Praxis Review for Science by nikeborome

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									 Principles of Biology
            By
  Frank H. Osborne, Ph. D.


Circulation and Transport
  Transport in Selected Organisms
Cytoplasmic streaming (cyclosis)
•Cytoplasmic streaming is a circulation of the
cytoplasm inside the cell. It is noticeable under
the microscope in plant cells.
•The cells of the leaf circulate their cytoplasm
pushing the chloroplasts along. It is possible to
see them move.
Cytoplasmic streaming (cyclosis)
  Transport in Selected Organisms
Transport in Vascular Plants
•Xylem transports water and minerals upward
from the roots.
•Phloem carries nutrients to all living cells in the
plant.
•Phloem can transport materials both upward
and downward.
Transport in Vascular Plants
  Transport in Selected Organisms
Circulation in the earthworm (closed system)
•The earthworm has five pairs of specialized
blood vessels on each side of the digestive system
near the mouth.
•The earthworm has a closed circulatory system
because the blood is always contained within
blood vessels.
  Transport in Selected Organisms
Circulation in the earthworm (closed system)
•As the 10 pumping blood vessels contract, they
push blood back toward the rear of the animal.
•The blood at the rear moves forward and is
circulated by the pumping vessels.
Earthworm
(closed system)
  Transport in Selected Organisms
Circulation in the grasshopper (open system)
•In the grasshopper, blood is pumped forward
through a main blood vessel known as the aorta.
•After it is pumped forward it passes through the
end of the blood vessel and into a large space
inside the body cavity known as a blood sinus.
 Transport in Selected Organisms
Circulation in the grasshopper (open system)
•The blood flows freely through the blood
sinus to the rear of the animal at which point
it is taken back into the blood vessel and
pumped forward again.
Transport in Selected Organisms
Circulation in the grasshopper (open system)
•This type of circulatory system is called an
open circulatory system because sometimes the
blood is not found within blood vessels. Most
molluscs and all arthropods have an open
circulatory system.
Grasshopper (open system)
      Human Circulatory System
The Heart
•The heart is a specialized pumping organ.
•Heart muscle can contract on its own.
Specialized pacemaker cells regulate the
contractions of the heart muscles. The pacemaker
cells produce electrical signals that cause the
heart muscles to contract.
•Systole is the contraction of the heart.
•Diastole is the relaxation period between heart
contractions.
The Heart
The Heart
      Human Circulatory System
The Heart
•Blood enters the heart through atria. The atria
contract and pump the blood into the ventricles.
Then the ventricles contract and pump the blood
out of the heart.
•The closing of the heart valves after the
contractions produces the heart sounds.
      Human Circulatory System
Arteriosclerosis and atherosclerosis
•Arteriosclerosis is a disease of old age. It is
characterized by a loss of elasticity of the arteries.
In older times it was known as "hardening of the
arteries."
•Atherosclerosis can occur at any age. It is
produced as a result of the closing of the lumens of
the arteries by buildup of cholesterol deposits and
calcification.
      Human Circulatory System
Blood vessels
•Blood is carried away from the heart by arteries.
They branch to form arterioles.
•Blood is carried toward the heart by venules.
These come together to form veins.
•Between arterioles and venules are the
capillaries. The capillaries are so small in
diameter that blood cells pass through in single
file.
Blood vessels
      Human Circulatory System
Arteries
•Blood is carried away from the heart by arteries.
•The pulmonary arteries carry blood from the
right ventricle of the heart to the lungs.
•The aorta leaves the left ventricle of the heart
and carries blood to the rest of the body. The
aorta is the largest blood vessel in the body.
Other arteries going to the body branch from it.
Human Circulatory System
Human Circulatory System
     Human Circulatory System
•Blood to and from the lungs is called the
PULMONARY CIRCULATION.
•Blood to and from the body is called the
SYSTEMIC CIRCULATION. This includes
all organs except the heart.
•Blood to and from heart muscle tissue is the
CORONARY CIRCULATION.
Pulmonary circulation
Systemic circulation
Coronary circulation
Major arteries
Artery           Target Organ
L/R Carotid      Brain
L/R Subclavian   Arms
L/R Renal        Kidneys
L/R Iliac        Legs
Mesenteric       Intestines
Hepatic          Liver
Coronary         Heart
Major arteries
      Human Circulatory System
Veins
•Veins carry blood back to the heart.
•Veins contain valves to prevent the
blood from flowing backward in them.
•The pulmonary veins leave the lungs and go to
the left atrium. All other veins enter the right
atrium through the inferior and superior venae
cavae with one exception, the hepatic portal vein.
     Human Circulatory System
Veins
•The hepatic portal vein carries blood from the
intestines to the liver. This enables the liver to
remove all of the nutrients from digestion before
the blood is sent to other parts of the body.
•The blood leaves the liver and returns to the
heart via the hepatic vein and the inferior vena
cava.
Major veins
Major veins
To superior vena cava   Origin
 Jugular                from brain
 Subclavian             from arms
To inferior vena cava
 Renal                  from kidneys
 Iliac                  from legs
 hepatic                from liver
Other: hepatic portal   from intestines to liver
Hepatic portal circulation
     Human Circulatory System
Blood
•Blood is a solution of plasma and cells.
•Plasma is 92% liquid and 8% solids.
•Plasma contains water, ions, proteins,
nitrogenous wastes (such as creatinine, urea and
uric acid), glucose, amino acids, cholesterol,
gases and hormones.
•Blood is slightly alkaline with a pH of 7.4.
      Human Circulatory System
Pathway of the blood
•Blood leaves the heart and travels to one or
more arteries that branch into smaller arteries
and finally into capillaries.
•Blood from the capillaries is collected in venules
that transfer it to veins that return it to the
heart.
      Human Circulatory System
Blood Pressure
•Blood pressure is the pressure required to close
off an artery. It depends upon whether or not
the heart is contracting.
•Systolic pressure is the pressure required to
close off an artery during systole, the contraction
of the heart.
•Diastolic pressure is the pressure required to
close off an artery during diastole, the relaxation
period between heart contractions.
                 Blood Cells
Red blood cells
•Red blood cells contain hemoglobin. Hemoglobin
carries O2 for the circulatory system.
•The red blood cells, which are called erythrocytes,
have many types of antigens on their surfaces. The
ABO system is the most widely known, followed by
the Rh system.
•These cells have no nuclei. They last about 90
days.
              Blood Cells
Red blood cells
                 Blood Cells
Red blood cells
•Sickle-cell anemia is a hereditary (genetic)
condition in which there is a slight alteration in
the amino acid sequence of the hemoglobin
protein. This alteration causes the erythrocytes
to sickle, or become flattened, when they are not
carrying oxygen.
Sickle-cell
                 Blood Cells
White blood cells
•There are five types of white blood cells, which
are also called leukocytes. The prefix "leuko-"
means lacking color or without color.
•These are the colorless blood cells. They are not
really white in color.
White blood cells
             Blood Cells
White blood cells
•There are two major groups of leukocytes
called the granular (polymorphonuclear)
leukocytes and the agranular (mononuclear)
leukocytes.
White blood cells
              Blood Cells
White blood cells: granular leukocytes
•The granular leukocytes have tiny spots or
granules visible when they are stained. They
are called polymorphonuclear ("poly" means
many, "morpho" refers to the shape or form)
because the nuclei of these cells take on many
shapes.
              Blood Cells
White blood cells: granular leukocytes
•The most numerous cells of this type are the
neutrophils. These cells are phagocytic and
move around the body looking for foreign
material to phagocytize.
              Blood Cells
White blood cells: agranular leukocytes
•The agranular leukocytes do not have visible
granules in their cytoplasm when they are
stained. They are also called mononuclear
because these cells each have a large,
prominent nucleus.
              Blood Cells
White blood cells: agranular leukocytes
•The lymphocytes are the cells that produce the
antibody molecules for the immune system.
The monocyte is a type of leukocyte that is
motile and phagocytic.
White blood cells
Granular (Polymorphonuclear) Leukocytes
  Neutrophils (60-70%)
  Eosinophils (1-3%)
  Basophils (0.3%)
Agranular (Mononuclear) Leukocytes
  Lymphocytes (20-35%)
  Monocytes (3%)
              How Blood Clots
•Formation of blood clots is important to prevent
blood from leaking out of the body due to
wounds or breaks in the capillaries.
•When blood clots form, it is the result of a series
of five steps. These steps involve platelets, which
are formed elements in the blood. Platelets are
not really blood cells per se, but they are not
blood proteins either.
             How Blood Clots
•The other materials involved are fibrinogen, a
protein that leads to formation of fibrin, the
clotting protein; and a series of blood proteins
called factors.
•Hemophilia is a disease characterized by a lack
of Factor VIII. In people with hemophilia, the
absence of Factor VIII prevents their blood from
clotting normally.
           The Immune System
•The blood cells in the immune system are
primarily the monocytes and the lymphocytes.
Both types are white blood cells of the agranular
category.
•Monocytes can behave like amoebas and move
out of the blood stream into the connective tissue
space. When they are in the connective tissue
space their name changes to macrophages.
       The Immune System
•The macrophages engulf and devour foreign
matter such as bacteria.
•Then they process the molecules of the
bacteria, thus initiating an immune
response.
       The Immune System
Types of lymphocytes: T-cells
•There are two types of lymphocytes involved
in the immune response. The T-lymphocytes
(T-cells) recognize the molecules that the
macrophages are carrying and make
antibodies against them.
        The Immune System
Types of lymphocytes: B-cells
•The second type of lymphocyte is the B-
lymphocyte (B-cell), which assists the T-cells
by making high concentrations of antibodies
against foreign molecules.
          The Immune System
•These antibodies are blood proteins that bind
and react with the foreign molecules (such as
bacterial surface proteins) and combat disease by
the bacteria.
•Sometimes the immune system
develops antibodies against your own
body tissues. This results in
autoimmune disease. Examples are
lupus, antithyroid, and ulcerative
colitis, non-Hodgkins lymphoma.
        The Immune System
•Human Immunodeficiency Virus (HIV) is a
virus that attacks the T-cells. Viruses are
different from bacteria in that they cannot
reproduce independently. They must invade a
host cell. In the case of HIV, the host cell is
the T-cell.
       The Immune System
•Acquired Immunodeficiency Syndrome (AIDS)
is a series of infections and other medical
problems that result in people with HIV virus
because their immune system does not
function properly due to HIV viral activity.
      The Lymphatic System
•The lymphatic system is a series of ducts in
the body. These ducts serve as collection
conduits for tissue fluid, which is otherwise
known as lymph.
•Tissue fluid is a liquid found in all body
spaces between the cells and surrounding body
structures and organs. These locations are
known as the connective tissue space.
Lymphatic
System
      The Lymphatic System
•The lymph ducts contain lymph nodes where
macrophages, T-cells and B-cells are ready to
respond to any bacteria or viruses they
encounter.
•The tissue fluid is eventually returned to the
bloodstream.
      The End


   Principles of Biology
Circulation and Transport

								
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