Transcript Chapter 16 - Cloudfront.net

Chapter 10
Circulation and Respiration
Cardiovascular System
• Components:
Heart
Blood vessels
Blood
• Blood is pumped away from the heart in
arteries
• Blood is pumped to the heart in veins
Components of Blood
• 55% of blood is plasma
• Plasma is the liquid part of blood and is mostly
water.
• Plasma is also made of proteins.
• There are three types of blood proteins:
1. Albumin – regulates the amount of water
in the blood
2. Globulins – antibodies
3. Fibrinogen – helps the blood clot
Components of Blood
•
•
•
•
Red Blood Cells (erythrocytes)
Red blood cells carry oxygen
RBCs have no nuclei
Their cytoplasm contains hemoglobin – a special
iron containing protein that unites with oxygen
• Anemia is a disorder resulting from too little
oxygen being carried by the blood.
• Sickle cell anemia is a disorder where the blood
is shaped incorrectly and therefore cannot carry
oxygen.
Components of Blood
• RBCs are produced in the bone marrow
• RBCs last about 120 days
• RBCs are stored in the spleen
Components of Blood
•
•
•
•
White Blood Cells (Leucocytes)
Produced in bone marrow
WBCs fight infections
If your blood has more than a normal
amount of white blood cells, you probably
have in infection
• In some cases it may be a sign of disease
like leukemia
Components of Blood
• Platelets are the blood clotters of the blood
• They cause the blood to clott and and
therefore “patch” a hole in the blood vessel
Blood Types
• Your immune system guards you against
invaders…
• Your body’s cells have “tags” that identify
them to your immune cells…
• This includes your blood cells…
• They have “tags” that scientists call
“types”…
Blood Types
• There are only 2 major “tags”
• They are called A and B
• A and B “tags” are referred to as
agglutinogens…due to the way they cause blood
cells to clump together if the wrong blood type is
present…
• A person with A type blood only has A “tags”…
• A person with B type blood only has B “tags”…
• A person with AB has A and B “tags”…
• A person with no agglutinogens has type O
blood…
Blood Types
• Anyone can receive type O blood because
it has no tags…
• Type O people are referred to as
“universal donors”
• Type AB people can receive donations
from anyone…
• Type AB people are referred to as
“universal acceptors”…
Blood Types
The Rh factor:
• Rh is another agglutinogen…
• Rh positive means the person has this
“tag”…
• Rh negative means the person does not…
The Heart
The Design of the Heart
External Features
•
•
•
•
Located in the center of your chest
About the size of your fist
Encased in a tough white sac – the pericardium
The pericardium membrane secretes a
lubricating fluid
• There are also arteries and veins extending from
the heart
The Heart
The Design of the Heart
Internal Features
•
•
•
•
•
•
Four hollow chambers
Two thin walled upper chambers – atria
Two thick walled lower chambers – ventricles
A thick vertical wall separates them – the septum
The atria push blood into the ventricles
The ventricles push blood out of the heart
The Heart
The Design of the Heart
Internal Features
• The walls of the heart have three layers:
1. Myocardium – contains the heart muscle
2. Endocardium – lines the interior of the heart
3. Epicardium – outer layer of slippery material
The Heart
The Design of the Heart
Internal Features
• Valves
Valves prevent blood from flowing the wrong
direction in the heart
• A-V Valves
control blood flow between the atria and ventricles
bicuspid (mitral valve) – left side
tricuspid – right side
called tri and bi to signify the number of cusps or
parts
The Heart
The Design of the Heart
Internal Features
• The semilunar valves
Keep the blood from coming back into the
ventricles
aortic semilunar – blood exits the left
ventricle to aorta (blood to body)
pulmonary semilunar – blood exits the right
ventricle to pulmonary artery (blood to lungs)
The Heart
Blood Flow of the Heart
• The role of the atria is to ensure the ventricles
are full of blood
• When full, the ventricles pump blood to the body
• The right side of the heart receives
deoxygenated blood – pumps it to the lungs
• The left side of the heart receives oxygenated
blood – pumps it to the body
The Heart
Blood Flow of the Heart
from the body to the right atrium and ventricle
• Blood returns from the body with little oxygen
• It returns to the heart through the venae cava –
the body’s largest vein
• The superior vena cava returns blood from the
upper body
• The inferior vena cava returns blood from the
lower body
The Heart
Blood Flow of the Heart
from the right ventricle to the lungs
• As soon as the right ventricle is fully inflated with
blood, it contracts
• The pressure closes the tricuspid valve and
opens the pulmonary semilunar valve
• The blood is then pumped out to the lungs to
receive oxygen and get rid of carbon dioxide
The Heart
Blood flow of the Heart
from the lungs to heart to body
• The oxygenated blood travels back to the heart through
four pulmonary veins (two for each lung)
• It enters the left atrium and then left ventricle inflating
them
• The left atrium contracts causing the left ventricle to fully
inflate and contract closing the bicuspid valve
• The blood is forced through the aortic semilunar valve
into the aorta – the body’s largest artery
• The blood is sent off to the body
Fueling the Heart
• The heart has two coronary arteries that
give the heart oxygen.
• The heart also has cardiac veins to carry
oxygen depleted away from the heart.
The Blood Vessels
There are three main kinds of blood vessels:
1. Arteries – carry blood away from the
heart
2. Veins – bring blood to the heart
3. Capillaries – link arteries and veins
The Blood Vessels
• The arteries branch and form smaller
blood vessels – arterioles
• Capillaries merge to form small blood
vessels – venules
Arteries
• The blood in arteries is under great
pressure
• Due to this, the walls of arteries are thicker
than the walls of veins
• Arteriole walls have three layers:
1. outer layer of fibrous connective tissue
2. middle layer of circular smooth muscle
3. inner layer of a smooth sheet of cells
Veins
• Veins are not as thick as arteries
• Even so, the layers of veins are the same
as arteries
• Veins have valves to keep blood from
flowing the wrong direction
Capillaries
• Capillaries are microscopic structures
• Some are so tiny, blood cells have to
squeeze through them
• The wall of a capillary is only one cell-layer
thick
• In capillaries is where gas exchange
occurs
Blood Circulation
The blood circulates through your body in
many ways:
1. Systemic Circulation
2. Pulmonary Circulation
3. Portal Circulation
4. Renal Circulation
Systemic Circulation
• Systemic Circulation is the circulation of the blood
through the body everywhere except the lungs.
• As blood leaves the heart it leaves through the aorta.
• The aorta branches into parts:
1. two carotid arteries – provide blood to the head and
brain
2. two subclavian arteries – provide blood to the rest of
the arms
3. two common iliac arteries – the branch of the aorta as
it approaches the legs
4. femoral arteries – the arteries of the legs
Systemic Circulation
• The blood returns to the heart through
veins.
• Jugular vein from the head
• Subclavian vein from the arms
• Femoral vein from the legs
• Ultimately the blood enters the heart
through the vena cava
Pulmonary Circulation
• Pulmonary circulation is the blood flow
from the heart and back
Portal Circulation
• The movement of blood from the digestive
organs to the liver
• After passing through the liver the blood
returns to the heart
• Hepatic portal vein takes blood from the
digestive system to the liver
• Hepatic vein returns blood to the heart
Renal Circulation
• The movement of blood from the body
organs through the kidneys
• The renal artery branches from the aorta
to carry blood to the kidneys
• The blood is filtered in the kidneys
• The renal vein returns the blood to the
heart