Transcript Circulation and Immunity

Circulation and Immunity
1.1 The Heart
1.2 Blood Vessels
1.3 Blood
1.4 Cardiovascular Disease
1.5 The Immune System
1.1 The Heart
• The main functions of the circulatory
system are:
1. To transport gases, nutrients and waste
materials
2. To regulate internal temperature
3. To transport hormones
4. To protect against disease
1.1 The Heart
• Stroke volume is the volume of blood
pumped in one beat
• Cardiac output is the volume of blood
pumped in one minute
• CO = SV x HR
1.1 The Heart
• The heart is a set of two pumps
• The right side of the heart pumps blood to
the lungs and back to the heart (pulmonary
circulation)
• The left side of the heart pumps blood to
the body systems and back to the heart
(systemic circulation)
• Coronary circulation is blood flow to the
heart muscles
1.1 The Heart
• The heart beats due to electrical signals
that coordinate the contraction of the
chambers
1. Diastole occurs when the ventricles of
the heart are relaxed
2. Systole occurs when the ventricles of the
heart are contracted
1.1 The Heart
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Factors that influence heart rate include:
Physical activity
Emotions
External temperature
For healthy living, exercise should
attempt to attain a target heart rate
1.2 Blood Vessels
• The major arteries and veins make up the
pulmonary and systemic pathways
• Artery: thick-walled blood vessel that carries
blood away from the heart
• Vein: thin-walled blood vessel with valves that
carries blood toward the heart
• Capillary: tiny blood vessel that connects the
smallest branch of an artery (arteriole) to the
smallest branch of a vein (venule)
1.2 Blood Vessels
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Major blood vessels include:
Aorta
Vena Cavae
Pulmonary Arteries
Pulmonary Veins
Blood pressure is the pressure exerted by
blood against the walls of blood vessels
1.2 Blood Vessels
• Blood pressure is measured in units of
mmHg
• Blood pressure is measured as systolic
pressure over diastolic pressure
• In general, the pressure in arteries is
greatest and in veins is least
• Blood pressure is measured with a
sphygmomanometer
1.3 Blood
• Blood is a mixture of a fluid portion and a
formed portion
• The fluid portion is called plasma and makes
up 55% of blood volume
• The formed portion is made up of cells
1. Red blood cells (erythrocytes): small cells
filled with hemoglobin to carry oxygen and
carbon dioxide
1.3 Blood
1. White blood cells (leucocytes): many types of
cells that respond to disease
2. Platelets (thrombocytes): cell fragments that
control blood clotting
1.4 Cardiovascular Disease
• Cardiovascular disease is the leading cause of
death in Canada
• Arteriosclerosis is hardening of the arteries
• Arteriosclerosis can lead to heart attacks,
strokes and embolisms
• Arteriosclerosis can be treated by medication,
angioplasty or coronary bypass
1.4 Cardiovascular Disease
• Cardiovascular disease is linked to
consumption of fats and cholesterol
• LDL cholesterol: increases risk of
cardiovascular disease
• HDL cholesterol: decreases risk of
cardiovascular disease
• Certain fats can raise or lower LDL and HDL
cholesterol
1.4 Cardiovascular Disease
• Certain fatty acids are essential including
omega-3 and omega-6
• Tradition Inuit diet is rich in omega-3 fatty
acids
• Other cardiovascular diseases include
aneurysms, septal defects and valvular
diseases
1.5 The Immune System
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A pathogen is a disease causing agent
Your body defends against pathogens in the
following ways
Protective barrier
Sweat and oil secretions
Blood clotting
Various other secretions
White blood cells
1.5 The Immune System
• Pathogens may be food-borne, water-borne,
blood borne or air-borne
• Microscopic pathogens include
1. Bacteria
2. Protozoa
3. Fungi
4. Viruses
1.5 The Immune System
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The immune response to a viral infection
includes
Macrophages
Helper T Cells
Killer T Cells
Supressor T Cells
Memory Cells
Antibodies
B Cells
1.5 The Immune System
• Vaccines use the bodies natural immune
response to create immunity to infections
• Vaccines have significantly improved human
health globally
• Autoimmune diseases such as multiple
sclerosis, arthritis and lupus are the result of
the immune system attacking normal body
cells