Transport in Humans Flashcards
Topic 2 H . 3
blood consists of
red blood cells
white blood cells
platelets
plasma
over half the volume of blood is made up from :
plasma
the other half of the blood is made from
red blood cells
platelets and white blood cells make up the ___ portion of the blood
smallest
red blood cells
Biconcave discs containing no nucleus to maximise the available capacity to carry the protein haemoglobin
white blood cells
Large cells containing a large nucleus; different types have slightly different structures and functions
platelets
clump together to ‘plug’ the damaged area ( blood clotting)
plasma
clear, straw- coloured aqueous solution and carries basically everything that needs transporting around your body
plasma is important for the transportation of : (4)
CO2- waste product of respiration, dissolved in the plasma and transported from respiring cells to the lungs
Digested food and mineral ions- dissolved particles absorbed from the small intestine and delivered to requiring cells around the body
Urea- a waste substance dissolved in the plasma and transported to the kidneys
Hormones- chemical messengers released into the blood from the endocrine organs (glands) and delivered to target tissues/organs of the body
Heat energy- (created in respiration) is transferred to cooler parts of the body or to the skin where heat can be lost
heat energy ( transported by plasma)
(created in respiration) is transferred to cooler parts of the body or to the skin where heat can be lost
hormones ( transported by plasma)
chemical messengers released into the blood from the endocrine organs (glands) and delivered to target tissues/organs of the body
urea ( transported by plasma)
urea is a waste substance dissolved in the plasma and transported to the kidneys
digested food / mineral ions ( transported by plasma)
dissolved particles absorbed from the small intestine and delivered to requiring cells around the body
carbon dioxide ( transported by plasma)
the waste product of respiration, dissolved in the plasma and transported from respiring cells to the lungs
red blood cells are
specialised cells which carry oxygen to respiring cells
red blood cells are adapted for their function in how many ways
3
what are the ways in which red blood cells are adapted for their function
- They are full of haemoglobin, a protein that binds to oxygen to form oxyhaemoglobin
- They have no nucleus which allows more space for haemoglobin to be packed in
- The shape of a red blood cell is described as being a ‘biconcave disc’ this shape gives them a large surface area to volume ratio to maximise diffusion of oxygen in and out
white blood cells are part of the body’s
immune system
white blood cells are specialised cells that defend against
pathogenic microorganisms
2 main types of white blood cells
- phagocytes
- lymphocytes
what do phagocytes do
ingest pathogens
why are phagocytes non specific
because they engulf then digest anything thats not supposed to be in the body
what do lymphocytes do
produce antibodies
what are antibodies
proteins with a shape that is specific (complementary) to the antigens on the surface of the pathogen
Lymphocytes provide
a specific immune response as antibodies produced will only fit one type of antigen on a pathogen
how do antibodies work
they lock on to invading pathogens and mark them for destruction
antibodies produces are ____ to the antigen
specific
____ cells can be produced in response to a foreign antigen
memory
what do memory cells do
remain in the body to remember a specific antigen and can reproduce very fast if the same antigen enters the body again which is why you’re immune to a lot of diseases if you’ve already had them
what is the role of the immune system
to prevent infectious organisms from reproducing and destroy them
main component of the immune system
white blood cells
an organism has immunity when
they have sufficient levels of antibodies to protect it from a particular disease
As a result, they do not suffer from the disease or its symptoms
responses to infection ( 8 stages)
The pathogen enters the blood stream and multiplies
A release of toxins (in the case of bacteria) and infection of body cells causes symptoms in the patient
Phagocytes that encounter the pathogen recognise that it is an invading pathogen and engulf and digest (non-specific response)
Eventually, the pathogen encounters a lymphocyte which recognises its antigens
The lymphocyte starts to produce specific antibodies to combat that particular pathogen
The lymphocyte also clones itself to produce lots of lymphocytes (all producing the specific antibody required)
Antibodies destroy pathogens
Phagocytes engulf and digest the destroyed pathogens
vaccines are used to
induce immunity to infectious diseases
a vaccine contains
a harmless version of a pathogen
how do scientists make sure the pathogen in the vaccine is harmless (3)
- killing it
- making it unable to grow or divide
- using fragments of it
a vaccine may be given through the (3)
orally, nasally, injection
- once in bloodstream, antigens contained inside the vaccine can trigger an immune response by (2)
- lymphocytes recognise antigens in bloodstream
the activated lymphocytes produce antigens - memory cells are produced from the lymphocytes
memory cells and antibodies subsequently remain circulating in the blood stream
why are vaccines needed sometimes
because when you’re injected with a new pathogen it can take lymphocytes a long time to produce antibodies to deal with it and can lead to sickness or death
future infection of a pathogen (for which you have been vaccinated) means
response that is much faster and much larger compared to the initial response
and the pathogen is unable to cause disease and the individual is said to be immune
what are platelets
Platelets are fragments of cells that are involved in blood clotting and forming scabs
when the skin is hurt/ broken, platelets
arrive to stop blood clotting
what is the process involving plasma and platelets and red blood cells to stop excessive blood loss
when you’re cut
Platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin
This forms an insoluble mesh across the wound
Red blood cells become trapped, forming a clot
The clot eventually dries and develops into a scab
the heart organ is a ____ pump
double
oxygenated blood coming from the _____ enters the ____ side of the heart and is pumped to ____
lungs
left
the rest of the body
deoxygenated blood enters from the ___ into the ___ side of the heart and then is pumped to the ___
body
right
lungs
right ventricle pumps blood at _____ pressure to the ____
lower
lungs
the left ventricle has a _____ muscle wall than the right ventricle,
why ?
thicker
because it has to pump blood at high pressure around the whole body
blood is pumped towards the heart inside the
veins
blood is pumped away from the heart in
arteries
valves are present to
prevent blood flowing backwards
veins and arteries the blood passes through in the heart
vena cava
right atrium
right ventricle
pulmonary artery
lungs
pulmonary vein
left atrium
left ventricle
aorta
which side of the heart is thicker and why
the left because thicker muscle walls of the ventricle produce a high enough pressure for the blood to travel around the whole body
heart rate is measured by
counting the number of times your heart beats in a minute
factors affecting heart rate (2)
exercise and level of adrenaline
The heart pumps blood to respiring cells to
supply oxygen and glucose and remove respiratory waste
during exercise, muscle cells respire ____
why
faster
to increase energy supply
respiration is aerobic during ____ exercise
and anaerobic during ____ exercise
moderate
intensive
increased respiration raises need for (3)
oxygen, glucose
and waste removal
when your heart rate increases, your nervous system responds by : (2)
Increasing heart rate to deliver oxygen and glucose more frequently
Increasing the volume of blood pumped to supply larger amounts of oxygen and glucose
at the end of exercise, heart rate can
remain high for a while as oxygen is needed in muscles to break down the lactic acid from anaerobic respiration
production of hormone ___ also ____ heart rate as part of ___ or ___ response after exercise
adrenaline
increases
flight or fight
when an organism is threatened the ______ glands release ____
adrenal glands
adrenaline
adrenaline binds to
specific receptors in the heart
adrenaline causes
cardiac muscle to contract more frequently and with more force, so heart rate increases and the heart pumps more blood.
coronary arteries are
the blood vessels which supply cardiac muscle with oxygen and glucose
in coronary heart disease, layers of ______ build up inside the _______ arteries
fatty material build up inside the coronary arteries
fatty material that clogs coronary arteries is formed from
cholesterol
what are the 2 sources of cholesterol in the body
- dietary cholesterol ( animal products eaten)
- cholesterol synthesised from liver
if the coronary artery becomes fully or partially blocked, what does it result in
flow of blood through arteries is reduced, resulting lack of oxygen for the heart muscle
Partial blockage of the coronary arteries creates a
restricted blood flow to the cardiac muscle cells and results in severe chest pains called angina
Complete blockage of arteries due to fatty material means
cells in that area of the heart will not be able to respire aerobically, leading to a heart attack
Risk factors of coronary heart disease (4)
- obesity
- high blood pressure
- high cholesterol
- smoking
how can smoking lead to coronary heart disease
Chemicals in smoke cause an increase in plaque build up and an increase in blood pressure
Carbon monoxide also reduces the oxygen carrying capacity of the red blood cells)
how does high cholesterol cause CHD
speeds build up of fatty materials in arteries leading to them being blocked
how does high blood pressure lead to CHD
increases blood force against heart and damages vessels
how does obesity cause CHD
strains heart because of extra weight and can lead to type 2 diabetes
three main types of blood vessels
- arteries
-veins - capillaries
smaller vessels that branch from arteries are called
arterioles
each vessel has a particular function true or false
true
arteries carry what type of blood
oxygenated
arteries carry blood at what pressure
high
arteries have what type of walls ( thin, thick, muscular ?)
thick muscular walls
arteries have a ____ lumen
narrow
in arteries, blood flows at a ____ speed
fast
how is the structure of an artery adapted to its function ? (2)
Thick muscular walls containing elastic fibres withstand the high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
A narrow lumen also helps to maintain high pressure
veins carry blood at what pressure
low
veins carry blood where
towards the heart
veins carry what type of blood
deoxygenated
veins have what type of walls
thin
veins have a ___ lumen
large
in veins, blood flows at a ___ speed
low
The structure of a vein is adapted to its function in the following ways (2)
A large lumen reduces resistance to blood flow under low pressure
Valves prevent the backflow of blood as it is under low pressure
capillaries carry blood at what pressure
low
veins have / contain
valves
capillaries carry what type of blood
oxygenated and deoxygenated
capillaries have walls that are
one cell thick
capillaries have ___ walls
leaky/ moist
speed of blood flow in capillaries is
slow
The structure of a capillary is adapted to its function in the following ways: (2)
Capillaries have walls that are one cell thick (short diffusion distance) so substances can easily diffuse in and out of them
The ‘leaky’ walls allow blood plasma to leak out and form tissue fluid surrounding cells
circulatory system consists of
a closed network of blood vessels connected to the heart
before capillaries, blood passes through the
arterioles
in organs, respiring cells use up the ____ from the blood
the oxygen from the blood
as capillaries move away from organs, they
widen into venules the veins
main blood vessels in the circulatory system
TOWARDS HEART - vena cava, pulmonary vein
away from heart-
AORTA, PULMONARY VEIN
TO LUNG- pulmonary artery
AWAY LUNG - pulmonary vein
TO KIDNEY - renal artery
AWAY FROM KIDNEY- renal vein
phagocytes carry out
phagocytosis
response to an infection
- pathogen enters blood and multiplies
- toxins are released and symptoms are felt
- phagocytes find pathogen and engulf and digest it
- then the pathogen will come across a lymphocyte
- lymphocytes produce specific antibodies
- lymphocyte clones itself to produce more
- antibodies destroy pathogen
- phagocytes engulf and digest the destroyed pathogens
how is CHD caught / risk factors (7)
- Diet
- Lack of exercise
- Stress
- Smoking
- Genetics
- Age
- sex
what artery delivers blood to the liver
hepatic artery
what artery delivers blood to the kidney
renal artery