Cardiovascular System Flashcards
Structure of cardiovascular system
Closed circulatory system containing the heart, blood and blood vessels (veins, venules, capillaries, arterioles, arteries)
Describe open and closed circulation, giving an example of each
- Open: has a start and end point e.g. lymphatic system
- Closed: continuous circuit e.g. cardiovascular system
Describe systemic circulation
Transports oxygenated blood from heart to body, and deoxygenated blood from body to heart
Describe pulmonary circulation
Transports oxygenated blood from lungs to heart and deoxygenated blood from heart to lungs
What is A and what is its function?
Superior vena cava
- Transports deoxygenated blood from the upper body to the right atrium
What is B and what is its function?
Pulmonary vein
- Transports oxygenated blood from the lungs to the left atrium
What is C and what is its function?
Pulmonary artery
- Transports deoxygenated blood from right ventricle to lungs via the pulmonary valve
What is D and what is its function?
Right atrium
- Collects deoxygenated blood from body via the venae cavae and pumps it to the right ventricle via the tricuspid valve
Which part of the heart collects deoxygenated blood from the body?
R) atrium, NOT VENAE CAVAE
(venae cavae transport not collect)
What is E and what is its structure and function?
R) AV valve or tricuspid valve - tRIcuspid=RIght
- S = valve with 3 flaps between R) atrium and R) ventricle
- F = prevents regurgitation of blood from R) ventricle to R) atrium
What is F and what is its structure and function?
Chordae tendineae
- S = thin, strong, fibrous chords connecting bicuspid and tricuspid valves to papillary muscle
- F = regulate opening/closing of AV valves
What is G and what is its function?
Right ventricle
- Collects deoxygenated blood from the right atrium and pumps it to the lungs via the pulmonary artery
What is H and what is its function?
Inferior vena cava
- Transports deoxygenated blood from the lower body to the right atrium
What is I and what is its function?
Aorta
- Transports oxygenated blood from left ventricle to organs and tissues via the aortic valve
Which artery pumps blood under the highest pressure?
Aorta
What is L and what is its function?
Left atrium
- Collects oxygenated blood from lungs via the pulmonary vein and pumps it to the left ventricle via the mitral/bicuspid valve
What is M and what is its structure and function?
L) AV valve or bicuspid/mitral valve
- S = valve with 2 flaps between L) atrium and L) ventricle
- F = prevents regurgitation of blood from L) ventricle to L) atrium
What is N and what is its function?
Left ventricle
- Collects oxygenated blood from the left atrium and pumps it to the body via the aorta
Which ventricle has a larger wall and why?
L) ventricular wall is thicker than R) so it can generate more pressure from contractions to distribute oxygenated blood around body
Which part of the heart pumps oxygenated blood to the body?
L) ventricle NOT AORTA
(aorta transports, not pumps)
Why do ventricles have thicker walls than the atria?
Ventricles pump blood out of heart to the body whereas atria just receive blood and transport it to ventricles
What is O and what is its structure and function?
Septum
- S = muscular wall between L) and R) ventricles
- F = separate L) and R) sides of the heart to prevent mixing of oxygenated and deoxygenated blood
What is P?
Descending aorta
What is Q and what is its function?
Pulmonary (semilunar) valve
- Prevents regurgitation of blood from pulmonary artery to R) ventricle
Where is the pulmonary valve located in relation to the aortic valve?
Anterior
What is R and what is its function?
Aortic (semilunar) valve
- Prevents regurgitation of blood from aorta to L) ventricle
Describe the 3 layers of the heart
- Pericardium: fibrous sac surrounding the heart
- Myocardium: cardiac muscle, involuntary and striated, transmits electrical stimuli
- Endocardium: lines chambers and valves within the heart
What is the epicardium?
Same thing as the visceral pericardium (serous membrane closest to heart)
Function of coronary arteries and veins
- Coronary arteries transport oxygenated blood to the myocardium, from the aorta, to supply the heart with nutrients e.g. O2 for contractions
- Coronary veins transport deoxygenated blood away from the myocardium, towards the right atrium, to remove waste from contractions e.g CO2
Pathway for deoxygenated blood through the heart
Deoxygenated blood enters through superior and inferior vena cava > R) atrium, tricuspid valve, R) ventricle, pulmonary valve, pulmonary artery, to lungs for oxygenation
Pathway for oxygenated blood through the heart
Oxygenated blood enters through pulmonary veins, L) atrium, bicuspid valve, L) ventricle, aortic valve, aorta, to body organs/tissues
What is the double pump?
‘Lub dub’ sound: atria contract and ventricles contract
State the order of the cardiac cycle
Ventricular diastole, atrial diastole, atrial systole, ventricular systole
Describe ventricular diastole
- Atria and ventricles relaxed
- Blood moves into venae cavae and pulmonary vein
- Semilunar and AV valves closed to prevent backflow of blood
Describe atrial diastole
- Atria and ventricles relaxed
- Blood moves from venae cavae/pulmonary vein into atria
- AV and semilunar valves closed to prevent blood going into ventricles before atrial systole
Describe atrial systole
- Atria contract
- AV valves open to allow blood to move from atria to ventricles
Describe ventricular systole
- Ventricles contract
- Semilunar valves open to allow blood to move from ventricles to pulmonary artery/aorta
- AV valves close to prevent backflow of blood from ventricles to atria
What is the cardiac conduction system and name the 4 components in order
- Electrical signals from nervous system causing the heart to contract
- SA node, AV node, bundle of His, Purkinje fibres
What is A and what is its structure and function?
Sinoatrial (SA) node
- S = collection of specialised pacemaker cells, located in upper wall of R) atrium
- F = spontaneously generates electrical impulses (depolarisation) which triggers atrial contraction
What is B and what is its structure and function?
Atrioventricular (AV) node
- S = collection of specialised pacemaker cells, located on the lower interatrial septum
- F = conducts electrical impulses from atria to bundle of His, controlling heart rate
What are C and D?
- E = left bundle branch
- F = right bundle branch
What is E and what is its structure and function?
Bundle of His
- S = specialised conductive cells, connects AV node to L) and R) bundle branches of the septum
- F = transmits electrical signals from AV node to bundle branches
What is F and what is its structure and function?
Purkinje fibres
- S = specialised conductive cells, located along the myocardium of ventricular walls
- F = ventricular contraction
Structure of blood
Connective tissue containing cells (erythrocytes - RBC, leukocytes - WBC), cell fragments (platelets) and fluid (plasma)
Name the 2 components of the buffy coat
Platelets and leukocytes (WBC)
Structure and function of RBC
- S = biconcave, no nucleus, contains haemoglobin (protein that contains iron and carries oxygen)
- F = transport oxygen to tissues around the body
How does the structure of a RBC support its function?
- Biconcave shape: increased SA:V ratio = increased rate of diffusion of O2, and more flexibility to fit through capillaries to deliver O2 close to cells
- No nucleus: more space for Hb to carry more O2
Structure and function of leukocytes (WBC)
- S = largest blood cell, made in bone marrow
- F = - protection: recognise, engulf and destroy pathogens (2nd line)
- immunity: produce antibodies or cytotoxins to destroy pathogens (3rd line)
Describe the structure and function of platelets
- S = small fragments of cells (no nucleus), made in red bone marrow
- F = formation of clots (coagulation, process of blood turning from a liquid into a gel) which prevents excess blood loss and prevents pathogens entering the body
What is haemostasis and how is this achieved?
- To control/stop bleeding
- Achieved through blood clot formation (also called cessation or stopping of blood flow)
Describe the process of blood clot formation
- Blood vessel gets damaged and leaks
- Vasoconstriction reduces blood flow to the area to prevent blood loss
- Platelets activate and stick to each other, forming a platelet plug to stop bleeding
- Coagulation: fibrinogen converted to fibrin which strengthens clot by trapping platelets and erythrocytes
Structure and function of plasma
- S = liquid component of blood, 90% water with dissolved chemicals
- F = - transport nutrients and wastes around the body via the blood
- absorb/give off heat e.g. evaporation (sweat) for thermoregulation)
Examples of chemicals found in plasma
- Nutrients (e.g. glucose, amino acids, vitamins, minerals)
- Wastes (e.g. urea/CO2)
- Proteins (albumin, antibodies)
- Hormones (insulin, glucagon, adrenaline)
Structure and function of arteries
- S = thick muscular wall, small lumen (internal diameter), no valves except pulmonary artery
- F = transport blood away from heart to body at high pressure with rapid blood flow, mostly transport oxygenated blood except for pulmonary artery
Structure and function of arterioles
- S = small arteries that branch off main arteries
- F = direct oxygenated blood from arteries into capillaries
Structure and function of capillaries
- S = connect arterioles and venules, one cell thick
- F = diffusion/gaseous exchange of nutrients into the blood and waste out of the blood (thin = short diffusion pathway) OR transport blood between arterioles and venules
Structure and function of venules
- S = capillaries converge into venules which converge into a vein
- F = direct deoxygenated blood from a capillary to a vein
Structure and function of veins
- S = thin, floppy walls, large lumen, valves to prevent backflow except pulmonary vein
- F = transport blood from body to heart (mostly deoxygenated except pulmonary vein), low pressure, slow blood flow
What is blood pressure and what is WNL?
- Pressure exerted on arteries during contraction and relaxation of the heart
- WNL= 120/80 mmHg
Systolic vs diastolic BP
- Systolic: the pressure exerted on aorta during contraction of the L) ventricle
- Diastolic: pressure exerted on aorta when the heart is at rest following ejection of blood
What is the instrument used to measure blood pressure?
Sphygmomanometer (systolic/diastolic)
Why is BP important?
Necessary to circulate blood around whole body, indicates heart health, for safety before being prescribed some medications
What factors affect blood pressure?
Blood volume, hydration, exercise, posture, age, gender, emotions, medications
What is hypertension and what can it cause?
- Abnormally high blood pressure
- Increased strain on heart can lead to MI, rupture of blood vessels > haemorrhage if heart or CVA if brain, arteriosclerosis, kidney failure, dementia, retinopathy
How to manage high BP without medication
Decrease intensity of physical activity, decrease salt intake, decrease stress
What is hypotension and what can it cause?
- Low BP
- Can cause dizziness, fainting, weakness, falls
How to prepare a hypotensive Pt for an MRI scan
Help them get onto the bed, monitor BP regularly, ask if they are feeling dizzy
Describe how the baroreceptor reflex responds to hypertension
- High BP (stimulus) STIMULATES baroreceptors in aorta and carotid arteries (receptors)
- Cardioregulatory and vasomotor centres in the medulla oblongata of the brain stem receive messages (coordinator)
- Cardioregulatory centre sends message to decrease CO, SV, HR (effector 1). Vasomotor centre sends message to vasodilate (effector 2)
- BP decreases back to WNL (response)
Describe how the baroreceptor reflex responds to hypotension
- Low BP (stimulus) INHIBITS baroreceptors in aorta and carotid arteries (receptors)
- Cardioregulatory and vasomotor centres in the medulla oblongata of the brain stem receive messages (coordinator)
- Cardioregulatory centre sends message to increase CO, SV, HR (effector 1). Vasomotor centre sends message to vasoconstrict (effector 2)
- BP increases back to WNL (response)
Describe how chemoreceptors respond to hypotension
- Low BP causes low O2, high CO2 and low pH (stimulus)
- Detected by chemoreceptors in aorta and carotid arteries (receptors) - Cardioregulatory and vasomotor centres in the medulla oblongata of the brain stem receive messages (coordinator)
- Cardioregulatory centre sends message to increase CO, SV, HR (effector 1). Vasomotor centre sends message to vasoconstrict (effector 2)
- BP increases back to WNL (response)
Describe how chemoreceptors respond to hypertension
- High BP causes high O2, low CO2 and high pH (stimulus)
- Detected by chemoreceptors in aorta and carotid arteries (receptors) - Cardioregulatory and vasomotor centres in the medulla oblongata of the brain stem receive messages (coordinator)
- Cardioregulatory centre sends message to decrease CO, SV, HR (effector 1). Basomotor centre sends message to vasodilate (effector 2)
- BP decreases back to WNL (response)
6 functions of blood
- Transport nutrients between heart and body and remove waste
- Thermoregulation through plasma
- Protection: WBC
- Control pH
- Remove toxins from the body
- Regulation of fluid and electrolyte balance through blood plasma
Describe the buffer system
- Bicarbonate ions react with H+ ions, forming carbonic acid (neutralise) to increase blood pH
- Carbonic acid breaks down into H+ ions and bicarbonate ions, decreasing blood pH
List the 3 mechanisms to maintain blood pH in order
- Buffer system- CV system
- Respiratory rate
- Secretion of H+ ions into urine
How to maintain a healthy CVS
- Avoid or quit smoking (e.g. through a Quitline or doctor) as smoking can cause sticky blood and high blood pressure = strain on heart and risk of AMI
- Healthy, balanced diet, low in salt, fat and LDL = these can cause atherosclerosis and block blood vessels = risk of AMI
- Regular exercise: allows heart to contract and relax with increased intensity and speed = strengthened heart muscle and reduced strain to pump blood to body. Exercise also promotes circulation of blood = less risk of swelling and DVT
- Attempt to reduce stress (e.g. see a psychologist or counsellor) to decrease risk of
irregularities in heart rate and lower blood pressure
Explain the effect of immobility on the CV system
Increased strain on heart to circulate blood, increased risk of swelling and DVT
Angi/o
Aort/o
Vessel
Aorta
Arteri/o vs arteriol/o
- Arteri/o = artery
- Arteriol/o = arteriole (small artery)
Atri/o
Cardi/o
Atrium
Heart
Coron/o
Haem/o
Heart
Blood
Haemat/o
Phleb/o
Blood
Vein
Sphygm/o
Vas/o
Pulse
Vessel, duct
Ven/o
Ventricul/o
Vein
Ventricle
Venul/o
Valvul/o
Venule (small vein)
Valve
Isch/o
Erythr/o
Deficiency, blockage
Red
Bar/o
Pressure
Ather/o
-stasis
Yellow, fatty plaque
Stop/control
What is a myocardial infarction and what is it caused by?
- Heart attack
- Caused by reduced blood flow in a coronary artery e.g. due to atherosclerosis or a blockage
Haemolysis
Abnormal condition of bursting of RBC
What is the role of the sympathetic and parasympathetic nervous system in the heart?
- Sympathetic: increases firing rate of SA node = increased HR
- Parasympathetic: vagus nerve decreases firing rate of SA node = decreased HR
Arteriosclerosis vs atherosclerosis
- Arteriosclerosis = abnormal condition of hardening of arteries
- Atherosclerosis = abnormal condition of hardening of arteries due to yellow fatty plaque
Bradycardia vs tachycardia
- Bradycardia = abnormal condition of slow heart rate
- Tachycardia = abnormal condition of fast heart rate
Anaemia
The abnormal condition of a low number of red blood cells in the blood
Cardiac output (CO or Q)
- Volume of blood ejected from each ventricle every minute
- SV x HR
Stroke volume (SV)
Volume of blood expelled by each contraction of ventricles
Heart rate (HR)
Number of heartbeats per minute
Aneurysm
Abnormal swelling or bulge in the wall of a blood vessel
Arrythmia
Abnormal condition of an irregular heartbeat (including fibrillation, tachy or brady)
Fibrillation
Abnormal condition of irregular HR
What is palpation?
Using fingers/hands to examine (e.g. pulse)
What is WNL for heart rate?
60-100bpm
What factors affect heart rate
Exercise, excitement, stress, shock, fear, smoking status, age
Ischaemia
Deficiency of blood flow caused by narrowing/obstruction of blood vessels
Describe CAD
- Coronary artery disease: blockage of coronary arteries, often due to atherosclerosis
What is auscultation?
The action of listening with a stethoscope (e.g. lungs/heart)
What is haemophilia?
An abnormal condition where blood clotting fails to occur
Arteriolitis
Venulitis
Inflammation of small arteries
Inflammation of small veins
What is CHF?
- Congestive heart failure
- Inability of the heart to pump the required amount of blood
-sclerosis vs -stenosis
- Sclerosis = abnormal condition of hardening
- Stenosis = abnormal condition of narrowing
Haemorrhage
Hyperleukocytosis
Excessive bleeding
State of excessive WBC
Angina
Abnormal condition of chest pain due to lack of blood flow and hence oxygen to the heart
