Download Circulation and Immunity

Circulation and Immunity
QUESTIONS?
- color of blood
- what does the septum do?
- blood pressure
- path of blood flow
- why mmHg?
- ECG
- why oxygen poor blood?
- how big is the heart?
- Bundle of His, Purkinjie fibres
- bubbles in the blood?
- blood type?
- heart attack
- pacemaker
- heart transplant
- heart murmurs
- blood transfusion
- blood thinning
3 main roles of the circulatory system:
1. Transports gases,
nutrients, and waste
materials throughout
the body
2. Regulates internal
temperature and
distribution of
hormones
3. Protects the body
against disease
Major Components
Blood vessels
The heart
Blood
Part 1: The Heart
What do you notice?
Organization
o Composed of 4 chambers: two atria (top chambers) and
two ventricles (bottom chambers)
o Right atrium and ventricle handle deoxygenated blood
o Left atrium and ventricle handle oxygenated blood
1.Once depleted of oxygen,
blood returns to the right atrium
of the heart through the superior
and inferior vena cava
Path of blood flow through
the body:
2.Blood moves through the right
atrium to the right ventricle,
where it is then pumped out of
the heart via pulmonary arteries
to the lungs. Here, CO2 will be
exchanged for O2.
3.Oxygenated blood travels back
to the heart where it enters the
left atrium through pulmonary
veins.
4.Blood flows into the left
ventricle and is pumped out of
the heart via the aorta, where it
then travels to other areas of the
body.
http://www.youtube.com/watch?
v=Rj_qD0SEGGk
Other important characteristics
o Valves ensure that blood flows only in one direction
o What if you had a “leaky” valve?
Other important characteristics
o Left and right atria/ventricles are separated by a wall of
tissue known as the septum
o Why is the muscle surrounding the left ventricle so much
thicker than the muscle surrounding the right ventricle?
Other important characteristics
In general, arteries contain
oxygenated blood, while
veins contain deoxygenated
blood. However, there are
two exceptions…
o The pulmonary arteries
carry deoxygenated
blood (from the right
ventricle to the lungs)
o The pulmonary veins carry
oxygenated blood (from
the lungs to the left
atrium)
The Beating Heart
Although heart rate is mediated by the
nervous system, the stimulus that triggers the
heart beat is located within the heart itself…
The Beating Heart
Which component is most likely
dysfunctional if someone is in need of
a pacemaker?
http://www.youtube.com/watch?v=SMXBR_YFocs
An electrocardiogram (ECG) can be used to
record the electrical activity of the heart:
o P = contraction of atria
o QRS = contraction of ventricles
o T = recovery of ventricles
* Note: Because ventricular recovery occurs at the same time as
atrial recovery, recovery of the atria cannot be detected
If this represents a normal ECG…
Then what is happening within the heart to cause this?
What would the ECG of a person
who is exercising look like?
Part 2: Blood Vessels
Arteries
o Carry oxygenated blood
away from the heart
o Highly elastic walls to keep
blood flowing in right
direction (allows arteries
to contract)
o Composed of three layers
o Part of the systemic
pathway, which is
responsible for
transporting oxygen-rich
blood to body tissues
Veins
o Carry deoxygenated
blood back to the heart
o Thin, rigid walls (do not
contract on their own)
o One-way valves
(important to counteract
the force of gravity)
o Composed of three layers
o Part of the pulmonary
pathway, which is
responsible for
transporting oxygen-poor
blood to the lungs
Varicose veins occur when the leaflets of valves fail to
close properly, causing blood to flow backwards and
pool in the veins
Common in veins of the legs…
WHY?
Capillaries
o Connect arteries and
veins to tissues
o Composed of a
single layer of cells
o Much smaller and
more widespread
than arteries and
veins
What supplies the muscle tissue of the heart with oxygen?
The coronary pathway
Oxygen and nutrients are delivered to the heart through
capillaries embedded directly in the heart wall. These capillaries
are supplied by two small arteries that branch off of the aorta.
Deoxygenated blood is carried away in coronary veins.
Blood pressure is the pressure exerted against
vessel walls as blood is transported throughout
the body
o Maximum pressure during
ventricular contraction =
systolic pressure
o Minimum pressure before
ventricular contraction =
diastolic pressure
o Normal blood pressure is
120/80 (systolic/diastolic)
Cardiac output is the amount of blood pumped by
the heart per unit of time
o Used to indicate extent of oxygen delivery to tissues
o Affected by heart rate (beats per minute) and stroke
volume (amount of blood forced out of the heart with
each beat)
What are some variables that might affect
heart rate???
Caffeine?
Exercise?
Lifestyle?
Anxiety?
Temperature?
Illness?
Dehydration?
Music?
Fear?
Cardiovascular Disorders
Arteriosclerosis
o Hardening of the arteries due
to a buildup of plaque
o Caused by lack of exercise,
smoking, and/or a diet high
in fat
o Leads to decreased blood
flow and increased blood
pressure
o Symptoms include chest
pain, blood clots, shortness of
breath, and heart failure
Treatments:
Aspirin
o Prevents platelets from sticking together, reducing the
formation of blood clots
Angioplasty
o Surgical procedure wherein a tube is inserted into a
clogged artery and inflated, forcing the artery to open
Treatments:
Coronary Bypass
o Segment of a healthy
artery/vein is used to
create a new pathway
from the aorta to an
unblocked portion of
the blood vessel,
thereby “bypassing” the
blocked segment
o What does a “double”
or “triple” bypass refer
to?
Cardiovascular Disorders
Congenital Heart Defects
o Structural defects present from
birth. May be genetic, or due to
drug/alcohol use during
pregnancy.
o Examples:
• Valve defects (leaky valve
leads to heart murmur)
• Septal defects (hole in
septum leads to mixing of
oxygenated and
deoxygenated blood)
MRI scan can be used to visualize the defect so
surgeons can determine a plan of action
Heart disease is the leading
cause of death in women. Why?
Heart attack symptoms
in women:
o Neck, shoulder, upper
back or abdominal
discomfort- often
triggered by stress or
anxiety. More likely to
occur during rest.
o Shortness of breath
o Nausea or vomiting
o Sweating
o Light-headedness or
dizziness
o Unusual fatigue
Heart attack symptoms
in men:
o Intense chest pain or
pressure that may
extend to arms- often
triggered by physical
activity. Tends to go
away with rest.
o Shortness of breath
o Cold sweat
o Pain in left arm
Part 3: Blood
Consists of two elements
1. Fluid portion
o plasma
2. Solid portion
o red blood cells
o white blood cells
o platelets
Plasma:
Plasma consists of water, dissolved gases,
proteins, sugars, vitamins, minerals, hormones,
and waste products. Plays a role in the transport
of carbon dioxide.
Red Blood Cells
(Erythrocytes):
Specialized for oxygen
transport
o lack of a nucleus allows
cells to carry
hemoglobin molecules
o hemoglobin is required
to bind oxygen
Sickle cell anemia
Genetic condition wherein red blood cells do not develop
properly. As a result, they can not bind hemoglobin, and are
unable to efficiently carry oxygen.
Symptoms?
White Blood Cells
(leucocytes):
Part of the immune response
o Contain a nucleus
o Double when your body is
fighting an infection
o Three categories:
1) Granulocytes
2) Monocytes
3) Lymphocytes
Leukemia
Cancer of the bone marrow (where white blood cells are
produced). Characterized by an abnormal increase in the
production of immature white blood cells, leukemia weakens the
immune system. It also prevents blood from clotting normally,
leading to frequent nosebleeds and bruising.
Platelets:
Play an important role
in blood clotting
o No nucleus
o Break down quickly
in the blood
Stages of blood clotting
1. Injured blood vessel releases chemical messengers
which attract platelets to the site
2. Collecting platelets rupture and release substances
that combine with other blood components to
produce an enzyme called thromboplastin
3. With the help of calcium ions, thromboplastin
reacts with prothrombin (a protein secreted by the
liver), producing thrombin
4. Thrombin reacts with fibrinogen (a protein found
within the plasma) to produce fibrin
5. Fibrin strands act as a sort of mesh, preventing
blood cells from escaping and forming a clot
Hemophilia
A hereditary disease that results from insufficient clotting
proteins in the blood. This increases the risk of bleeding to
death upon injury.
How might hemophilia be treated?
Functions of the Blood
1. Transport (nutrients, wastes, hormones)
2. Homeostatic Regulation (temperature)
o Blood coming to the skin from
the body’s interior is usually
warmer than the skin itself.
Through the process of
diffusion, heat is lost from the
body as more blood passes by
the skin. The greater the heat
gradient, the faster heat is lost
through the body surface.
The nervous system can therefore control the loss of heat by
adjusting the amount of blood that flows by the skin’s surface…
Vasoconstriction and vasodilation are also
influenced by…
Blood Pressure
o High blood pressure can be
reduced through vasodilation
o Low blood pressure can be
increased through
vasoconstriction
Exercise
o Vasodilation increases blood
flow to tissues
Alcohol and nicotine
o Promotes vasodilation
Review:
In groups of two, create a Jeopardy-style
questionnaire to review the circulatory system up to
this point (www.jeopardylabs.com)
This should include all three sections we have covered
(the heart, the blood vessels, and the blood)
Once complete, hand in the link to your review game.
You will be marked according to:
1. Appropriateness of categories (5)
2. Questions cover a range of knowledge (5)
3. Questions are sufficiently complex (5)
4. Answers provided are correct (5)
More review:
jeopardylabs.com/play/the-circulatory-system116
The blood (specifically, white blood cells) also
plays an important role in immunity. However, the
blood does not work alone in this regard…
The lymphatic system acts in conjunction
with the circulatory system to protect the
body against infection
Immunity
The lymphatic system
o A network of vessels and nodes
closely associated with the
capillaries of the cardiovascular
system
o Vessels collect a fluid called
lymph, which is similar to the
composition of blood plasma
(“interstitial fluid”)
o Lymph helps to maintain the
balance of fluids in the body,
bathing cells in interstitial fluid as
it mixes with general blood
circulation.
Immunity
The Lymphatic System
o Lymph nodes are where white blood cells mature; they also contain
macrophages (a type of white blood cell that traps and destroys
bacteria).
o Infections often lead to an increase in the number of macrophages.
As a result, lymph glands may swell when you are sick.
Immunity
First line of defence:
Stomach acid
skin
cilia
Eyelashes & tears
Physical and chemical barriers of the body
Immunity
Second line of defence:
Non-specific defences (“cell-mediated immunity”)
White blood cells such as macrophages,
neutrophils, and monocytes destroy harmful
bacterial through a process known as
phagocytosis:
http://www.youtube.com/watch?v=ygkvXT1BmaA
Immunity
Third line of defence:
Specific defences (“antibody-mediated immunity”)
Antibodies are proteins that recognize the
antigens displayed by foreign particles and
trigger a series of events to quickly neutralize or
destroy them...
o Antibodies specific to
different pathogens are
generated after white
blood cells destroy said
pathogens through
phagocytosis
o Over time, exposure to
various foreign substances
leads to the development
of an immune system
unique to each individual.
Antibody-Mediated Immunity:
http://www.youtube.com/watch?v=hQmaPwP0KRI