Download The circulatory System is comprised: *Blood *Blood vessels *Heart

The circulatory System is comprised:
*Blood
*Blood vessels
*Heart
The circulatory system carries blood to
and from all the cells of our body.
• It brings cells nourishment and
other important molecules, and
takes away their wastes.
• Is a fluid tissue.
• Is red and viscous.
• Blood constituents: is made up
of: Plasma and the Blood
cells.
• On average our body contains
5.6 L for males and 4.5 L for
females, of blood but we can
lose up to 1 L before it
becomes life threatening.
Plasma
• Plasma is clear yellow fluid and makes
up 55% of our blood volume.
• Plasma contains 90% water and 10%
dissolved substances such as :
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Nutrients: Ex. Glucose
Hormones: Ex. Testosterone
Antibodies: Proteins that can destroy bacteria
Other Proteins: that help in the coagulation of
blood.
– Waste Products: Carbon dioxide, urea
• Its function is to transport these
dissolved substances throughout the
body.
Blood Cells (Formed Elements)
• Makes up 45% of blood volume
• Three basic kinds of blood cells :
– Red blood cells
– White blood cells.
– Platelets.
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about 5 billion / mL
Red, biconcave disks
Made in bone marrow
No nucleus, few organelles
Contain the protein hemoglobin (contains
iron) to transport oxygen(O2) to body cells.
• As Hemoglobin takes in oxygen it turns
from a wine colour to bright red.
• Transports CO2, goes from bright red to
wine colour.
• Part of the immune system
• 4-11 million (5 types)
• Provides immunity to defend against
invaders such as bacteria and viruses.
• made in the bone marrow and can be
stored in the lymph nodes until
needed
• Some can travel outside of the normal
blood stream, in the lymphatic system
to track down sites of infections.
Platelets
– 150-400 million
– Irregular shaped
– Come from large cells in bone marrow
– Transparent cells
– Function in blood-clotting process.
Blood Types.
• There are 8 different blood types in humans, based on the
ABO-Rh system.
• A+, A-, B+, B-, AB+, AB-, O+, O• Blood type is determined by the kind of antigen present on
the surface of the red blood cells of a person.
• An antigen is a protein or carbohydrate that acts as a label,
to signal the body to recognize foreign substances that enter
the body.
Antigens and Antibodies.
• There are 3 basic antigens that can be found
on the surface of red blood cells :
– Antigen A
– Antigen B
– Antigen Rh
• There are also 3 basic antibodies
corresponding to these antigens :
– Anti- A, B, and Rh, each react to their particular
antigen and cause the blood to clump together.
Antigens and Antibodies.
• A person with antigen A and the Rh factor on
their RBC’s is said to be of type A+ .
• This also means that their plasma will
contain the antibodies against the B antigen,
but not against A or Rh.
• A person with antigens A,B and Rh has no
antibodies against these in their plasma.
They are said to be AB + blood.
• A person with no antigens (type O -) will have
all the antibodies in their plasma. (A, B, Rh )
Blood Transfusions.
• The injection of blood into a person.
• Donor: person giving blood for the purpose of a
transfusion.
• Recipient: person who receives blood from a
transfusion.
• Donor’s blood cannot contain any antigens that the
recipient’s blood doesn’t have.
• O- is a universal donor because it has no antigen for the
antibodies to react to.
• AB+ is the universal receiver
• Blood Compatibility: one person can receive blood
from another person.
The Cardiovascular System
•Comprised of blood, blood vessels and the
heart.
• The blood vessels act as a closed
circuit for transportation.
• Circulation due to pressure supplied
by the heart.
• Three types:
– Arteries “red”
– Veins “blue”
– Capillaries “both”
• Contain blood that is being sent
away from the heart to body parts.
• transport blood high in Oxygen and
low in Carbon Dioxide
• Exception: pulmonary artery
• Arteries are largest blood vessels.
• thick walled and under high
pressure, which is why we can feel a
pulse every time the heart beats.
• Largest: Aorta→ main lead from
heart.
• Arteries branch into arterioles (small
arteries) which branch into
capillaries.
Arteries
Capillaries
• These are the smallest blood
vessels
• Narrow and are single-cell thick
allowing for gas exchange, both at
the lungs and at the cells.
• connect the arteries to the veins.
• Exchange site for nutrients and
cellular waste.
• Nutrients and gas pass from
capillaries to extracellular fluid to
cells.
• Waste travels the reverse path.
• Capillaries lead into venules (small veins) Veins
that lead into veins that carry blood
towards the heart with the aid of one-way
valves and muscle contractions.
• Mainly transporting CO2
• Exception: pulmonary vein
• thinner walls than arteries
• No pulse and are under low blood pressure
• Largest: Vena Cava (superior & inferior)
leading towards heart.
Varicose
veins
*In a normal vein,
the valves close to prevent backward
flow of blood.
*In a varicose vein, the flaps cannot close because the
vein is abnormally widened, blood can flow in the
wrong direction.
Blood Flow
• Oxygenated blood flows from heart
arteries
arterioles
capillaries (gas exchange)
deoxygenated blood (CO2)
venules
veins
heart.
• The heart is the pump of the circulatory (cardiovascular) system.
• ~size of fist, located in thoracic cage between lungs.
• It is composed of 4 chambers; the left and right atria and left and
right ventricles.
• The left and right sides of the heart are separated by a septum.
• The left atrium receives O2 blood from lungs via pulmonary vein and
pumps it down into left ventricle. The ventricle pumps into the
Aorta.
• The right atrium receives CO2 blood from vena cavas and pumps it
down into right ventricle. The ventricle pumps blood to lungs via
pulmonary artery.
Chambers of
the heart.
• control the flow of blood, making
sure that it flows in only one
direction.
• found in the heart and in the veins,
especially those of the legs, where
they help to return the blood back
up to the heart.
• Valves between the atria and
ventricles are called
atrioventricular valves.
• Atrioventricular valves: tricuspid
valve (right side), mitral valve (left
side)
Septum
Circulation
• Pulmonary circulation: blood
circulation between the right
side of the heart and the lungs.
• Rich in CO2 passes through right
ventricle pulmonary artery
pulmonary arterioles
pulmonary capillaries of the
lungs pulmonary venules
pulmonary vein
left atrium.
• Gas exchange between
capillaries and alveoli.
• Blood rich in O2 returns via
pulmonary vein towards left
side of heart.
• Is a shorter route.
Pulmonary Circulation
Systemic Circulation
• Blood circulation between the left side
of the heart and the rest of the body
(both upper and lower regions).
• Blood is rich in O2 as it leaves the left
ventricle and enters aorta.
• Leads to smaller arteries and arterioles
to capillaries
• Drops off O2, nutrients and other
substances, picks up CO2 and other
waste.
• Blood returns to heart via the superior
and inferior vena cava.
• Is a longer route.
• Diastolic pressure : Is the pressure inside of the arteries
after the contraction, when the heart muscle relaxes
the atria refills with blood (diastole).
• Systolic pressure : Is the pressure inside the arteries at
the moment of the muscular contraction of the heart’s
ventricles (systole).
• The tool used to measure blood pressure is called a :
Sphygmomanometer.
• Optimal blood pressure in an adult at rest is 120/80
mmHg, in which 120 describes systolic pressure and 80
describes diastolic pressure.
• Your pulse is a wave of high pressure that can be felt
at the arteries following the contraction of the
ventricles of the heart. (Systolic pressure)
• The average pulse for a human at rest is around 75
beats / minute.
• The maximum amount of times your heart can beat in
a minute is calculated by: 220 – age.
• High blood pressure/Hypertension: condition that can lead to
cardiovascular disease.
• Constricted arteries decreases blood flow, causes excessive
pressure against vessel walls. The heart works harder to pump
blood through the narrowed arteries.
• If the condition persists, damage to the heart and blood vessels is
likely, increases risk for stroke, heart attack, and kidney or heart
failure.
• Hypertension is defined as blood pressure greater than or equal to
140/90 mm HG at rest.
FYI
• Is a system of thin tubes that
runs parallel to the circulatory
system.
• It is the go-between for the
circulatory system and cells.
•The exchange of substances,
ex: nutrients, occurs between
the extracellular/interstitial
fluid.
• Extracellular fluid: clear liquid
surrounds cells, contains water,
white blood cells and other
substances from plasma.
Blood
(in capillaries)
Lymphatic Vessels
• These tubes are called lymphatic vessels.
• The lymphatic vessels branch through all parts of the body
carrying a colourless liquid called lymph (extracellular
fluid).
• Muscle contractions move the lymph through the vessels
and the large vessels contain valves to keep the flow in the
right direction.
• Water constantly leaks out of plasma into extracellular
fluid, this fluid becomes lymph.
• Lymph contains a high number of lymphocytes (white
blood cells), cellular waste and water.
• Lymph is eventually returned to the circulatory system via
the veins.
• Along the lymph vessels are small
bean-shaped lymph nodes or
glands: they act as filters of the
blood and lymph to fight off
infections.
• High concentration of white blood
cells.
• White blood cells leave capillaries
through a process called
diapedesis. They do this by
altering their shape to pass
through the pores.
• Foreign invaders usually make
their way into extracellular fluid,
lymph or blood.
Lymph nodes/
glands
3) Fighting infection
• Makes special white blood cells (lymphocytes) that produce
antibodies
• Lymphocytes consume invaders through phagocytosis.
• Phagocytosis: white blood cells ingest and destroy
microorganisms.
• Antibodies recognize antigens of specific invaders.
• Can neutralize invader and/or mark for destruction.
• Antigens are substances recognized as foreign by the body
triggering production of antibodies.
• White blood cells are immunizing: can remember how to
produce a particular antibody.
The Lymphatic System also includes:
• Spleen→ acts a filter for lymph
fluid: destroys any microorganisms
and worn out red blood cells. Aids
in production of red blood cells.
• Thymus → produces white blood
cells.
• Tonsils → protects entrance of
oral and nasal cavity from bacteria
and viruses.
The lymphatic system does three main jobs in the body:
1) Drains fluid back into the bloodstream from the
tissues
2) Filters lymph through spleen
3) Fights infections