Cardiovascular system Flashcards
Functions
Transport:
- Deliver oxygen and nutrients to cells and tissues
- Remove carbon dioxide and other waste products from cells and tissues
Protection:
- carries the cells and chemicals of immune system
Regulation: Homeostasis
Types of blood vesssels
Arteries: carry blood away from heart
Arterioles: smallest branch of artery
Veins: carry blood towards heart
Venules: collect blood from capillaries
Capilaries: network between artery and vein and called exchage vessels
Vascular pathway of blood flow
Arteries –> arterioles –> capilariese –> venules –> veins
What is the pulmonary and systemic circuit
Pulmonary circuit: blood to and from gas exchange surfaces of lungs (from right ventricle and left atrium through pulmonary semilunar valve)
systemic circuit: carries blood to and from the body (from left ventricle to right atrium through aortic semilunar valve)
Blood alternates between pulmonary and systemic circuit
Location of heart
In the thorax behind the sternum, between the lungs in the inferior mediastinum, a space between the two pleural cavities
orientation of heart
Base point toward right shoulder, apex directed toward left hip
What is the name of the thin membrane that surrounds the heat and its two parts
Pericardium,
the two parts are the parietal pericardium (line surface of pericardial cavity) and visceral pericardium/ epicardium (cover heart)
What is the fluid between the two layers of the pericardium
Pericardial fluid
Name the three layers of the heart wall
Epicardium
Myocardium (contains cardiac muscles)
Endocardium/ endothelium
What are the structural differences between the left and right ventricles
Right ventricular wall is thinner whil the left ventricular wall is thicked to overcome pressure in the aorta
Right ventricle is pouch-shaped which the left ventricle is round
What is the structure that seperates the atria
Interatrial septum
What is the structure that seperates the ventricles
Interventricular septum
What is the function of valves
To prevent the backflow of blood
What would happen if the valves malfunction and are unable to close properly
The cardiac output will be decreased and less blood will be pumped around the body. This will result in the patient experincing symptoms such as breathlessness and feel faint
What are the names of the valves betweem the atria and ventricles
Atriventricular (AV) valves: Tricuspid (right) and Bicuspid (left) valves
What are the names of the valvues that are betweem the ventricles and pulmonary artery/ aorta
Pulmonary semilunar
valve and aortic semilunar valves
What does the cardiac veins do
drain the myocardium of blood
What does the coronary sinus do
A large vein posterior of the heart that receives blood from cardiac veins and empties into right atrium
Where does the right coronary artery supply blood too
Right atrium, portions of both vebtricles and cells of sinoatrial (SA) and atrioventricular nodes
Where does the left coronary artery supply blodo too
Left ventricle, left artium and interventricular septum
What does the right coronary artery branch into
Marginal and posterior interventricular arteries
What does the left coronary artery branch into
Circumflex and anterior interventricular arteries
What is the artery that is known as the widow maker
LAD artery, left anterior decending artery
What are the two types of cardiac muscle cells and what do they do
Conducting system (controls and coordiantes heartbeat ) and contracticle cells (prodcuce contractions that propel blood)
What is the name of the proptery of the heart to contract automatically
automaticity
What are the structure of the conducting system
Sinoatrial (SA) node: on the wall of right atrium
Atriocentricular (AV) node: at junction between atria and ventricles
Conducting cells: that interconnect SA and AV nodes and distribute stimulus through myocardium
SA node –> AV node –> AV bundle and bundle brances –> purkenji fibres
What holds the valves open
chordae tendineae
What are the muscles that contract to cause the valves to open
papillary muscles
How does the conducting system send signals
SA node activity and atrial activation begin (0 sec)
Stimulus spread acros the atrial surfaces and reached the AV node (50 msec)
There is a 100 msec delay at the AV node. Atrial contraction begins (150msec)
The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the Purkinje fibers (175 msec)
The impulse is distributed by purkinhe fibers and relayed thorughout the ventricular contraction begins (225 msec)
What is the pacemaker of the normal heart
SA node
What happens if the SA node cannot work
Av node will generate the impulse, if that does no work the abrnormal cells will work, if not a artifical pacemaker will be inserted when natural pacemaker fails
What is the normal heart rate
70-80 beats per minute
What is the heart rate when AV node generates impulse
40-60 beat per minutet
What are the 2 types of abnormal pacemaker function
Bradycardia, abnormally slow heart rate < 60 bpm
tachycardia, abnormally fast heart rate > 100bpm
What is the ectopic pacemaker
it is abnormal cells that generate high rate of action potentials
bypass conducting system and disrupt ventricular contractions, disrupting the rate and rhythm
What are the three types of ECG waves
P wave (atrial contraction, at SA node), QRS complex (ventricular contraction) and T wave (ventricular relaxation)
What causes the heart sounds
First heart sound (“Lubb”) is at the apex of the heart, where AV valves are closing
Second heart sound (“Dupp”) is due to semilunar valves closing
(sound is due to blood hitting against the closed valves)
Third and fourth heart sounds dare faint- due to atrial contraction and blood flow into ventricles
how to calculate cardiodynamics
CO = HR x SV
Cardiac output (mL/min)- amount of blood pumped by left ventricle in 1 minute
HR (Beats per minute)
Stroke volume (mL/beat)- amount of blood ejected by ventricle during a single beat
What is the blood pressure gradient
Ventricle pumps with highest pressure –> h.p. arterial circulation –> pressure drop relatively at capillaires –> low pressure venous circulation –> lowest pressuer at venae cavae and atrium
What factors determine blood pressure
Cardiac output
Peripheral resitance (diameter of arterial walls, affected by neural and hormonal factors)
thickness/ viscosity of blood
What are the factors influencing blood pressure
Age (increases BP)
Emotion (eg sympathetic simulation or adrenaline/ non adrenaline hormone results in vasoconstriction raising BP)
Exercise (BP increases due to increased venous return)
Hormones (adrenaline, non adrenlaline, thyroid hormone, renin-angiotensin aldosterone stimulation)
Sleep (decreases BP, decreased venous return)
Pregnancy (increases BP due to increased metabolism)
How to record blood pressure
systolic pressure/ distolic pressure
What is the normal blood pressure
less then or equal too, 120mmHg/ 80mmHg
What are the three stages of hypertension and what is the BP for it
prehypertension
120-139mmHg/ 80-89mmHG
Hypertension stage 1
140-159mmHg/ 90-99mmHg
Hpertension stage 2
160mmHg/ 100 mmHg (or higher)
Systolic increase by 20mmHg and distolic increases by 10mmHg per stage
Types of heart issues that could take place (5)
Hypertension
Atherosclerosis (narrowing of arteries with deposistion of plaque, this can cause thrombosis)
Myocardial Infarction (death of myocardial tissue due to block in coronary artery)
Angina pectoris (block in coronary artery)
Aneurysm (dialtion of b.v. due to weakening of wall- due to atherosclerosis and hypertension)
