Transcript modules/groups/homepagefiles/gwp/1537126/4759570/File/33_2x

Lesson Overview
Blood and the Lymphatic System
Objectives 33.2
Blood & Lymph
-Explain the functions of blood
plasma, red blood cells, white blood
cells, and platelets.
-Describe the role of the lymphatic
system.
-List three common circulatory
diseases.
- Describe the connection between
cholesterol and circulatory disease.
Lesson Overview
Blood and the Lymphatic System
vocab
Word
Denition
Plasma
Straw-colored liquid portion of the blood
Red blood cell
Blood cell containing hemoglobin
Hemoglobin
Iron-containing protein in read blood cells that binds oxygen and
transports it to the body
White blood cell
Type of blood cell that guards against infection, fights parasites,
and attacks bacteria
Platelet
Cell fragment released by bone marrow that helps in blood
clotting
Lymph
Fluid that is filtered out of the blood
Atherosclerosis
Condition in which fatty deposits called plaque build up inside
artery walls and eventually cause the arteries to stiffen
Lesson Overview
Blood and the Lymphatic System
Plasma
The human body contains 4-6 liters of blood. About 55 percent of total
blood volume is plasma.
Plasma is about 90% water and 10% dissolved gases, salts, nutrients,
and waste products.
The water in plasma helps to control body temperature.
Lesson Overview
Blood and the Lymphatic System
Red Blood Cells
The most numerous cells in blood are red blood cells (RBCs), or
erythrocytes. The main function of red blood cells is to transport
oxygen. Red blood cells get their color from the iron in hemoglobin.
Red blood cells circulate for an average of 120 days before they are
destroyed in the liver and spleen.
Lesson Overview
Blood and the Lymphatic System
White Blood Cells
White blood cells (WBCs), or leukocytes, guard against infection,
fight parasites, viruses and bacteria.
The body can increase the number of active WBCs dramatically when
it is fighting an infection. In a healthy person, WBCs are outnumbered
by RBCs by almost 1000:1.
Lesson Overview
Blood and the Lymphatic System
Platelets
Blood clotting is made possible
by cell fragments called
platelets.
When platelets come in contact
with the edges of a broken blood
vessel, their surface becomes
sticky and they cluster around
the wound, forming a clot.
The clot seals the damaged
area and prevents further blood
loss.
Lesson Overview
Blood and the Lymphatic System
The Lymphatic System
As blood passes through capillaries,
some move through capillary walls and
into the fluid between cells.
Most of this fluid, lymph, is
reabsorbed into capillaries. The rest
goes into the lymphatic system, where
it is “screened” for microorganisms,
and returns it to the circulatory system.
Lesson Overview
Blood and the Lymphatic System
Circulatory System Diseases
Diseases of the circulatory system can progress for many years before
they are discovered.
Tissues in the heart and brain begin to die within moments if their oxygen
supply is interrupted.
Individuals with high blood pressure are at an increased risk for both heart
disease and stroke.
Lesson Overview
Blood and the Lymphatic System
Atherosclerosis
Atherosclerosis is a condition in which fatty deposits called plaques
build up in artery walls and eventually cause the arteries to stiffen.
Eventually, the heart can be weakened or damaged by oxygen
deprivation, leading to a heart attack.
Lesson Overview
Blood and the Lymphatic System
Stroke
The sudden death of brain cells when their blood supply is interrupted is
called a stroke.
Some strokes are caused by a blood clot that blocks a blood vessel in
the brain. A stroke can also occur if a weak blood vessel breaks and
causes bleeding in the brain.
Lesson Overview
Blood and the Lymphatic System
High Blood Pressure
High blood pressure, or hypertension, is usually defined as a reading
of 140/90+.
Lesson Overview
Blood and the Lymphatic System
Cholesterol
Cholesterol is a lipid that is part of animal cell membranes. It is used to
make hormones, bile and vitamin D.
There are two types of cholesterol —low-density lipoprotein (LDL) and
high-density lipoprotein (HDL).
LDL is the cholesterol carrier that is most likely to cause trouble in the
circulatory system because it becomes part of plaque.
HDL, often called “good” cholesterol, generally transports excess
cholesterol from tissues and arteries to the liver for removal from the
body.