Download Circulatory SystemP1 - Ms. Ghtaura`s Class

Part 1
The
Circulatory
System
Ms. Ghtaura
Functions of the circulatory system
– Transportation
• Respiratory:
• Nutritive: carry
• Excretory: removes
to cells (e.g. amino acids and glucose)
products (e.g. urea)
– Regulation
• Hormones: carries
from the
endocrine glad to target organ tissue (e.g. insulin)
• Temperature: controls
by adjusting blood
flow to
of body
– Protection
• Clotting:
blood loss when blood vessel is
• Immunity: defends against
and
destroying microorganisms or foreign substances
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by
Composition of Blood - Plasma
Blood is a fluid used for transporting suspended cells & dissolved substances
It is composed of
and
Plasma is composed of the following:
i.
ii. gases:
iii.
: glucose, amino acids, lipids, & vitamins
iv. ions (salts):
with trace amounts of Ca2+, K+, & Zn2+
v. waste:
vi. hormones: secreted from cells
vii.
:
a.
: made by liver for blood clotting
b.
: made by liver to maintain osmotic pressure of blood by increasing
solute concentration of blood
c.
: made by liver to transport small molecules
 antibodies: made by white blood cells during immune response to
foreign invader
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Composition of Blood – Blood Cells
Blood is a fluid used for transporting suspended cells & dissolved substances
It is composed of plasma and blood cells
Blood cells are produced from stem cells in
within certain bones and are
composed of the following:
i.
Red blood cells: transport
& some
• biconcave disc:
provides large
surface area for
• each contains large
amount of
Ms. Ghtaura
Composition of Blood – Blood Cells
Blood is a fluid used for transporting suspended cells & dissolved substances
It is composed of plasma and blood cells
Blood cells are produced from stem cells in bone marrow within certain bones and are composed of the following:
ii.
White blood cells: defend body against disease caused by
invaders, i.e. provide immunity
against pathogens
• larger than red blood cells
• function of certain cells:
a. detect antigen: protein, polysaccharide, or glycoprotein on surface of
foreign invaders that
• triggers immune response, i.e. any molecule not
by
host & stimulates production of antibodies
b. produce antibody: protein that binds to specific antigen, which activates
other white blood cells that destroy
Ms. Ghtaura
Composition of Blood – Blood Cells
Blood is a fluid used for transporting suspended cells & dissolved
substances. It is composed of plasma and blood cells
Blood cells are produced from stem cells in bone
marrow within certain bones and are composed of
the following:
iii. Platelets: cell fragments involved in blood
with
NOTE: if accidently cut your hand using knife, then
platelets control bleeding, while microorganisms
(e.g. bacteria) on blade trigger immune response by
white blood cells
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Blood Vessels - Veins
• Veins
– carry blood from
to
• Venules
– Veins branch into
– carries
from
capillaries to
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Blood Vessels - Arteries
• Arteries
– carry blood from
to
• Arterioles
– Arteries branch into
– carries blood from
to
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Blood Vessels - Capillaries
• Capillaries
– exchanges nutrients
from blood with
from cells
– A single–cell layer thick
wall and narrow
diameter facilitates
rapid
between
and
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Circuits
• Pulmonary Circulation
– carries
blood from
right ventricle to lungs &
oxygenated blood from lungs to
left atrium of heart, i.e. pathways
between heart & lungs
• Systemic Circulation
– carries
blood from
left ventricle through body &
deoxygenated blood from body to
right atrium of heart, i.e. pathways
between
&
NOTE: volume of blood entering/exiting
pulmonary circulation always equal to volume of
blood exiting/entering systemic circulation
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The Heart
Pulmonary circulation
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Blood Vessels in the Heart
Anterior
vena cava
A. vena cava:
– i. anterior: carries
blood from head & arms to
– ii. posterior: carries
blood from abdomen & legs to
heart
B. aorta: carries
from heart to body
C. pulmonary:
blood
– i. arteries: carries
from heart to lungs
– ii. veins: carries
from lungs back to heart
blood
blood
posterior vena
cava
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Pulmonary veins
Pulmonary
arteries
Heart Chambers
A.
B.
•
atria: collects blood from veins & pumps
blood into ventricles
– Left atrium – oxygenated blood from
the
enters the left
atrium via the
veins
– Right Atrium – deoxygenated blood
enters the right
via
the
and
vena cava
ventricles: pump blood out from heart to
arteries
– Left ventricle – collects oxygenated
blood from the left
via
the
valve
– Right Ventricle – collects
deoxygenated blood from the right
atrium via the atrioventricular valve
septum: wall that
sides
right & left
NOTE: heart muscles receive oxygenated blood
from aorta via coronary arteries & deoxygenated
blood returned via coronary veins
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Valves in the Heart
A.
atrioventricular valves:
(bicuspid/mitral or tricuspid
valve) prevent backflow of
blood from
into
atria during contraction of
•
B.
chordae tendineae: connective
tissue that prevents
atrioventricular valves from
inverting during
of
ventricles, i.e. provides
structural support for valves
semi–lunar valves:
(pulmonary or aortic valve)
prevent backflow of blood
from
into
during relaxation of ventricles
Chordae tendineae
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Passage of blood flow
deoxygenated
blood
oxygenated blood
anterior &
posterior vena cava
right atrium
left atrium
atrioventricular
valve
right ventricle
left ventricle
semilunar valve
pulmonary trunk
pulmonary arteries
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Coronary arteries and veins
•
arteries bring
oxygen and nutrients to
the
cells
• Coronary veins
the blood from the
muscular tissue of the
into the
atrium
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Heart Beat
•
•
•
•
•
•
•
SA (sinoatrial) node is
in the
upper dorsal wall of the right atrium
AV (atrioventricular) node is located n the
base of the right atrium
The SA node
a heartbeat
every 0.85 seconds, causing the atria
(when full of blood) to contract
By the time this signal reaches the AV
node, the delay allows the atria to finish
its
and then allows the
ventricles to begin their contraction via AV
bundle and
fibres.
Atrioventricular bundle (AV bundle or
bundle of HIS) and the Purkinje Fibres
consist of
cardiac muscle
fibres that help the
to contract
bundle runs down the
septum
Purkinje fibres spread through the
ventricular
(tissue)
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Heart Beat
• The cardiac control center is located in the
via the autonomic nervous system.
• The nervous system has two divisions:
–
–
(in the brain)
division - decreases rate during rest
division - increases rate by during exercise or stress
• When our bodies are active or under stress, the sympathetic division
increases the
and
nodal activity via hormones such
as epinephrine and norepinephrine
• As a result, our heart beat is stronger and faster
The heart contains nervous tissue
(modified myocardial tissue) which
make up the
and
nodes
in the heart
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Heart Beat
1. diastole: ventricles relaxed
– initially,
relaxed, atrioventricular valves open, and
valves
closed
– sinoatrial (SA) node in right atrium
impulse, which stimulates contraction of
both atria
– when impulse reaches junction between
atrium &
ventricle,
atrioventricular (AV) node stimulated
2. systole: ventricles contract
– atria begin to and atrioventricular valves begin to
– impulse travels through Purkinje fibres, which
& semi–lunar valves open
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contraction of both
Blood Pressure
• Is the measure of blood against the wall
of a blood vessel
• Systolic pressure is the
arterial pressure reached when blood is
pushed out of the heart
– Systole = contraction of
• Diastolic pressure
force
exerted on artery between
(occurs when the ventricles are relaxed)
– Diastole = relaxation of ventricles
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Blood Pressure
arterial pressure measured with a
on arm
• recorded with systolic pressure
“
” diastolic pressure in
(millimetres of mercury)
• normal blood pressure range of
brachial artery is typically
90/60 to
/
mmHg
Ms. Ghtaura
Abnormal Conditions
1. hypotension: low blood pressure caused by
decreasing blood volume from:
–
– excessive
(exercise, diarrhea, or vomiting)
2. hypertension: high blood pressure caused by:
– increasing blood
(high salt intake)
– increasing rate of
flow (stress)
–
to blood flow (atherosclerosis)
Ms. Ghtaura