The circulatory system Flashcards
What is the name of the human transport system?
the circulatory system
what is the circulatory system made up of?
the blood system and the lymphatic system
what is the blood system made up of?
blood tissue
blood vessels
heart
what does blood consist of?
cells in a watery medium called plasma
plasma
liquid watery part of the blood
function of the plasma
transport of blood cells and dissolved substances
composition of plasma
90% water
10% dissolved substances
6 dissolved substances in plasma
proteins minerals food excretory products hormones enzymes
example of proteins in blood
antibodies
4 minerals in plasma
Na+ Cl-
Ca++
Iron
4 food in plasma
glucose
amino acids
fatty acids
vitamins
3 excretory products in the blood
urea
lactic acid
CO2
where does urea enter the blood
the liver
where does lactic acid enter the
muscles
where does CO2 enter the blood
all cells
where do hormones enter the blood
the endocrine glands
3 types of blood cells
red blood cells
white blood cells
platelets
red blood cells AKA
erythrocytes
white blood cells aka
leukocytes
platelets aka
thrombocytes
shape of red blood cells
biconcave circular disks
what do red blood cells not have
no nucleus, no mitochondria
how do red blood cells fit into capillaries
they are flexible cells
what do red blood cells have that allows them to carry out their function
haemoglobin
what is haemoglobin?
an O2 carrying red pigment that has iron
where are red blood cells produced?
in the bone marrow of the ribs and pelvis
where are old red blood cells broken down?
in the liver and in the spleen
lifespan of red blood cells
around three months
function of red blood cells
to transport oxygen
haemoglobin + oxygen ->
oxyhemoglobin
colour of haemoglobin
blue
colour of oxyhemoglobin
red
anaemia
lack of haemoglobin (low red cell count) may be due to a lack of iron in the diet
symptoms of anaemia
pale skin colour
lack of energy
size and count of white blood cells
larger than red blood cells but fewer of them
describe the organelles of white blood cells
have a nucleus and a cytoplasm
shape of white blood cells
no definite shape
where are white blood cells made
down marrow of ribs, pelvis etc.
function of white blood cells
protect against disease
2 types of white blood cells that we learn about
monocytes and lymphocytes
what type of cells are monocytes
phagocytes
what makes monocytes phagocytes
their function is to engulf bacteria and viruses
size of monocytes
large white blood cells
size of lymphocytes
small white blood cells
where are lymphocytes also produced?
in the lymph nodes
function of lymphocytes
to produce antibodies
leukaemia
a form of cancer where there is an increase in the number of immature white cells
what do leukaemia lead to?
the inability to fight infection and anaemia
shape of platelets
fragments of large cells
where are platelets made?
in the bone marrow
shape and organelles of platelets
no nucleus, no definite shape
function of platelets
blood-clotting
function of blood clotting
prevents the loss of blood and the entry of microorganisms
thrombosis
a blood clot that forms inside a blood vessel and may block it
haemophilia
blood clots cannot form (due to lack of clotting factors)
2 functions of blood
transport
defence against disease
7 things that the blood transports
food excretory products enzymes hormones heat O2 CO2
2 ways in which white blood cells protect against disease
they engulf foreign bodies
they produce antibodies
1 way in which platelets defend against disease
they cause the clotting of blood, preventing the entry of microorganisms
what are the blood groups based on
the antigens based in the blood
4 main blood groups
A B AB O
antigens in A
A
antigens in B
B
antigens in AB
A and B
antigens in O
A and B absent
when is it important to know a persons blood group?
if they are in need of a blood transfusion
what happens in the donor and the receiver of blood are different?
agglutination or clumping of cells occurs
universal donor
blood group O (negative)
Rh
rhesus factor
Rh positive
has Rh antigen
Rh negative
does not have Rh antigen
A+
A and Rh
O-
A B and Rh all absent
vascular system
blood system
system
a group of organ joined together for particular functions
what organisms do not require a vascular system?
single-celled organisms
why is it ok for amoeba not to have a transport system?
because they are very small
why is it good for multicellular organisms to have a transport system
they are larger and have greater metabolic needs
type of circulatory system that we have
a closed system
what does it mean that we have a closed circulatory system
blood circulates inside vessels
where are materials exchanged between the blood and the cells?
in tiny thin-walled vessels called capillaries
advantage of a closed system and capillaries
much more efficient
In the circulatory system: what does the heart do?
pumps blood into the arteries that carry it to the arterioles and from these it goes into the capillaries
In the circulatory system: what do the capillaries do?
in the capillaries in all the organs, exchange of materials takes place between blood and cells
In the circulatory system: what do the venules do?
blood is collected by the capillaries by a series of venues that carry it to veins
In the circulatory system: what do the veins do?
the veins return the blood to the heart
summary of the circulatory system
heart arteries arterioles
capillaries
venules veins heart
how thick is a capillary
1 cell thick
how many layers in the walls of major blood vessels?
3
3 layers of the walls of major blood vessels
tough outer layer of collagen (protein)
middle layer of muscle and elastic fibres
a thin lining called the endothelium
function of arteries
to carry blood away from the heart under high pressure
2 things that help the blood flow in arteries
thick muscle layer contracts and pushes it on
elastic fibres can expand and recoil it push it on
function of collagen layer in artery
prevents over expansion of the arteries
pulse definition
expansion or vibration in an artery caused by the pumping of the heart
average pulse rate of a human adult
about 70 bpm
where can you feel the pulse
at certain places like the wrist
why can you feel the pulse at certain places like the wrist ?
because this is where you would find an artery near the surface
function of the veins
carry blood back to the heart under low pressure
2 things that help blood flow in veins
valves prevent back flow of blood
contraction of skeletal muscles of the body squeeze the veins and push the blood on towards the heart
which cut can you see the valves of the vein
in the longitudinal section
arteriole
small blood vessel branching from an artery
venue
small blood vessel branching from a vein
3 structural differences between arteries and veins
artery:
wall has thick layer of muscle
small lumen
no valves
3 other differences between artery and vein
artery:
carries blood under high pressure
carries blood away from the heart
carries oxygenated blood except the pulmonary artery
what are capillaries
tiny tubes that link arterioles to venues
what occurs in the capillaries
the exchange of materials (food, H2O, gases, waste products etc.) takes place between the blood and the cells
2 structural adaptations for exchange in capillaries
thin walls to allow materials to pass in and out with ease
large surface area-all body cells are close to a capillary
where is the heart found?
in the thoracic cavity
what protects the heart
the ribcage
4 major components of the heart
the septum the atria the ventricles and the valves
septum
divides the heart into right and left sides. separates the oxygenated and the deoxygenated blood
atria
relatively thin chambers
receive blood from the veins and pass it into the ventricles
ventricles
thick walled chambers that pump blood out of the heart
valves in the heart
prevent the back flow of blood when it is under pressure (blood can flow in one direction only)
3 valves in the heart
bicuspid valve
tricuspid valve
semi-lunar valves
where could you find the bicuspid valve?
between the left atrium and the left ventricle
where could you find the tricuspid valve?
between the right atrium and right ventricle
what holds the bicuspid and tricuspid valves to the heart
the chordae tendinae
where could you find the semi-lunar valves?
at the base of the pulmonary artery and the base of aorta
blood flow on the right side of the heart
vena cava (CO2) right atrium right ventricle pulmonary artery lungs
blood flow on the left side of the heart
pulmonary vein (O2) left atrium left ventricle aorta general body
What is different about the heart muscle to other muscles of the body?
it never tires
what type of pump is the heart?
a double pump
Left
oxygenated
Right
deoxygenated
how many circuits is there from the heart
2
2 circuits from the heart
the pulmonary and systemic circuit
function of pulmonary circuit
pumps blood to lungs to receive O2
pulmonary circuit route
Heart Lungs Heart
function of systemic circuit
pumps blood with O2 around the body
systemic circuit route
Heart Rest of body Heart
2 advantages of double circulation
oxygenated blood separated from deoxygenated blood
ensures that blood is pumped under sufficient pressure to deliver oxygen al around the body
Portal blood system
a vessel that has capillaries at both ends. The blood flows directly from one organ to another without passing through the heart
example of a Portal blood system
the hepatic portal vein brings blood (rich in digested food but low in O2) from the digestions to the liver
the cardiac cycle
the sequence of events that takes place during the completion of one heartbeat
contraction
systole
relaxation
diastole
what does the cardiac cycle involve?
the rhythmical contraction and relaxation of the heart muscles and the opening and closing and closing of the heart valves so that blood can flow through the heart
1 first thing that happens during diastole
blood flows into both atria from the veins
2 what happens after the blood flows into both atria
the bicuspid and tricuspid valves open so that the blood can flow into the relaxed ventricles
3 what occurs when the heart is full of blood
the atria contract together forcing more blood into the ventricles and then they relax (atrial systole 0.1 seconds)
4 a very short time after the atria contract
the ventricles contract (systole), forcing blood into the pulmonary artery and the aorta
5 what happens when the ventricles contract
the semi-lunar valves open and the bicuspid and tricuspid valves close (ventricle systole 0.3 seconds)
6 after the semi-lunar valves open and the bicuspid and tricuspid valves close
the ventricles relax (diastole)
semi-lunar valves close to prevent backflow of blood into ventricles
7 after the whole process is over
the atria fill up with blood again from the veins
the pacemaker
SA node
SA
sino atrial
where can you find the SA node
in the wall of the right atrium
function of SA node
sends out electrical impulses that cause the atria to contract
AV node
atrioventricular node
where can you find the AV node?
in the septum between the right atrium and right ventricle
function of the AV node
send electrical impulses down the septum to cause the ventricles to contract
what sets off the AV node
the electrical impulses of the SA node
4 factors affecting the rate of the heart beat
exercise excitement fear body temperature drugs sleep infection
blood supply to the heart muscle
coronary circulation
from where does the muscle of the heart receive blood?
from the coronary arteries that arise at the base of the aorta
where does the blood go after it has gone through the heart muscle
into the coronary veins that return blood to the right atrium
blood pressure
the force exerted by the blood against the wall of an artery
area of highest blood pressure
the aorta after the left ventricle contracts
area of lowest blood pressure
the vena cava leading into the right atrium
where is human blood pressure usually taken
in an artery in the upper part of the arm
what are they recording with the blood pressure machine
the amount of pressure required to stop the blood flow through this artery
higher figure in blood pressure
systolic pressure, when the ventricles contract
lower figure in blood pressure
diastolic pressure, when the ventricles are relaxing
normal blood pressure reading
120/80
2 effects of smoking on the circulatory system
increases heart rate and blood pressure, greater risk of heart attack and stroke
damages endothelium, risk of a blood clot, risk of heart attack or stroke
high amount of cholesterol in the diet
formation of blockages in the arteries, greater risk of heart attack or stroke
high salt intake in diet
high blood pressure
increased risk for heart attack and stroke
obesity
can cause high blood pressure and heart attacks
lack of iron
anaemia (low red cell count)
regular and aerobic exercise 2
the heart becomes stronger and more efficient
the arteries dilate (widen)
recovery time
the length of time taken for the pulse rate to return to normal after a period of exercise
how is tissue fluid formed?
when blood reaches the arterial end of a capillary it is under high pressure and some plasma leaks out the walls of the capillaries, this is tissue fluid
what happens between cells and tissue fluid
exchanges occur eg. food O2 urea
most of the tissue fluid goes
back to the capillaries near the venules
some of the tissue fluid goes
into the lymph vessels that lie between the cells
the tissue fluid that enters the lymph vessels is called
lymph
describe lymph
colourless watery fluid
2 components of lymph
plamsa and white cells (lymphocytes
3 things that blood has that lymph doesn’t
red cells
white cells
clotting proteins
3 things that make up the lymphatic system
lymph capillaries
lymph vessels
lymph nodes
what are lymph nodes
swellings (glands) found along the vessels
circulation of lymph
flows in lymph vessels in one direction only, from he tissues to the blood system
flow of lymph is maintained by:
valves to prevent backflow
contraction of skeletal muscles sqeezes the ducts and forcing the lymph
2 functions of the lymphatic system
transport
defence against disease
2 things transported in the lymphatic system
plasma
digested lipids
how is plasma collected by the lymph system
leaked under pressure through capillaries and the lymph returns this tissue fluid to the blood
function of returning tissue fluid to blood
maintains the volume and concentration of the blood
if lymph vessels are blocked
there is a fluid build up and swelling (oedema)
where does the lymph absorb the digested lipids?
in the small intestine, in the lymph lacteals un the villi
2 ways in which the lymph system can defend against disease
filters the plasma
produces lymphocytes
what does the lymph remove from the plasma
bacteria, viruses, caner cells etc,
what happens to the substances filtered out of the blood by the lymph
they are attacked by lymphocytes in the nodes
what do lymphocytes do?
they respond to antigens and make specific antibodies
what happens to lymph nodes when they are fighting an infection?
they become swollen
To dissect and display a sheep’s heart
before you begin
put on rubber gloves, wash the heart with cold water and drain it and dry it with paper towels
To dissect and display a sheep’s heart
how do you find the ventral (front) side
by feeling the walls of the ventricles, the left side will feel much firmer
To dissect and display a sheep’s heart
how and where do you place to heart
on a dissecting board ventral side up
To dissect and display a sheep’s heart
first cut
using a scalpel cut the wall of the left atrium and left ventricle
To dissect and display a sheep’s heart
how to examine structure of left side
using your fingers push open the heart at the first cut
To dissect and display a sheep’s heart
what can you examine after the first cut?
atrium, ventricle and bicuspid valve
To dissect and display a sheep’s heart
second cut
same as the first on the right side this time
To dissect and display a sheep’s heart
3rd cut
cut open the base of the aorta and find the semi-lunar valve
To dissect and display a sheep’s heart
2 openings at the base of the aorta
lead into the coronary arteries
To dissect and display a sheep’s heart
when you have completed the dissection
flag label the parts identified
To dissect and display a sheep’s heart
final step
wash and sterilise instruments and board
