Transcript Circulation and Respiration

Circulatory
System
Circulatory System
 A system made up of three parts:
 Heart
 Blood vessels
 Blood
 Transport nutrients and gases to
different parts of the body where they
can be used by the cells
 Transport waste for removal along
with excretory system
Types of Blood Vessels
 Artery: a muscular blood vessel that carries
blood away from the heart.

Arteriole: a small arterial branch that delivers blood
directly to a capillary bed.
 Vein: one of the blood vessels that
carries blood to the heart.
 Venule : a small venous branch that carries blood
from a capillary bed to a vein.
 Capillary: the smallest blood vessel that
allows oxygen to be exchanged.
Components of Blood
Components of Blood
 Plasma- fluid part of
blood
 White blood cellsdestroy bacteria and
viruses
 Platelets- made from
bone marrow and
repair damaged areas
of your body
 Red Blood Cellsoxygen carries
Structures of the heart
The Heart
 Two sides separated by a thick wall
 Each side has an atrium and a ventricle
 Atrium: receives blood entering the heart
 Ventricle: pumps blood from the heart to the
rest of the body
 One way valves (their closing makes your
heartbeat)
 A double pump
 Right side = pumps blood to the lungs
 Left side = pumps blood to the rest of the
body
Regulation of Heart Beat
 Heart beat varies from person to
person…why?
 Pacemaker- located in the right
atrium, this group of cells regulate
the rate at which the cardiac muscles
contract (SA Node)
 Brain Stem regulates heart rate, but
pacemaker works independently
• Sinoatrial node is
located in the wall of
the right atrium, near
the junction of the
atrium and the superior
vena cava.
• contracts on its own
about 72 times per
minute.
• The “pacemaker” of the
heart because it
contracts the most in a
minute and because
cardiac muscle cells are
connected to each other
by intercalated discs
•Atrioventricular node.
•When the SA node initiates
a contraction, Purkinje
fibers rapidly conduct the
impulse to another site
near the bottom of the
right atrium and near the
center of the heart. This
region is the AV node, and
slows the impulse briefly.
Purkinje fibers
(conduct impulses 5x
more rapidly than
surrounding cells)
form a pathway for
conduction of the
impulse that ensures
that the heart muscle
cells contract in the
most efficient pattern.
• With the AV node
holding up the impulse
just enough to let the
atria finish their
contraction before the
ventricles begin to
contract, blood can fill
the ventricles.
And, since the Purkinje
fibers have carried the
impulse to the apex of
the ventricles first, the
contraction proceeds
from the bottom of the
ventricles to the top
where the blood leaves
the ventricles through
the pulmonary arteries
and the aorta.
• The impulse then travels
to a large bundle of
Purkinje fibers called
the Bundle of His, where
they move quickly to
the septum that divides
the two ventricles.
The cardiac cycle
The contraction of the heart cause the distinctive sounds heard
when listening to the heart with a stethoscope. The "lubdub" sound is the sound of the valves in the heart closing.
When the atria end their contraction and the ventricles
begin to contract, the blood is forced back against the
valves between the atria and the ventricles, causing the
valves to close. This is the "lub" sound, and signals the
beginning of ventricular contraction , known as systole.
The "dub" is the sound of the valves closing between the
ventricles and their arteries, and signals the beginning of
ventricular relaxation, known as diastole.
https://www.youtube.com/watch?v=GbttJ-5do9M
Pulmonary and Systemic Circulations
 Pulmonary Circulation: the pathway
that blood follows from the heart to
the lungs (right side of the heart)
 Systemic Circulation: the route that
blood travels from the heart to most
of the body and then back to the
heart (left side of the heart)
The Pulmonary and Systemic Circuits
Systemic Circuit
Pulmonary Circuit
 Left side of the heart
 Right side of the heart
 Larger in size (must pump
blood to the rest of the body)
 Smaller in size (only
pumps blood to the
lungs)
 blood leaves through the aorta,
goes to all the organs of the
body through the systemic
arteries, and then returns to
the heart through the systemic
veins
 blood leaves the heart
through the pulmonary
arteries, goes to the
lungs, and returns to
the heart through the
pulmonary veins.
"When it leaves the right, it comes right back, but when it leaves the left, it has
left for good."
How does the heart get blood?
 Coronary arteries
 arise from the aorta right after it leaves the
heart.
 branch into capillary beds that course
throughout the heart walls and supply the heart
muscle with oxygenated blood.
 Coronary Veins
 return blood from the heart muscle,
 empty directly into the right atrium.
Flow of blood through the body
Right ventricle  pulmonary arteries 
Lungs  pulmonary veins  left atrium
 left ventricle  aorta  arteries 
capillaries  veins  vena cavas 
right atrium  right ventricle
http://www.naturalhealthschool.com/im
g/heart.gif
Blood Types
 Blood type- classification based on
whether certain proteins are present
on the surface of the red blood cells.
 Types A, B, O, or AB
 If different blood types are mixed,
RBC’s will clump together
 RH Factor- determines a blood type is
in a blood group (positive or
negative)
How is your blood type determined?
 Each biological parent donates one of their two ABO
alleles to their child.


A mother who is blood type O can only pass an O allele
A father who is blood type AB could pass either an A or a B allele

This couple could have children of either blood type A (O from mother and A
from father) or blood type B (O from mother and B from father).
Remember the father has a greater genetic influence than the mother!
Rh+ = Rh+/Rh+ or Rh+/RhRh-= Rh-/Rh Just like the ABO alleles, each biological parent
donates one of their two Rh alleles to their child.


A mother who is Rh- can only pass an Rh- allele
A father who is Rh+ could pass either an Rh+ or Rh- allele

This couple could have Rh+ children (Rh- from mother and Rh+ from father) or
Rh- children (Rh- from mother and Rh- from father).
Chances of having a specific
blood type:
Parent
1
AB
AB
AB
AB
B
A
A
O
O
O
Parent
2
AB
B
A
O
B
B
A
B
A
O
X
X
X
X
X
X
X
X
O
A
X
X
X
X
B
X
X
X
X
AB
X
X
X
X
X
X
X
X
Tutorial (class on Wednesday)
 http://www.biology.arizona.edu/hum
an_bio/problem_sets/blood_types/Int
ro.html
 GOOD RESOURCE:
http://sjesci.wikispaces.com/He
art+and+Lungs