Week 2 - Circulatory system Flashcards
What’s the circulatory system?
Extensive system composed of blood vessels and the heart
What’s a double circulatory system in mammals?
- System carries blood from heart to lungs and back
2. System carries blood to all other organs and back.
What does pulmonary relate to?
Towards lungs
What does systematic relate to?
Towards body
What is Pulmonary circulation?
Transport of oxygen from lungs to heart and C02 from heart to lungs.
What is systematic circulation?
Transport of oxygen to heart and body cells. And transport of C02 from body cells to heart.
What are the 3 functions of the circulatory system?
Transport (e.g hormones)/Regulation (volume of fluid in circulation)/Protection (e.g platelets from clotting).
What supplies heart muscle with oxygenated blood?
Coronary arteries
What controls the heart?
- Heart rate set by sinoatrial node (SAN)
- Impulse slowed down at atrioventricular node (AVN)
- Impulse is recovered and propogated by the purkyte fibres
What’s a P wave?
electrical charge spreading across atria
What’s a QRS complex?
Electrical charge spreading upwards through ventricles
What’s a T wave?
Ventricles relax and return to resting state
What’s an ST Segment?
Period when no further electrical charge passes through the heart.
How are arteries compared to veins?
Thicker, more elastic wall, no valves, narrower lumen so higher blood pressure maintained, muscle coat in arteries is thicker.
What causes vein blood to flow in spurts?
Skeletal muscles contracting
Other name for red blood cells?
erythrocytes
Function of arteries and features?
Not compared to veins card
- Carries blood away from heart to organs
- Stretch as blood passes through and then recoils back into shape
- Thick walls with muscle and elastic fibres
Function of capillaries and features?
- Network of tiny vessels linking arteries to veins
- Narrow with very thin walls
- Enables easy diffusion
- Substances pass easily into blood through capillary walls
How are capillaries specialised?
- Allow exchange of materials
- One cell of endothelium cells
- Diameter of lumen is same size as red blood cell
Functions of veins? And features?
- Carries blood away from organs towards heart
- Blood low in oxygen in oxygen is deep purple red
- Thinner walls than arteries so less hydrostatic pressure
- Valves that close to prevent backflow
- Skeletal muscle squeezes veins blood back towards heart
How can coronary heart disease lead to death?
During the disease coronary arteries can become narrow due to fat build up in vessel lining.
So blood flow is reduced therefore oxygen supply is reduced
Can cause pain, heart attack or even death as heart muscle doesn’t get enough oxygen so starts dying.
What are some of the main components of blood?
White blood cells.plasma, platelets, red blood cells
What happens in haemoglobin?
Oxygen binds to one haem group. This enhances binding of oxygen on other three sites ensuring haemoglobin molecule becomes saturated.
How many haemoglobin in a red blood cell?
250 million haemoglobin in each red blood cell.
Simplistic process of blood clotting to avoid infection by pathogens?
Damage to tissue > platelets collect in damaged area > platelets release clotting factor prothrombin activator.
Simple process of blood transport in heart?
- Deoxygenated blood enters right atrium and passes into right ventricle
- Pumped to lungs
- Oxygenated blood enters the left atrium and passes into left ventricle
- Pumped via the aorta to the rest of the body.
Find the labelled heart in Moodle powerpoint and learn it.
Yeah.
Process of an impulse across a heart?
- Electrical impulses from the SAN spread across atria walls, causing contraction
- Impulses pass to ventricles via the ANV
- Impulses pass down the purkyne fibres to heart apex
- Impulses spread through ventricle walls causing contraction from bottom upwards. Blood is squeezed (contracted) into arteries.
Vena Cava - Transports what? Where?
de-oxygenated blood from body to right atria of heart.
Pulmonary vein - Transport what? Where?
Oxygenated blood from lungs to left atria of heart.
Pulmonary artery - Transport what? Where?
Deoxygenated blood from away from right ventricle of heart to lungs.
Aorta - Transport what? Where?
Transport oxygenated blood from left ventricle of heart to rest of body.
Coronary artery - Transport what? Where?
Supplies cardiac muscle with oxygenated blood.
