shortness of breath, fever, and vomiting
Murmur- abnormal or irregular heart sounds; can be caused by valve stenosis
Valve stenosis
defect in valves failing to open which makes heart pump faster
Fibrillation-rapid uncoordinated shuddering of heart muscle
cause by defect in the intrinsic conduction system, specifically the SA node
Varicose veins- swollen and twisted veins caused by when valves in veins do not work and cause backflow or pooling of blood
Layers of the heart
Epicardium
outer connective tissue layer
Myocardium
Middle, thick muscle layer
Endocardium
Inner Lining
Pericardium
Double serous membrane ( produces serous fluid)
Visceral pericardium
Next to the heart
Parietal pericardium
outside layer
Pericardial cavity
Created by two layers of pericardium: filled with serous fluid
intrinsic factors
Heart contractions
atria contract simultaneously
atria relax, the ventricles contract together, then relax
systole- contraction (ventricular)
diastole- relaxation (ventricular)
Heart sounds- two distinct sounds heard during cardiac cycle
Lup- long first heart sound caused by closing of Av valves
Dup- short second sound caused by closing of semilunar valves
cardiac output
Amount of blood pumped by each side of heart in 1 min
CO- (heart rate x stroke volume)
Heart rate- how many times the heart beats per minute
stroke volume- volume of blood pumped by each ventricle in 1 contraction
Internal conduction system
internal control of heart rate- Heart muscle cells contract, without nerve impulses, in a regular, continuous way
Elements of Intrinsic Conduction system: SA mode, AV node, Av Bundle, bundle branches, Purkinje fibers, ventricular wall
Sinoatrial node
located at right atrium; starts heart beat and sets pace
sequential stimulation occurs at other autorhythmic cells
Atrioventricular node- at junction between atria and ventricles
Atrioventricular Bundle
Right and left bundle branches-located at the interventricular septum
Purkinje fibers- specialized myocardial muscle fibers that conduct electric impulse; spread within muscles of ventricular wall
Regulation of heart rate
Stroke Volume usually remains relatively constant
Starling's law of heart- more cardiac muscle is stretched, stronger contraction
Changing heart rate is most common way to change cardiac output
Increased heart rate
sympathetic nervous system- crisis or low blood pressure
Hormones- Epinephrine and Thyroxine
Exercise
Decreased blood volume
Decreased Heart rate
Parasympathetic nervous system
high blood pressure or blood volume
Decreased venous return
Major arteries and veins of the body
Aorta
leaves left ventricle to rest of the body
Pulmonary trunk
leave right ventricle to lungs branch into pulmonary arteries
Vene cava
(supeerior and inferior) enters right atrium from upper and lower parts of body
Pulmonary veins
(four) enters left atrium from lungs
Anatomy of the heart
Heart chambers
atria
receiving chambers
Left atrium- receives blood from lung
right atrium-receives blood from rest of the body
Ventricles
discharging chambers
left ventricle- discharges blood to the rest of the body
right ventricle- discharges blood to lungs
Types of circulation
Pulmonary circulation
flow of blood to and from the lungs to heart
Systemic circulation
flow of blood from rest of body to the heart
Coronary circulation
flow of blood to myocardium of heart
coronary arteries- supplies blood to the heart
cardiac veins- carries blood away from the heart
Heart Valves
atrioventricular valves
bicuspid ( mitral) valve (left)
Tricispid valve (right)
semilunar valves
Pulmonary semilunar valve- between right ventricle and pulmonary trunk
Aortic semilunar valve- between left ventricle and aorta
function of valves
close to prevent backflow
blood flow in only on direction
Major functions of the cardiovascular system
Deliver oxygen and nutrients and to remove carbon dioxide and other waste products
A closed system of heart and blood vessels
blood flow through the heart and body
superior and inferior vena cava, right atrium, triscuspid valve, right ventricle, pulmonary valve, pulmonary trunk/ artery, lungs, pulmonary vein. left atrium, mitral/biscuspid valve, left ventricle, aortic valve, aorta, body
Cardiac cycle
events of one complete heart beat
mid-to-late diastole- blood flows into ventricles
Ventricular systole- blood pressure build before ventricle contracts, pushing out blood
Earlyy diastole- atria finish refilling, ventricular pressure is low