Download Blood and Lymph - Biology R: 4(A,C)

Blood and Lymph

Imagine an intruder in your home. What
are your first reactions? Think for a
second… What do you think you would do
now? What does your body do when there
is an intruder? Relate to functions of white
blood cells. This is only one function of
blood…
What do you think this is a picture
of? Use knowledge of biology to
justify your answer.
What is blood?


The circulatory system carries blood through a series of
blood vessels to different parts of the body.
Blood is connective tissue containing dissolved
substances and specialized cells.
– Oxygen from lungs
– Nutrients from digestive tract
– Wastes from tissues

Blood helps regulate body’s internal environment.
– Body temperature
– Fight infection
– Clots to repair damaged blood vessels
Figure 37-7 Blood
Section
37-2
Plasma
Platelets
White blood
cells
Red blood cells
Whole Blood Sample
Sample Placed in Centrifuge
Blood Sample That
Has Been
Centrifuged
Components of Blood
Blood plasma
 Red blood cells (RBC)
 White blood cells (WBC)
 Platelets

Blood Volume Activity

Calculate your blood volume and volume
of each component.

Human body contains 4-6 liters of blood =
8% of total mass of body
– 45% consists of cells (RBC, WBC & platelets)
– 55% is straw-colored fluid = plasma
Blood Plasma
Structure: 90% water and 10% plasma proteins
(dissolved gases, salts, nutrients, enzymes,
hormones, waste products and proteins)
 Functions: transport substances, regulate
osmotic pressure and blood volume, fight viral
and bacterial infections and gives blood the
ability to clot

Red blood cells
Also known as erythrocytes
 Most numerous cells in blood
 Disk shaped and thinner in center than edges
 Transport oxygen
 Red from hemoglobin = iron-containing protein that
binds to oxygen in the lungs and transports it to tissues
throughout the body where oxygen is released
 Produced from cells in red bone marrow, as they fill with
hemoglobin, organelles are forced out (no nuclei)
 Circulate for 120 days before they are worn out from
squeezing through capillaries and they are destroyed in
liver and spleen

White blood cells
Also known as leukocytes
1 WBC : 700 RBC
 Produced in red bone marrow, but released into blood
with nuclei and no hemoglobin
 Some live for months, most live only a few days
 The “army” of the circulatory system, because attack
foreign substances or organisms (cancer cells, allergic
reactions, transplanted organs)
 Called “phagocytes” because they “eat” and digest
foreign cells
 Increase number of white cells when body is fighting an
infection
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Different types of WBC
Neutrophils
 Eoxinophils
 Basophils
 Monocytes
 Lymphocytes
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Cell Type
Function
Neutrophils
Engulf and destroy small bacteria and foreign substances
Eosinophils
Attack parasites; limit inflammation associated with allergic reactions
Basophils
Release histamines that cause inflammation; release anticoagulants, which prevent blood clots
Monocytes
Give rise to leukocytes that engulf and destroy large bacteria and substances
Lymphocytes
Some destroy foreign cells by causing their membranes to rupture; some develop into cells that
produce antibodies, which target specific foreign substances
Platelets
Blood clotting and healing are made possible by
plasma proteins and cell fragments = platelets
 Produced from large cells in bone marrow that
break into thousands of small pieces and
wrapped in a piece of cell membrane
 When platelets contact broken blood vessels
(wound), their surface becomes sticky and
platelets cluster releasing clotting factors, which
start a series of chemical reactions creating a
sticky tangle of fibrin fibers = scab

Figure 37-10 Blood Clotting
Section
37-2
Break in Capillary Wall
Clumping of Platelets
Clot Forms
Blood vessels injured.
Platelets clump at the site
and release thromboplastin.
Thromboplastin converts
prothrombin into thrombin..
Thrombin converts
fibrinogen into fibrin, which
causes a clot. The clot
prevents further loss of
blood..
Figure 14-4 Blood Groups
Section 14-1
Blood types and Transfusions worksheet: use
the information below to check your answers
Phenotype
(Blood Type
Go to
Section:
Genotype
Antigen on
Red Blood Cell
Safe Transfusions
To
From
One major problem…
As blood circulates, some fluid leaks from
the blood into surrounding body tissues,
which is required to move nutrients and
other substances from the blood into body
tissues
 More than 3 liters of fluid leak everyday!
 If this went unchecked, your body would
swell with fluid – YUCK!
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The Lymphatic system
A network of vessels called the lymphatic
system collects the fluid that leaks from
the blood and returns it to the circulatory
system
 Collection occurs in vessels
 The collected fluid = lymph

Figure 37-12 The Lymphatic System
Section
37-2
Superior
vena cava
Thymus
Heart
Thoracic
duct
Spleen
Lymph
nodes
Lymph
vessels
Lymph and Ducts
Lymph is collected in lymphatic capillaries
and flows into larger vessel containing
valves to prevent lymph from flowing
backwards
 Ducts collect the lymph and return it to
the circulatory system through two
openings in the superior vena cava just
below your shoulders (clavicles)
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Lymph Nodes
Small bean-shaped enlargements along the
vessels
 Filter lymph by trapping bacteria and other
microorganisms that cause disease
 Nodes become enlarged when large numbers of
microorganisms are collected = “swollen glands”
 Contain specialized white blood cells called
lymphocytes = protect the body from infection

Lymph Vessels
Return lymph fluid to circulatory system
 Also absorb nutrients from digestive tract
(fats and vitamins – A, D, E & K) and carry
them to the blood

Edema
Lymph moves through the lymphatic
system under osmotic pressure from blood
and contractions of skeletal muscles
 Edema = swelling of tissue due to
accumulation of excess fluid when
lymphatic vessels are blocked due to
injury or disease
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