Download Unit 5 Human Body Systems * Part 1

Unit 6 - Circulatory
and Immune Systems
Circulatory System Key
Questions
1. What is the function of the circulatory
system?
2. How do necessary molecules enter the
circulatory system and cells?
3. What are the parts and functions of the
circulatory system?
Human Circulatory System
Made of 3 key parts:
• 1. A system of blood vessels
• 2. A heart
• 3. Blood
Human Circulatory System
Types of Blood Vessels
1. Arteries
• Typically carry oxygenated blood AWAY from
the heart to the rest of the body.
• Thick-walled and elastic vessels that expand
and contract to accommodate the forceful
flow of blood (under great pressure)
Human Circulatory System
• Pulse =
feeling of rhythmic
contractions
caused by blood
flow through
arteries.
Human Circulatory System
• 2. Veins
• Return deoxygenated blood back to
the heart from all parts of the body
• Thin walled vessels that have
valves in them to prevent blood
from flowing backwards.
Human Circulatory System
• 3. Capillaries
• Tiny blood vessels that are thin
enough to allow for diffusion of
materials between cells and
capillaries
Human Circulatory System
•4. The Heart
A. Function of the heart – to
pump the blood
Human Heart
How the Heart Works
(3 min.)
https://www.youtube.co
m/watch?v=oHMmtqKgs
50
Human Circulatory System
• B. Characteristics:
• 4 chambered muscle that continually
pumps blood throughout the circulatory
system.
• Made of 2 different sides: one side
contains oxygenated blood (left), and one
side contains deoxygenated blood (right).
• Divided into 2 types of chambers: atria
and ventricles.
Blood Flow and Gravity!
• Experiment:
• Hold one hand high in the air.
• Hold your other hand down by your side
for one minute.
• Quickly compare your 2 hands – what
happened???
Human Circulatory System
• Label Heart Diagram and color the flow of
blood through heart
Blood
Human Circulatory System
• 5. Blood
A. Functions: Transports things
like nutrients, and wastes
throughout an organism.
Human Circulatory System
• b. Made of cells and plasma
Human Circulatory System
1. Plasma:
a. Made mostly of water (90%)
b. Where all materials are dissolved
and transported
Human Circulatory System
• 2. Cells include: red blood cells
(RBC’s), white blood cells (WBC’s),
and platelets
Human Circulatory System
Red blood cells - Function
• Transport oxygen throughout
body
FYI – Blood Typing
• There are 4 blood types in humans:
• A, B, AB, and O
• Due to presence or absence of
antigens (markers) on surface of
RBC’s
Human Circulatory System
• 4 major
blood
types:
• A, B,
AB, O
Statistics
• http://www.redcrossblood.org/learn-about-blood/bloodtypes
Human Circulatory System
Platelets – Function:
• Cause blood to clot
Blood clotting:
Platelet Ruptures
Releases Enzymes
Clotting Begins
Human Circulatory System
• White blood cells - function
• Fight off pathogens
Video-2:23
https://www.youtube.co
m/watch?v=CRh_dAzXuo
U
Heart Rate During Exercise
• Why does your heart rate increase
during exercise???
• To deliver more nutrients to cells and take
away wastes
When Things Go Wrong:
Circulatory System
1. Sickle Cell Anemia
• Hereditary disease where red blood cells form an abnormal
crescent shape.
• Deliver less oxygen to cells than normal rbc’s.
• Causes extreme pain
• No Cure
2. Hemophilia
• Inherited rare bleeding
disorder where blood
does not clot properly
• Decreased amount of or
missing clotting factor
• No cure. Treatment
includes injections of
clotting factors
3. Leukemia
• Cancer of the blood-forming tissues and lymphatic system.
• Usually starts with white blood cells, so the immune system has a
lessened ability to fight off infection
• Treatment varies depending on type
4. High Blood Pressure
• Also called hypertension
• When pressure is 140/90
or greater.
• Left untreated, can
weaken walls of vessels
5. Heart Attack
• When the coronary
arteries become
blocked
• Can’t provide
nutrients to heart
tissue
• Leads to tissue death
6. Heart Valve Replacements
• Valve Replacements
7. Pacemakers
• Small device
placed in the
chest or
abdomen to
help control
abnormal heart
rhythms.
• Uses electrical
pulses to get the
heart to beat at
a normal rate
8. Artificial Heart/New Tech
• Artificial Heart
• Mimics a real human heart
• Requires external power system
energizes and regulates the pump
through a system of compressed air
hoses that enter the heart through the
chest.
• Since the system is cumbersome and
open to infection, the use of an
artificial heart is meant to be
temporary.
9. Stents
• Open up blocked vessels
Yellow – plaque
Red = blood flow
The Immune System
Key Questions
1. What are pathogens, and how do they affect
living things?
2. What are the functions of the immune system,
and how does it protect humans?
3. What is active and passive immunity?
4. What are antibodies, and how do they protect
us?
5. What are vaccines, and how do they protect
us?
The Immune System
• Part 1: Define Pathogen:
• Viruses, bacteria, and other
microorganisms that cause disease.
Pathogens are found in food, air, water
everywhere!
‘Where Germs Really Thrive’
• Question:
• Which surface holds more germs, the top of a
desk or the toilet seat?
‘Where Germs Really Thrive’
• Answer: The top of a desk has 400 times more bacteria
than the average toilet seat!
• Info:
• Computer keyboards have more germs than door
handles.
• Other high-germ areas:
• Bathroom sinks
• Clean laundry (if not washed in hot water)
• Phones
The Immune System
Part 2. Defense systems against
pathogens:
a. First Line Defenses:
• Skin, sweat, mucus, tears, stomach
acid, etc.
The Immune System
b. Second Line Defenses:
• Kicks in if pathogen gets past the 1st
line
• Results in swelling, redness, warmth
• Attracts special WBC’s to come and
ingest pathogens (non-specific).
Phagocytosis
Video Clip on server: WBC Chasing Bacteria (30 sec.)
The Immune System
c. Third Line Defenses:
• The Immune System! (Specific)
• Put into action when 2nd line did not work!
The Immune System
• 1. Define Immunity: When the body
is able to fight off infection.
The Immune System
Key terms:
a. Define Antigen:
• A marker on a cell that can cause an
immune response.
• Identifies it as being foreign
Antigen
The Immune System
C. Define Antibody:
• Specific proteins created by WBC’s that
bind to antigens to help destroy
pathogens.
• Immunity results from the production of
antibodies specific to a given antigen.
• Video Clip on server: Virus Invades Your Body (3:27)
The Immune System
• Organisms acquire immunity in
following ways:
• 1. Active Immunity: When body
produces its own antibodies to
attack a particular antigen. Occurs
in response to either:
The Immune System
1. Get infected and recover.
* For example: When a person is infected
with the chicken pox virus for the 1st time,
the body develops antibodies against the
organism. The antibodies then remain in
the blood and protects the individual from
infection by that same organism again.
The Immune System
2. Get a Vaccine
• A. Define vaccine = injection with a solution that
contains dead or weakened pathogens.
• Causes body to make antibodies
• Organisms in vaccine are too weak to cause an
infection.
• Booster shots – given to “boost up” levels of
antibodies in body.
The Immune System
2. Passive Immunity:
• Do not make own antibodies
• Temporary immunity
• Examples: antibiotics, mom to baby
Question:
1. Why can we get some illnesses again, like
the ‘flu’ if we’ve already had it?
• Some pathogens have a high mutation
rate.
• Our body would see the mutated
pathogen as something new and it would
have to make new specific antibodies.
History and Influenza
• 1918 Flu Virus – ‘Spanish Flu’
• Deadliest epidemic in history
• Killed 50 million people worldwide
• Killed mostly young, strong, healthy adults
• Immune systems were over-stimulated
• Different from most flu viruses – infects cells deep
in the lungs
• Lungs filled with fluid
http://www.pbs.org/wgbh/nova/body/1918-flu.html
(12 min.)
The Immune System
2. Allergies
a. When the immune system over
responds to allergens (things that are
not harmful like dust)
b. Results in runny nose, itchy eyes,
swollen throat
The Immune System
3. Transplanted Organs
a. Immune system reacts to foreign
antigens by producing antibodies to
fight off new organ
b. Recipient needs to take medication
forever to decrease immune
response
The Immune System
4. HIV and AIDS
a. HIV is the virus that can lead to the
development of AIDS (Acquired Immune
Deficiency Syndrome)
b. HIV needs a host cell in order to reproduce
and make more copies of itself
c. HIV destroys specific white blood cells in the
immune system which decreases the ability
to fight off infection
This is an electron microscope image of
HIV. The small, green spheres are the HIV
virus on the surface of white blood cells.
• d. HIV is transmitted through bodily fluids
• Sexually through semen and vaginal secretions
• Through contact with blood and breast milk (IV
drug use)
FYI
• When a person is first exposed to HIV, their body
produces antibodies against the virus and can
keep it under control for years.
• During these years, the virus is at constant battle
with the immune system. The body tries to get
rid of the virus, but is only able to keep it under
control.
The nature of hiv
• After several years, the immune system starts to
lose its battle against HIV.
• Then, after an average of 10 years of fighting HIV,
if the person is not taking HIV treatment, the
immune system starts to weaken. This is when
full-blown AIDS begins.
Symptoms of Advancing HIV
• Chronic yeast infections or thrush (yeast infection of the
mouth) Fever and/or night sweats Easy bruising Bouts of
extreme exhaustion Unexplained body rashes Appearance
of purplish lesions on the skin or inside mouth Sudden
unexplained weight loss Chronic diarrhea lasting for a month
or more
Preventing infection
• To prevent the spread of HIV, you must prevent contact with
an infected person by:
• Abstaining from sex
• Not using IV drugs
• Not using any drugs/alcohol since they impair your judgment
• Using latex condoms during any sexual contact
• Being in a relationship with only one person and knowing their
status
Testing
• There are several tests that can be used to determine if a
person has HIV:
• The most common – HIV antibody test (ELISA)
• Tests for body’s production of antibodies in
response to HIV
Treatment
• There is no cure for HIV/AIDS. The complexity of HIV has
made it difficult to treat.
• HIV is a ‘retro-virus’ – it uses RNA as its genetic
material instead of DNA
• It has a high mutation rate (changes in genetic
material)
treatment
• Current treatment:
• Using antiretroviral drugs to keep the amount of HIV in
the body at a low level.
• These drugs need to be taken every day for the rest of
the person’s life.