Transcript Circulatory System_Teacher

Circulatory System
Arteries, Veins, Capillaries,
the Heart, Vessels
The Circulatory System and
You...
• Blood accounts for approx 7% body weight and totals
approx 6 liters in volume
– That’s about 5 soda bottles OR a little over a gallon of
milk
• The circulatory system can be divided into three
branches
– pulmonary circulation (feeding the lungs)
– coronary circulation (feeding the heart)
– systemic circulation (feeding the remaining tissue)
Arteries
vs. Veins
Arteries have muscular walls
that squeeze the blood along
Veins have little muscle
to squeeze blood along,
and rely on our skeletal
muscles to do so.
Artery vs. Vein Comparison
Arteries:
Veins:
1. Muscular walls
2. No valves
3. Squeeze blood
along
4. Carry blood away
from the heart
1. Little muscle
2. Need one way valves to
prevent backflow
3. Rely on skeletal muscle
movement to carry
blood along
4. Carry blood to heart
blood
Blood Flowing through an Artery is
Squeezed Along
Blood Flowing through a Vein
• Backflow is stopped by one way valves
Flow occurs in this Direction only
Varicose Veins
• Occur when the valves tire and pooling of blood
occurs
• Happens most often in lower body
• Very painful disorder
bilateral varicosis with
megaplasia of long
saphenous vein and
insufficiency of
femoral vein.
Capillaries
• Extremely narrow and thin, and
leaky
– 5mm-10mm in diameter
– 0.5mm wall thickness
• Composed of thin cells
• Transfer oxygen and food to
tissues
• Remove wastes, CO2
• Arterial  Venuous
Blood
Blood
Human Cardiovascular System
The heart is located in the thoracic cavity between the lungs. It is
surrounded by a protective pericardium—a double-walled sac
with fluid between the two layers.
Circulation
Overview
Overview of
Blood Flow
Right Side of the Heart
– the Pulmonary Circuit
1. Lungs exchange CO2 and O2
2. Right side of heart is smaller
A. Pumps blood to lungs via
Pulmonary Artery
B. Capillaries in alveoli
supply oxygen
C. Blood goes back to the
heart via the Pulmonary
Vein
3. The only time you will ever see
tired blood in arteries is when it is
traveling to the lungs
4. The only time you’ll ever see
oxygenated blood in veins is in
the Pulmonary vein, because it
carries the blood to the heart (as
veins do) to be pumped to the rest
of the body.
The Left Side of the Heart – The
Systemic Circuit
Left side of heart is BIGGER
A. Pumps blood to BODY out of
the aorta, up to the head or
down to the lower body
B. Oxygen rich blood rushes to
the body
C. Arteries carry blood away from
the heart.
The Heart is a Double Pump
Superior
Vena Cava
Right
Atrium
Tricuspid
Valve
Right
Ventricle
Inferior
Vena Cava
Pulmonary
Valve
Pulmonary
Arteries
Pulmonary
Vein
Left Atrium
Bicuspid
Valve
Aortic
Valve
Left
Ventricle
Another Animated View – Watch Carefully!
Check out the Atrioventricular Valve (tricuspid)
Doing its Job Preventing Backflow between the
Right Ventricle and Atrium
Heart Attacks
Occur because of
coronary blockage due
to cholesterol
blockages which
obstruct blood flow to
the heart itself
Click the heart to see an
animation --------->
4 Root Cause of Heart Attacks
1. Heredity – the liver cranks out
cholesterol, and there are two types:
A. LDL – low density – bad, creates blockages
B. HDL – high density – good, scrubs our tubes 
2. Lack of regular exercise
3. Unhealthy, high-fat diets
4. Generally being a couch potato does not help

Arterial Blockage 1-0-1
Blood Flowing through an Artery is
Squeezed Along
Blood Pressure
• Healthy reading is 120 over 80,
but what does this mean?
Systolic Pressure
• 120 mm of Hg is the minimum
pressure the blood exerts to
push blood through the artery of
the arm, when cuffed
Diastolic Pressure
• 80mm of Hg is the residual or
left over pressure after the blood
surge went through
Solutions to Blood Pressure
• Reduce the volume of water in
the blood
• Water is attracted to salt, so
reduce salt intake
• Exercise to shed excess water
• Eat healthier
• Record pressure regularly
• Medication needed in extreme
cases
Cardiac cycle
• With each beat of the heart:
– systole-contraction of the heart
– diastole-relaxation of the heart
• Electrocardiogram
– recorded with electrodes on surface of the chest
– P wave – depolarization (squeezing) of atria
– QRS complex-depolarization (squeezing) of
ventricles
– T wave-repolarization (recharging) of ventricles
Flash Animation of this Whole Process
Components of Blood
Erythrocytes make up about 99% of the cells in the blood.
Components of Blood
Whole Blood
Plasma
Formed Elements
(46-63%)
(37-54%)
1. Water (92%)
1. Red Blood Cells (99.9%)
2. Plasma Proteins (7%)
2. Platelets
3. Other Solutes (1%)
3. White Blood Cells
(0.1%)
Functions of Blood
• Transportation of dissolved
gases, nutrients, hormones, and
metabolic wastes
• Regulation of the pH and
electrolyte throughout the body
• Restriction of fluid losses
• Defense against toxins and
pathogens
• Stabilize of body temperature
These red blood cells function
in oxygen transport
Blood and
Transportation
• Red blood cells are packed
with the protein hemoglobin
(Hb) which carries O2
• CO2 is carried by Hb, and
dissolved in plasma in multiple
ways
• Nutrients absorbed at the GI tract, or released by the liver or
adipocytes, are distributed by blood
• Hormones (blood-borne chemical messengers) are transported
from glands to their target organs via the bloodstream
• Metabolic wastes produced by cells are absorbed by the blood
and carried to the kidneys for excretion
Blood & Protection
• Blood transports white blood
cells, specialized cells that
migrate into tissues to fight
infections and remove debris.
• Blood delivers antibodies,
proteins that attack invading
organisms and foreign
compounds.
• Blood contains enzymes that
respond to a break in a blood
vessel wall by forming a clot to
restrict further fluid loss.
Above, we have a SEM image of
a blood clot. Notice the RBCs.
Transports, organic and inorganic
molecules, formed elements, and heat
Water (92%)
Albumins (60%): Contribute to plasma
osmotic pressure; Transport lipids,
steroid hormones
Plasma
Plasma
Proteins (7%)
Globulins (35%): Transport ions,
hormones, lipids; Immune function
Fibrinogen (4%): Essential component
of clotting system
Other Solutes (1%)
Regulatory Proteins (<1%): Enzymes, Hormones
Electrolytes: Ions necessary for vital cellular activity. Contribute to
osmotic pressure of body fluids. Major electrolytes are Na+,K+,
Ca2+, Mg2+, Cl-, HCO3-, HPO42-, SO42Organic Nutrients: Used for ATP production, cell growth and
maintenance; Includes lipids, carbohydrates, and amino acids
Organic Wastes: Carried to sites of breakdown or excretion; Includes urea, uric
acid, creatinine, bilirubin, and ammonium ions
Red Blood Cells
(Erythrocytes)
• Most abundant blood
cells (99.9% of formed
elements)
– In ♂, 1µL of blood contains
4.5-6.3 million RBCs
– In ♀, 1µL of blood contains
4.2-5.5 million RBCs
• Contains the red pigment
hemoglobin which binds
and transports O2 and
CO2
• Each RBC is a biconcave
disc
Diameter → 8µm
Thickness → 2.5µm
Interesting Facts about RBC’s
• Increased RBC production when O2 decreases
- high altitude training
• Lack nucleus to carry more O2
• Life span of 120 days
• Broken down in liver (bilirubin into bile…)
Hemoglobin
• Each chain contains a
single molecule of
heme, an iron-containing
pigment
– The iron ion in heme is able to
reversibly bind an oxygen molecule.
– Meaning, O2 can bind to Hb at the
lungs and then be released at the
tissues
• Based on the above, how
many molecules of O2 can
each Hb protein bind?
RBC Disorders
1. Anemia
•
•
Fe (Iron) deficiency
Pale apperance, and some weakness
2. Pernicous Anemia
•
•
Will cause low vitamin B12 absorption
RBC’s will not grow up / mature
Hemophilia
• hereditary bleeding disorders
• Hemophilia A
– Most common type (83%)
– X-linked
• Hemophilia B
– Less common.
– Also X-linked
What symptoms do
you suppose are
characteristic of
hemophiliacs?
Components of Blood – Platelets,
The Blood Clotters that stop Bleeding
WBC’s (Leukocytes)
•
Larger than RBC’s
•
•
Have nucleus – often multilobed
Less numerous (under 0.1% of
blood volume)
•
Types are based on presence or
absence of granules in their
cytoplasm.
1. GRANULAR
2. AGRANULAR
Components of Blood
Granular Leukocytes
•
•
•
Granules in cytoplasm
Multi-lobed nucleus (polymorphonuclear) 
Types Include
1. Neutrophils
» Specialize in attacking and digesting bacteria
that have been “marked” for destruction
2. Eosinophils
» phagocytize antibody-coated bacteria, protozoa,
and cellular debris
3. Basophils – the allergy causers
» migrate to injury sites and discharge the contents
of their granules – histamine (a vasodilator)
Agranular Leukocytes
•
•
No granules
The Explorers of the immune system
1.
Lymphocytes (B&T)
» Continuously migrate from the bloodstream thru
peripheral tissues and back into the bloodstream
» T cells: defend against foreign cells and tissues
and coordinate the immune response
» B cells: produce and distribute antibodies that
attack foreign materials
2.
Monocytes – the largest WBC’s
» Becomes a MACROPHAGE in tissue and
WBCs in order of abundance:
Never (neutrophils
Let (lymphocytes)
Monkeys (monocytes)
Eat (eosinophils)
Bananas (basophils)
How do I remember the
relative percentages?
60 + 30 + 6 + 3 +1
(i.e., 60% neutrophils, 30%
lymphocytes, 6% monocytes, 3%
eosinophils & 1% basophils)
WBC Disorders
Leukemia
• a form of cancer characterized by uncontrollable
production of abnormal WBC’s
• WBC’s will attack tissues and RBC’s
Mononucleosis
• Caused by the Epstein Barr virus
• Signs of mono include fever, sore throat, headaches,
white patches on the back of your throat,
swollen glands in your neck,
feeling tired and not feeling
hungry
WBC Disorders
AIDS
• HIV decreases the T-Cell Count
• Attacking T-Cells is like turning off the master switch to
the immune system. It’s scouts cannot react and
summon the armies of WBC’s to do battle
• As a result, infections and disease follow
Cool Flash Movie --- >
HIV Infection Rates Globally
1990-1999
Platelet Functions
• Clot formation
• Clot is a temporary patch
(platelet plug) in the walls of
damaged blood vessels.
This Presentation Brought to you
Couresy of the Hart Foundation