The Blood & Lymphatic

System

Composition of Blood

Red Blood Cells

White Blood Cells

Platelets

Red Blood Cells (aka erythrocytes)

Structure

Do not have a nucleus

Contain specialized proteins called

hemoglobin

Hemoglobin contains iron which

facilitates the transport of oxygen and

carbon dioxide

How healthy are your RBCs?

Perform a Complete Blood Count or Full Blood

Count

Take different measurements and compare them to the

rest of the hematocrit

Mean Corpuscular Volume (MCV): measures the

average volume of cytoplasm in a RBC

Red Blood Cells

Mean Corpuscular Hemoglobin (MCH): measures

the mass of hemoglobin in each RBC

Red Blood Cells

Mean Corpuscular Hemoglobin Concentration

(MCHC): measures the concentration of

hemoglobin in an average RBC; look at intensity

of the red color.

Red Blood Cells

Blood Type

Different blood types exist because there are

different proteins on the blood cells called

agglutinogens; can be classified as either A, B, and

D.

ABO Blood Group System classifies people with

varying proteins (A or B) on their red blood cells

Red Blood Cells

Blood Type

Type A has the A protein on the blood cell; also have B

antibodies

Red Blood Cells

Blood Type

Type B has the B protein on the blood cell; also have A

antibodies

Red Blood Cells

Blood Type

Type AB has both A and B protein on the blood cell; has

not antibodies

Red Blood Cells

Blood Type

Type O has neither the A or B protein on the blood cell;

have both A & B antibodies

Red Blood Cells

The D protein is called the Rh factor (or Rhesus

factor)

Rh-positive people HAVE the D protein on their blood

cells

Rh-negative people DO NOT HAVE the D protein on

their blood cells

Red Blood Cells

Successful blood transfusions depend on the

combination from donor to recipient.

Example: Recipient with blood type A can only receive

blood from a donor that is either blood type A or type

O. If they don’t, the blood will agglutinate, or clump

up together! Here’s why:

Red Blood Cells

Donor:

Type B

Recipient

So… the recipient’s immune system attacks the “foreign blood”!

It might be possible for a mother’s immune system

to attack her baby’s blood because of the

incompatible Rh factor. This is called

erythroblastosis fetalis.

Can be prevented with a drug called Rhogam

Red Blood Cells

It might be possible for a mother’s immune system

to attack her baby’s blood because of the

incompatible Rh factor. This is called

erythroblastosis fetalis.

Can be prevented with a drug called Rhogam

Red Blood Cells

It might be possible for a mother’s immune system

to attack her baby’s blood because of the

incompatible Rh factor. This is called

erythroblastosis fetalis.

Can be prevented with a drug called Rhogam

Red Blood Cells

It might be possible for a mother’s immune system

to attack her baby’s blood because of the

incompatible Rh factor. This is called

erythroblastosis fetalis.

Can be prevented with a drug called Rhogam

Red Blood Cells

It might be possible for a mother’s immune system

to attack her baby’s blood because of the

incompatible Rh factor. This is called

erythroblastosis fetalis.

Can be prevented with a drug called Rhogam

Red Blood Cells

Function: carry oxygen throughout the body

This is possible because of hemoglobin which can carry

up to 4 O2 molecules at a time.

The oxygen-carrying efficiency of hemoglobin is

measured as percent saturation. Depending on the

pressure, hemoglobin will keep or release its oxygen.

Red Blood Cells

Partial pressure (mmHg)

Percent

Saturation

(Greater the

number, the

better

hemoglobin is

at getting O2)

Maternal hemoglobin

Fetal hemoglobin

Llama hemoglobin

White Blood Cells (aka leukocytes)

Granulocytes (polymorphonuclear WBCs): contain

granules of toxic chemicals that are released to kill

microorganisms and regulate reactions to foreign

materials in the body.

Neutrophils (40-70%): most common type of

white blood cell; secrete antibiotics and eat the

remains of bacteria and damaged cells

antibiotic: chemical that harms or kills bacteria

White Blood Cells (aka leukocytes)

Eosinophils (5%): produce secretions that defend

against large parasitic organisms in the body;

contain a toxin called major basic protein that

harms/kills parasites

White Blood Cells

Basophils (0.5%): secrete histamine, which is

involved in stimulating the immune response

White Blood Cells

Basophils (0.5%): secrete histamine, which is

involved in stimulating the immune response

Allergies cause an overproduction of histamine leading

to a runny nose, sneezing, and watery eyes.

White Blood Cells

Basophils (0.5%): secrete histamine, which is

involved in stimulating the immune response

Allergies cause an overproduction of histamine leading

to a runny nose, sneezing, and watery eyes.

Type of basophil called a mast cell releases chemicals

that start the immune response; cause inflammation

(swelling and redness) of tissues

White Blood Cells

Agranulocytes (mononuclear WBCs): lack

granules

Monocytes (1-5%): develop into two types of

macrophages

White Blood Cells

Agranulocytes (mononuclear WBCs): lack

granules

Monocytes (1-5%): develop into two types of

macrophages

Circulating monocytes: detect infectious agents (called

pathogens) traveling through in the blood; also

involved in bone growth and maintenance

Tissue monocytes: remove dead cells and attack

microorganisms that are more difficult to kill like fungi

White Blood Cells

Lymphocytes (20-50%): present in the blood and lymphatic

system

White Blood Cells

Lymphocytes (20-50%): present in the blood and lymphatic

system

B lymphocytes: assists with the immune response by making

antibodies; produced and mature in the bone marrow

T lymphocytes: responsible for stimulating the immune

response and killing infected cells; produced in the bone

marrow and mature in the thymus gland

White Blood Cells

What are they?

Not true cells, but are cell fragments that come

from larger cells called megakaryocytes

Covered with many proteins that allow the

platelets to stick to a variety of materials

Stickiness helps to reduce blood flow to a damaged

area during injuries that break the blood vessels

Platelets (aka thrombocytes)

Blood Clotting process; generally a two-

step process

Platelets adhere to an injured area

Activation of the clot formation

When blood vessels are intact, they produce

prostacyclin which prevents platelet activation.

Platelets

blood vessel

clot

Platelets

Clotting Cascade: a reaction that occurs

when there is damage to a blood vessel or

body tissue

Damaged tissue releases various tissue

components into the blood

Collagen and clotting factors alert other parts of

the body that there is damaged tissue

Platelets adhere to the damaged tissue and to

each other

Platelets

Prothrombin (secreted by platelets) is converted

into thrombin

Thrombin catalyzes the reaction to convert

fibrinogen into fibrin

Platelets

Fibrin forms a sticky, meshwork that forms a

temporary barrier. This prevents blood loss and

possible passage of pathogens into damaged

tissue

Calcium helps make fibrin sticky

Vitamin K is needed for the synthesis of all the clotting

factors

The scab is what eventually forms

platelets

fibrin

white blood cell

red blood cell

Platelets

Since clots are temporary structures, and

scabs don’t last forever, healthy cells near

the clot release Tissue Plasminogen

Activator (TPA).

Initiates the conversion of plasminogen into

plasmin, which digests fibrin and thereby

dissolves the clot; reduces damage to

cardiovascular diseases caused by blood clots.

Lympatic System: Structures

Lymphatic vessels:

thin ducts that carry

a clear fluid called

lymph; drain excess

fluids that

accumulates in

tissues which

prevents edema

Lympatic System: Structures

Lymph removes bacteria and foreign materials

from cells; transports fat from the digestive

system; moves mature lymphocytes to the blood

Lymph flow comes from gravity or movement of

skeletal muscles

Lymphatic System: Structures

lymphatic trunks: division of the lymphatic

vessels; drain lymph from larger areas of the

body; has collections of small regions of

lymphatic tissue

tonsils: lymphoid tissue found in the throat

Peyer’s Patches: lymphoid tissue found in the digestive

system

Lymphatic System: Structures

lymph nodes (lymph glands): eliminate antigens from

the lymph; have 4 components

Lymphatic System: Structures

blood vessels: enter and exit the lymph

node through the hilum

lymphatic sinuses: fluid-filled sack

Lymphatic System: Structures

filler tissue (stroma): divided into regions by walls

in the capsule called trabeculae

lymphocytes: B and T lymphocytes are found in

the stroma; help with the immune response

Lymphatic System: Structures

Lymph Glands:

spleen: located in the upper left region of the

abdomen near the stomach; divided into two

regions

Lymphatic System: Structures

Lymph Glands:

spleen: located in the upper left region of the

abdomen near the stomach; divided into two

regions

red pulp: storage area for red blood cells; responsible

for removing old or damaged RBCs from the

circulations

white pulp: contain B-lymphocytes and T-lymphocytes

Lymphatic System: Structures

Thymus: produces secretions that mature the

T-lymphocytes; this is where the T cells are

“educated” so that they don’t attack the

body. This is called “self-tolerance”.

Immune Response

Immune Response: triggered by the presence

of a foreign antigen

Innate Immunity: aka nonspecific immunity; uses

barriers that block a variety of infections to

protect the body

Physical Barriers: block virtually all kinds of

pathogens

Skin: blocks microorganisms from entering tissues;

constant shedding removes microbes; skin secretions

prevent microbes from overgrowing

Mucous membranes: catch incoming pathogens before

they can enter the bloodstream

Immune Response

Chemical Barriers: saliva, tears, stomach acids,

etc.

Fever: increasing the body temperature prevents

growth of microbes

Interferons: a group of proteins that “interfere”

and prevent viruses from multiplying in the cells

Immune Response

Acquired Immunity: occurs when the body

adapts to specific infections; it’s like the body

learns about the “invader” and kills it as

effectively as possible.

Immune Response

Macrophages engulf (eat) the invaders and

present the antigen on its surface

A helper T-cell attaches to the macrophage and

receives information. The helper T-cell activates

B cells and other T cells and the immune system

responds in 2 ways:

Immune Response

Cell-mediated immunity: the T cells that are

activated seek out infected cells and kill them

Immune Response

Humoral immunity: the B cells that are activated

divide into plasma cells (make lots of antibodies)

and memory cells (stores information about the

pathogen and initiates a faster immune response

the second time around)

Inflammatory Response

Inflammatory Response: an intentional

action that increases blood circulation to

an affected area

Causes swelling, redness, warmth, or pain in

the area of immune response

Immunization & Vaccination

Natural immunity: fighting the disease the

old-fashioned way (getting sick and fighting it

yourself)

Artificial immunity: faking out your immune

system to prepare it for a real attack;

example: vaccines

Immunization & Vaccination

Immunity against a disease

can be acquired through

active or passive immunity

Active: exposing antigens to

your immune system cells;

either naturally or artificially

Passive: when the antibodies

are basically given to you;

example would be breast milk

Anemia

Hemophilia

Leukemia

Cancer of bone marrow

Hodgkins Lymphoma

Lymphedema

Build up of fluids

Elephantiasis

Some autoimmune diseases