Cardiovascular System- ALL NOTES Flashcards
What are the 3 phases of the Cardiac Cycle (Haemodynamic)?
1) Ventricular filling
2) Ventricular systole
3) Early diastole
What does Haemodynamic mean?
-This is the Cardiac Cycle, how the blood flows through the body of which takes place through 3 phases.
What does Systole mean?
-Heart Contraction
What does Diastole mean?
-Heart Relaxation
Diagram of the heart?
Valves graph diagram?
What phase of Cardiac cycle is the sound S1 (LUBb)?
-Isvolumetric contraction, caused by the closure of AV vavles
What phase of Cardiac cycle is the sound S2 (DUBb)?
-Isvolumetric relaxation, cause by the closure of SL vavles
What phase of Cardiac cycle is the sound S3?
-Early ventricular filling, caused by tensing of the chordae tendinease and the atrioventricular ring.
- Adults: Ventricular systolic failure, normal in children
What phase of Cardiac cycle is the sound S4?
-Atrial contraction, caused by vibration of the ventricular wall, stiff ventricle, hypertrophy or ischemic ventricle
Electrical system within the heart, what is it?
–Right artrium, there is a SA node, which involuntary stimulates heartbeat. It is a muscle which contracts and generates electrical signals and sends a pulse throughout the body
- AV node of the left side of the heart
- These signals inter nodal tracts
Electrical system within the heart, what is it?
–Right artrium, there is a SA node, which involuntary stimulates heartbeat. It is a muscle which contracts and generates electrical signals and sends a pulse throughout the body
- AV node of the left side of the heart
- These signals inter nodal tracts
Heart Electrical flow diagram?
What is the Bundle Of His?
-It is an elongated segment connecting the AV node and the left and right bundle branches of the septal crest.
-It carries electrical impulses through the centre of the heart.
What happens if the Bundle Of His fibres are blocked?
-You will have problems with your heartbeat
What are the purkinje fibres?
-Fibres of which carry the electrical impulse to the ventricles.
What is the atrioventricular node?
-The atrioventricular node sends an electrical signal to the bundle of his. The electrical signal moves to the purkinje fibres
What are the 4 key properties of the Cardiac Muscle?
-Auto-rhythically
-Excitability
-Conductivity
-Contractility
What does heart Auto-rhythically mean?
-Ability to initiate heartbeat, consistent and continuous at regular pace without any external stimuli
What does the heart Excitability mean?
- Ability to respond to stimuli of adequate strength and duration (threshold or more)
- Ability to generate and process action potential
What does heart Conductivity mean?
-Ability to conduct and transmit impulse through the cardiac tissue
What does heart Contractility mean?
-Ability to contract in response to stimulation (mechanical)
What are the Excitation- Contraction Coupling in Contractile Myocytes steps?
1) AP from adjacent cell excites myocytes and trigger membrane depolarisation in T-tubules
2) Calcium enter the cells via voltage gated channel opens and calcium enters the cells
3) Calcium binds to Ryanodine receptor (RYR) and induce Calcium release from SR
4) Calcium binds to troponin and triggers acting-myosin complex and contraction
5) Calcium unbind from troponin and pumped back into SR
6) Calcium unbinding cause relaxation and excess Ca2+ exchanged with Na+
7) Na+ gradient is maintained by sodium-potassium-ATPase pump
Excitation- Contraction Coupling in Contractile Myocytes steps diagram?
What is the sinus rhythm of the heart?
-This is the wave of depolarisation that begins in the SA node and spreads over the heart (it proceeds contraction)
What can we use an ECG for?
-To see the sinus rhythm of the heart, where the ECG shows the depolarisation and depolarisation of the atria and ventricles as it shows up as 3 distance waves on the ECG
What is the ECG alphabet order?
P,Q,R,S,T
What is the Isoelectric signal line on an ECG?
-This is the flat line of the graph, the x-axis
What is the order of reading a ECG?
-Cardiac cycle starts with arium contraction, when atria systole takes place you can see the deflation in the chart (This is at point P, a slight wave/peak)
- Delay happens when waiting for ventricle to be filled before it can generate the next contraction (this will be shown as a straight line)
- When the ventricle contracts QRS (This will be a large wave where R is the top of the wave/ peak)
- T is ventricular relaxation and when there is a depolarisation happening
How long does a cardiac cycle take? how many beats per minute in a normal individual?
-Around 0.8 seconds
-Therefore, beats per minute 0.8 x 60 = 75bmp, in a normal individual 70-100
What does a Sinus Bradycardia mean?
-is when the heartbeat is less than 70bmp; if it is prolonged = abnormal
What does a -Sinus Tachycardia mean?
-is when the heartbeat is over 100bpm; if it is prolonged= abnormal
Why is the R wave bigger than the others?
-This is because the walls of the ventricles are very thick due to the amount of work they have to do, and consequently, more voltage is required. The ventricles are larger than the atria, requiring a stronger electrical stimulation to depolarise them.
Is there a U wave in an ECG?
When would a sinus bradycardia occur?
-Seen in athletes and occur during sleep
-No treatment is usually required
When would sinus tachycardia occur?
-normally in exercise
-Hypovolemia/ underlying health issues
What is sinus Arrythmia?
-Regularly irregular sinus rhythm
What can cause sinus arrhythmia ?
-Heart block/ disease
-Respiratory disease?
How can you detect sinus arrhythmia ?
Cardiac cells have what to ensure electrical flow of the heart?
-Cardiac cells have specialised cells regulating the electrical flow of the heart
What are the 2 most common heart sounds ?
-LUB
-DUB
What are the roles of blood?
-Transportation, protection and regulation
What does blood transport?
-O2, CO2, nutrients, electrolytes, metabolic waste, hormones and cytokines
How does the blood protect?
-Platelets to prevent blood loss and antibodies and WBC to aid immune response
How does the blood help regulation?
-First response to adapt to change in conditions eg body temp and pH
What colour is high oxygen blood and where is it found?
-Scarlet red, found in artery
What colour is lower oxygen blood and where is it found?
-Dark red, found in vein
What percentage of the blood is made up of plasma?
-55%
What percentage of blood is made up of solids?
44%
What percentage of blood is made up of Buffy coat?
1%
What is carried in the plasma?
-Plama proteins (albumin, globulin) nutrients, gases, electrolytes, metabolic wastes make up 10% dissolved in 90% water
What is the word used for blood production?
-Haematopoiesis
What are haemocytoblasts?
-Committed cells that will become blood cells
How di blood cells travel from the red bone marrow into circulation?
-Through blood sinusoids
What is leucopoiesis ?
-Formation of white blood cells
What is erthropoeisis?
-Production of red blood cells
What is thrombopoiesis?
-Production of platelets
What are the two types of leucocytes?
-Granulocytes and granulocytes
What are the types of granulocytes?
-Neutrophils, eosinophils, basophils
What is a neutrophil?
-A type of granulocyte that is large, common and has 3-4 lobes that contain hydrochloric acid to fight bacterial infections
What are eosinophils ?
-A type of granulocyte that has 2 lobes connected by a thick strand of chromatin that fights parasitic infection
What are basophils?
-Large granules with a horse shaped nucleus of 2 lobes joined together that contain histamine which migrate into the infected tissue and act as mast cells to encourage inflammation
What is the collectiv ename for granulocytes?
-Polymorphonuclear cells
What are the types of agranulocytes?
-monocytes, thrombocytes and lymphocytes
What are monocytes?
-An agranulocyte that is formed of a large horseshoe lobed nucleus that migrate into tissue and protect and prevent bacteria infections
What are thrombocytes ?
-Platelets or fragments that contain no nucleus so cannot reproduce but contain lots of mitochondria to give a lifespan of 7-10 days to help with blood clotting and receptors for coagulation
What are the two subcategories of lymphocytes?
-Big and small
What are the two types of small lymphocytes?
-B plasma cells and T cells
What are the types of T cells?
-T-helped
-T-suppressor
-T-cytotoxic
What does a T-helper cell do?
-It releases cytokines and stimulates B-cell maturation
What does T-suppressor cell do?
-Regulates immune response through a negative feedback system
What does a T cytotoxic cell do?
-Removes malignant cells
What do B cells do?
-Produce anti-bodies after receiving signal from T cells
What are big lymphocytes?
-Natural killer cells that recognise a virus in infected cells and acts like a bomb to kill them
What is a Philia ?
-Surplus or excess
What is penia?
-Deficiency
What are the risks of leucopenia?
-Low WBC-risk of infection
What are the risks of neutropenia?
-Risk of bacterial infections
What are the risks of thrombocytopenia ?
-Risk of blood loss and low platelets and autoimmune disease in children
What is leucocytosis?
-sign of infection as high WBC count
What is neutrophilia?
-Sign of bacterial infection
What is eosinophilia?
-Sign of parasitic infection
What is lymphocytosis?
-Sign of viral infection
What is monocytosis?
-Sign of bacterial infection in tissues eg TB
What makes up haemoglobin?
-Four haem groups containing a central iron that can bind to an oxygen that have 4 polypeptides between them
What is erthyropoiesis ?
-Red blood cell production
How is erythropoiesis regulated?
-Regulated with hormone erythroprotein, which is secreted by the kidney in response to hypoxia. Its a negative feedback loop
What is hypoxia?
-Deficiency in the amount of oxygen reaching the tissues
What can cause hypoxia?
-Haemorrhage or injury, iorn deficiency. high altitude or lung disease
What hormone enhances EPO production ?
-Testosterone
What is haem broken down into
-Bilirubin secreted in bile, stercoblin
-brown pigmented excreted in faeces
What is globing broken down into?
-amino acids
What are the symptoms of anaemia?
-Fatigue, pallor, dyspnoea ad=nd chills
How can anaemia be caused?
-Blood loss or RBC deficiency
What are the two genetic conditions effecting RBC?
-Thalassemia and sickle cell anaemia
What is thalassmia?
-A genetic condition where a globing chain in hb is absent or malfunctions leading to RBC becoming thin and delicate and lacking hb
What is sickle cell anaemia?
-A genetic mutation where one amino acid os wrong in the globin B chain which causes RBC to be crescent C shape so O2 levels are low and higher risk of blocked vessels leading to stroke
What is Polycythamia?
-Too many RBC which can increase the viscosity of the blood leading to stroke chi and renal disease
What is haemostasis?
-Blood clotting
How does haemostasis occur?
-Vascular spasm causes site of injury on skin to contract, platelets stick to exposed collagen to block the site and stimulate ADP thromboxane A2 and serotonin. At the same time, thrombin is produced from prothrombin to form fibrinogen then fibrin-a mesh like polymer to cover the injury site
What is thrombosis?
-Blood clotting attached to a bloodd vessel
What is an embolism ?
-part of the blood clot that breaks off and moves through the blood vessel until it reaches a vessel that is too small to let it pass
If a person has group A blood, what antigen and antibodies do they have?
-Antigen A and antibody B
If a person has group B blood, what antigen and antibodies do they have?
-Antigen B and antibody A
If a person has group AB blood, what antigen and antibodies do they have?
-antigen A and no antibodies
If a person has group O blood, what antigen and antibodies do they have?
-No antigens and antibodies A and B
What makes a blood group + or - ?
-That presence or lack of a Rhesus factor
What are the three types of capillaries?
-Continuous
-fenestrated
-sinusoids
What are continuous capillaries?
-Smooth and skeletal muscle, important in blood brain barrier as a very tight junction to restrict toxin exchanges
What are fenestrated capillaries?
-Higher permeability of larger biomolecules through small pores in the structure.
-Found in intestinal villi, kidney glomeruli and endocrine cells
What are sinusoidal capillaries?
-Found in red bone marrow and liver, intercellular clefts are larger with fewer tight junctions to allow huge molecule perfusion eg blood cells, proteins and wastes
What is venous return?
-The flow of blood back to the heart
How does venous return work?
-Calf/skeletal muscle pump contracts
-Pulsatile arteries adjacent to vein complement the muscle pump/pressue and venous return occurs
How does heart muscle get oxygenated ?
-Two small arteries branch off the aorta and profuse blood to the myocardium
What is blood pressure?
-The pressure exerted on the walls of a blood vessel
What is the top number on blood pressure?
-Systolic
What is the bottom number on blood pressure?
-Diastolic
What is the systolic blood pressure?
-Pressure exerted when heart contracts
What is diastolic blood pressure?
-Pressure exerted when heart relaxes
What is considered normal blood pressure?
-90/60 to 120/80
How is blood pressure regulated?
-Autoregulation, neural, hormonal
How is blood pressure regulated via auto regulation?
-Changes in blood flow are detected by local receptors during micro perfusion
How is blood pressure regulated neurally?
-Short term regulation in responses to transient changes in arterial pressure via baroreflex mechanisms
How is blood pressure regulated hormonally?
-Erythroproietin, anti-diuretic hormone, adrenaline/nonadrenaline
How does neural regulation of high blood pressure occur?
-Baroreceptors firing rates increases and arterial blood pressure increases so vagal activity increases and sympathetic cardiac activity decreases which decreases heart rate and thus cardiac output
How does neural regulation of high blood pressure occur?
-Baroreceptors firing rates decrease and arterial blood pressure decreases so vagal activity decreases and sympathetic cardiac activity increases which increases heart rate and thus cardiac output
What does harm-dynamic mean?
-Mechanical flow
What happens in the ventricles during ventricular filling?
-Diastole
What happens to the atria during ventricular filling?
-Diastole then systole
What happens to the atria during ventricular systole?
-Diastole
What happens to the ventricles during ventricular systole?
-Systole
What happens to the atria and ventricles in early diastole?
-Diastole in both
Where does the ‘Lub’ sound come from?
-Atrioventricular valves closing
Where does ‘dub’ sound come from ?
-Closing of semilunar valves
Where does electrical flow come from in the right side of the heart?
-Sino-artial node- pacemaker
What does the electrical flow come from in the left side of the heart>
-Atria ventricular node- middle of the hart has lower depolarisation than SA
What happens in the fibrous mid line?
-No electrical conductivity
What is the function of the bundle of his?
What are the parking fibres?
What are they key properties of cardiac muscle?
-Auto-rhymicity, excitability, conductivity and contractibility
Why do some athletes abuse artificial EPO?
-More oxygen carrying capacity, endurance becomes better
What are the3 main types of circulation?
-Veins
-Capillaires
-Arteries
What do arteries do?-
-Carry blood away from the heart
What do veins do?
-Carry blood towards the heart
How does blood flow through the right side of the heart?
How does blood flow through the left side of the heart?
How does the electrical flow flow through the heart?
How does the human body breathe in?
How does the human body breathe out?
