Transcript Transport & Circulation

Transport & Circulation
Griffin Van, Catherine Vernon, & Brandon
George
Transport in Invertebrates
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Certain invertebrates have a thin body wall which
makes it unnecessary for a circulatory system to
exist, which includes but is not limited to (sponges,
cnidarians, and flatworms).
Cells are either part of an external layer or line the
gastro-vascular cavity.
Each cell is exposed to water and can
independently exchange gases and rid its self of
wastes.
Invertebrates with a
Circulatory System
Most animals have a circulatory system that
serves the needs of the cells.
 The circulatory system transports oxygen and
nutrients, such as glucose and amino acids, to
the cells.
 There are two type of circulatory fluids
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› Blood: which is always contained in blood vessels
› Hemolymph: flows into a body cavity called a
hemocoel, (a hemolymph is a mixture of blood
and tissue fluid)
Open vs. Closed Circulatory
systems
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Open Circulatory Systems
› “The open circulatory system is common to
mollusks and arthropods. Open circulatory
systems (evolved in crustaceans, insects, mollusks
and other invertebrates) pump blood into a
hemocoel with the blood diffusing back to the
circulatory system between cells. Blood is
pumped by a heart into the body cavities, where
tissues are surrounded by the blood.”
› Hemolymph is only seen in animals with an open
circulatory system, which consists of blood vessels
and open spaces
Open vs. Closed Circulatory
Systems
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Closed Circulatory Systems
› “Vertebrates, and a few invertebrates, have
a closed circulatory system. Closed
circulatory systems have the blood closed at
all times within vessels of different size and
wall thickness. In this type of system, blood is
pumped by a heart through vessels, and
does not normally fill body cavities.”
Extra Credit
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Which of the following is a mixture of
blood and tissue fluid?
› A. ostia
› B. hemolymph
› C. gastro-vascular cavity
› D. hemocoel
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Transport in Vertebrates
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Cardiovascular system
– In all vertebrates
– Closed circulatory system
– Strong muscular heart in atria, receive blood and
muscular ventricles pump blood through the blood
vessels
– three types of blood vessels:
• arteries, carry blood away from heart
• capillaries, exchange materials with tissue fluid
• veins, return blood to the heart
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Evolution
– Fish have an inefficient one circuit pathway
because they have low blood pressure oxygen
leaves the gills.
• One atrium and one ventricles
• The ventricle pumps and sends blood to gills (gas
exchange)
• After passing through the gills it goes back to the dorsal
aorta and blood is pumped through out the body
• Veins return oxygen poor blood back to a sinus venosus
chamber that leads to the atrium and the atrium pumps
blood back to the ventricle
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Evolution cont.
– Most vertebrates have a two circuit system; that
has the systematic circuit (blood to lungs) and the
pulmonary circuit (blood to lungs). This is and
adaption to breathing air on land.
– In birds and mammals, the heart is in two halves.
Left and right, right pumps blood to the lungs and
the right is larger and pumps it to the rest of the
body. This is advantageous because the blood
pressure is in balance.
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Blood
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The functions of blood:
› 1) Transports gases, nutrients, waste products,
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and hormones throughout the body
2) Helps destroy pathogenic microorganisms
3)Distributes antibodies that are important in
immunity
4) Aids in maintaining water balance and PH
5) Helps regulate body temperature
6) Carries platelets and factors that ensure
clotting and prevent blood loss
(Mader, 606)
Composition of Blood in
Humans
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Two main Portions:
Plasma› Is about 93% water and
is then composed of
proteins, nutrients, salts
and wastes.
› It serves to hold the
blood cells in
suspension
› Each microliter (µL; or
mm³) of human blood
contains 5-6 million red
cells, and there are
about 25 trillion in the
body’s ≈5.6L of blood.
Blood: Plasma
› Protiens and salts serve to maintain the bloods
optimal PH of ≈7.4, any significant changes in this
PH could be catastrophic
› Additionally, salts and proteins uphold blood’s
osmotic pressure so that water has an automatic
tendency to enter blood capillaries
 As blood enters the capillary bed on the arteriole end,
the blood pressure in the capillary vessel is greater than
the osmotic pressure of the blood in the vessel. The net
result is that fluid moves from the vessel to the body tissue.
Plasma Cont.
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Plasma Proteins make up about 7%-8% of
plasma itself, they include but are not
limited to:
› Albumin- the most abundant plasma protein,
which transports bilirubin (a product that
results from the breakdown of hemoglobin)
› Regulatory Proteins- transport enzymes,
proenzymes ( the precursor to enzymes), and
hormones
› Globulins- ex: lipoproteins- which transport
cholesterol
Blood: Formed Elements
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Red Blood Cells (erythrocytes)
› The average human adult has about 25 trillion red
blood cells in their body
› In each of these cells there is about 250 million
hemoglobin molecules, hemoglobin is the iron
containing element of blood that transports
oxygen from the lungs to the rest of the body
› Red blood cells are continuously being
manufactured in the red bone marrow of the
skull, the ribs and the vertebrae.
› Erythroprotein, a hormone produced by the
kidneys serves to stimulate the production of red
blood cells
Blood: Formed Elements
White Blood Cells (Leukocytes)
 Differ from Red Blood cells in that they lack
hemoglobin, the component of blood that
gives it the color red, because of this White
Blood cells appear translucent under a
microscope. White blood cells spend most of
their time outside the circulatory system,
patrolling interstitial fluid and the lymphatic
system.
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› Types:
 Neutrophils- a type of white blood cell that
phagocytizes foreign material at the sight of
infection
Types of White Blood Cells
continued.
 Monocytes- are very similar to neutrophils:
however, they can become macrophages
(cells that digest pathogens and stimulate
lymphocytes) and can produce antigens(a
substance that signals the production of
antibodies (a Y-shaped protein that signals
other parts of the immune system to attack or
directly neutralizes the threat itself)
Types of White Blood Cells
continued.
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Lymphocytes- are white blood cells that
are divided into large and small
lymphocytes
› Small Lymphocytes: Include T and B cells
 T cells attack infected cells that contain viruses
 B cells contain a protein known as a B cell
Receptor, which allows the cell to bind with a
certain antigen
Esinophils- are white blood cells that are
essential in releasing enzymes that fight
parasites and destroy allergens
 Basophils- are the least common white
blood cells, they contain heparin (an
anticoagulant), and vasodilator histamine
which promotes blood flow to tissues
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Platelets: (thrombocytes)
Form as a result of the breaking up of
megakaryocytes found in red bone
marrow (cytokinetic fragmentation).
 About 200 billion are produced per day
 They are major components of blood
coagulation
 Third cellular component of blood, along
with erythrocytes and leukocytes.
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Blood Clotting
Platelets serve as a temporary seal for the
damaged part of the vessel.
 Platelets soon release a clotting factor known
as prothrombin activator which converts
prothrombin to thrombin
 Thrombin is an enzyme that creates two
amino acid chains from each fibrinogen
molecule. These fragments join end to end
and form fibrins.
 After blood vessel repair is initiated, the
enzyme plasmin, destroys the fibrin network
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Antibiotics
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Chemicals produced by microorganisms
that are used to fight or kill unwanted
organisms
› Penicilium-is a fungus that makes penicillin
which kills bacteria
ABO System
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There are four types of blood: A,B, AB,
and O.
Type AB blood is considered a universal
recipient
 Type O blood is considered a universal donor
 A person with A or B blood must receive blood
from either their own blood type, or O.
 If the wrong blood type is given to a recipient,
agglutination may occur which is the
clumping of the red blood cells
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Hemolytic Disease of the
Newborn (HDN)
Is a disease seen in newborn children
where anti RH antibodies cross a
placenta and destroy the babies red
blood cells.
 This disease can be fatal if immediate
blood transfusion does not occur
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AIDS
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Acquired immune deficiency is a syndrome
caused by HIV (Human immunodeficiency)
› Cause- HIV virus affects a certain lymphocyte
that plays a vital role in antibody production, this
weakens the immune system and causes the
body to be vulnerable to pathogens
› Transmission- HIV can only be transferred through
bodily fluids from an infected person, as the virus
is short lived and cannot break through the skin
› Cure- There is no cure; however, there are
medications that can help reduce HIV in the
body
Extra Credit
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Which type of blood cell fights infection?
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Least common white blood cell that is a
component of blood coagulation?
› A. basophil
› B. monocyte
› C. macrophage
› D. esinophil
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The Transport System
Types of circulatory systems
Some invertebrates have no circulatory
system.
 Many invertebrates have an open
circulatory system.
 Some invertebrates have a closed
circulatory system.
 All vertebrates have a closed circulatory
system.
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Blood vessels in vertebrates
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Vertebrates have three main types of blood
vessels.
› Arteries, which carry blood away from the heart,
and typically carry oxygenated blood.
 Arteries are characterized by branching, forming
smaller arterioles
 Arterioles ultimately form microscopic capillaries
› Capillaries, which enable the actual exchange of
water and chemicals between the blood and the
tissues.
 Capillaries merge to form venules, and then veins
› Veins, which carry blood from the capillaries
back toward the heart.
Blood vessel wall
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Arteries and veins have three layers, but the
middle layer is thicker in the arteries than it is in
the veins:
› Tunica intima (thinnest layer): single layer of
simple squamous endothelial cells glued by a
polysaccharide intercellular matrix.
› Tunica media (thickest layer in arteries): circularly
arranged elastic fiber, connective tissue, and
polysaccharide substance, usually rich in vascular
smooth muscle (arteries).
› Tunica adventitia (thickest layer in veins): entirely
made of connective tissue and contains nerves
Structure
Blood vessels
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The thick walls of arteries and veins prevent passage
of materials; the walls of capillaries are so thin that
materials pass relatively easily.
Smooth muscle in the walls of arteries results in
vasoconstriction or vasodilatation, necessary to
maintain appropriate blood pressure and blood
supplies.
Vasoconstriction (narrowing of blood vessels): When
blood vessels constrict, the flow of blood is restricted or
decreased, thus, retaining body heat or
increasing vascular resistance.
Vasodilatation (widening of blood vessels): when
blood vessels dilate, the flow of blood is increased due
to a decrease in vascular resistance.
Each vertebrate class exhibits different
adaptations of the heart and circulation
The human heart
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The human heart is well adapted for pumping blood.
The heart is surrounded by the pericardium, a fluid
filled sac, composed of dense connective tissue.
The smooth, inside lining of the heart, the
endocardium, is composed of cardiac muscle fibers
and collagen fibers.
The middle layer of the heart muscle is called the
myocardium.
The interartial septum divides the atria; the
interventricular septum divides the ventricles.
Valves prevent backflow of blood.
Relative wall thickness in the
heart
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Left Ventricle: Very thick wall, since is has
to pump blood at a very high pressure to
the whole body.
Right Ventricle: Somewhat thick wall
because it has to pump blood at a high
pressure to the lungs.
Right atrium/ left atrium: Thin walls, as it
only has to pump blood to the ventricles.
Coronary Arteries
Coronary arteries supply heart muscle with oxygen and nutrients.
 The vessels that deliver oxygen-rich blood to the myocardium are
known as coronary arteries.
› Right coronary artery, left anterior descending coronary artery,
circumflex coronary artery, left main coronary artery
› These arteries, when healthy, are capable of auto-regulation
to maintain coronary blood flow at levels appropriate to the
needs of the heart muscle.
› The coronary arteries are the only source of blood supply to
the myocardium.
 The vessels that remove the deoxygenated blood from the heat
muscle are known as cardiac veins.
› Great cardiac vein, the middle cardiac vein, the small cardiac
vein, and the anterior cardiac vein
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Fun fact
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An average heart pumps 2.4 ounces (70
milliliters) per heartbeat. And, as we already
mentioned, an average heartbeat is 72 beats
per minute. Therefore an average heart
pumps 1.3 gallons (5 Liters) per minute. In
other words it pumps 1,900 gallons (7,200
Liters) per day, almost 700,000 gallons
(2,628,000 Liters) per year, or 48 million gallons
(184,086,000 liters) by the time someone is 70
years old. That's not bad for a 10-ounce
pump.
The human heart
The natural pacemaker of the heart is called the
sinoatrial node (SA node) and it is located in the
right atrium. The heart also contains specialized
fibers that conduct the electrical impulse from the
pacemaker to the rest of the heart.
 The heart rate is regulated by the nervous system,
with a normal human heart rate of about 72
beats/minute.
 Cardiac output varies with the body’s need.
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› Sympathetic nerves increase heart rate and increases
the force of contraction.
› The parasympathetic nerves do the opposite.
Nervous system and
circulation
The myogenic mechanism is
how arteries and arterioles react to an
increase or decrease of blood
pressure to keep the blood flow within
the blood vessel constant.
 Medulla oblongata (medulla) contains
the cardiac centers and deals with
autonomic, involuntary functions, such
as heart rate and blood pressure
(parasympathetic and sympathetic).
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Nervous system and
circulation
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Epinephrine (adrenaline) regulates heart rate and
blood vessel diameters.
› Component of fight-or-flight response of the
sympathetic nervous system.
› In the heart, epinephrine or adrenaline, increases
heart rate. Also, it allows for vasoconstriction
(narrowing of blood vessels) and vasodilatation
(widening of blood vessels).
 Vasoconstriction regulate the body and maintains mean
arterial pressure.
 Dilation decreases blood pressure and increase blood
flow in the body to tissues that need it the most. It is often
in response to lack of oxygen or other nutrients (can be
localized or systemic).
Everyone's pulse (average heart rate
per minute) changes as we age. Here
is a list of average pulse rates at
different ages:
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Newborn: 130 bpm
3 months: 140 bpm
6 months: 130 bpm
1 year: 120 bpm
2 years: 115 bpm
3 years: 100 bpm
4 years: 100 bpm
6 years: 100 bpm
8 years: 90 bpm
12 years: 85 bpm
adult: 60 - 100 bpm
P wave - coincides
with the spread of
electrical activity
over the atria and
the beginning of its
contraction.
QRS complex coincides with the
spread of electrical
activity over the
ventricles and the
beginning of its
contraction.
T wave - coincides
with the recovery
phase of the
ventricles.
EKG (electrocardiogram)
measures the heart’s electrical
waves.
Blood pressure
Blood pressure depends on blood flow
and resistance to blood flow.
 When cardiac output increases, blood
pressure increases.
 Blood pressure is highest in the arteries.
 Blood pressure is carefully regulated by
the parasympathetic nervous system.
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Pulmonary and systemic
circuits
The pulmonary circulation oxygenates the
blood.
 The systemic circulation delivers the
oxygenated blood to the tissues (arteries)
and returns deoxygenated blood back to
the heart (veins).
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› Blood leaves the left ventricle and flows into
the aorta
› Most of the blood supplies the tissues of the
body
› Veins return blood to the right side of the
heart
The lymphatic system and
circulation
The functions of the lymphatic system
include return of interstitial fluid to the
circulatory system, immunity, and the
absorption of lipids from the
gastrointestinal tract.
 The lymphatic system consists of
lymphatic vessels and lymph tissues.
 The lymphatic system plays an important
role in fluid homeostasis.
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Extra Credit
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The sinoatrial node is also known as the “...” of the heart?
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What is the progression of blood throughout the heart [four
chambers, in order]?
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The heart is surrounded by the __________ a fluid filled sac, composed
of dense connective tissue.
› A. Myocardium
› B. Septum
› C. Pericardium
› D. Endocardium
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Videos
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http://www.youtube.com/watch?v=9fxm
85Fy4sQ
Bibliography
Biology by: Sylvia S. Mader
 IB Study Guides: Biology by: Andrew Allott
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http://www2.gsu.edu/~bioasx/closeopen.ht
ml