1B Mammalian Transport Systems Flashcards
Diffusion
The free movement of particles from an area of high concentration to an area of low concentration down a concentration gradient
Single circulation system
The heart pumps the blood to the organs of gas exchange and the blood travels around the body and then returns to the heart where it is recirculated
Double circulation
Two separate circuits one for deoxygenated blood that flows from the body to the heart to the lungs and the other for the oxygenated blood from the lungs to the heart to the body
Leucocytes
White blood cells - Large but can change shape, contains nucleus, fights pathogens and protects body against infections, responsible for inflammatory response tissue damage
Erythrocytes
Red blood cells - Contain hemoglobin, made in the bone marrow, bioncave shape, no nucleus
Platelets
Megakaryocytes - Found in the bone marrow, helps in blood clotting
Oxyhaemoglobin
Process in which oxygen binds to haemoglobin (is reversible)
Carbaminohaemoglobin
Molecule formed when haemoglobin is combined with carbon dioxide
What happens with carbon dioxide bonds with water?
Carbonic acid is first formed and it is then broken down into hydrogen carbonate ions (-) and hydrogen ions (+)
Carbonic anydrase
Enzyme responsible for the catalysis between carbon dioxide and water to create carbonic acid
Bohr effect
The change in the oxygen dissociation curve of haemoglobin that occur due to a rise in carbon dioxide levels and a reduction of haemoglobin affinity for oxygen
Fetal haemoglobin
A unique form of haemoglobin found in fetuses that has a higher affinity for oxygen that adult haemoglobin, allows fetus to absorb oxygen from maternal blood
What are the chemicals released when platelets are broken and what are their functions?
Serotonin - Constricts blood vessels, making them narrower, cutting off blood flow
Thromboplastin - Enzyme that initiates the sequence of chemical changes necessary for blood clotting
Describe the process of blood clotting
Thromboplastin catalyses prothrombin to thrombin. Thrombin catalyses fibrinogen to fibrin.
Fibrin forms a mesh over wound and traps exit cells.
Special proteins from platelets make the clot tighter forming a scab.
Artery
Vessels that carry blood away from the heart
All arteries except two carry oxygenated blood. What are they?
Pulmonary artery (from heart to lungs) and Pulmonary artery (fetus to placenta)
Veins
Vessels that carry blood to the heart
Other than two veins all veins carry deoxygenated blood. What are these veins?
Pulmonary vein (Lungs to heart) and umbilical vein (placenta to fetus)
Capillaries
Tiny vessels that spread through out the tissues of the body
What are some features of an artery?
Narrow lumen, thick walls, no valves, elastic fibers within walls
What are some features of a capillary?
Thin walls, no elastic fibers, small diameter, can be found anywhere near body cells
What are some features of a vein?
Wide lumen, thin walls, valves
What separates the ride and left side of the heart and why are they separated?
The septum separates them and it is to prevent the mixing of oxygenated and deoxygenated blood.
What special properties aid the heart in its functions (3)?
Myoglobin = Higher affinity for oxygen
Cardiac muscle = Never get fatigued even after constant use
Coronary arteries = Constant blood supply to heart
Myoglobin
A respiratory pigment that has a stronger affinity for oxygen compared to haemoglobin.
Atrioventricular valves
Valves that are present between the atrium and the ventricles (bicuspid and tricuspid)
Bicuspid valve
Found in the left side of the heart between the left atrium and left ventricle
Tricuspid valves
Valve found on the right side of the heart between the right atrium and the right ventricle
In what order does the blood flow during a full cardiac cycle?
Body - Vena cava (superior and inferior) - Right atrium - Tricuspid valve - Right ventricle - Semilunar valve - Pulmonary artery - Lungs - Pulmonary vein - Left atrium - Bicuspid valve - Left ventricle - Semilunar valve - Aorta - Body
Which side of the heart is thicker and why?
The left side of the heart is much thicker as it needs to provide sufficient force for the blood to circulate through out the entire body
Systole
Contraction of the heart
Diastole
Relaxation of the heart
What happens in the valves during an atrial systole?
Atrioventricular valve open, semilunar valve closed
What happens to the valves during a ventricular systole?
Atrioventricular valve closed, semilunar valves open
What happens to the valves during a diastole?
Atrioventricular valves closed, semilunar valves are partially open
Athrosclerosis
A condition in which yellow fatty acid deposits build up on the lining of the arteries, causing them to be narrowed
Describe the process of athrosclerosis
Damage to the endothelium - Inflammatory response - White blood cells arrive on sight - Chemicals including cholesterol are released - Plaque is built up (atheroma) - Calcium salts and fibrous tissue build up - Plaque hardens - Lumen narrows
How can the endothelium be damaged?
High blood pressure, smoking
Aneurysm
A weakened bulged area of an artery wall caused by a collection of blood behind a plaque buildup inside the lumen
Angina
A condition in which plaque deposited on the endothelium of arteries reduce blood flow to coronary arteries
What are the symptoms of angina?
Breathlessness, Fatigue, Gripping pain in chest that extends down the left arm and up to the lower jaw
Myocardial infarction
Events which take place when atherosclerosis leads to a formation of a blood clot (thrombosis) that blocks the coronary arteries completely and deprives the heart of oxygen
Thrombosis
A clot that forms in a blood vessel
Stroke
Event caused by an interruption to the normal blood supply to an area of the brain due to internal hemorrhage (damaged capillaries) or a thrombosis
What are the symptoms of a stroke?
Dizziness, numbness, slurred speech, blurred vision (usually in one eye), confusion, paralysis
