Cardiovascular Flashcards
The
cardiovascular system + lymphatic system =
- Circulatory system
Why does the heart provide energy?
- To drive blood down so that it can overcome friction as it travels around the vascular system
Chemical energy in heart cells is converted to M______ energy in the blood
• Mechanical energy
What are the four chambers of the heart?
- Left and right atria
- Left and right ventricles
What are the two circuits in the circulatory system?
- Pulmonary
* Systematic
How is the heart divided into left and right sides?
• By a septum
Name the valves associated with each chamber?
- Tricuspid
- Bicuspid
- Aortic
- Pulmonary
what is the structural difference between atria and ventricles?
Atria: Thin walled
Ventricles: Thick walled
What are the major blood vessels of the heart?
- Superior and inferior vena cava
- Pulmonary trunk
- Pulmonary veins
- Aorta
How many pulmonary veins are there in the heart and what is their function?
•4
- Return blood from the lungs back to the left atrium
What is the function of the aorta?
- Coveys blood from the left ventricle to the body
There’s 2 sides of the heart, left and right. What is the function of each heart?
- Right heart: receives blood from the systematic circulation and pumps out into the pulmonary circulation
- Left heart: receives blood from the pulmonary circulation and pumps into the systematic circulation
What are the two nodes in the right atrium?
- Sinoatrial (SA) node
* Atrioventricular (AV) node
Left ventricle ——-> right atrium
What type of circulation is happening?
- Systematic circulation
Left atrium
- Pulmonary circulation (lungs)
The function of the heart is to pump blood through both P_____ and S______ C______
- Pulmonary
* Systematic circuits
What is the function of the heart?
- To pump blood through both pulmonary and systematic circuits
Where is the heart located?
• Behind the sternum
The base of the heart is the broad superior portion, for the attachment of the great…..
• Vessels
The apex of the heart is the inferior blunt tip, immediately above the D_____
• Diaphragm
What are the 3 layers of the heart?
- Endocardium (lined by endothelial cells)
- Myocardium (thickest, contains cardiac muscle)
- Epicardium (connective tissue)
Which double walled structure surrounds the heart?
• Pericardium
What 3 parallel circuits can the cardiovascular system be split into?
1) Pulmonary (lungs)
2) Coronary (heart)
3) Systematic (rest of the body)
What type of blood does the pulmonary circuit carry?
- Carries deoxygenated blood from the heart —> lungs for gas exchange and returns oxygenated blood to the heart
What type of blood does the systematic circuit carry?
- Carries oxygenated blood from the heart to supply the whole body and returns deoxygenated blood back to the heart
De-oxygenated blood is pumped by the right ventricle to the lungs via the P______ A_____
• Pulmonary artery
Re-oxygenated blood returns to the left atrium of the heart visa the P_____ V____
• Pulmonary vein
What type of blood is provided for organs and tissues or the body?
• Oxygenated
The left ventricle pumps blood into the A____ which then branches into smaller A_____
- Aorta
* Arteries
True or False
Atrial contraction is weak
True
The atria function mainly as a P_____ C______ C_____
• Passive conducting chamber
How is oxygenated blood supplied to the heart muscle?
- Through left and right coronary arteries
Venous blood drains into the Coronary S____ and then into the right atrium
• Sinus
1) coronary arteries supply blood to the heart muscle
(right and left)
2) cardiac veins collect and return blood to the right atrium through the coronary sinus - what is the next step
3) cardiac veins run with coronary arteries
What are the functions of the right coronary artery?
- Supplies right atrium and ventricle
- SA node
- AV node
- Inter ventricular septum
What are the functions of the left coronary artery?
- Supplies left atrium
- & Ventricle
- AV bundle
- Inter ventricular septum
Cardiac muscle cells consist of cardiac muscle cells which are known as?
• Cardiocytes
The two types of cardiac muscle cell are C____tile and C_____tile
- Contractile
* Conductile
What provides a strong union between the adjacent cells where the end of one muscle fibre abuts to another?
• Intercalated disk
Which channel are gated?
• Connexin channels
When these are opened, ions flow from the first (depolarised cell) to the second
What is pacemaker activity?
• directly control the heart rate
Does a pacemaker cell have a steady resting membrane potential?
No, after an action potential the membrane immediately begins to depolarise until threshold is reached and another action potential is triggered.
What 3 waves does an ECG consist of?
- The P wave
- QRS complex
- T wave
The P wave corresponds to A____ De______
• Atrial depolarisation
When does the P wave occur?
- Just before atrial contraction begins
What does the QRS complex correspond to?
• Ventricular depolarisation and begins just before isovolumetric contraction
What does the T wave represent?
• Ventricular repolarization and takes place during reduced ejection
How long does the P-Q interval last for?
- around 160ms
What does the P-Q interval represent?
- Time between atrial excitation and ventricular excitation
What does prolongation of the P-Q interval suggest?
- Suggests damage to the atrial conducting pathway or the A-V node
How long does the S-T segment last?
• Around 120ms
What does the S-T segment represent?
• The time when the ventricles are fully depolarised during plateau of the ventricular action potential
How long does the Q-T interval last?
• Around 400ms
What is the Q-T interval?
- The period from the beginning of ventricular depolarisation to the end of repolarisation
The R-R interval is the time between S______ heart beats
• Successive
A heart beats at 75 per minute what is the cardiac cycle?
• 0.8s
Cardiac output (CO) = Heart rate (HR) x S______ V_____ (SV)
• Stroke volume
What is Cardiac output?
- The volume of blood pumped by each ventricle per unit time
The SA node is innervated by both S________ and P______ branches of the autonomic nervous system
- Sympathetic
* Parasympathetic
What transmitter is realised by postganglionic S fibres and P fibres?
S fibres: Noradrenaline
P fibres: Acetylcholine
S effects are mediated via B1 A___receptors and P effects are mediated via M___carinic receptors
- Adrenoreceptors
* Muscarinic receptors
In the resting state what is the dominant tone?
Hint: which side or the autonomic nervous system
- Parasympathetic
Describe “Lub” and “Dub”
Lub: loudest at apex
Dub: loudest at base
What are the most fundamental heart sounds?
S1 and S2
What is S1 and S2 caused by?
S1: caused by closure of AV valves and tensing of the valves and muscles during contraction - Lub
S2: relates to closure of semilunar valves - Dub
Systematic blood pressure is a fluid driven through a circuit of closed vessels, operates under P____
• Pressure
Blood flows along a pressure gradient
When does pressure occur?
• When the flow is opposed by resistance
The steepest drop in pressure occurs in the A_____ which offer the greatest resistance to flow
- Arterioles
Which vessel carries blood towards the heart?
• Veins
Describe the arterial pressure of systolic and diastolic pressure
- Systolic pressure: High (120mmHg)
- Diastolic pressure: Low (80mmHg)
