Circulation Flashcards
What are the components of the circulatory system?
-Heart
-Blood vessels (veins, arteries, capillaries)
-Blood
What are the functions of the circulatory system?
-Move blood around the body
-Move oxygen and water to the cells
-Move glucose
-Remove carbon dioxide
What is a single circulatory system?
A circulation system where the heart pumps blood to the organs and then the blood travels around the body back to the heart
What is systemic circulation?
Carries oxygenated blood from the heart to the cells of the body where oxygen is used and carries the deoxygenated back to the heart
What is pulmonary circulation?
Carries deoxygenated blood to the lungs and oxygenated blood back o the heart
What does partial pressure mean?
pO2 or ppO2
Concentration of oxygen
What is haemoglobin?
Carries oxygen and gives erythrocytes their colour
-Made of 4 polypeptide chains
-Each chain has a haem group containing iron
-Globular shape
-Each haem group picks up 4 molecules of oxygen
What is the haemoglobin reaction?
Haemoglobin + oxygen = oxyhaemoglobin
Hb + 4O2 = HBO8
-A reversible reaction
What does having a high affinity for oxygen mean?
-Attracted to oxygen
-Easily loads oxygen
-Releases oxygen less readily
-In organisms who live in environments with low oxygen e.g lugworms
-These organisms will have a low metabolic rate (respire more slowly)
-They find it more useful to have haemoglobin which takes in oxygen quicker than it releases it
What is the curve on the graph for high affinity for oxygen?
Graph curves to the left
What does having a low affinity for oxygen mean?
-Slowly takes up oxygen
-Releases oxygen quicker
-Found in organisms who live in environments with lots of oxygen e.g humans
-They respire and use more oxygen
-It is more important to have haemoglobin which releases oxygen quicker than it takes it in
What is the curve on the graph for low affinity for oxygen?
Graph curves to the right
What is fetal haemoglobin?
-Has a different quaternary structure to adult haemoglobin
-Higher affinity for oxygen than adult haemoglobin when at the same partial pressure
-Maintains a diffusion gradient across the placenta
What is myoglobin haemoglobin?
-Higher affinity for oxygen than adult and fetal haemoglobin
-Stores oxygen in the muscles
-Found in human muscles
What is an artery?
Vessels that carry blood away from the heart towards the cells of the body
What is a vein?
Vessels that carry blood toward the heart from the cells of the body
What is a capillary?
Minute vessels that spread throughout the tissues of the body
How is blood pumped around the body?
-Deoxygenated blood is brought into the right atrium from the vena cava
-The pressure of the blood opens the tricuspid valve and forces the deoxygenated blood into the right ventricle
-The blood is then forced into the pulmonary artery to go to the lungs
-After the lungs, the blood enters through the pulmonary vein into the left atrium
-Blood enters the left ventricle through the bicuspid valve
-Blood is then pumped into the aorta and into the body
What are the features of the capillaries?
-No valves
-Very thin
-Permeable walls, only one cell thick
-Very small lumen
-Function is to allow exchange of materials between the blood and the tissues
What are the features of arteries?
-Small lumen
-No valves (except in the heart)
-Thick walls with smooth elastic to resist high pressure
-Blood is at a high pressure
-Function is to carry blood from the heart to the tissues
What are the features of veins?
-Large lumen to reduce resistance to flow
-Valves to prevent back flow
-Thin walls
-Blood at a low pressure
-Function is to carry blood from tissues to the heart
How does your heart contract?
-The sinoatrial node (SAN, hearts natural pacemaker) in the top right of the atrium creates and sends impulses across the atrium
-The impulse creates a contraction which pushes blood into the ventricles
-The atrioventricular node (AVN) sends an impulse down the bundle of his to the purkyne tissues
-The purkyne tissue causes contraction and pushes blood back to the atrium to be released
What is the cardiac cycle?
The cycle of contraction and relaxation in the heart
What is systole?
The contraction of the heart
-Atrial systole is when the atria contract together and force blood into the ventricles
-Ventricular systole is when the ventricles contract
What is diastole?
When the heart relaxes and fills with blood
What is tissue fluid?
The liquid which surrounds the cells, allowing for transport between blood and cells
How is tissue fluid formed through pressure?
Hydrostatic pressure from the heart contractions forces fluid out of the capillaries
-Fluid moves out of tiny gaps in the capillary walls
-Dissolved gases and nutrients move with it
-Larger plasma proteins and cells do not
How is tissue fluid formed through osmosis?
Hydrostatic pressure causes a loss of water from the capillaries giving them a negative water potential
-Water moves down the water potential gradient into the capillaries
What is lymph?
Not all fluid passes back into the capillaries, the excess output needs to be collected to avoid swelling
-The excess is drained into the vessels of the lymphatic system
What is atherosclerosis?
-The arteries become narrowed due to the build up of plaque on the inside of the arteries
-The fatty acids take up space in the artery causing less space for the blood to travel through
-This causes high pressure in the artery
What factors increase the chance of atherosclerosis?
-Obesity
-Smoking
-Alcohol
-High cholesterol and triglyceride levels
What is a stroke?
When part of the blood circulation to the brain is cut off
What are the two types of stroke?
-Ischemic stroke = caused due to a blocked artery to the brain, usually due to fatty build ups
-Hemorrhagic stroke = caused by a leaking or burst blood vessel in the brain, usually due to high blood pressure
What is an aneurysm?
An abnormally large bulge in a blood vessel cell wall which can potentially burst causing internal bleeding
What are the two kinds of heart attack?
-Angina = where plaque builds slowly in the coronary arteries which reduces the volume of blood flow to the heart muscle
-Myocardial infarction = where the coronary artery becomes completely blocked and part of the heart muscle is starved of oxygen
What is the Bohr effect?
-Increased carbon dioxide levels lower the pH levels of the blood
-This affects the ability of the haemoglobin to transport oxygen
-A lower pH causes haemoglobin to release more oxygen
-A higher pH causes haemoglobin to hold onto more oxygen
How is carbon dioxide transported?
-Binds to haemoglobin into carbaminohaemoglobin
-Dissolves as CO2
-Hydrogen carbonate ions
What is the function of an erythrocyte?
Contains haemoglobin to carry oxygen around the body
What is the function of neutrophils?
Engulf and digest pathogens by phagocytosis
What is the function of eosinophils?
Important in the response against pathogens and help develop immunity
What is the function of basophilis?
Produce histamines in inflammation and in allergic reactions
What is the function of monocyte?
Engulf pathogens by phagocytosis
What is the function of a lymphocyte?
Important in the specific immune response of the body
What is the function of plasma?
Important for transporting and helps maintain body temperature
What is the function of platelets?
Involved in the clotting mechanism of blood
