Transcript CIRCULATORY SYSTEM

Circulatory System
• Every single living cell in the body needs a supply of
oxygen and nutrients for energy, growth, repair, and
heat production.
• Each organ has it’s own separate circuit of an artery
and vein which branch into smaller vessels and are
linked by capillaries.
• This individual circuit ensures that every part of the
body receives a rich supply of nutrients.
• In this way not all of the blood goes to each organ in
turn. If this were the case then the furthest organ
from the heart would receive no fresh blood.
• The only organ to receive all of the blood is the lungs
so that all the blood is oxygenated.
Circulatory System
• The Heart:
A muscular pump that pumps blood around the body
through a system of vessels
• Blood Vessels:
These transport blood around the body that is
Arteries, veins & capillaries
• Blood:
Carries important substances to and from the cells in the
body through the blood vessels. That is plasma, white blood cells, red
blood cells & platelets
• Lymphatic system:
this is the body’s secondary line of defense,
stops the build up of toxins and excess fluid in the body
COMPOSITION OF BLOOD
RED BLOOD CELLS
• Transport of gases – mainly oxygen
WHITE BLOOD CELLS
• Fight infection
PLATELETS
• Clotting
PLASMA
• Transport – mainly carbon dioxide,
hormones, nutrients and waste products
Circulatory System
• The circulatory system is the body’s
transport system
• The system is made up of the heart, blood,
blood vessels and lymphatic system
• Blood carries important substances to the
cells in the body
• Blood carries waste products away from the
cells to the excretory organs
• Blood is transported in blood vessels called
arteries, veins and capillaries
• The heart is a muscular pump, which forces
the blood around the body, through the blood
vessels, in a constant circuit
FUNCTIONS OF BLOOD
TRANSPORT
•
•
•
Red blood cells contain haemoglobin which carries oxygen from the lungs to
cells of the body
Carbon dioxide is carried from cells to the lungs
Plasma – liquid consisting mainly of water – carries nutrients (glucose, amino
acids, vitamins, minerals), gases, waste products and hormones
DEFENCE
•
White blood cells digest micro-organisms (which invade the body) and help
fight infection
CLOTTING
•
Platelets form a clot over damaged skin, which prevents further blood loss
REGULATION
•
•
Blood absorbs heat, which is produced by the muscles and liver and
transports it around the body to maintain a constant internal temperature
Blood helps regulate the body’s pH balance
Blood Clotting
The process that prevents blood from clotting in an undamaged
vessel is a complex one.
Once a vessel has been damaged, platelets adhere to the damaged
area forming a plug the plasma protein fibrinogen is converted into
fibrin that creates fibres to radiate from the platelets forming a
network which traps red blood cells.
This blood clot stops further blood loss and prevents entry of bacteria.
Once the clot has dried it shrinks to form a scab, which protects the
tissues underneath while healing takes place.
Heparin is a protein normally present in the blood, which is formed in
the liver and it’s function is to prevent blood clotting in the vessels – it
is called an anti – coagulant.
BLOOD VESSELS
ARTERIES
VEINS
CAPILLARIES
Direction
Carry blood away from
the heart
Carry blood towards
the heart
Link arteries and
veins
Blood
Type
Carry oxygenated blood
Carry deoxygenated
blood
Responsible for
tissue fluid
exchange in cells
Structure
Thick, muscular elastic
walls
Less thick walls, contain
valves which prevent
back flow of blood
Walls are very thin
- only one cell thick
to allow the process
of diffusion
Pressure
Blood is carried under
high pressure
Blood is carried under
low pressure
Blood pressure is
higher at arterial
side
Location
Generally deep seated –
except pulse areas
Generally superficial
Form networks in
tissues
Divisions
Divide into smaller
vessels called arterioles
which deliver blood to
capillaries
Divide into smaller
vessels called venules
which continue from
capillaries
Smallest blood
vessels
Tissue fluid Exchange
Blood rich in oxygen and nutrients is transported
around the body at high pressure via the arteries.
The arteries divide into smaller and smaller
vessels until they become capillary networks in
the tissues.
Fluid escapes thorough the thin walls of the
capillaries, bathing the cells delivering nutrients
and oxygen in exchange for waste products.
Tissue fluid Exchange
The tissue fluid passes back through the capillary
walls into the venous side of the capillary network,
where the pressure is lower.
Any left over fluid and molecules too large to go
Through the blood capillary, pass into the
lymphatic capillary and now becomes lymph fluid.
TISSUE FLUID EXCHANGE
Capillary
LYMPHATIC SYSTEM
• The lymphatic system is the body’s secondary
line of defence (immunity)
• Prevents the build up of toxins and excess fluid
in the body
• Consists of lymph fluid, lymph nodes, lymph
ducts and lymph vessels
• The lymphatic system is part of the circulatory
system
• The lymph fluid contains waste products – this
fluid is transported by lymph vessels (which
also have valves)
• The fluid is then filtered by the lymph nodes
and then returned back to the venous system
by the lymph ducts
THE LYMPHATIC SYSTEM
The lymphatic system is really part of the vascular
system – the blood is contained in a closed system
of vessels which is kept circulating by the heart,
from the capillaries some fluid escapes called
plasma, this is by diffusion and filtration.
This fluid then bathes the tissues directly, when this
fluid is collected into the lymph vessels it becomes
lymph, which is later returned to the blood stream.
Lymph vessels start as fine, blind ended lymph
capillaries which then join to form lymphatics which
are similar in general course and structure to that of
veins.
THE LYMPHATIC SYSTEM
They are semilunar and numerous through and
have many more finer (pocket) valves, this is
because the lymph is not pumped by the heart.
The composition of lymph is similar to blood
plasma but has less protein, less food materials and
more waste material – it has no erythrocytes but has
More leukocytes.
THE LYMPHATIC SYSTEM
Lymph drainage is through lymph nodes
– before the lymph can be returned to the
blood stream it is filtered through one or
more of the lymph nodes, which are bean
shaped structures, situated at strategic
points in the course of the lymph vessels.
THE LYMPHATIC SYSTEM
After passing through the nodes the lymph
is then collected into the main lymph
vessels – vessels – lymph from the
right side of the head and thorax and right
arm, drain into the right lymphatic duct,
while lymph from the rest of the body drains
into the thoracic duct.
THE LYMPHATIC SYSTEM
The lymphatic system acts as the
body’s secondary line of defence
against bacterial invasion, this is
through the presence of
leukocytes at the site of infection.
BODY LYMPHATIC SYSTEM
PAROTID
Buccal Lymph Nodes
SUBMANDIBULAR
CERVICAL UPPER
& LOWER
Thoracic Lymph Nodes
SUBMENTAL
Axillary Lymph Nodes
Abdominal Lymph Nodes
Iliac Lymph Nodes
Inguinal Lymph Nodes
Papliteal Lymph Nodes
THE HEART RATE – PULSE
The left ventricle contracts so strongly that it can
be felt as a pressure wave or ‘pulse’ at certain
places along an artery where the artery is nearer
the surface of the skin.
Measuring your pulse:
• The pulse can be felt strongly in two main places
– the neck and the wrist.
• To feel for your pulse you must use two fingers
not your thumb as this has a pulse of it’s own.
EXPERIMENT
1.
Take a measurement of your resting heart rate timed over 30
seconds and then double to find your resting heart rate per
minute.
2. To increase you heart rate do some vigorous exercise for 3
minutes or until you are out of breath.
3. After the exercise take you pulse again.
4. How long does it take to go back to your resting heart rate?
A healthy adult has a resting pulse rate of 60–80 beats a minute.
Someone who is unfit or who has a sedentary lifestyle may have a
pulse of 120 beats a minute.
A trained athlete or a very fit person may have a pulse of 35-40
beats a minute.
THE HEART
•
•
•
•
•
•
•
•
•
•
•
Is a hollow muscular organ ‘pump’
Pumps blood around the body
Comprises of 4 chambers
Upper chambers = Atria
Lower chambers = Ventricles
Divided into 2 halves by the septum
Left side deals with oxygenated blood
Right side deals with de-oxygenated blood
Situated in the thoracic cavity
Between the lungs – slightly to the left
Protected by the rib cage
Deoxy, bld(from body)
Lungs(oxy)
VC
PV
RA
LA
LV
RV
Aorta
PA
body
Aorta (Arch)
Superior Vena cava
Pulmonary Artery
Pulmonary Vein
Right Atrium
Left Atrium
Mitral Valve
Tricuspid Valve
Inferior Vena cava
Right Ventricle
Septum
Left ventricle
CIRCULATION OF BLOOD THROUGH THE HEART
Humans and other mammals have a double circulatory
system; the blood circulates around 2 separate pathways
joined at the heart.
The systemic Circulation
Or the general circulation, carries oxygenated blood from
the heart to parts of the body and back again- (not
including the lungs)
In both circuits, gases exchange places in the capillary vessels.
The pulmonary Circulation
Carries blood from the heart to the lungs be oxygenated
and back to the heart.
CIRCULATION OF BLOOD THROUGH THE HEART
The pulmonary Circulation
Deoxygented blood comes from the body and
travels into the heart’s upper chamber, the
right atrium, via the vena cava.
The atrium contracts and blood is forced into
the right ventricle. The right ventricle
contracts and blood passes out of the heart
into the Pulmonary artery.
The pulmonary artery goes to the lungs where the
blood picks up oxygen – this is now oxygenated
blood.
CIRCULATION OF BLOOD THROUGH THE HEART
The systemic Circulation
The oxygenated blood travels from the lungs via
the pulmonary vein to the left atrium of the
heart.
The left atrium contracts and blood is forced
into the left ventricle. The left ventricle
contracts and blood passes out of the heart via
the Aorta.
The oxygenated blood is transported around
the body through arteries that branch from
the main artery - aorta.
BLOOD CIRCULATION
Label the following on diagram (use the letters as key)
A – a blood vessel rich in oxygen
B- a blood vessel low in oxygen
C- a blood vessel rich in carbon dioxide
D- a blood vessel low in carbon dioxide
E- a blood vessel under high pressure
F- a blood vessel under low pressure
G- a blood vessel that has valves
C
B
G
F
D
A
E
Subclavian
Jugular
Vena Cava
Axillary
Cephalic
Brachial
Basilic
Median
Great Saphenous
Radial
Femoral
Popliteal
Short Saphenouse
Anterior Tibial Vein
Posterior Tibial Vein
Subclavian
Carotid
Axillary
Aorta
Brachial
Radial
Iliac
ulnar
Deep Palmer Arch
Superficial
Palmer Arch
Femoral
Digital
Arch
Popliteal
Anterior Tibial
Posterior
Tibial
Blood Groups
There are four different blood groups, A, B, AB & O.
Blood from one individual cannot always be safely mixed with that of another,
this is due to the two types of protein that may be present on the red blood cells
– A and B. These proteins are Antigens to individuals who lack them.
Antigen – any substance that the body regards as foreign or potentially
dangerous and against which it will produce an antibody.
Antibodies - are found in the plasma and can cause the red cells of other
groups to clump together and can be fatal as the clumps of red cells block the
blood vessels and obstruct the circulation – this is called Agglutination – (can
also cause kidney damage).
The antibodies are called Agglutinins.
*Agglutinated cells block the flow of blood disrupting circulation and
the distribution of O2, gases and nutrients
Blood Groups
Blood
group
A
B
AB
O
Agglutinogen Agglutinin
(Antigen on (antibody in
RBC)
plasma)
A
Anti - B
B
Anti - A
A+B
None
None
Anti A + Anti
B
Blood Groups Transfusion Considerations
Doner /
Recipient
A
A
B
B
AB
X
X
X
X
Universal
Recipient
AB
O
O
X
X
X
Universal
Donor
The Rhesus Factor
In addition to ABO grouping there is another antigen
present in the blood of about 85% of the population-it
is known as the Rhesus Factor, (named after the
group of monkeys it was discovered in).
Those who have this factor are known as Rhesus
+ positive) – 85%
Mother-fetus incompatibility
Normally, anti-Rh+ antibodies do not exist
in the first-time mother unless she has
previously come in contact with Rh+
blood. Therefore, her antibodies are not
likely to agglutinate the red blood cells of
her Rh+ fetus.
Rh (Rhesus) Factor
• Up to 8 genes determine if a person is
Rh positive.
• The most common of these are the C, D
& E genes which determine if a person
has C, D and/or E antigens on the walls
of the cells.
• People who do not have Rh antigens on
their cell membranes are Rh negative.
BLOOD SUPPLY TO THE HEAD AND NECK
VESSEL
AREA SUPPLIED/DRAINED
Internal carotid artery
Supplies blood to brain and eyes
External carotid artery
Main vessel supplying book to upper part of
neck/face – subdivides into branches
supplying other areas: facial, occipital,
temporal
Facial artery
Supplies upper/lower and facial muscles
Superficial temporal artery
Supplies the face by its transverse (across)
facial branch
Occipital artery
Supplies upper part of the neck and back of
scalp
Internal jugular vein
Brains blood from brain
External jugular vein
Main vessel draining blood from face/neck –
blood is supplied to it by smaller veins
which drain different area
Facial vein
Drains front of scalp and superficial
structures of the face
Retromandibular vein
Drains face below jaw and back of scalp
Blood Pressure
The blood pressure is the amount of pressure exerted on an arterial
wall due to the contraction of the left ventricle.
The pressure in the arteries varies during each heartbeat. The
maximum pressure of the heartbeat is known as the systolic
Pressure and represents the pressure exerted on the arterial wall
during active ventricular contraction. Systolic pressure can therefore
be measured when the heart muscle contracts and pushes blood out
into the body through the arteries.
The minimum pressure, or diastolic pressure, represents the static
pressure against the arterial wall during rest or pause between
contractions. Therefore the minimum pressure is when the heart
muscle relaxes and blood flows into the heart from the veins.
Superficial Temporal Artery
Occipital Artery & Vein
Retromandibular vein
Facial Artery
Facial Vein
Jugular Vein
Carotid Artery
PAROTID
SUBMANDIBULAR
SUBMENTAL
CERVICAL UPPER & LOWER
LYMPH SUPPLY TO THE HEAD AND NECK – ANSWER GUIDE
NODES/DUCT/VESSEL
AREA DRAINED
Submental Nodes
Drain lymph from chin
Submandibular Nodes
Drain lymph from middle of cheeks
Parotid Nodes
Drain lymph from sides of cheeks and forehead
Thoracic Duct
Main collecting duct – collects lymph from left side of head
and neck, left arm, lower limbs and abdomen.
Left Subclavian Vein
Lymph from thoracic duct drains into this vein
Right Lymphatic Duct
Very short in length – collects lymph from right side of
head and neck and right arm
Right Subclavian Vein
Lymph from right lymphatic duct drains into this vein