circulatory system Flashcards
what is the circulatory system?
the link between cells inside the body which have certain requirements and the environment outside the body
what are the functions of blood?
transport O2 and nutrients to all cells
- transport CO2 & waste away from cell
- transport hormones
- maintaining Ph of body fluid
- maintain body temp
- protect against disease
what is plasma?
- 55%
- watery liquid
- transport cells, nutrients, hormones and proteins
what are erthrocytes?
- 41%
- red blood cells
- bioactive shape
- don’t contain a nucleus
- transport oxygen from lungs to cells
what are leucocytes?
- 1%
- white blood cells
- fight infection
what are the different types of leucocytes?
- neutrophils = contains enzymes to digest pathogens
- monocytes = form other cells
- lymphocytes = involved in immune response
- basophils = responsible for allergies, produces heparin and histamine to defence
- eosinophils = inflammatory responses
what are thrombocytes?
- platelets
- clot blood when needed
what occurs during blood clotting?
- vasoconstriction: muscles in small artery’s contract
- platelet plug: platelets build up in the affected area to stop blood flow
- coagulation: blood clots to reduce blood flow
what are capillaries?
- form a network to carry blood to cells in the body
- one cell thick for easy diffusion
- link between arteries and veins
what are arteries?
- carry blood away from the heart
- thick, muscular walls, elastic
- no valves
what are veins?
- carry blood towards the heart
- thin, inelastic walls
- often have valves
what is the heart?
- pump that pushes blood around the body
- enclosed by the pericardium
- left and right separated by the septum
how does blood flow through the heart?
- enters through the superior vena cava and inferior vena cava
- goes into the right atrium
- then through the tricuspid valve
- it goes through the right ventricle
- into the pulmonary valve
- out through the pulmonary artery
- goes to the lungs where it becomes oxygenated
- returns back through the pulmonary vein
- into the left atrium
- through the mitral valve
- into the left ventricle
- through the aorta where it is pumped to the rest of the body
what is the cardiac cycle?
- Comprises two separate “circuits” in the body in which blood will travel
- Left and right of the heart function as 2 separate pumps
what is diastole?
- heart muscle relaxes
what is diastole?
- heart muscle relaxes
what is systole?
- heart muscle contracts
what is cardiac output?
the amount of blood leaving one of the ventricles every minute
what is heart rate?
number of times the heart beats per minute
what is stroke volume?
the volume of blood forced from a ventricle of the heart with each contraction
how is carbon dioxide transported through the blood?
- 7% dissolved in plasma & carried in solution
- 22% combines carbinohaemoglobin
- 70% is carried in the plasma bicarbonate ions
- CO2 diffuses into the blood when CO2 conc. is high
- CO2 diffuses out of blood when CO2 conc. is low
how are nutrients and waste transported in the blood?
- dissolved in plasma to be transported
- nutrients = essential elements + molecules from food > inorganic nutrients transported as ions
- metabolic wastes = substances produced by cells which is harmful if accumulate
how oxygen transported in the blood?
- 97% is carried with hemoglobin molecules
- oxyhemoglobin occurs when conc. is high (capillaries and lungs)
- breaks down when oxygen conc. is low
- oxygenated blood = blood with high oxyhemoglobin
- deoxygenated blood = blood with low oxyhemoglobin
- red blood cells are well suited to function due to: contain hemoglobin, no nucleus, biocave shape.
