Circulatory system Flashcards
what does blood consist of
red blood cells, white blood cells, platelts and plasma
composition of blood
45% RBC
55% Plasma
<1% white bloot cells and plateltes
red blood cells
biconcave discs containing no nucleus but plenty of protein hemoglobin
white blood cell
large cells containing a big nucleus, different types have structures and functions
platelets
fragments of cells
plasma
straw coloured liquid
how is plamsa important for transport
- transports CO2
- digested food and mineral ions
- transports urea
- hormones
- heat energy
adaptations of red blood cells
- full of haemoglobin
- no nucleus
- biconcave disc which gives large SA:V
what do red blood cells do
carry oxygen to respiring cells
Types of white blood cells
phagocytes
lymphocytes
what do phagocytes carry out
phagocytosis
what is the digestive enzyme which ingests the pathogen
lysosome
how do you recognise phagocytes
multi-lobed nucleus
granular cytoplasm
how to recognise lymphocytes
large round nucleus which takes up nearly whole cell
non granular cytoplasm
what do lymphocytes produce
antibodies
what are antibodies
Y-shaped proteins with a shape that is specific to the antigen on the surface of the pathogen
agglutination
antibodies attach to the antigens
what happens which signals phagocytes that cells are presents and need to be destroyed
release of chemicals
what do lymphocytes produce to neutralise _________
antitoxins to neutralise toxins
why are vaccines used
to induce immunity to infectious diseases
what do vaccines contain
- weakened or dead pathogen which is either a fragment or one which is unable to grow
importance of vaccination
- reduce likelihood that an infected individual with spread the pathogen to others
- prevents spread of disease
- reduces cases of certain diseases
disadvantages of vaccinations
- mutations in pathogens DNA
- side effects
plateltes function
help with the clotting of blood
what do platelets release
chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin and form insoluble mesh
what does a clot develop into
a scab
importance of blood clotting
- prevents continued blood loss
- prevents entry of microorganisms
- seals the skin again
what type of organ is the heart
double pump organ
how does blood pump to the heart from the lungs
oxygenated blood enters the left side of the heart and is pumped to the rest of the body
why is the left ventricle able to pump blood at high pressure
it has thicker muscle walls that the right ventricle
how does blood enter from the rest of the body to the heart
deoxygenated blood enters the right side of the body and is pumped to the lungs
does the right ventricle pump blood at low pressure or at high pressure
lower pressure
what is the name of the wall that separates two sides of the heart
septum
do veins pump towards the heart or away from the heart
towards
do arteries pump blood towards the heart or away from the heart
away
function of coronary arteries
supply the cardiac muscle tissue of the heart with oxygenated blood
why does the coronary arteries supply the cardiac muscle with oxygenated blood
the heart muscle needs constant supply of oxygen for aerobic respiration
why are valves present
to prevent the backflow of the blood
where does the deoxygenated blood coming from the body flow through
vena cava
where does the deoxygenated blood coming from the body flow to
right atrium
where does the blood flow flow from in order to go to the right ventricle and through where?
right atrium, and through the tricuspid valve
where does the blood flow through after going into the right ventricle and through where?
to the pulmonery artery through the semi lunar valve
where does the blood go after it reaches the pulmonary artery
travels through the lungs and moves through the capillaries past the alveoli where gas exchange takes place
is there high or low pressure where gas exchange takes place
there is a low pressure blood flow to prevent damage to the capillaries
how does the oxygenated blood enter the left atrium
through the pulmonary vein
how does the blood flow to the rest of the body
the atrium contracts and forces blood through the bicuspid valve into the left ventricle
the left ventricle contracts and blood is forced through the semi lunar valve out through the aorta
pacemaker
the group of cells in the right atrium which controls the natural resting heart rate
role of pacemaker
to coordinate the contraction of the heart muscles and regulate the heart rate
how to pace maker initiate a contraction in the cardiac muscle
it sents out electrical impulses
what needs to happen in order to supply oxygen and glucose to respiring cells
the heart needs to pump blood around the body
how to the nervous system respond to an increase in respiration
- heart rate increases to deliver oxygen and glucose and remove waste more frequently
- volume of blood is pumped out of the heart in bigger quantities.
- produced adrenaline
why do we continue breathing heavily straight after excercise
oxygen is needed in muscles to break down the lactic acid from anaerobic respiration.
pays off the oxygen debt
will a physically fit person have a lower resting heart rate or a higher resting heart rate
lower
what occurs if a patient has the coronary heart disease
a layer of fatty material build up inside the coronary arteries due to cholesterol
what are the sources of cholestrol in the body
dietary cholesterol
cholesterol synthesised from the lung
what happens to the arteries due to build up of the cholesterol
it loses its elasticity and can’t stretch to accommodate the blood which is forced.
what does build of of cholesterol cause
partial blockage (angina)
complete blockage (heart attack)
ways to treat CHD
increase the width using a stent or prescribing statins to lower blood cholesterol
risks which increase the chance of CHD
- obesity
- high blood pressure
- high cholesterol
- smoking
three types of blood vessels
arteries
veins
capillaries
key features of arteries
- carries blood at high pressure away from heart
- carries oxygenated blood
- have thick muscular walls containing elastic fibres
- narrow lumen
- blood flows at fast speed
adaptations of arteries
- thick muscular walls containing elastic fibres to withstand the high pressure of blood and maintain the pressure.
- narrow lumen to help maintain pressure
features of veins
- carries blood at low pressure towards heart
- carries deoxygenated blood
- thin walls
- large lumen
- contains valves
- blood flows through at a slow speed
adaptation of veins
- large lumen= reduces resistance to blood flow under low pressure
- contains valves to prevent the back flow of blood as it is at low pressure
features of capillaries
- carries blood at low pressure
- carries both deoxygenated and oxygenated blood
- have walls that are one cell thick
- leaky walls
- slow speed
adaptations of capillaries
- walls that are one cell thick so substances can easily diffuse
- leaky walls allow blood plasma to leak out and form tissue fluid surrounding the cells
arterioles
narrow vessels connect arteries to capillaries
venules
connected capillaries to veins
is the circulatory system a closed network or an open network
closed
closed network of blood vessels connected to heart- explain
- Oxygenated blood is carried away from the heart and towards organs in arteries
-These narrow to arterioles and then capillaries as they pass through the organ
- In the organs, respiring cells use up the oxygen from the blood
- The capillaries widen to venules and finally veins as they move away from the organs
-Veins carry deoxygenated blood back towards the heart
what collects all excess tissue fluid that leaks out from capillaries
lymphatic vessels which delivers it back to the circulatory system
towards the kidney
renal artery
away from kidney
renal vein
