B5 Flashcards
what is double circulation
blood passes through the heart twice (4 chambers) and has pulmonary and systemic circuit
what is single circulation?
single path to circulate to whole body:
blood travels from 2 chambered heart –> gill capillaries –> rest of body –> heart
what are the advantages of a double circulation
atria receive low pressure blood, ventricles pump at high pressure
what are the blood vessels
veins, capillaries, arteries
what is the valve between the right atrium and ventricle called
tricuspid valve
what is the valve at the pulmonary artery called
pulmonary valve
what is the valve at the aorta called
aortic valve
what is the valve between the left atrium and ventricle called
bicuspid/mitral valve
how is heart activity monitored
ECG (electrocardiogram), pulse rate, listen to sound of valves closing
what is coronary heart disease
narrowing of arteries supplying blood to heart, caused by fatty deposits on inside walls
what are risk factors for coronary heart disease
diet, lack of exercise, stress, age, sex, genetic predisposition, smoking
what are the phases of the heart contracting
atrial systole, ventricular diastole –> atrial diastole, ventricular systole –> cardiac diastole
explain atrial systole and ventricular diastole
atria contract, pushing blood into ventricles, which are relaxed to receive blood
explain cardiac diastole
all chambers relax to allow blood to flow into heart
explain atrial diastole and ventricular systole
after atria relax, ventricles contract to push blood out of heart
what are the adaptations of arteries
have narrow lumen and thick muscular wall to transport blood away from the heart under high pressure
what are the adaptations of veins
have wide lumen and thin walls to transport blood to heart under low pressure. valves to prevent back flow
what are the adaptations of capillaries
tiny lumen and thin walls to allow gaseous exchange
what are the components of blood
red blood cells, white blood cells (lymphocytes and phagocytes), platelets, plasma
what is the function of red blood cells
transports oxygen, haemoglobin binds with oxygen to form oxyhaemoglobin
what is the function of platelets
clotting blood to prevent entry of pathogens and prevent blood loss
what are platelets made of
cell fragments
what is the function of plasma
transport blood cells, ions, nutrients, hormones, urea, co2
what are the types of white blood cells
lymphocytes and phagocytes
what is the function of white blood cells
fight infection by phagocytosis and antibody production
what is a pathogen
microorganisms that can cause disease
how are pathogens transmitted
direct: bodily fluids
indirect: food, animals, water, air
what is a transmissible disease
disease in which pathogen can be passed from one host to another
what are the body’s defences against pathogens
mechanical: skin (sweat is acidic), hair, cilia
chemical: stomach acid, mucus
describe the actions of phagocytes
- phagocyte uses receptors in cell membrane to identify pathogen as foreign
- membrane of phagocyte change shape to surround pathogen, take into wbc
- pathogen in phagocyte surrounded by membrane called phagosome
- phagocyte adds digestive enzymes (from lysosomes) to phagosome, destroy pathogen by breaking up into small pieces
- broken pieces of pathogen used by cell or released
how to control spread of disease
treat water supply and sewage, hygienic food prep, waste disposal, kill vectors, personal hyegiene
what are the features of viruses
protein coat, genetic material
what are memory cells
type of lymphocyte, remain in blood after pathogens in infection have been destroyed. recognise pathogens that infect after first infection
what is active immunity
defence against pathogen by antibody production in body
what is passive immunity
receive antibodies from external source
how is active immunity gained
infection by pathogen or vaccination
what is the process of vaccination
- weakened pathogens/their antigens put into body
- antigens stimulate immune response by lymphocytes, produce antibodies
- memory cells produced, give long-term immunity
how do vaccines prevent spread of disease
prevent pathogens that cause disease and spread between people
what are antibodies
proteins produced by lymphocytes
features of antibodies
antibodies specific to just one antigen (pathogen), complementary shape
how do antibodies work
bind to antigen,
- so phagocyte recognise
- reduce mobility
- stick many pathogens tg
- cause pathogen cell wall to burst, killing them
- block from reaching cells of body
