Download The Circulatory System

Frank Johnson
Andy Murillos
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Made up of 2 systems
 Cardiovascular System
 Lymphatic System
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Moves 2 Major Fluids
 Blood & Lymph
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Transports nutrients Gases,
Hormones, & Blood
 Fight disease
 Stabilize body temperature & pH
 Maintain Homeostasis
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Made up of
 Blood –Fluid in body that carries nutrients and
wastes to the parts of the body
 Blood Vessels –Carry blood to necessary sections
of body
 Heart –Major organ of Cardiovascular system;
pumps blood through blood vessels
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Pumps oxygenated blood to all tissues of the body
Divided into a left and right side and then into 4
chambers
 The left Atrium & Ventricle
 The right Atrium & Ventricle
It pumps about 5 quarts of blood a minute, and beats
around 100,000 times a day, or 35 million times a year
 Sits just left of center in your body, in the pericardial
cavity
 Covered in coronary arteries that supply it with
oxygenated blood.
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Left Ventricle of the Heart  Arteries  Body
Tissues  Veins  Right Atrium  Right
Ventricle  Lungs Pulmonary Veins  Left
Atrium
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The 4 valves control the blood flow by only
opening one way when pushed on. They each
open and close once per beat
There are 2 phases of a heartbeat
 Systole: The contraction phase
▪ Ventricles contract forcing blood into your body tissues
and lungs. Tricuspid and Mitral valves open
 Diastole: The relaxation phase
▪ Ventricles relax, and fill up with blood from the upper
chambers (left & right atria). Pulmonary and Aortic
valves open
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Electrical signals continuously tell the heart to beat. The time
between the start of one heartbeat and the next is called a cardiac
cycle.
 Atrial stystole: small amount of blood goes into relaxed ventricles
 Atrial Diastole: Atria rest
 Ventricular systole (1st) : Pressure in ventricles forces tricuspid and mitral
valves closed, but cannot force open pulmonary and aortic
 Ventricular systole (2nd) : Aortic and Pulmonary finally open and blood is
forced through them.
 Early Ventricular Diastole: Ventricles relax, pressure drops, and blood
flows against tricuspid and mitral valves
 Late Ventricular Diastole: All chambers are relaxed and the ventricles fill
back up passively as tricuspid and mitral valves reopen (also called cardiac
diastole)
Atrial Systole
through Ventricular
Systole 1st
Ventricular Systole 2nd
Early and Late Ventricular
Diastole
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Arrhythmia –An irregular heartbeat
 Atrial Fibrilation –A Fib is a very common disorder where
the brain will send too many signals to the heart causing it
to beat over 300 times a minute but it is an irregular beat
 Atrial Flutter –similar to A Fib, but it is a completely
regular beat. Neither is life threatening, but can lead to
other diseases
Myocardial Infarction –(Heart attack) blockage of
coronary arteries keeps oxygen from getting to the
heart, causing permanent damage to the heart tissue.
 Hypertrophic Cardiomyopathy –Inherited disease that
causes certain parts of the heart muscle to be thicker,
making it work harder to push blood out.
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Carry blood throughout the body
Three Major Types
 Arteries –Carry oxygenated blood (red blood)
away from heart to tissues in body
 Veins –Carry deoxygenated blood (blue blood) to
the heart then lungs to be re-oxygenated
 Capillaries –Enable exchange of water and
chemicals from blood to tissues
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3 Layers
 Tunica Interna (intima) –Thinnest layer; single layer of
simple squamous endothelium surrounded by elastic
bands, and connective tissue
 Tunica Media –Thickest layers; connective tissue
surrounded by elastic bands
 Tunica Externa (adventitia) –All connective tissue
▪ Elastic is there to avoid pressure build ups, and allow for smooth
blood flow
ARTERIES
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Elastic Arteries –Largest of
arteries –About and inch thick,
they transport large amounts of
blood away from heart
Muscular Arteries –Medium
sized arteries –around 0.4 cm,
distribute to muscles and organs
Arterioles –Smallest other than
arteries –around 30 micrometers
thick, they bridge muscular
arteries to continuous capillaries
Thicker, more elastic and
stronger than veins
VEINS
Large Veins –Largest of Veins
–Equivalent to Elastic artery
 Medium Veins –Similar to
muscular arteries, they just
carry deoxygenated blood
 Venules –Collect blood from
capillary beds, similar to
arterioles
 Usually contain valves to
avoid backflow and
sometimes collapse under
pressure
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Only blood vessel that allows the exchange between
blood and surrounding fluid, the walls are extremely
thin
Made up of and endothelial tube inside a basement
membrane, there is no tunica media or externa
Around 8 micrometers around the same diameter of a
RBC
2 major types
 Continuous: paired with arteries; has a complete
endothelial lining
 Fenestrated: Paired with veins; have pores in their lining
that allow for a more rapid exchange of water and solutes
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They do not function individual, but as a network called a capillary
bed/plexus
The entrance is guarded by smooth muscle called a precapillary
sphincter
Then there is a metarteriole which completes the bridge from
arteriole to capillary
Many arteries might converge into a single capillary bed, they are
called collaterals
The exchange of water into these capillaries then to the lymphatic
system serves 4 major purposes
 Ensures Plasma and interstitial fluid are always in communication
 Accelerates the distribution of nutrients, hormones, etc.
 It assists in the transport of insoluble lipids that cannot enter the
bloodstream through the capillaries
 Has a flushing action that carries bacterial toxins and chemical stimuli
to lymphoid tissues.
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Main Functions
 Transports nutrients to body through blood
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vessels
Regulation of pH and ion composition
Restriction of fluid loss at injury sites
Defense again toxins and pathogens
Stabilization of body temperatures
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Consists of 2 Parts
 Plasma –Fluid connective tissue
 Formed Elements –Blood cells and cell fragments
suspended in plasma
▪ 3 Types include: Red Blood Cells (erythrocytes/RBC’s),
White Blood Cells (leukocytes/WBC’s), and Platelets
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All whole blood shares three characteristics
 Temperature (100.4°F), Viscosity (5 times greater
than water), and pH (between 7.35 and 7.45)
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Hemopoiesis is the process that produces
formed elements
Composed of 55% plasma and 45% blood
cells
Blood Cells are mainly red blood cells (RBC’s)
and white blood cells
RBC’s contain hemoglobin which turn bright
red when oxygenated
Oxygen binds to a iron-containing protein in
red blood cells
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55% of whole blood is Plasma
 Blood’s liquid medium
 92% water, 8% plasma proteins
 Yellow in color
 Used to transport dissolved nutrients and waste
such as carbon dioxide
On Left:
Erythrocytes
separated
from plasma
On Right:
Freshly Drawn
Blood
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They have a special shape that helps their
function
 It gives them a greater surface area to volume ratio,
which allows for a more rapid transfer of the oxygen
they carry
 It allows them to stack up like plates to flow faster
through the blood vessels
 They can bend and flex when entering very small
capillaries and branches
▪ They also have no nuclei, or organelles. They contain only
cytoskeleton.
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Hemoglobin (Hb) makes up 95% of an RBC’s intracellular
proteins.
Each molecule has 2 alpha chains and 2 beta chains of
polypeptides
Each chain has a molecule of heme, a pigment complex
Each heme holds an iron ion so that the iron can bond to
oxygen making oxyhemoglobin. When these bond the
RBC’s turn bright red.
When the oxygen is released it becomes deoxyhemoglobin.
Once they travel through the capillaries and the oxygen has
been dispersed the alpha and beta chains bond to the carbon
dioxide waste that is left forming carbaminohemoglobin.
These are carried to the lungs so that the CO2 can be exhaled
through the lungs and then oxygen can be rebonded to the
heme units and the cycle can start over.
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Antigens are substances that can trigger an immune
response to fight off an infection. Most are proteins
Your cell membranes contain surface antigens that
your immune defense recognizes as normal, and
doesn’t attack
Blood types are classified based on the presence of
certain surface antigens
There are 4 surface antigens on RBC’s called
agglutinogens. They are called A, B, and Rh.
Type A Blood contains only the “A” antigen, Type B
only the “B” antigen, and type O contains neither.
The distinction from + and – depends on the presence
of the Rh antigen.
Unlike RBC’s they contain nuclei and other organelles, and
they lack hemoglobin.
 They help defend the body against invasion by pathogens,
remove toxins, wastes and abnormal or damaged cells
 Usually divided into two groups
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 Granular Leukocytes (granulocytes) –Abundant stained
granules
▪ The neutrophils, eosinophils, & basophils
 Agranular Leukocytes (agranulocytes) –Few if any stained
granules
▪ Monocytes and Lymphocytes
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Are generally found in connective tissue proper or organs
of the lymphatic system.
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Neutrophils, Eosinophils, Basophils, and
Monocytes protect the body against
nonspecific threats. They are activated by a
variety of things, but do not differentiate one
threat from another.
Lymphocytes, however, are responsible for
specific defenses: mounting of counter
attack against a specific pathogen
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50-70% of circulating WBCs.
Named because their granules are neutral and are difficult to
stain acidic or basic dyes.
Have a very dense, segmented nucleus that forms 2-5 lobes
resembling beads on a string, giving them another name
polymorphonuclear leukocytes or PMNs
Around 12 micrometers across, their cytoplasm is filled with pale
granules containing lysosomal enzymes, and bactericidal
compound
Highly mobile, usually first to arrive at injury
They eat bacteria and digest them
They live for around 10 hours in the blood stream, when actively
fighting off pathogens they might last 30 minutes.
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2-4% of circulating WBCs
Named because their granules stain darkly with eosin.
Also named acidophils, because acid dyes stain them
as well.
Look like neutrophils, but have only 2 lobes on
nucleus
They attack things coated with antibodies, they will
engulf bacteria, protozoa, or cellular debris.
Primary mode of attack is exocytosis of toxic
compounds
They defend against large invaders, like worms
Their production increases dramatically during
infections, and allergic reactions.
Have numerous granules that stain darkly with any
dyes
 Smaller than neutrophils and eosinophils, they only
account for around 1% of the circulating WBCs
 They go to injury sites and discharge histamines a
chemicals that dilates blood vessels and causes
swelling to increase
 They attracts other basophils and eosinophils
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From left to right:
Neutrophil, Eosinophil,
Basophil
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Monocytes
 Twice as big as an RBC; they have a large, kidney bean
shaped nucleus. It accounts for 2-8% of the total
WBCs in circulation, and only uses the bloodstream to
reach tissues. When it arrives, it enters those tissues
and becomes a macrophage, or an aggressive
phagocyte.
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Lymphocytes
 Slightly larger than RBCs and lack a lot of deeply
stained granules. They account for 20-30% of the WBC
population, however there are many more than that,
because they are usually in surrounding tissues, not
the bloodstream
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There are 3 Classes of them that cannot be
distinguished under a light microscope
 T Cells: Responsible for cell mediated immunity, a
defense against invaders, and coordination of
immune response. They can attack directly or get
other lymphocytes to attack.
 B Cells: In charge of humoral immunity, a defense that
involves the production of antibodies, which then
attack the foreign cells.
 NK Cells: (Natural Killer) are responsible for
surveillance, or detecting the foreign invader.
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Flattened discs that assist in blood clotting
It will circulate for 9 to 12 days before being
replaced
1/3 of the platelets in the body are held in the
spleen at any given time.
They have 3 function
 Transport important blood clotting chemicals
 Form patches on walls of damaged blood vessels
 Contraction after clot formation has occurred.
Platelets contain actin and myosin and they shrink the
clot as the break in the wall disappears
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The act of controlling/minimizing bleeding
There are three stages
 Vascular: A vascular spasm occurs, contracting the
blood vessel in order to slow or stop blood flow.
 Platelet: Platelets stick to endothelial cells and try to
form a platelet plug to close off the break in the
vessel wall. If it is not a serious injury this will happen
in about 15 seconds after the injury
 Coagulation: Also known as blood clotting, involves
several factors that make a sort of web that traps
platelets and block off the whole
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Anemia: body does not have enough healthy RBCs because of a
lack of hemoglobin
Blood Cholesterol: Too much cholesterol in the blood can stick to
walls of arteries, blocking blood flow to the heart and causing
heart attacks
Hemophilia: Lack of blood clotting factors cause small cuts to
bleed profusely
Leukemia: Cancer of the leukocytes. These cancerous cells do not
die off when they should, and can block other cells from
performing correctly
Sickle Cell Anemia: abnormal hemoglobin cause RBC’s to become
fragile and prevents them from carrying as much oxygen as is
necessary
 Left: Sickle Cell
 Right: Hairy Cell Leukemia
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Made up of: Lymph: a fluid that is like plasma but has fewer suspended
proteins, Lymphatic Vessels (lymphatics): begin in tissues and end at
connections to veins, Lymphoid Tissues/Organs: connected to lymphatic
vessels and contain lymphocytes
Lymphocytes are the main cells of this system, and they respond to
invading pathogens (viruses), abnormal body cells (cancer cells), and
foreign proteins (bacteria toxins).
Serves 3 Purposes
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Production, Maintenance, and Distribution of Lymphocytes: They are stored in
lymphoid organs (thymus/spleen) and red bone marrow
 Return of fluid and solutes from peripheral tissue: Capillaries deliver more fluid than
they return, and if not for these lymphatic vessels the balance of blood volume would
be off
 Distribution of hormones, nutrients, and waste products from tissues to the
bloodstream
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Lymphatic Capillaries (terminal lymphatics) : Start of the
network, they branch through peripheral tissues
They are different than Blood Capillaries because they
 Originate as blind pockets
 Are thick in diameter
 Have thinner walls
 In sectional
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Capillaries flow into larger vessels
similar to veins in thickness and the
presence of valves
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2 kinds of Vessels collect lymph
 Superficial lymphatics: located in the SubQ layer of skin, and in the
tissues of mucous membranes lining: digestive, respiratory, urinary,
and reproductive tracts. And in serous membranes lining the pleural,
pericardial, and peritoneal cavities.
 Deep Lymphatics: larger than the superficial ones, and they
accompany arteries and veins, supplying organs.
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They both converge to form Lymphatic trunks, which empty into
the 2 biggest lymph vessels in the body called lymphatic trunks
 Thoracic Duct: Collects lymph from the body below diaphragm and
from the left side only above it. Starts at cisterna chyli. Comes from
Left & Right Lumbar Trunk and Intestinal Trunk. Also from left
subclavian and left jugular trunk. Empties into left subclavian vein
 Right Lymphatic Duct: formed by merging of right jugular, subclavian,
and bronchomediastinal trunks. Empties into right subclavian vein
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Connective tissues dominated by lymphocytes. Areas around this that
contain densely packed lymphocytes are called lymphoid nodules.
Lymphoid tissues linked with the digestive system are part of MALT
(mucosa-associated lymphoid tissue).
Large nodules in the walls of the pharynx are called tonsils. Most people
have 5
 1 Pharyngeal tonsil (adenoid), on the posterior superior wall of the
nasopharynx
 2 Palatine tonsils, the ones in the back of your throat
 2 Lingual tonsils, usually not visible, because they are located under the
attached base of the tongue
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A special connective tissue separates these organs from
surrounding tissues
Lymph Nodes: Small oval organs that are around an inch in
diameter that function like a kitchen filter. They are covered
by dense connective tissue that form a wall called trabecula.
They can swell often due to the infection of peripheral
tissues. There are two types of vessels that connect to each
lymph node.
 Afferent Lymphatics: carry lymph to lymph node; attached from
peripheral tissue
 Efferent Lymphatics: carry lymph away; attached at the base
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Located right behind the sternum, its pink and has a
grainy consistency.
Covered by a capsule that separates it into two lobes.
Septae are fibers that divide the lobe into lobules
(smaller lobes).
It produces and sends out several hormones that are
important to immune divisions, and helps stimulate T
Cell growth.
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Largest amount of lymphoid tissue. Lies along border
of stomach and between the 9th and 11th ribs on the
left.
It removes abnormal blood cells and other
components, stores iron from recycled RBC’s and
initiates the immune response.
It is shaped very specifically to fit against the left
kidney, stomach, and diaphragm.
Its smooth and soft.
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Innate –Genetically determined, and present at birth.
Only broken down in the presence of AIDS or other
conditions that depress specific immunity
Acquired Immunity –Not present at birth, but once
your are exposed to an antigen once you become
immune. It can come on Actively or passively
 Active Immunity: Comes from either a vaccine or a natural
exposure to new antigens
 Passive Immunity: Transfer of antibodies from one person
to another. Can happen in the case of a mother and her
baby or through injection of antibodies.
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There are 4
 Specificity –The act of dispatching a specific
lymphocyte to a specific kind of injury
 Versatility –The presence of a variety of lymphocytes
to deal with different kinds of invaders
 Memory –The immune system remembers every
antigen it encounters, thus the 2nd time it encounters
the same one, the response is faster and longer
 Tolerance –The failure to respond to certain antigens
is called tolerance.
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Rheumatoid Arthritis –When antibodies attack normal
antigens in connective tissues, especially around joints.
Allergy & Asthma –Overreaction by immune system
against generally harmless antigens. Also called
Hypersensitivity
HIV/AIDS –Viruses that weaken your immune system and
allow opportunistic infections
Multiple Sclerosis –Caused by the immune system
attacking the nervous system. Causes loss of control over
bodily functions; more prevalent in women than men.
Graves Disease –Caused by an enlarged thymus, and
causes bulging eyes, inability to sleep, anxiety, heat
intolerance, and excessive energy